Title: Linear motion guide unit
Abstract: A linear motion guide unit has a guide rail made of a thin plate, and a stopper construction installed detachably to the guide rail to prevent a slider from becoming untethered while on a sliding movement relative to the guide rail. A linear motion guide unit is disclosed in which a slider fits for linearly sliding movement in a guide rail made of a thin steel material formed in an U-shape in cross section, and there is provided a stopper construction to keep the slider against getting out of the guide rail. The stopper construction is comprised of a stopper pin installed detachably to the guide rail at any lengthwise end thereof to cause the stopper pin to bear against any fore-and-aft end of widthwise opposing side walls of the slider, whereby the slider comes to rest to prevent it from becoming untethered from the guide rail.
Patent Number: 7,008,107 Issued on 03/07/2006 to Kuwabara
| Inventors:
|
Kuwabara; Hideki (Gifu-ken, JP)
|
| Assignee:
|
Nippon Thompson Co., Ltd. (Tokyo, JP)
|
| Appl. No.:
|
437380 |
| Filed:
|
May 14, 2003 |
Foreign Application Priority Data
| May 14, 2002[JP] | 2002-137970 |
| Current U.S. Class: |
384/45; 384/43; 384/49 |
| Current Intern'l Class: |
F16C 29/06 (20060101); F16C 29/04 (20060101) |
| Field of Search: |
384/43,45,49,59,20,21,520,521
|
References Cited [Referenced By]
U.S. Patent Documents
| 3185530 | May., 1965 | Hahn et al.
| |
| 4582371 | Apr., 1986 | Mottate.
| |
| 4647226 | Mar., 1987 | Mottate.
| |
| 4701057 | Oct., 1987 | Kashiwabara.
| |
| 4701058 | Oct., 1987 | Mottate.
| |
| 4778284 | Oct., 1988 | Teremachi.
| |
| 4799806 | Jan., 1989 | Seki.
| |
| 4806022 | Feb., 1989 | Takahiro.
| |
| 4832509 | May., 1989 | Merrifield.
| |
| 4892415 | Jan., 1990 | Katahira.
| |
| 5395170 | Mar., 1995 | Tamura et al.
| |
| 5518317 | May., 1996 | Osawa.
| |
| Foreign Patent Documents |
| 1 302 026 | Jan., 1973 | GB.
| |
| 1300/17/1982 | Aug., 1982 | JP.
| |
| 37621/1987 | Mar., 1987 | JP.
| |
| 2003/63/1996 | Aug., 1996 | JP.
| |
| 2948944 | Jul., 1999 | JP.
| |
Primary Examiner: Bucci; David A.
Assistant Examiner: Hansen; Colby
Attorney, Agent or Firm: Browdy and Neimark, PLLC
Claims
What is claimed is:
1. A linear motion guide unit comprising: a guide rail plate member formed to
have a bottom and first side walls extending lengthwise along widthwise opposite
sides of the bottom, one to each side, the first side walls being made on their
inside surfaces with first raceway grooves extending lengthwise, one to each inside
surface, and a slider fit for linear movement in between the first side walls widthwise
opposite to one another, the slider being provided on sidewise outside surfaces
thereof with second raceway grooves, one to each outside surface, which are in
opposition to the first raceway grooves to define load raceways between them to
allow rolling elements to run through there, whereby the slider is movable in a
sliding manner between the first side walls of the guide rail by virtue of the
rolling elements;
whereby a stopper construction is installed detachably to any one of forward
and aft ends of the guide rail once the slider has fit in the guide rail, so that
the slider comes into abutment against the stopper construction while on a movement,
thereby being prevented from becoming untethered from the guide rail,
wherein the slider has a casing of a plate formed in an U-shape in cross section,
which is composed of a top portion and second side walls bent along widthwise opposite
sides of the top portion to head downwards,
wherein the second raceway grooves are cut in sidewise outside surfaces of the
second side walls,
wherein the slider is composed of the casing and a circulator laid underneath
the casing, which is provided therein with non-loaded areas, each of which includes
therein turnarounds communicating with the associated load raceway defined between
the raceway grooves confronting one another, and a return passage connecting the
turnarounds with each other,
wherein the rolling elements are allowed to run through a recirculating circuit
comprised of the load raceway, turnarounds and return passage, and
wherein the circulator is comprised of upper and lower circulator halves of synthetic
resin, which are made therein with grooves semicircular in cross section to produce
the turnarounds and the return passages that are circular in cross section to render
them suitable for the rolling elements of balls wherein the circulator is made
concaved on a lower surface thereof to form a recess extending along a fore-and-aft
area corresponding with the stopper pin for the stopper construction so as to allow
the stopper pin to go by underneath the slide without any interference between them.
2. A linear motion guide unit comprising: a guide rail plate member slim in thickness
formed to have a bottom and first side walls extending lengthwise along widthwise
opposite sides of the bottom, one to each side, the first side walls being made
on their inside surfaces with first raceway grooves extending lengthwise, one to
each inside surface, and a slider fit for linear movement in between the first
side walls widthwise opposite to one another, the slider being provided on sidewise
outside surfaces thereof with second raceway grooves, one to each outside surface,
which are in opposition to the first raceway grooves to define load raceways between
them to allow rolling elements to run through there, whereby the slider is movable
in a sliding manner between the first side walls of the guide rail by virtue of
the rolling elements;
whereby a stopper construction is installed detachably to any one of forward
and aft ends of the guide rail once the slider has fit in the guide rail, so that
the slider comes into abutment against the stopper construction while on a movement,
thereby being prevented from becoming untethered from the guide rail,
wherein the slider has a casing of a thin plate formed in an U-shape in cross
section, which is composed of a top portion and second side walls bent along widthwise
opposite sides of the top portion to head downwards,
wherein the second raceway grooves are cut in sidewise outside surfaces of the
second side walls,
wherein the slider is composed of the casing and a circulator laid underneath
the casing, which is provided therein with non-loaded areas, each of which includes
therein turnarounds communicating with the associated load raceway defined between
the raceway grooves confronting one another, and a return passage connecting the
turnarounds with each other,
wherein the rolling elements are allowed to run through a recirculating circuit
comprised of the load raceway turnarounds and return passage, and
wherein the circulator is made concaved on a lower surface thereof to form a
recess extending along a fore-and-aft area corresponding with the stopper pin for
the stopper construction so as to allow the stopper pin to go by underneath the
slider without any interference between them.
3. A linear motion guide unit constructed as defined in claim 2 wherein the stopper
construction is comprised of a stopper pin that fits in any one of a hole and a
threaded hole formed in a plane surface of the bottom of the guide rail, with a
part of the stopper pin being raised above the hole.
4. A linear motion guide unit constructed as defined claim 3 wherein the stopper
pin for the stopper construction is installed to the guide rail in relation to
bear against any one end of the second side walls of the casing, so that the slider
comes to rest to be kept against becoming untethered from the guide rail whole
on a movement.
5. A linear motion guide unit constructed as defined claim 3 wherein the stopper
pin for the stopper construction is a screw of a pan head having a rounded surface
of the top of the head.
6. A linear motion guide unit constructed as defined in claim 3 wherein the threaded
hole made in the guide rail to fit on the stopper pin doubles as a threaded hole
used to fasten the guide rail to any stationary structure including a machine bed.
7. A linear motion guide unit constructed as defined claim 2 wherein the stopper
pins for the stopper construction attached to the guide rail are placed on the
bottom of the guide rail along linear lines lying on traveling paths of the widthwise
opposing second side walls of the casing, located in a preselected relation to
one another, in which they lie on any diagonal line of the plane surface of the
bottom at lengthwise opposite ends of the guide rail.
8. A linear motion guide unit constructed as defined claim 2 wherein the fore-and-aft
concaved surface provided on the lower surface of the circulator lies sidewise
midway area to cause no interference with a screw that is used to fasten the guide
rail to any stationary structure including a machine bed.
9. A linear motion guide unit constructed as defined in claim 2 wherein the slider
is made with a threaded hole used to fasten any part including works thereto.
10. A linear motion guide unit constructed as defined claim 2 wherein the casing
is integrated with the circulator in a way that the widthwise opposite second side
walls of the casing fit in sidewise recesses of the circulator, one to each recess,
which are made over the middle areas of the widthwise opposing sides save the lengthwise
opposite ends of the circulator.
11. A linear motion guide unit constructed as defined claim 2 wherein the casing
is positioned in alignment with the circulator in a way that a hole made in the
casing fits over a tenon raised above a top surface of the circulator.
12. A linear motion guide unit constructed as defined claim 2 wherein the circulator
has a hole while the casing has a hole used for riveting, which is made in alignment
with the hole in the circulator, and wherein the casing is joined together with
the circulator, using riveting.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a linear motion guide unit having wide application
in sliding parts incorporated in, for example, semiconductor manufacturing equipments,
various assembling machines, numerical control (NC) processors, measurement/testing
instruments, and so on. More particularly, it relates to a linear motion guide
unit in which a slider is forced to move lengthwise relative to a track rail.
2. Description of the Prior Art
Linear motion guide units have been universally recognized for fundamental
and versatile means to more encourage the recently remarkable growth of mechatronics.
Although the linear motion guide units have been extensively built in machinery
in fields as diverse as semiconductor manufacturing equipments, a variety of assembling
machines, numerical control (NC) processors, measurement/testing instruments, and
so on, the expansion of uses accompanied by the current developments in advanced
technologies requires more and more such linear motion guide units that can manage
growing demands for shrinkage in size, weight reduction, high precision, low-frictional
resistance, high-speed moving, easy assemblage, versatility and the like.
There is conventionally known a linear motion guide unit of the sort disclosed
in, for example Japanese Utility Model Laid-Open No. 37621/1987, which is a co-pending
application filed by the present assignee. With the prior linear motion guide unit
in which a table fits for linearly sliding movement in a guide way made of a thin
steel material formed in an U-shape in cross section, there are provided stoppers
to keep the moving table against getting out of the guide way. The stoppers are
provided by forward and aft bent ends of the guide way as shown in FIG. 1 of the
document referred to earlier. The moving table could be protected from any runaway
out of the guide way after any one of forward and aft end caps on the moving table
has come in abutment against the associated stopper. Should the table get out of
the guide way, rolling elements would fall apart from one another. As an alternative
shown in FIG. 4 of the reference document, the stoppers of tiny plate are secured
with fastening screws on forward and aft ends of the guide way, one to each end.
With this alternative, the table is also made to come in engagement at any one
of its forward and aft ends with the associated stopper as shown in FIG. 5 of the
reference document. Besides, this alternative is made in such construction that
the rolling elements are not allowed to run in recirculating way.
With the prior stopper stated earlier to keep the table against getting out
of the guide way of the thin steel member formed in an U-shape in cross section,
however, it is needed to go to the trouble of making any extra part that should
be bent. The table would be hard to fit in the guide way, once the extra parts
got bent to provide the stoppers. The alternative stopper of tiny plate secured
with fastening screws on the guide way needs a number of parts, and therefore takes
up relatively much space. In contrast, the advanced technology looks to shrink
the stopper down to make the linear motion guide unit compact in construction.
In Japanese Patent No. 2948944, which is also a co-pending application filed
by
the present assignee, another sort of linear motion guide unit is disclosed, in
which any one of members confronting one another for sliding relative movement,
as shown in FIG. 1 of the reference document is made therein with a lengthwise
slot while the other has a stopper pin extending to fit in the slot. This prior
construction allows leaving any specific stopper mechanism out of the linear motion
guide unit. Since the stopper construction for the linear motion guide unit referred
to earlier needs to cut the lengthwise slot in the fixed second member, however,
it would be very tough to cut the lengthwise slot in a guide rail slim in thickness
or make the stopper construction extending across the entire width of the linear
motion guide unit. This means that this prior stopper construction is applicable
to large linear motion guide units, but hardly suited for small guide unit especially
slim or thin in thickness.
Japanese Utility Model Laid-Open No. 130017/1982, which is also a co-pending
application filed by the present assignee, discloses another linear motion guide
unit of cross-roller way type, in which rolling elements, as shown in FIGS. 1 and
2 of the reference document, are allowed to roll over only a definite travel instead
of rolling through a recirculating circuit. This linear motion guide unit is mainly
composed of a bed, table, and guide rails for the bed and the table, all of which
are made of steel material. As seen from FIG. 1 of the reference document where
the table is partially cut away, a stopper is constituted with first bolts fastened
inside the table at the widthwise middle near forward and aft ends of the table,
and a second bolt fastened on the upper surface of the guide rail for the bed midway
between the first bolts inside the table so as to come in collision against the
first bolts. The stopper in the linear motion guide unit of cross-roller way type
recited earlier, because of being constituted with just bolts, is simple in construction,
but needs much space to fasten the bolts underneath the table. Thus, this prior
stopper construction would be also suited for only the relatively large linear
motion guide units.
In Japanese Patent Laid-Open No. 200363/1996 there is disclosed lubricating means
for the linear motion guide unit in which the track rail has no stopper construction
to have the slider come to rest at any lengthwise end of the guide rail. This prior
disclosure, although doing with the linear motion guide unit made smaller in construction,
but does not involve technical concept about how to install the stopper construction
to get the slider come to rest at any lengthwise end of the guide rail. The stopper
construction, if necessary, may be as simple as any tentative stoppers extending
between the raceway grooves at the lengthwise ends of the guide rail.
With linear motion guide unit to be made shrunken in size and compact in construction
where both the slider and the guide rail are made slim or thin in thickness, it
still remains a major challenge to realize how to provide a stopper construction
to keep a slider against getting out of the guide way, especially, protecting the
small rolling elements against falling apart from one another, which would occur
when the slider became untethered from the guide rail while on a linear movement.
SUMMARY OF THE INVENTION
The present invention, therefore, has as its primary object to solve the major
challenge as described just above and more particular to provide a linear motion
guide unit shrunken down sufficiently to fit it into a variety of machines including
inspection and testing instruments, semiconductor manufacturing equipments, and
so on. Moreover, the present invention provides a stopper construction compliable
with very small linear motion guide unit that is constituted with a guide rail
and a slider both of which are made of plate members slim in thickness. With the
stopper construction of the present invention, there are provided stopper pins
so most simple in construction as to allow attaching and/or detaching with ease
them from the guide rail at forward and aft ends of the guide rail, one to each
end, while the slider is made to cause the stoppers to bear against any one of
forward and aft ends themselves on a casing of the slider without any specific
part being provided to bear against the stoppers.
The present invention is concerned with a linear motion guide unit comprising;
a guide rail of plate member slim in thickness formed to have a bottom and first
side walls extending lengthwise along widthwise opposite sides of the bottom, one
to each side, the first side walls being made on their inside surfaces with first
raceway grooves extending lengthwise, one to each inside surface, and a slider
fit for linear movement in between the first side walls widthwise opposite to one
another, the slider being provided on sidewise outside surfaces thereof with second
raceway grooves, one to each outside surface, which are in opposition to the first
raceway grooves to define load raceways between them to allow rolling elements
to run through there, whereby the slider is movable in a sliding manner between
the first side walls of the guide rail by virtue of the rolling elements; and
wherein a stopper construction is installed detachably to any one of forward
and aft ends of the guide rail once the slider has fit in the guide rail, so that
the slider comes into abutment against the stopper construction while on a movement,
thereby being prevented from becoming untethered from the guide rail.
Here the wording "once the slider has fit in the guide rail" means every situation:
for example, while on linear movement of the slider with respect to the guide rail,
at the time of assembling the slider with the guide rail, at the time when the
linear motion guide unit is transported or in storage, and so on.
In an aspect of the present invention, a linear motion guide unit is disclosed
in which the stopper construction is comprised of a stopper pin that fits in a
hole and/or a threaded hole formed in a plane surface of the bottom of the guide
rail, with a part of the stopper pin being raised above the hole. In another aspect
of the present invention, a linear motion guide unit is disclosed in which the
stopper pin for the stopper construction is a screw of a pan head having a rounded
surface of the top of the head.
In another aspect of the present invention, a linear motion guide unit is disclosed
in which the slider has a casing of a thin plate formed in an U-shape in cross
section, which is composed of a top portion and second side walls bent along widthwise
opposite sides of the top portion to head downwards, and wherein the second raceway
grooves are cut in sidewise outside surfaces of the second side walls.
In another aspect of the present invention, a linear motion guide unit is disclosed
in which the stopper pin for the stopper construction is installed to the guide
rail in relation to bear against any one end of the second side walls of the casing,
so that the slider comes to rest to be kept against becoming untethered from the
guide rail while on a movement. In a further another aspect of the present invention,
there is disclosed a linear motion guide unit in which the stopper pins for the
stopper construction attached to the guide rail are placed on the bottom of the
guide rail along linear lines lying on traveling paths of the widthwise opposing
second side walls of the casing, with located in a preselected relation to one
another, in which they lie on any diagonal line of a plane surface of the bottom
at lengthwise opposite ends of the guide rail.
In another aspect of the present invention, a linear motion guide unit is disclosed
in which the slider is composed of the casing and a circulator laid underneath
the casing, which is provided therein with non-loaded areas, each of which includes
therein turnarounds communicating with the associated load raceway defined between
the raceway grooves confronting one another, and a return passage connecting the
turnarounds with each other, and wherein the rolling elements are allowed to run
through a recirculating circuit comprised of the load raceway, turnarounds and
return passage.
In another aspect of the present invention, a linear motion guide unit is disclosed
in which the circulator is made concaved on a lower surface thereof to form a recess
extending along a fore-and-aft area corresponding with the stopper pin for the
stopper construction so as to allow the stopper pin to go by underneath the slider
without any interference between them. In a further another aspect of the present
invention, there is disclosed a linear motion guide unit in which the circulator
is comprised of upper and lower circulator halves of synthetic resin, which are
made therein with grooves semicircular in cross section to produce the turnarounds
and the return passages that are circular in cross section to render them suitable
for the rolling elements of balls.
In another aspect of the present invention, a linear motion guide unit is disclosed
in which the threaded hole made in the guide rail to fit on the stopper pin doubles
as a threaded hole used to fasten the guide rail to any stationary structure including
a machine bed and so on.
In another aspect of the present invention, a linear motion guide unit is disclosed
in which the circulator is provided underneath the lower surface thereof with a
fore-and-aft recess, which lies sidewise midway area to cause no interference with
a screw that is used to fasten the guide rail to any stationary structure including
a machine bed and so on. In a further another aspect of the present invention,
there is disclosed a linear motion guide unit in which the slider is made with
a threaded hole used to fasten any part including works and so on thereto.
In another aspect of the present invention, a linear motion guide unit is disclosed
in which the casing is integrated with the circulator in a way that the widthwise
opposite second side walls of the casing fit in the sidewise recesses of the circulator,
one to each recess, which are made over the middle areas of the widthwise opposing
sides save the lengthwise opposite ends of the circulator.
In another aspect of the present invention, a linear motion guide unit is disclosed
in which the casing is positioned in alignment with the circulator in a way that
a hole made in the casing fits over a tenon raised above a top surface of the circulator.
In a further another aspect of the present invention, there is disclosed a linear
motion guide unit in which the circulator has a hole while the casing has a hole
used for riveting, which is made in alignment with the hole in the circulator,
and wherein the casing is joined together with the circulator, using riveting.
With the linear motion guide unit of the present invention constructed as stated
earlier, just a simple stopper construction is able to serve certainly the purpose
that the slider is kept against becoming untethered from the guide rail while on
a linear movement, even the small linear motion guide unit in which both the guide
rail and the slider are made of plate members slim or thin in their thickness.
Moreover, the stopper construction is made detachable from the guide rail. Thus,
the stopper construction is made after the slider has fit in the guide rail. In
contrast, the slider can be withdrawn out of the guide rail after the stopper construction
has been taken apart from the guide rail.
With the linear motion guide unit of the present invention constructed as stated
earlier, moreover, the slider can come into collision against the stopper constructions
made on the guide rail at the forward and aft ends thereof, thereby coming to rest
to be kept against becoming untethered from the guide rail while on a sliding movement
relative to the guide rail. The stopper construction of the present invention,
as being made of just stopper pin screwed into the threaded hole in the guide rail,
may help make very small linear motion guide unit that is suited for small machines.
Moreover, the stopper construction of the present invention makes sure of stopping
the slider, even inexpensive in production.
Eventually, the stopper construction of the present invention helps built
the smaller linear motion guide unit that is applied well to a variety of machines
including semiconductor manufacturing equipments, inspection instruments, measuring
instruments, processors, assembling machines, and so on to move machines with accuracy
in a sliding manner.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view, partially broken away, showing a preferred embodiment
of a linear motion guide unit in accordance with the present invention:
FIG. 2 is a front elevation, partially cut away, of the linear motion guide
unit of FIG. 1:
FIG. 3 is a side elevation of the linear motion guide unit shown in FIG. 1,
the view being taken on the planes of the lines I—I of that figure to illustrate
in cross section the reader's right half, as seen into the interior:
FIGS. 4(A) and 4(B) are a top plan view and a front view, respectively, of
the linear motion guide unit of FIG. 1 to illustrate a phase where a slider is
kept against escape out of a guide rail after having moved relatively to the guide
rail from another phase shown in FIG. 1:
FIGS. 5(A) and 5(B) are a front elevation and a side elevation, respectively,
of a stopper bolt used in the linear motion guide unit shown in FIG. 1:
FIG. 6 is a top plan view illustrating a casing for the slider of FIG. 1:
FIG. 7 is a front elevation of the casing of FIG. 6:
FIG. 8 is a side elevation of the casing of FIG. 7:
FIG. 9 is a top plan view showing a carriage, called circulator hereinafter,
of the slider in the linear motion guide unit of FIG. 1, in which there is provided
a non-loaded area to allow rolling elements to recirculate through there:
FIG. 10 is a side elevation of the circulator of FIG. 9:
FIG. 11 is a bottom view of the circulator of FIG. 9:
FIG. 12 is a cross section of the circulator of FIG. 9, the view being taken
on a plane along a line III—III of that figure:
FIG. 13 is a cross section of the circulator of FIG. 9, the view being taken
on a plane along a line II—II of that figure:
FIG. 14 is a top plan view, partially cut away, of a guide rail in the linear
motion guide unit shown in FIG. 1: and
FIG. 15 is a side elevation of the guide rail of FIG. 14.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of a linear motion guide unit according to the present
invention
will be explained hereinafter in detail with reference to the accompanying drawings.
The linear motion guide unit of the present invention is envisaged to use it in
sliding parts incorporated in, for example, semiconductor manufacturing equipment,
various assembling machines, numerical control (NC) machines, measuring/testing
instruments, inspection machines, and so on, and thus comprised of an elongated
guide rail
1 made of a plate member thin in thickness, and a slider
2
allowed traveling lengthwise with respect to the guide rail
1, the slider
2 being also made of a assembly of slim plate members. What both the guide
rail
1 and the slider
2 are made of plate members slim in thickness
helps shrink more the linear motion guide unit down in size. The linear motion
guide unit of the present invention is envisaged to prevent the slider
2
against getting untethered from the guide rail
1 while on a linear movement.
To cope with this, stopper constructions
36 are fastened in a detachable
manner to the guide rail
1 at forward and aft ends of the guide rail
1
in the adjacency of at least any one of widthwise opposite sides of the guide rail
1. Thus, the slider
2, after having reached any one of the lengthwise
opposite ends of the guide rail
1, is caused any associated one of the forward
and aft ends of the slider
2 to bear against the associated stopper construction
36, eventually coming to rest at an extreme position where the slider
2
is still kept against getting untethered.
The linear motion guide unit is principally comprised of the elongated guide
rail
1 of plate member slim in thickness formed to have a bottom
6
and first side walls
5 extending lengthwise along widthwise opposite sides
of the bottom
6, one to each side, the side walls
5 being made on
their inside surfaces
38 with first raceway grooves
11 extending
lengthwise, one to each inside surface, and the slider
2 fit for linear
movement in between the widthwise opposite side walls
5, the slider
2
being provided on sidewise outside surfaces
40 thereof with second raceway
grooves
12, one to each outside surface, which are in opposition to the
first raceway grooves
11 to define load raceways
10 between them
to allow rolling elements or balls
9 to run through there.
This elongated guide rail
1 is made of a metal plate material, which
is bent along widthwise opposite sides thereof to a specific angle or U-shape in
cross-section having the side walls
5. The slider
2 is constituted
with many thin plate members combined together, only the top plate
7 of
which is bent along widthwise opposite sides
8 thereof save lengthwise opposite
ends
39 to a right angle heading downwards. That is to say, the top plate
7 is bent at the widthwise opposite sides
8 save forward and aft
preselected areas so as to make second side walls
8, thereby providing a
casing
3 of thin metal plate formed in an U-shape in cross section. The
second raceway grooves
12 in the embodiment discussed here are cut in the
sidewise outside surfaces
40 of the second side walls
8, with extending
over almost entire length thereof. Moreover, the top plate
7 is cut away
at
24 to separate the major sides walls
8 from the forward and aft
ends
39 to make bending of the side walls
8 much easier.
Especially, the linear motion guide unit according to the present invention
features that the slider
2, while traveling relatively to the guide rail
1 after once it has fit in the guide rail
1, is caused to bear against
any one of the stopper constructions
36 fastened in a detachable manner
to the guide rail
1, thus, coming to rest at an extreme position where the
slider
2 is still kept from escape out of the guide rail
1. Here
the wording "once the slider
2 has fit in the guide rail
1" means
every situation: for example, while on linear movement of the slider
2 with
respect to the guide rail
1, at the time of assembling the slider
2
with the guide rail
1, at the time when the linear motion guide unit is
transported or in storage, and so on.
Moreover, the stopper construction
36 is made up of a hole or threaded
hole
32 produced in the bottom
6 of the guide rail
1, and
a stopper pin
16 having external threads that fit in the hole or threaded
hole
32. With stopper constructions in the embodiment discussed here, the
threaded stopper pins
16 are screwed into the threaded holes
32 made
in the bottom
6 of the guide rail
1.
When the stopper pin
16 fastened to the guide rail
1 collides
or comes into abutment against any one of forward and aft ends
41 of the
side walls
8 of the casing
3, the slider
2 can come to rest
with respect to the guide rail
1 so as to remain tethered to the guide rail
1 without getting escaped out of the guide rail
1. That is to say,
the stopper construction to protect the slider
2 against becoming untethered
or escaping out of the guide rail
1 is made such that the slider
2
will come to rest just when any one of the lengthwise opposite ends
39 on
the side walls
8 of the casing
3 of the slider
2, as seen
from FIGS. 4(A) and 4(B), has been caused to come into abutment against the associated
any one of the stopper pins
16 installed on the guide rail
1 at the
forward and aft ends
37 thereof.
The stopper pins
16 attached to the guide rail
1, as shown in FIG.
4, are placed on the bottom
6 of the guide rail
1 along linear lines
lying on traveling paths of the widthwise opposing side walls
8 of the casing
3, with located in a preselected relation to one another, in which they
lie on any diagonal line of a plane surface
42 of the bottom
6 or
symmetrically across 180° at lengthwise opposite ends
37 of the guide
rail
1. The stopper pins
16 are installed on the guide rail
1
at the forward and aft ends
37 of the guide rail
1, one to each end,
in a relation to one another where they are diagonally arranged on widthwise opposite
side walls
5 of the guide rail
1, one to near each side wall. This
arrangement of the stopper pins
16 as stated just earlier renders the hole-making
operation to produce the threaded holes
32 in the guide rail
1 much
easier and also helps make sure of better kinetic balance at the time when the
slider
2 comes to rest. As an alternative, four threaded holes
32
in which the stopper pins
16 are screwed, although not shown, can be arranged
at the forward and aft ends
37 of the guide rail
1, two to each end,
thereby to make the kinetic balance much better. Nevertheless, just one threaded
hole
32 at any one of the forward and aft ends, as shown here, would be
sufficient to get the slider
2 stopping.
The slider
2 is principally composed of the casing
3 and a carriage
4 called herein circulator, which is provided therein with non-loaded areas,
each of which includes therein turnarounds
13 communicating with the load
raceway
10 defined between the raceway grooves
11,
12 confronting
one another, and a return passage
14 connecting the turnarounds
13
with each other. The rolling elements or balls
9 are allowed to run through
a recirculating circuit
35 comprised of the load raceway
10, turnarounds
13 and return passage
14. The circulator
4 is made concaved
on a lower surface thereof to form sidewise opposing recesses
17 along fore-and-aft
areas
17 corresponding with the stopper pins
16 so as to allow the
stopper pins
16 to go by underneath the slider
2 without any interference
between them. The fore-and-aft recess
17 is formed to get curved in cross section.
With the linear motion guide unit constructed as stated earlier, accordingly,
the circulator
4 is allowed to travel over the stopper pins
16 without
experiencing any collision against the stopper pins
16 thanks to the circulator
4 being recessed on the lower surface thereof to get clear of the stopper
pins
16. This makes certain of a traveling stroke of the slider
2
relatively to the guide rail
1, which increases by as much as a lengthwise
measure of forward and aft aprons
39 of the casing
3.
Where the rolling elements
9 are balls, both the turnarounds
13
and the return passages
14 have to be made circular in cross section to
make sure of allowing the balls to roll smoothly through the recirculating circuits
without experiencing any rattling vibration. To cope with this, the circulator
4 is usually divided into upper and lower circulator halves
26,
27
of synthetic resin to bypass any sophisticated technical requirements to produce
the turnarounds
13 and the return passages
14 circular in cross section
in the circulator
4. Grooves
47,
48 semicircular in cross
section are cut in the upper and lower circulator halves
26,
27,
respectively, and then mated with one another to complete the turnarounds
13
and the return passages
14 circular in cross section in the circulator
4.
In other words, the circulator
4 is made up of the upper and lower circulator
halves
26,
27 that are mated together with one another in a relation
forming therein both the turnarounds
13 and the return passages
14,
which are circular in cross section.
The circulator
4 made of synthetic resin, even if having come into collision
against the stopper pin
16 of the guide rail
1 while on sliding travel
of the slider
2 relatively to the guide rail
1, would be damaged.
To refrain this obstacle, the lower circulator half
27 is made concaved
at
17 on sidewise spaced lower surfaces
43 to allow the stopper pin
16 to pass through below the circulator
4 without coming into interference
with the lower circulator half
27.
The circulator
4 is receded sidewise inwardly at
30,
31
to fit over or conform to the side walls
8 of the casing
3 to join
it together with the casing
3. That is to say, the upper circulator half
26 is recessed inwardly over the middle areas
30 of the widthwise
opposing sides save the lengthwise opposite ends
44 while the lower circulator
half
27 is also recessed inwardly over the middle areas
31 of the
widthwise opposing sides save the lengthwise opposite ends
45. Thus, the
side walls
8 of the casing
3 can fit in the recessed middle areas
30,
31 save for the forward and aft ends
44,
45 of
the circulator
4 to join the casing
3 with the circulator
4.
Moreover, the upper and lower circulator halves
26,
27 have
claw halves
23, respectively. Once the upper and lower circulator halves
26,
27 has been mated with one another, the claw halves
23
merge together with one another into the complete claw
23 to make sure of
smooth running of the rolling elements
9 at boundaries between the load
raceways
10 and the associated turnarounds
13.
The casing
3 is made therein with holes
20 that are used to align
and position the circulator
4 thereto. In order to assemble the casing
3
integrally with the circulator
4 at a precise position relative to the circulator
4, a tenon
33 raised above a top surface of the upper circulator
half
26 for the circulator
4 fits in the associated hole
20
in the casing
3.
The stopper pin
16 for the stopper construction
36 is a screw of
a pan head having a rounded surface of the top of the head. This rounded top of
the pan head screw
16 is expected to disperse well an impact force that
might occur due to any possible collision of the fore-and-aft ends
41 of
the casing
3 against their associated stopper pins
16. Thus, even
relatively small pin would be expected to serve well for absorbing the kinetic
energy of the slider
2.
The threaded hole
32 made in the guide rail
1 to fit on the stopper
pin
16 doubles as a threaded hole used to fasten the guide rail
1
to any stationary structure including a machine bed and so on. Besides the threaded
hole
32 for the stopper pin
36, the guide rail
1 is made with
other threaded holes
21 to fasten the guide rail
1 to any stationary
structure including a machine bed and so on. Correspondingly, the lower circulator
half
27 of the circulator
4 is provided underneath the lower surface
thereof with a fore-and-aft recess
34, which lies sidewise midway area to
allow fastening screws fit in the guide rail
1 to pass through below the
circulator
4 without encountering any interference with the lower circulator
half
27. The slider
2 is also made with threaded holes
19
used to fasten any parts including works and so on thereto.
The forward and aft aprons
39 of the casing
3 have holes
25
used for riveting or caulking, which are made at preselected locations
15,
for example four corners in the embodiment shown herein, in alignment with holes
28 made in the circulator
4, which are also arranged at preselected
locations, for example four corners shown in figures. The casing
3 is joined
together with the circulator
4 with rivets that fit in the holes
25
of the casing
3 and the holes
28,
29 of the circulator
4,
followed by experiencing riveting.
The guide rail
1, as shown in FIG. 1, is made with the threaded holes
21 that are used to fasten the guide rail
1 to the stationary structure
including a machine bed and so on. Where the screws to fasten the guide rail
1
to the stationary structure are allowed to fit in the threaded holes
21
from the side of the stationary structure, the screws come into engagement with
the threaded holes
21 to clamp the guide rail
1 together with the
stationary structure. In contrast, where the screws are permitted to access to
the guide rail
1 from only the opposite side or the side of the slider
2,
they extend simply through the threaded holes
21 in the guide rail
1
to be mated with any threaded holes in the stationary structure to tighten the
guide rail
1 on the stationary structure. In the latter case stated just
above, the screw is made smaller in diameter than the inside caliper of the threaded
hole
21 in the guide rail
1. The screws driven from the plane surface
42 of the guide rail
1 can not bypass the fatal matter that the screw
heads rise above the plane surface
42 of the bottom
6 of the guide
rail
1. To deal with this matter, the lower circulator half
27 of
the circulator
4 is made underneath the lower surface thereof with the lengthwise
recess
34, which lies sidewise midway area to allow fastening screws fit
in the guide rail
1 to pass through below the circulator
4 without
causing any interference with the lower circulator
4.
The casing
3 of the slider
2 is provided therein with the threaded
holes
19 that are used to fasten any parts including works and so on. That
is, the threaded holes
19 serve as fastening holes to mount the parts including
works, small articles and so on to the slider
2. Moreover, the upper circulator
half
26 of the circulator
4 just below the casing
3 is made
in an upper surface thereof with holes
18, which are arranged in alignment
with the threaded holes
19 of the casing
3. Thus, the fastening screws,
if should extend downwards out of the threaded holes
19 beyond the casing
3, are permitted fit in the associated holes
18 in the circulator
4, without causing any interference with calculator
4.
The following will explain how to fasten the casing
3 to the circulator
4 to complete the slider
2 of an assemblage of the casing
3
with the circulator
4.
The circulator
4 is joined together with the casing
3 in a way
the side walls
8 of the casing
3 fit in the sidewise recesses
30,
31 of the circulator
4, one to each recess, while the tenons
33
raised above a top surface
46 of the upper circulator half
26 fit
in the holes
20 of the casing
3 to align and position the circulator
4 to the casing
3, thereby bringing the holes
28,
29
for fastening at four corners of the circulator
4 into perfect alignment
with the holes
25 for riveting at four corners of the casing
3. Then,
aluminum rivets are placed to pass through the aligned holes
28,
29
and
25, and manipulated by riveting operation to produce rivet fastenings
22 to grip the casing
3 together with the circulator
4. Further,
the rolling elements
9 are charged into the recirculating circuits
35.
Thereafter, the slider
2 is brought into combination with the guide rail
1 while keeping the rolling elements
9 against falling apart from
one another. As an alternative, the slider
2 can be combined with the guide
rail
1 prior to being charged with the rolling elements
9. The stopper
pins
16 are finally driven in the threaded holes
32 to finish assemblage
of the linear motion guide unit.
With the linear motion guide unit constructed as stated earlier, the stopper
construction
36 may be provided by just the stopper pin
16 that simply
fit in the threaded hole
19 in the guide rail
1. While making the
linear motion guide unit itself less in space and compact in construction, the
stopper construction made so as to allow the stopper pin
16 to attach and
detach easily it from the guide rail
1 can make certain of keeping the slider
2 against untethered from the guide rail
1. Since the stopper pin
16 can be attached and detached from the guide rail
1 with easy work
of just screwing in and out the stopper pin
16, the slider
2 is simply
replaced for new one with respect to the guide rail
1. Fitting relation
of the slider
2 in the guide rail
1, for example, may be altered easily.
The slider
2 sometimes has become untethered from the guide rail
1
while on a linear movement and the rolling elements have come apart out of the
slider
2. Thus, the stopper construction for the linear motion guide unit
of the present invention is envisaged to make sure of preventing the slider
2
from escape out of the guide rail
1, thereby keeping the rolling elements
against coming apart away from one another.
As the present invention may be embodied in several forms without departing from
the spirit of essential characteristics thereof, the present embodiments are therefore
illustrative and not restrictive, since the scope of the invention is defined by
the appended claims rather than by the description preceding them, and all changes
that fall within meets and bounds are therefore intended to embraced by the claims.
*
