Title: Ergonomic handle attachment for welding torch
Abstract: An over-handle is mounted on a rotor-ring for rotation around the handle of the torch. The accessory is for use with a torch of the kind in which a (coated) electrode is mounted in an electrode holder, and is tightened therein by the welder screwing the holder into the torch handle. The orientation of the electrode relative to the handle is unpredictable, and the rotatable over-handle enables the over-handle to be orientated to suit the orientation of the electrode. A rotatable accessory in the form of a pick hammer is also disclosed.
Patent Number: 6,940,041 Issued on 09/06/2005 to Zamuner
| Inventors:
|
Zamuner; Frank (Oakville, CA)
|
| Assignee:
|
Lincoln Global, Inc. (Monterey Park, CA)
|
| Appl. No.:
|
640057 |
| Filed:
|
August 14, 2003 |
| Current U.S. Class: |
219/144; 219/136; 219/141 |
| Intern'l Class: |
B23K 009/28 |
| Field of Search: |
219/136,137.31,138,139,141,142,144
|
References Cited [Referenced By]
U.S. Patent Documents
| 1296358 | Mar., 1919 | Bowers.
| |
| 2118274 | May., 1938 | Sweda.
| |
| 2395214 | Feb., 1946 | Bourque.
| |
| 2428138 | Sep., 1947 | Blakemore.
| |
| 2438792 | Mar., 1948 | Sandrik.
| |
| 2540204 | Feb., 1951 | Holslag.
| |
| 2558083 | Jun., 1951 | Green.
| |
| 4161643 | Jul., 1979 | Martin et al.
| |
| 4174062 | Nov., 1979 | Francis.
| |
| 5854461 | Dec., 1998 | Sorenson.
| |
| 6069340 | May., 2000 | DeCanio.
| |
Primary Examiner: Shaw; Clifford C.
Attorney, Agent or Firm: Fay, Sharpe, Fagan, Minnich & McKee, LLP
Parent Case Text
This is a Continuation-in-Part of patent application number U.S. Ser. No. 09/794,494,
filed Feb. 28, 2001, now granted/issued as patent number 6,610,963.
Claims
1. An apparatus including welding torch, having a service cable, wherein:
the torch includes a torch-handle, and includes an over-handle mounted on the
torch-handle;
the over-handle, so mounted, is guided on the torch-handle for rotation about
a rotation-axis of the torch-handle;
wherein the over-handle and the torch handle are positioned to create a space
for receiving a web area of a person's hand;
the over-handle is functionally operable, and its manner of operation is such
that the efficacy thereof is substantially affected by the orientation of the over-handle
relative to the torch-handle;
a stator-ring is fixedly secured to the torch handle;
a rotor-ring is fixedly secured to the over-handle;
wherein the stator-ring and the rotor-ring are so structured, mutually, that
the rotor-ring is guided for, and constrained against, all modes of movement relative
to the stator-ring, other than rotation about the rotation-axis of the torch-handle;
the over-handle includes a detent mechanism, which defines N detent-orientations
of the rotor-ring upon the stator-ring;
in respect of each one of the N detent-orientations;
when the rotor-ring lies at the detent-orientation, the detent mechanism provides
a heavy resistance to rotational movement of the rotor-ring away from the detent-orientation;
when the rotor-ring lies close to the detent-orientation, the detent mechanism
provides a large resistance to rotational movement of the rotor-ring in the direction
away from the detent-orientation, and provides a small, or negative, resistance
to rotational movement of the rotor-ring in the direction towards the detent-orientation.
2. The apparatus of claim 1, wherein, in respect to each one of the N detent-orientations,
the said heavy resistance;
is weak enough that the rotor-ring can be rotated, against the heavy resistance,
by hand manipulation, away from the detent-orientation; and
is strong enough, in the absence of hand manipulation thereof, to hold the rotor-ring,
with the accessory secured thereto, at the detent-orientation.
3. The apparatus of claim 1, wherein:
the stator-ring includes N indentations, respective to the N detent-orientations;
the rotor-ring includes a ball and spring assembly, which is so structured that,
upon the rotor-ring being rotated upon the stator-ring, the ball enters into, and
rises out of, the N indentations, one by one, being urged into the indentations
by action of the spring.
4. The apparatus of claim 1, wherein the detent-orientations are equally pitched
circumferentially about the stator-ring, and the number N is about twenty.
5. The apparatus of claim 1, wherein the torch-handle includes a cylindrical
portion, which is suitable for being gripped by a person, and the rotation-axis
is co-axial with the axis of the cylindrical portion.
6. The apparatus of claim 1, wherein:
the torch includes an electrode, and an electrode-holder;
the structure of the torch is such that the electrode can be inserted into the
electrode holder, and can be clamped or gripped therein by the action of rotating
the electrode-holder relative to the torch handle;
and the structure of the torch is such that the rotatable accessory can be rotated
about the torch-handle while the electrode-holder is held stationary relative to
the torch-handle.
7. The apparatus of claim 6, wherein:
the structure of the torch is such that the electrode-holder can e screwed into
and (out of) the torch-handle, and such action is effective to tighten and the
electrode in the electrode-holder, respectively;
the electrode holder is so structured that the electrode, when tightened into
the electrode-holder, lies substantially radially with respect to the axis of the
torch-handle.
8. The apparatus of claim 6, wherein:
the action of rotating the electrode-holder relative to the torch-handle, to
clamp or grip the electrode therein, takes place about an electrode-holder axis;
and the electrode-holder axis is co-axial with the rotation-axis of the over-handle.
9. The apparatus of claim 6, wherein the structure of the torch is such that:
in respect of a first occasion of operation of the torch, the electrode lies
at a first electrode-orientation angle relative to the torch-handle, and the over-handle
can be rotated to, and left at, a first over-handle-orientation angle relative
to the torch-handle;
in respect of a second occasion of operation of the torch, the electrode lies
at a second, different, electrode-orientation angle relative to the torch-handle,
and the over-handle can be rotated to, and left at, a second over-handle-orientation
angle relative to the torch handle.
10. The apparatus of claim 9, wherein:
when the electrode lies at the first electrode-orientation angle relative to
the torch-handle, and the over-handle lies at the first over-handle-orientation
angle relative to the torch-handle, the over-handle thereby lies oriented at a
first electrode-over-handle-orientation angle relative to the electrode; and
when the electrode lies at the second electrode-orientation angle relative to
the torch-handle, and the over-handle lies at the second, different, over-handle-orientation
angle relative to the torch-handle, the over-handle thereby lies orientated at
a second electrode-over-handle-orientation angle relative to the electrode;
the structure of the torch is such that the first electrode over-handle-orientation
angle can be made equal, by hand manipulation of the over-handle, to the second
electrode-over-handle-orientation angle.
11. An apparatus, including a welding torch, having a service cable, wherein:
the torch includes a torch-handle, and includes an accessory mounted on the torch-handle;
the accessory, so mounted, is guided on the torch-handle for rotation about a
rotation-axis of the torch-handle;
the accessory is functionally operable, and its manner of operation is such that
the efficacy thereof is affected by the orientation of the accessory relative to
the torch-handle;
a stator-ring is fixedly secured to the torch handle;
a rotor-ring is fixedly secured to the accessory;
wherein the stator-ring and the rotor-ring are so structured, mutually, that
the rotor-ring is guided for, and constrained against, all modes of movement relative
to the stator-ring, other than rotation about the rotation-axis of the torch-handle;
the accessory includes a detent mechanism, which defines N detent-orientations
of the rotor-ring upon the stator-ring;
in respect of each one of the N detent-orientations;
when the rotor-ring lies at the detent-orientation, the detent mechanism provides
a heavy resistance to rotational movement of the rotor-ring away from the detent-orientation;
when the rotor-ring lies close to the detent-orientation, the detent mechanism
provides a large resistance to rotational movement of the rotor-ring in the direction
away from the detent-orientation, and provides a small, or negative, resistance
to rotational movement of the rotor-ring in the direction towards the detent-orientation;
wherein
the accessory comprises an over-handle, fixedly secured to the rotor-ring;
the over-handle extends outwards and rearwards from the rotor ring;
the over-handle overlies, and is spaced from, the torch-handle;
the over-handle is so disposed in relation to the torch-handle as to create a
space between the torch-handle and an undersurface of the over-handle;
the space thus created is so shaped and sized as to be capable of, and suitable
for, receiving the first web area of the hand of a person, into that space, the
first web area being the webbed area between the thumb and the forefinger;
the configuration of the space created between the torch-handle and the over-handle
is such that, when the first web area of the hand is located in the said space,
the first web area is gripped between the torch-handle and the over-handle securely
enough that the person can manipulate and manhandle the torch, with the service
cable attached, substantially without exerting any muscular squeeze or grip on
the torch-handle.
12. The apparatus of claim 11, wherein:
the space thus created is so shaped and sized as to be capable of, and suitable
for, exerting a slight squeeze-grip upon the first web area of a person's hand,
when the first web area is located in the said space;
the over-handle is open at the sides of the hand-grip component, to the extent
that, when the first web area of a person's hand is located in the said space,
the fingers of the hand can lie to the right side of the torch-handle, and the
thumb of the hand can lie to the left side of the torch-handle;
the shape of the over-handle is such that, when the first web area of a person's
hand is located in the said space, the attachment-component lies in front of the
first web area.
13. The apparatus of claim 12, wherein the over-handle includes a plate portion,
which extends outwardly and rearwardly with respect to the torch-handle at a suitable
angle to the torch-handle as to facilitate the placement of the said first web
area of the hand into the space between the plate portion and the torch-handle.
14. The apparatus of claim 13, wherein the plate portion extends outwardly and
rearwardly at an angle of about forty-five degrees with respect to the torch-handle.
15. The apparatus of claim 13, wherein the over-handle includes left and right
curved over side-portions.
16. The apparatus of claim 11, wherein, in respect to each one of the N detent-orientations,
the said heavy resistance;
is weak enough that the rotor-ring can be rotated, against the heavy resistance,
by hand manipulation, away from the detent-orientation; and,
is strong enough, in the absence of hand manipulation thereof, to hold the rotor-ring,
with the accessory secured thereto, at the detent-orientation.
17. The apparatus of claim 11, wherein:
the stator-ring includes N indentations, respective to the N detent-orientations;
the rotor-ring includes a ball and spring assembly, which is so structured that,
upon the rotor-ring being rotated upon the stator-ring, the ball enters into, and
rises out of, the N indentations, one by one, being urged into the indentations
by action of the spring.
18. The apparatus of claim 11, wherein the detent-orientations are equally pitched
circumferentially about the stator-ring, and the number N is about twenty.
19. The apparatus of claim 11, wherein the torch-handle includes a cylindrical
portion, which is suitable for being gripped by a person, and the rotation-axis
is co-axial with the axis of the cylindrical portion.
20. The apparatus of claim 11, wherein:
the torch includes an electrode, and an electrode-holder;
the structure of the torch is such that the electrode can be inserted into the
electrode holder, and can be clamped or gripped therein by the action of rotating
the electrode-holder relative to the torch handle;
and the structure of the torch is such that the rotatable accessory can be rotated
about the torch-handle while the electrode-holder is held stationary relative to
the torch-handle.
21. The apparatus of claim 20, wherein:
the structure of the torch is such that the electrode-holder can be screwed into
and out of the torch-handle, arid such action is effective to tighten and loosen
the electrode in the electrode-holder, respectively;
the electrode holder is so structured that the electrode, when tightened into
the electrode-holder, lies substantially radially with respect to the axis of the
torch-handle.
22. The apparatus of claim 20 wherein:
the action of rotating the electrode-holder relative to the torch-handle, to
clamp or grip the electrode therein, takes place about an electrode-holder axis;
and the electrode-holder axis is co-axial with the rotation-axis of the accessory.
23. The apparatus of claim 20, wherein the structure of the torch is such that:
in respect of a first occasion of operation of the torch, the electrode lies
at a first electrode-orientation angle relative to the torch-handle, and the accessory
can be rotated to, and left at, a first accessory-orientation angle relative to
the torch-handle;
in respect of a second occasion of operation of the torch, the electrode lies
at a second, different, electrode-orientation angle relative to the torch-handle,
and the accessory can be rotated to, and left at, a second accessory-orientation
angle relative to the torch handle.
24. The apparatus of claim 23, wherein:
when the electrode lies at the first electrode-orientation angle relative to
the torch-handle, and the accessory lies at the first accessory-orientation angle
relative to the torch-handle, the accessory thereby lies oriented at a first electrode-accessory-orientation
angle relative to the electrode; and
when the electrode lies at the second electrode-orientation angle relative to
the torch-handle, and the accessory lies at the second, different, accessory-orientation
angle relative to the torch-handle, the accessory thereby lies orientated at a
second electrode-accessory-orientation angle relative to the electrode;
the structure of the torch is such that the first electrode-accessory-orientation
angle can be made equal, by hand manipulation of the accessory, to the second electrode-accessory-orientation
angle.
25. An apparatus including a welding torch, having a service cable, wherein:
the torch includes a torch-handle, and includes an accessory mounted on the torch-handle;
wherein the torch-handle includes a cylindrical portion, which is suitable for
being gripped by a person, and a rotation-axis which is co-axial with the axis
of the cylindrical portion;
the accessory, so mounted, is guided on the torch-handle for rotation about a
rotation-axis of the torch-handle;
the accessory is functionally operable, and its manner of operation is such that
the efficacy thereof is substantially affected by the orientation of the accessory
relative to the torch-handle;
a stator-ring is fixedly secured to the torch handle;
a rotor-ring is fixedly secured to the accessory;
the stator-ring and the rotor-ring are so structured, mutually, that the rotor-ring
is guided for, and constrained against, all modes of movement relative to the stator-ring,
other than rotation about the rotation-axis of the torch-handle;
the accessory includes a detent mechanism, which defines N detent-orientations
of the rotor-ring upon the stator-ring;
in respect of each one of the N detent-orientations;
when the rotor-ring lies at the detent-orientation, the detent mechanism provides
a heavy resistance to rotational movement of the rotor-ring away from the detent-orientation;
when the rotor-ring lies close to the detent-orientation, the detent mechanism
provides a large resistance to rotational movement of the rotor-ring in the direction
away from the detent-orientation, and provides a small, or negative, resistance
to rotational movement of the rotor-ring in the direction towards the detent-orientation;
wherein the torch includes an electrode, and an electrode-holder;
the structure of the torch is such that the electrode can be inserted into the
electrode holder, and can be clamped or gripped therein by the action of rotating
the electrode-holder relative to the torch-handle;
and the structure of the torch is such that the rotatable accessory can be rotated
about the torch-handle while the electrode-holder is held stationary relative to
the torch-handle;
the structure of the torch is such that the electrode-holder can be screwed into
and out of the torch-handle, and such action is effective to tighten and loosen
the electrode in the electrode-holder, respectively;
the electrode holder is so structured that the electrode, when tightened into
the electrode-holder, lies substantially radially with respect to the axis of the
torch-handle;
the action of rotating the electrode-holder relative to the torch-handle, to
clamp or grip the electrode therein, takes place about an electrode-holder axis;
the electrode-holder axis is co-axial with the rotation-axis of the accessory;
the accessory comprises an over-handle, fixedly secured to the rotor-ring;
the over-handle extends outwards and rearwards from the rotor-ring;
the over-handle overlies, and is spaced from, the torch-handle;
the over-handle is so disposed in relation to the torch-handle as to create a
space between the torch-handle and an undersurface of the over-handle;
the space thus created is so shaped and sized as to be capable of, and suitable
for, receiving the first web area of the hand of a person, into that space, the
first web area being the webbed area between the thumb and the forefinger;
the configuration of the space created between the torch-handle and the over-handle
is such that, when the first web area of the hand is located in the said space,
the first web area is gripped between the torch-handle and the over-handle securely
enough that the person can manipulate and manhandle the torch, with the service
cable attached, substantially without exerting any muscular squeeze or grip on
the torch-handle.
26. An apparatus including a welding torch, having a cables wherein:
the torch includes a torch-handle, and includes an accessory mounted on the torch-handle;
the accessory, so mounted, is guided on the torch-handle for rotation about a
rotation-axis of the torch-handle, wherein the rotatable accessory comprises a
pick;
the accessory is functionally operable, and its manner of operation is such that
the efficacy thereof is substantially affected by the orientation of the accessory
relative to the torch-handle;
a stator-ring is fixedly secured to the torch handle;
a rotor-ring is fixed to secured to the accessory;
the stator-ring and the rotor-ring are so structured, mutually, that the rotor-ring
is guided for, and constrained against, all modes of movement relative to he stator-ring,
other than rotation about the rotation-axis of the torch-handle;
the accessory includes a detent mechanism, which defines N detent-orientations
of the rotor-ring upon the stator-ring;
in respect of each one of the N detent-orientations;
when the rotor-ring lies at the detent-orientation, the detent mechanism provides
a heavy resistance to rotational movement of the rotor-ring away from the detent-orientation;
when the rotor-ring lies close to the detent-orientation, the detent mechanism
provides a large resistance to rotational movement of the rotor-ring in the direction
away from the detent-orientation, and provides a small, or negative, resistance
to rotational movement of the rotor-ring in the direction towards the detent-orientation.
27. The apparatus of claim 26, wherein, in respect to each one of the N detent-orientations,
the said heavy resistance;
is weak enough that the rotor-ring can be rotated, against the heavy resistance,
by hand manipulation, away from the detent-orientation; and,
is strong enough, in the absence of hand manipulation thereof, to hold the rotor-ring,
with the accessory secured thereto, at the detent-orientation.
28. The apparatus of claim 26, wherein:
the stator-ring includes N indentations, respective to the N detent-orientations;
the rotor-ring includes a ball and spring assembly, which is so structured that,
upon the rotor-ring being rotated upon the stator-ring, the ball enters into, and
rises out of, the N indentations, one by one, being urged into the indentations
by action of the spring.
29. The apparatus of claim 26, wherein the detent-orientations are equally pitched
circumferentially about the stator-ring, and the number N is about twenty.
30. The apparatus of claim 26, wherein the torch-handle includes a cylindrical
portion, which is suitable for being gripped by a person, and the rotation-axis
is co-axial with the axis of the cylindrical portion.
31. The apparatus of claim 26, wherein:
the torch includes an electrode, and an electrode-holder;
the structure of the torch is such that the electrode can be inserted into the
electrode holder, and can be clamped or gripped therein by the action of rotating
the electrode-holder relative to the torch handle;
and the structure of the torch is such that the rotatable accessory can be rotated
about the torch-handle while the electrode-holder is held stationary relative to
the torch-handle.
32. The apparatus of claim 31, wherein:
the structure of the torch is such that the electrode-holder can be screwed into
and out of the torch-handle, and such action is effective to tighten and loosen
the electrode in the electrode-holder, respectively;
the electrode holder is so structured that the electrode, when tightened into
the electrode-holder, lies substantially radially with respect to the axis of the
torch-handle.
33. The apparatus of claim 31, wherein:
the action of rotating the electrode-holder relative to the torch-handle, to
clamp or grip the electrode therein, takes place about an electrode-holder axis;
and the electrode-holder axis is co-axial with the rotation-axis of the accessory.
34. The apparatus of claim 31, wherein the structure of the torch is such that:
in respect of a first occasion of operation of the torch, the electrode lies
at a first electrode-orientation angle relative to the torch-handle, and the accessory
can be rotated to, and left at, a first accessory-orientation angle relative to
the torch-handle;
in respect of a second occasion of operation of the torch, the electrode lies
at a second, different, electrode-orientation angle relative to the torch-handle,
and the accessory can be rotated to, and left at, a second accessory-orientation
angle relative to the torch handle.
35. The apparatus of claim 34, wherein:
when the electrode lies at the first electrode-orientation angle relative to
the torch-handle, and the accessory lies at the first accessory-orientation angle
relative to the torch-handle, the accessory thereby lies oriented at a first electrode-accessory-orientation
angle relative to the electrode; and
when the electrode lies at the second electrode-orientation angle relative to
the torch-handle, and the accessory lies at the second, different, accessory-orientation
angle relative to the torch-handle, the accessory thereby lies orientated at a
second electrode-accessory-orientation angle relative to the electrode;
the structure of the torch is such that the first electrode-accessory-orientation
angle can be made equal, by hand manipulation of the accessory, to the second electrode-accessory-orientation
angle.
Description
This invention relates to torch-mounted accessories for improving the operation
and performance of a welding torch.
BACKGROUND TO THE INVENTION
The invention is particularly applicable to the kind of torch in which:
- an electrode is clamped into an electrode holder;
- the clamp is tightened by screw thread action;
- the screw thread is between the electrode holder and a cylindrical torch-handle;
- and the orientation at which the electrode holder comes to rest on the
torch-handle, upon tightening, can vary unpredictably, for example due to the replacement
of a spent electrode with a new one of slightly different dimensions—and
of course the welder might apply more or less tightening force to the new electrode.
GENERAL FEATURES OF THE INVENTION
The invention provides that the accessory is rotatable on the torch-handle. As
a result, for example, the accessory can be rotated to the appropriate orientation
for best operational convenience of the accessory, once the orientation of the
electrode holder (and the electrode) have been set.
Preferably, the accessory comprises an over-handle, of the kind used
to relieve gripping stress in the hand of the welder.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
By way of further explanation of the invention, exemplary embodiments of the
invention
will now be described with reference to the accompanying drawings, in which:
FIG. 1 is a cross-section of a known type of welding torch, in which a (coated)
electrode is gripped in an electrode-holder.
FIG. 2 is the same cross-section, but shows rotatable accessories mounted on
the torch handle, in accordance with the invention.
FIG. 3 cross-section of the accessory shown in FIG. 2.
FIG. 4 is a cross-section on line 4—4 of FIG. 3.
FIG. 5 is a side view of the torch of FIG. 2, in use.
FIG. 6 is a view in the direction of arrow 6 of FIG. 5, showing a possible
condition of the torch.
FIG. 7 is a view of another rotatable accessory that accords with the invention.
FIG. 8 is a pictorial view of another rotatable accessory that accords with
the invention.
The apparatuses shown in the accompanying drawings and described below are examples
which embody the invention. It should be noted that the scope of the invention
is defined by the accompanying claims, and not necessarily by specific features
of exemplary embodiments.
As shown in FIG. 1, the torch
20 includes a handle
23, in the form
of a cylindrical tube of plastic material. An electrode holder
24 comprises
a plastic body
25, in which is housed a brass insert
26. The brass
insert
26 has a threaded stem
27. The stem
27 is hollow, and
a push rod
28 is slidable therein.
In the handle
23 of the torch
20 is a brass fitting
29,
which
is formed with a female thread
30, complementary to the threaded stem
27.
The fitting
29 is made from hexagonal bar, at
32, and the plastic
handle body
34 is moulded with an internal hexagonal form, sized to prevent
relative rotation between the fitting
29 and the handle body
34.
The structure of the torch
20 is such that, when the holder
24
is rotated about the handle
23, the holder
24 screws into the handle
23. This action drives push rod
28 effectively upwards relative to
the holder
24, which causes lever
35 to rock about pin
36,
and causes the tappet
37 to clamp the electrode
38 firmly against
the internal trough
39 of the brass insert
26. Thus, when the electrode
38 is finished, the welder unscrews the holder
24 from the handle
23, by hand; this relieves the push rod
28 and lever
35, whereby
the stump of the electrode drops away. The welder inserts a new electrode into
the holder, and screws the holder back down into the handle, until the new electrode
is gripped tightly.
The welder stops screwing the electrode holder
24 into the handle
23
at the point where the new electrode
38 is gripped tightly. But probably,
the orientation at which the holder
24 comes to rest relative to the handle
23, with this new electrode, is different from the orientation at which
the holder came to rest in respect of the previous electrode, now discarded. The
handle
23 is a right cylinder, so the fact that the holder
24 now
lies orientated to the north of the handle axis, instead of to the west, is immaterial
as far as the normal operation of the torch is concerned.
Torches of the kind as depicted in FIG. 1, with a right-cylindrical handle
23 and a screw-in electrode holder
24, are in widespread use in industry.
The depicted lever clamp arrangement is common, but other mechanisms for clamping
and gripping the electrode
38, responsively to the holder
24 being
screwed into the cylindrical handle
23, are often encountered.
The rotatable accessory of the present invention is for use with torches of this
type, in which the orientation at which the electrode holder
24 comes to
rest is unpredictable.
An example of a rotatable accessory that embodies the invention is shown in FIG.
2. A stator sleeve
40 is annular in form, and is sized and adapted to slide
axially over the plain cylindrical upper end
42 of the handle body
34.
An upper extension
43 of the stator sleeve
40 is slit, and is clamped
by means of a circumferential screw clamp
45 onto the end
43.
The stator-sleeve
40 includes a stator-ring
46. A rotor-ring
47
is assembled over the stator-ring
46, and the rotor-ring
47 is held
in place, against a shoulder
48, by means of a circlip
49. The rotor-ring
46 is adapted and dimensioned for guided rotation around the stator-ring
46.
The outer surface of the stator-ring is formed with a series of indentations
or sockets
50, which will be described below.
An over-handle
51 is attached to the rotor-ring
47. A post
53
is welded to the outer surface of the rotor-ring
47, and the handle-plate
52 that forms the main part of the over-handle is shaped to partly slip
over the post
53, and partly engage the outer surface, and the handle-plate
is welded to the post
53 and the rotor-ring surface.
The rotor-ring
47 is provided with a through-hole
54, which contains
a ball
56. The post
53 is threaded inside, and carries a grub-screw
57. The grub-screw presses down on the ball
56, and presses the ball
into the indentation or socket
50. The arrangement serves as a rotational
detent. In order for the rotor-ring
47 to rotate, the ball
56 has
to ride up, out of the indentation
50, against spring
59. Thus, when
the welder comes to rotate the rotor-ring, the effort required to do so varies
from very light when the rotor ring is moving such that the ball is entering into
one of the indentations, to much heavier when the ball is riding up and out of
the indentation.
It is recognised that the detent mechanism can readily be made such that the
resistance
due to the spring will hold the rotor-ring against rotation, normally, unless the
welder forcefully turns the rotor-ring; and yet the resistance is light enough
that the welder can easily turn the rotor-ring with their hands.
The over-handle
51 is very effective in relieving the muscle strain a
welder feels after a period of time manipulating the torch
20. The strain
arises because the heavy service cable
60 is a constant drag on the torch,
and because the welder must hold the torch steady all the time during operation.
One of the main reasons for the muscle strains associated with welding is that
the welder must be constantly exert a strong clasping or gripping force around
the torch handle. Thus, the strain on a welder's hand arises mainly from the fact
that the hand is exerting a grip, rather than from the weight of the torch, as
such. Carpal tunnel syndrome is a predominant disability of welders, and it arises
mainly because of the welder's need constantly to exert a squeeze-grip on the torch handle.
To operate the torch, the welder places their hand around the tubular handle
23,
with the fingers on one side and the thumb on the other side (FIG.
5). The
presence of the over-handle
51 means that the first web area of the hand,
i.e the web area between the thumb and the forefinger, lies between the torch-handle
23 and the over-handle
51. The over-handle slopes back at an angle
of about forty-five degrees, and the effect is that the welder can now control
and manipulate the torch simply by resting the first web area under the over-handle.
That is to say, the welder can exert enough physical control of the torch, to
manipulate the torch during welding operations, without needing to grip the torch
handle. Of course, generally, the welder will exert a light grip on the torch handle,
rather than leave the fingers completely loose, but the point of the over-handle
is that the welder is relieved of the constant need, all the time, to exert a strong
gripping or clasping force on the torch handle. The presence of the over-handle
means the welder can maintain proper manipulative control over the torch with the
gripping/clasping muscles of the hand in a more or less relaxed state, whereby
the welder can continue operations for many hours without suffering disabling hand
fatigue and strain.
The principle of the ergonomic over-handle for a welding torch is described in
detail in patent publication CA-2,338,949.
When carrying out a welding operation (see FIG.
5), the welder's wrist
and arm lie on the other side of the torch-handle
23 from the electrode
38. Thus, the requirement arises for the over-handle
51 to be on
the opposite side of the torch from the electrode. In fact, the over-handle
51
should be more or less diametrically opposite the electrode
38. It would
be unacceptable if the over-handle
51 were to lie at an angle that was substantially
different from 180 degrees relative to the electrode. (See FIG.
6. It will
be understood that the welder really cannot conduct welding operations if the electrode
38 is left protruding at the as-illustrated odd angle to the right, relative
to the over-handle
51.)
However, as mentioned, the orientation of the electrode holder
24
at which the holder comes to rest, relative to the handle, is not predictable.
As mentioned, this is because proprietary welding electrodes vary as to their diameter,
and welders vary as to the pressure they use to tighten the tappet
37 in
the holder
24 down onto the electrode
38.
It may happen that, at the point where the electrode has become fully tightened
into the holder, the electrode and the over-handle do not lie diametrically opposite
each other on the handle, but instead lie at some odd angle relative to each other.
In fact, relative to the handle
23, the angle the electrode
38 makes
when it comes to rest (i.e when the electrode becomes tight), may be regarded as
simply random.
Because the orientation of the electrode
38 can vary relative to the
handle
23, and because the over-handle
51 needs to lie preferably
diametrically opposite the electrode
38, therefore the structure of the
torch should be such that the orientation of the over-handle
51 can be varied,
relative to the handle. The over-handle
51 is rotatable on the handle
23,
to accommodate this desideratum. Upon inserting a new electrode, the welder tightens
the holder
24 down into the handle
23, until the new electrode is
tightly gripped; then, they simply spin the over-handle
51, on the rotor-ring
47, to an orientation that is diametrically opposite where the electrode
came to rest. The detent mechanism is so constructed that the welder can easily
turn the over-handle by hand action, and yet the over-handle remains firmly in
the as-set orientation. It remains there until the welder moves it to a new orientation.
The over-handle-plate
52 is of sheet metal (aluminum), bent to shape,
and welded to the post
53. A piece
62 of foam rubber is glued to
the over-handle-plate. This provides some comfort, and also increased friction
to assist the welder in manipulating the torch when exerting only a very light
grip on the handle. In the example as illustrated, the central flat area
63
of the over-handle-plate, i.e the area left between the left and right bent-over
sides
64, was seven cm wide. The foam rubber was ten mm thick. The over-handle-plate
made an angle of forty-five degrees relative to the axis of the handle
23,
and its length in the FIG. 5 view was five cm.
The torch
20 as shown has also been furnished with another rotatable accessory,
namely the rotatable pick
65. When welding, it is often a requirement for
the welder, immediately after completing a weld, to chip away the oxide slag that
has built up around the weld, and a suitable small pick hammer should be part of
the welder's toolkit, for this purpose. However, a separate pick hammer tool can
become lost; also, if separate, the welder has to set down the torch, and then
take up the pick hammer, which can be tiresome and disruptive to smooth operations.
As shown, the pick
65 is attached to the torch, and the welder can bring
the pick into operation without setting the torch down. When the welder is using
the pick to clean a weld, generally they will be disposed to orientate the pick
more or less diametrically opposite the electrode, so the electrode is out of the
way during the hammering action. At the same time, the welder will be disposed
to set the over-handle now in line with the electrode, for ease of manipulation
of the torch now as a pick-hammer. Thus, the rotatable over-handle and the rotatable
pick now lie in the orientations as will be understood from FIG.
3.
The pick
65 had a length of nine cm from the axis of the handle, and a
diameter of thirteen mm. Alternatively, the pick may be provided with a chisel-shaped
end. Generally, it is not preferred that the pick be removable from the rotor-ring,
because the pick might tend to work loose in that case.
Even without a rotatable over-handle, it can be beneficial to provide a rotatable
pick on the torch, so that the pick can be out of the way while the torch is being
used for welding, and the electrode can be out of the way when the pick is being
used. When the rotatable over-handle is also present, the orientations of these
accessories can be set and re-set quickly and conveniently, and the improvement
in smooth operation, overall, i.e including both welding and picking, is quite noticeable.
FIG. 7 shows a rotatable accessory which includes only an over-handle, but no
pick. That can be beneficial where the welder does prefer to use a separate pick-hammer
tool for the picking action.
FIG. 7 shows also a split sleeve
67. This sleeve would be supplied with
the rotatable accessory
68. The sleeve optionally fits inside the stator-sleeve
40 of the accessory, and enables the accessory to be used with a (cylindrical)
handle of somewhat slimmer dimensions. However, generally, proprietary torch handles
vary only very slightly as to diameter—because of course they all have to
cater for the same range of sizes of welders' (gloved) hands.
FIG. 8 shows an over-handle of an assembly-structure that is fabricated as a
one-piece casting or moulding. In FIG. 8, the over-handle
70 is moulded
in plastic. The rotor-ring and the over-handle are combined together in the one-piece
moulding. A recess for receiving the spring
72 and ball
73 is formed
as a blind hole within the shape of the over-handle. Thus, a post is not required,
nor a grubscrew. The stator-ring
74 for use with the one-piece over-handle
assembly-structure may be substantially the same as the stator ring
46 of
the previous drawings.
*
