Title: Coordinated lift system
Abstract: A lift system that coordinates the raising and lowering of a vehicle relative to a surface by using wireless communications is provided. The lift system includes at least two lift mechanisms each having a post, a carriage, an actuating device and a control device. The carriage is slidably coupled to the post and is adapted to support a portion of the vehicle. The actuating device is coupled with the carriage and is capable of moving the carriage relative to the post. The control device is coupled with the actuating device and is capable of communicating by wireless signals with the other control device. The control devices communicate by wireless signals to coordinate the movement of the carriages relative to the posts to raise or lower the vehicle. Further, a rechargeable battery may provide power to the control device to allow for increased mobility of the lift system.
Patent Number: 7,014,012 Issued on 03/21/2006 to Baker
| Inventors:
|
Baker; William J. (St. Joseph, MO)
|
| Assignee:
|
Gray Automotive Products, Inc. (St. Joseph, MO)
|
| Appl. No.:
|
634457 |
| Filed:
|
August 5, 2003 |
| Current U.S. Class: |
187/247; 187/210 |
| Current Intern'l Class: |
B66B 1/28 (20060101); B66F 7/10 (20060101) |
| Field of Search: |
187/224,226,227,233,247,248,249,250,276,277,413,203, 207,210,213
254/11,12,45,47,419,424,427,273,290-292,275
414/564,610,613,628,630
|
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| |
Other References
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Lifting Equipment, dated Jan., 2000.
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of Heavy Machinery, No. 12, pp. 6-10, dated 1995.
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in Power Transmission Design, pp. 57-59, dated Aug., 1994.
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in SAE Technical Paper Series 851516, pp. 1-6, dated Sep. 9-12, 1985.
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|
Primary Examiner: Salata; Jonathan
Attorney, Agent or Firm: Shughart Thomson & Kilroy, P.C.
Goverment Interests
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation application and claims priority from non-provisional
application Ser. No. 10/166,134 filed Jun. 10, 2002 now U.S. Pat. No. 6,634,461,
the contents of which are incorporated by reference.
Claims
What is claimed is:
1. A wireless lift system for coordinated lifting of a structure and comprising:
(a) a first lift mechanism and a second lift mechanism;
(b) each of said first and second lift mechanisms including an elongated vertical
guide member, a carriage slidingly engaged with said guide member and adapted to
supportively engage a structure to lift and/or lower the structure, an actuator
engaged between said guide member and said carriage, a controller coupled to said
actuator and enabling selective activation of said actuator to thereby move said
carriage along said guide member, and a rechargeable battery coupled to said actuator
by way of said controller to thereby selectively provide operating power thereto;
(c) each lift mechanism including a radio-frequency transceiver coupled to the
controller associated therewith to enable wireless communication between controllers
of said lift mechanisms; and
(d) the controllers of said lift mechanisms enabling cooperation of said lift
mechanisms by way of said wireless communication between said controllers to thereby
enable coordinated lifting and/or lowering of said structure.
2. A system as set forth in claim 1 wherein each lift mechanism includes:
(a) said actuator including a hydraulic cylinder and a hydraulic pump communicating
hydraulic fluid to said cylinder under pressure; and
(b) said rechargeable battery being coupled to said hydraulic pump by way of
said controller to thereby selectively provide operating power to said hydraulic
pump.
3. A system as set forth in claim 1 wherein:
(a) said carriage is adapted to engage a part of a vehicle to thereby lift said
vehicle.
4. A system as set forth in claim 1 and including:
(a) an additional lift mechanism substantially similar to said first and second
lift mechanisms and capable of operation in coordination therewith.
5. A system as set forth in claim 1 wherein each lift mechanism includes:
(a) a height sensor engaged with said carriage, coupled to said controller, and
communicating to said controller a height signal corresponding to a location of
said carriage relative to said guide member to thereby enable said coordinated
lifting and/or lowering of said structure.
6. A lift system as set forth in claim 1 wherein each lift mechanism includes:
(a) a surface engaging wheel rotatably connected to said guide member; and
(b) a handle connected to said guide member to enable selective manual movement
of said lift mechanism upon said surface.
7. A wireless lift system for coordinated lifting of a vehicle and comprising:
(a) a plurality of lift mechanisms, each lift mechanism being manually movable
and including an elongated vertical guide member and a carriage slidingly engaged
with said guide member and adapted to supportively engage a vehicle to lift and/or
lower the vehicle;
(b) each lift mechanism including a hydraulic cylinder engaged between said guide
member and said carriage, a hydraulic pump communicating hydraulic fluid with said
hydraulic cylinder, and a rechargeable battery coupled to said hydraulic pump and
selectively providing operating power therefor;
(c) each lift mechanism including a controller coupling said battery to said
hydraulic pump and enabling selective activation of said hydraulic pump to thereby
cause movement of said carriage along said guide member;
(d) each lift mechanism including a height sensor engaged with said carriage,
coupled with said controller, and communicating to said controller a height signal
corresponding to a location of said carriage relative to said guide member;
(e) each lift mechanism including a radio-frequency transceiver coupled to the
controller associated with said lift mechanism to enable wireless communication
between controllers of said lift mechanisms; and
(f) the controllers, of said lift mechanisms enabling cooperation of said lift
mechanisms by way of said wireless communication between said controllers to thereby
enable coordinated lifting and/or lowering of said vehicle.
8. A lift system as set forth in claim 7 wherein each lift mechanism includes:
(a) a surface engaging wheel rotatably connected to said guide member; and
(b) a handle connected to said guide member to enable selective manual movement
of said lift mechanism upon said surface.
9. A method for controlling and powering lift mechanisms to coordinate lifting
of a structure and comprising the steps of:
(a) providing a first lift mechanism and a second lift mechanism, each of said
first and second lift mechanisms including an elongated vertical guide member,
a carnage slidingly engaged with said guide member and adapted to supportively
engage a structure to lift and/or lower the structure, an actuator engaged between
said guide member and said carnage, a controller coupled to said actuator and enabling
selective activation of said actuator to thereby move said carriage along said
guide member, a rechargeable battery coupled to said actuator by way of said controller
to thereby selectively provide operating power thereto, and a radio-frequency transceiver
coupled to said controller to enable wireless communication with a controller of
another of said lift mechanisms;
(b) engaging said carnage of each of said first and second lift mechanisms with
a structure to be lifted;
(c) selectively applying electrical power from said battery of each lift mechanism
to the actuator thereof to cause movement of the carriage thereof along the guide
member thereof; and
(d) communicating radio-frequency signals between the controllers of said lift
mechanisms by way of the transceivers thereof to control selective application
of said electrical power from batteries of said lift mechanisms to actuators thereof
to thereby coordinate lifting of said structure.
10. A method as set forth in claim 9 and including the steps of:
(a) providing each lift mechanism with a height sensor engaged with the carriage
thereof and coupled with the controller thereof; and
(b) communicating to said controller a height signal corresponding the a location
of the carriage thereof relative to said guide member thereof to thereby enable
coordinated lifting of said structure.
11. A method as set forth in claim 9 and including the steps of:
(a) providing each lift mechanism with a wheel connected to said guide member
and a handle connected to said guide member; and
(b) manually moving each lift mechanism, using the handle and wheel thereof,
to thereby engage the carriage thereof with said structure.
12. A method as set forth in claim 9 and including the step of:
(a) adapting the carriage of each of said lift mechanisms to engage a part of
a vehicle to thereby enable wireless, coordinated lifting of said vehicle using
said lift mechanisms.
13. A method for controlling and powering lift mechanisms to coordinate lifting
of a vehicle and comprising the steps of:
(a) providing a plurality of lift mechanisms, each of said lift mechanisms including
en elongated vertical guide member, a carriage slidingly engaged with said guide
member and adapted to supportively engage a vehicle to lift and/or lower said vehicle,
an actuator engaged between said guide member and said carriage; a controller coupled
to said actuator and enabling selective activation of said actuator to thereby
move said carriage along said guide member a rechargeable battery coupled to said
actuator by way of said controller to thereby selectively provide operating power
thereto; a radio-frequency transceiver coupled to said controller to enable wireless
communication with a controller of another of said lift mechanisms; and a height
sensor engaged with said carriage, coupled with said controller, and communicating
to said controller a height signal corresponding to a location of said carriage
relative to said guide member;
(b) engaging said carriage of each of said lift mechanisms with a respective
part of said vehicle to be lifted;
(c) selectively applying electrical power from said battery of each lift mechanism
to the actuator thereof to cause movement of the carriage thereof along the guide
member thereof; and
(d) communicating radio-frequency signals between the controllers of said lift
mechanisms by way of the transceivers thereof to control selective application
of said electrical power from batteries of said lift mechanisms to actuators thereof
to thereby coordinate lifting of said structure.
14. A method as set forth in claim 13 and including the steps of:
(a) providing each lift mechanism with a wheel connected to said guide member
and a handle connected to said guide member; and
(b) manually moving each lift mechanism, using the handle and wheel thereof,
to thereby engage the carriage thereof with said structure.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a coordinated lift system. In particular, the
present invention relates to a coordinated lift system having at least two lift
mechanisms that communicate by wireless signals to coordinate the raising and lowering
of a vehicle.
The need to lift a vehicle from the ground for service work is well established.
For instance, it is often necessary to lift a vehicle for tire rotation or replacement,
steering alignment, oil changes, brake inspections, exhaust work and other automotive
maintenance. Traditionally, lifting a vehicle has been accomplished through the
use of equipment that is built-in to the service facility. These built-in units
are located at a fixed location at the service facility and adapted to contact
the vehicle frame to lift the vehicle from the ground. However, built-in units
are very expensive and sometimes impractical due to their immobility.
In an effort to increase mobility and reduce the need to invest in permanent
lifting
equipment, a device commonly known as a mobile column lift (MCL) was developed.
A set of MCL's are typically used to independently engage each of the tires and
lift the vehicle from the ground. Using a basic form of MCL's to lift a vehicle
in a generally level orientation, a user must go back and forth between each MCL
to incrementally raise each of the MCL's until the vehicle reaches the desired
height or involve several people. While this MCL is less expensive and provides
more mobility than the built-in units, using a plurality of MCL's to lift the vehicle
is a time consuming and tedious process.
Another method for lifting a vehicle using multiple MCL's is described in
U.S. Pat. No. 6,315,079 to Berends et al. The lifting device in Berends includes
using a number connecting lines or wires to connect the MCL's to one another. Even
through the lines or wires that are connected between the MCL's allow the vehicle
to be raised or lowered in a uniform fashion, this device also suffers from a number
of drawbacks and deficiencies. For instance, the lines and wires used to connect
the MCL's extend across and are looped within the working area. The presence of
the wires and lines in the work area poses a hazard to people working near the
vehicle. Vehicles also end up driving over these connecting lines causing damage.
Accordingly, there remains a need for a mobile lift system that is able
to coordinate the raising or lowering of a vehicle without having to physically
connect the lift mechanisms to one another. The present invention fills these needs
as well as various other needs.
BRIEF SUMMARY OF THE INVENTION
In order to overcome the above-stated problems and limitations, and to achieve
the noted objects, there is provided a lift system that coordinates the raising
and lowering of a vehicle relative to a surface through the use of wireless communications.
In general, the lift system includes at least two lift mechanisms, each including
a post, a carriage, an actuating device and a control device. The carriage is slidably
coupled to the post and is adapted to support a portion of the vehicle. The actuating
device is coupled with the carriage and is capable of moving the carriage relative
to the post. The control device is coupled with the actuating device and is capable
of communicating by wireless signals with another control device. The control devices
on each lifting mechanism communicate with each other by wireless signals to coordinate
the movement of each carriage relative to the posts to raise or lower the vehicle
relative to the surface.
Additionally, the control device may include a transceiver, a sensor,
a display and a stop mechanism. The transceiver is capable of transmitting and
receiving wireless signals from another control device. The sensor may be positioned
externally relative to control device and is used for determining the position
of the carriage relative to the post. Further, the stop mechanism operates to prevent
movement of the carriage relative to the post. The lift system may also include
a rechargeable battery that provides portable power to the control device and actuating
device to move the vehicle relative to the surface. Furthermore, the present invention
may include a remote control device capable of communicating with the control box
using wireless signals to raise or lower the vehicle relative to the surface without
being stationed to a particular location.
A method for the coordinated lifting and lower of a vehicle relative to a surface
is also provided. The method includes providing for first and second lift mechanisms,
placing the first and second lift mechanisms in contact with a portion of the vehicle,
sending a wireless signal from the first lift mechanism, receiving the wireless
signal at the second lift mechanism wherein wireless signal instructs the second
lift mechanism to move the vehicle relative to the surface, and moving the vehicle
using the first lift mechanism in coordination with the second lift mechanism.
Further objects, features, and advantages of the present invention over the
prior art will become apparent from the detailed description of the drawings which
follows, when considered with the attached figures.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
In the accompanying drawings which form a part of the specification and are to
be read in conjunction therewith and in which like reference numerals are employed
to indicate like parts in the various views:
FIG. 1 is a perspective view showing a plurality of lift mechanisms supporting
a vehicle in a raised position according to the present invention;
FIG. 2 is a schematic diagram showing the input and output components associated
with the control boxes mounted on each of the lift mechanisms;
FIG. 3 is a flow chart illustrating the operation of the control box when placed
in an independent mode, a portion thereof also applying to the operation of the
control box when placed in a synchronized mode;
FIG. 4 is a flow chart illustrating a portion of the operation of the control
box when placed in the synchronized mode, the wireless communications being shown
in dashed lines; and
FIG. 5 is a schematic diagram illustrating the communications between a master
control box, slave control boxes and associated output device, the wireless communications
being shown in dashed lines.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings in detail, and initially to FIG. 1, numeral
10 generally designates a lift system constructed in accordance with a first
preferred embodiment of the present invention. Generally, lift system
10
includes four lift mechanisms
12 that communicate by wireless signals to
coordinate the movement of a vehicle
14 relative to a surface. It will be
understood and appreciated that the number of lift mechanisms
12 used in
the present invention may vary depending on the type of vehicle being lifted. For
instance, six lift mechanisms may be used to lift a three axle vehicle for service.
Furthermore, it will be understood that lift system
10 is not limited for
use with vehicles, but also may be used to raise or lower other objects relative
to the surface.
Each lift mechanism
12 includes an upstanding post
18 supported
by a base
20. Base
20 includes a pair of flanges
22 that are
coupled to one another by a cross piece
24. A pair of front wheels
26
are rotatably coupled with an end portion of flanges
22. Further, a pair
of rear wheels
28 are rotatably coupled adjacent to cross piece
24.
Wheels
26,
28 are adapted to allow lift mechanism
12 to be
rolled along the surface and placed in a position to support vehicle
14.
A handle
30 is coupled to wheels
26,
28 and may be moved about
a pivot point established adjacent to wheels
28. Handle
30 may be
used to place wheels
26,
28 in contact with the surface so that lift
mechanism
12 may be rolled into position. Once lift mechanism
12
is in position, handle
30 may then be used to raise wheels
26,
28
so that they are no longer in contact with the surface. The lift mechanism is thereby
placed in a stable position for raising and lowering vehicle
14.
Post
18 is mounted to cross piece
24 and extends upwardly from
the surface. Lifting mechanism
12 also includes a carriage
32 that
is slidably coupled to post
18. Specifically, carriage
32 includes
a slot portion
34 that engages a portion of post
18 to enable carriage
32 to move longitudinally with respect to post
18. Carriage
32
further includes a pair of forks
36 that extend outwardly from slot portion
34 and are adapted to support a portion of vehicle
14. In particular,
forks
36 are adapted to support vehicle
14 at each wheel, but it
will be understood that carriage
32 may also be adapted to support the frame
or any other portion of vehicle
14.
Carriage
32 may be moved relative to post
18 using a piston
and cylinder assembly
38. The piston may be secured to post
18 and/or
base
20 in a generally upright position. The cylinder is coupled to carriage
32 in such a way that the cylinder and carriage
32 move upwardly
or downwardly in conjunction with one another. Generally, a power unit
39
is used to move a fluid into the cylinder in such a manner to cause piston to rise
and will be described in further detail below. The movement of the piston causes
carriage
32 move upwardly relative to the surface. As fluid is removed from
the cylinder, the piston moves downwardly and carriage
32 is lowered through
the use of gravity. It will be understood that piston and cylinder assembly
38
may operate to move carriage
32 through the use of either hydraulic or pneumatic
forces. Further, it is also within the scope of this invention to use a double
acting cylinder to move carriage
32 relative to post
18.
As best seen in FIG. 1, each lift mechanism
12 also includes a control
box
40 that is adapted to communicate with the other control boxes in lift
system
10 by wireless signals to coordinate the raising and/or lifting of
vehicle
14. With additional reference to FIG. 2, a rechargeable battery
42, or other power source, may provide power to control box
40 by
selectively activating a power switch
43. An antenna
44 may be coupled
to each control box
40 to enhance the quality of the wireless communication
between the control boxes. Furthermore, control box
40 may include a transceiver,
not shown, that is capable of sending and receiving wireless communications to
and from other control boxes in lift system
10.
Control box
40 provides for a number of input components
46.
One input component is a height sensing mechanism
48 which is adapted to
determine the height of carriage
32 relative to the surface and relay that
information back to control box
40. It should be understood that height
sensing mechanism
48 may be separate from and positioned in a different
location relative to control box
40. Other input components include an emergency
stop button
50, an interlock function
52, a selector switch
54
and a motion switch
56. Emergency stop button
50 allows a user to
instruct control box
40 to stop moving carriage
32 relative to post
18. Interlock function
52 should be engaged before lifting or lowering
of carriage
32 can occur. When lift system
10 is in a synchronized
mode, interlock function
52 also allows a user to specify which one of the
control boxes will be the master control box. Once a master control box is selected,
the remaining control boxes are designated as slave control boxes and operate under
instructions provided by the master control box. A more detailed discussion of
the coordinated operation of lift mechanism
12 will be provided below. Selector
switch
54 allows control box
40 to be changed between independent
and synchronized modes, which will also be discussed in more detail below. Motion
switch
56 is adapted to instruct control box
40 to raise or lower
carriage
32 relative to the surface. The emergency stop, interlock or motion
input components
46 described above may be activated by a remote control
device
58. Remote control device
58 may communicate with control
box
40 to initiate some input devices
46 from a location that is
remote from lift mechanism
12. It will be appreciated that it is also within
the scope of this invention to provide for other input devices such as, but not
limited to, a level sensor that is adapted to determine the position of post
18
relative to a vertical axis.
Control box
40 also provides for output components
59. These
output device may include power unit
39, a lowering valve solenoid
62,
a holding valve solenoid
64, a safety release solenoid
66. Output
components
59 are interconnected between control box
40 and piston
and cylinder assembly
38 and power unit
39 and are used to control
the movement of carriage
32 relative to post
18. In particular, power
unit
39 is used to activate the pump in piston and cylinder assembly
38
to move fluid within the cylinder to raise carriage
32. Lowering valve solenoid
62 may be activated to release fluid from the cylinder thereby allowing
gravity lower carriage
32 toward the surface. Holding valve solenoid
64
normally maintains the position of carriage
32 relative to post
18.
Safety release solenoid
66 is a backup mechanism that normally functions
upon the failure of piston and cylinder assembly
38 to prevent carriage
32 from inadvertently falling downwardly towards the surface. During the
lowering operation of lift system
10, either holding valve solenoid
64
or safety release solenoid
66 may be activated to release carriage
32
and allow it to move relative to post
18. Another output device that is
coupled with control box
40 is a display
68. Display
68 may
be used to convey information such as, but not limited to the height of one or
more of the lift mechanisms, the frequency at which the control boxes are communicating
with each other, the amount of power in battery
42, whether control box
is operating in independent or synchronized mode and whether control boxes have
been interlocked with each other.
In operation, one or more lift mechanisms
12 are first placed in a position
to support a portion of vehicle
14. In particular, forks
36 are placed
on opposite sides of the tire in a support position. In order to provide a mobile
and convenient lift system, each of the lift mechanisms
12 may be powered
by rechargeable battery
42. Specifically, the energy stored in the battery
may provide the power required for the operation of the lift mechanism, including
the control box. The battery may be replenished during the operation of lift mechanism
12, or while lift mechanism
12 are not in use.
Each lift mechanism
12 provides for a dual mode of operation, specifically,
an independent mode and a synchronized mode. The independent mode allows each lift
mechanism to operate independent of one another to raise or lower each of their
carriages relative to the surface by inputs received at each of their separate
control boxes. The operation of a lift mechanism in an independent mode is best
illustrated in FIGS. 2 and 3. The first step
70 is to turn on control box
40. Next, the height sensing mechanism
48 is used to determine the
height of carriage
32 relative to the surface at step
74. The height
information obtained by height sensing mechanism
48 is transmitted to control
box
40 and then provided on display
68 as shown by step
76.
The next step
78 is to move selector switch
54 to the independent
mode position, if it is not already in such a position. Selector switch may also
54 be moved to a synchronized mode which is depicted by letter A and will
be described in further detail below. Once the selector switch
54 is in
the independent mode, the next step
80 is for control box
40 to determine
whether the interlock function
52 has been engaged. If interlock function
52 is not engaged, then lift mechanism
12 must wait until such function
is engaged at step
82, and then return to step
78. Once interlock
function
52 is engaged at step
80, the user then has to option to
raise or lower the carriage
32 using motion switch
56 at step
84.
If the user wants to raise vehicle
14 relative to the surface, control box
40 activates power unit
39 which turns the pump on at step
86
and causes piston and cylinder assembly
38 to move carriage
32 in
an upward direction. As carriage
32 raises vehicle
14, the height
is monitored by returning to step
74. Once vehicle
14 reaches the
desired height operator releases interlock
52 and motion switch
56,
the pump turns off, and control box
40 displays the new height. On the other
hand, if user wants to lower vehicle
14, control box
40 activates
lowering valve solenoid
62, holding valve solenoid
64 and safety
release solenoid
66 at step
87 to move carriage
32 in an downward
direction. As carriage
32 lowers vehicle
14, the height is monitored
by returning to step
74. Once vehicle
14 reaches the desired height,
the lowering valve solenoid
62, holding valve solenoid
64 and safety
release solenoid
66 are deactivated, and the holding valve and a backup
mechanism are ready to maintain the position of carriage
32. The backup
mechanism is generally a mechanical device, such as a latch, that releasably engages
carriage
32 in order to maintain its position relative to post
18.
As previously stated, the lift system
10 may also be placed in a synchronized
mode. The synchronized mode allows input commands at one control box to influence
other control boxes within the system to provide a coordinated lift of vehicle
14. The synchronized mode begins in a similar fashion as in the independent
mode. Specifically, as best seen in FIGS. 2 and 3, the control box on one of the
lift mechanisms is turned on at step
70 and proceeds to perform steps
74
and
76 as was described in the independent mode. The next step
78
is to move selector switch
54 to the synchronized mode position, if it is
not already in such a position. As best seen in FIGS. 2 and 4, once the selector
switch
54 is in the synchronized mode, the next step
88 is to determine
which of the control boxes
40 will take part in the coordinated lift of
vehicle
14. Once all of the participating control boxes are turned on, the
lift system moves to step
90 where each of the control boxes are adjusted
to the same general radio frequency, each of the height sensing mechanisms
48
provide a height measurement to their respective control boxes, and the control
boxes provide the height measurement on the display. Further, any other lift mechanisms
that will take part in the lift should also be set up at step
90. On the
other hand, if no other control boxes are turned on, then lift mechanism
12
proceeds to step
92 where it scans for a clear radio frequency channel and
signals the height. In addition, lift mechanism displays the height as the operator
sets up the other participating lift mechanisms in step
92. Once the lift
mechanism is placed in synchronized mode, it is searching to communicate with one
or more lift mechanisms.
As best seen in FIGS. 2 and 4, the lift system moves from step
90 to step
102, or from step
92 to step
102 if other lift mechanisms
need to be set up. In step
102, each of control boxes wait for a command
from its own box, remote control
58, or one of the other control boxes by
wireless communication. Generally, if the command is sent from another control
box, the sending control box is designated as the master control box
94,
and the receiving control boxes are designated as slave control boxes
96
as shown in FIG.
5. If none of the control boxes receive a command, then
proceed to step
104 where master control box
94 may be established
by selecting the interlock function on any one of the control boxes. If the interlock
is not selected, then return to step
102 where each of the lift mechanisms
wait for a command. If the interlock is selected, then the operator chooses to
raise or lower the vehicle at the master control box
94 as shown in step
105. With additional reference to FIG. 5, master control box
94 proceeds
to command slave control boxes
96 to raise or lower by one or more wireless
signals
98 at step
118 by motion switch
56, and waits for
a response from each of the slave control boxes
96 at step
106. Once
the wireless signals are sent by the master control box at step
118, slave
control boxes
96 wait to receive a command at step
102. If one or
more of slave controls do not receive the wireless signal from master control box,
then remains at step
102.
However, if slave control boxes
96 receive wireless signal
98
from master control box
94, then slave control boxes
96 must determine
whether to raise, lower or hold the vehicle at step
107. As best seen in
FIGS. 4 and 5, if the wireless signal
98 provides an instruction to raise
vehicle
14, master control box
94 and each of slave control boxes
96 activate power unit
39 which turns the pump on at step
108
to cause piston and cylinder assembly
38 to move the vehicle in an upward
direction. If the wireless signal
98 provides an instruction to lower the
vehicle
14, master control box
94 and each of slave control boxes
96 activate lowering valve solenoid
62, holding valve solenoid
64
and safety release solenoid
66 to cause piston and cylinder assembly
38
to move the vehicle downwardly which is shown by step
110. The pump and
lowering valve solenoid
62 are preferably activated in intervals when the
lift mechanisms are raising and lowering the vehicle from the surface respectively.
However, it will be understood and appreciated that the intervals may be such a
short duration that the lift mechanisms operate to smoothly raise or lower the
vehicle relative to the surface. The operation of the pump and lowering valve solenoid
62 may also be conducted in a continuous manner without any intervals.
Notwithstanding whether vehicle is being raised or lowered as described
in steps
108 and
110, height sensing mechanisms
48 on each
lift mechanism
12 determines the new height of the carriage relative to
the surface, conveys that information to their respective control boxes
94,
96, provides the height on display
68 and waits for another command
as illustrated in FIGS. 2,
4 and
5. Slave control boxes
96
then send the height information by one or more wireless signals
112 to
master control box
94 to create a feedback loop. It will be understood and
appreciated that any of the wireless signals sent or received in lift system
10
may be accomplished through the use of a transceiver device. At step
114,
the master control box
94 compares its own height measurement with the height
measurements sent by slave control boxes
96 during the lifting or lowering
of the vehicle and determines if an adjustment is needed at step
116. If
the heights of each of slave control boxes
96 are within a predetermined
tolerance range, master control box
94 sends a signal to all of the lift
mechanisms continue to lift or lower the vehicle at step
118. Once vehicle
14 has reaches a desired height, the lift system may then proceed from step
118 and return to step
102 where slave control boxes
96 wait
for a further command. Alternatively, if master control box
94 receives
a wireless signal
112 that indicates that one or more of the other lift
mechanisms are not at the proper height and an adjustment is need, master control
box
94 will determine what rate of speed the lift mechanisms must operate
to perform a coordinated lift of vehicle
14 and instructs the slow mechanisms
to catch up in step
120 by one or more wireless signals
122 and returns
to step
102.
In order to provide for a safe working environment for a user, lift system
10
includes safety features to prevent the inadvertent movement of vehicle
14.
Specifically, lift system
10 may provide for security features need to prohibit
false signals from interfering with the communication between the control boxes.
For instance, each control box may have a unique identifier associated therewith,
where each wireless communication sent by that control box includes its unique
identifier. The unique identifier may be in the form of a serial number. The receiving
control boxes would only react to a command from another control box if it recognizes
that control boxes serial number. This type of security feature would prevent outside
interference from moving the lift mechanism inadvertently. In addition, lift system
10 may also utilize other types of safety features. Specifically, as best
seen on FIGS. 2 and 5, safety release solenoid
66 may activate a independent
mechanical latch during the lowering command that normally prevents the carriages
on the lift mechanisms from falling to the surface upon a failure of piston and
cylinder assembly
38. Furthermore, emergency stop button
50 may also
be activated at any point from any lift mechanism during the raising or lowering
of vehicle
14 to stop further movement of carriage
32 relative to
post
18.
It can, therefore, be seen that the invention is one that is designed to overcome
the drawbacks and deficiencies existing in the prior art. The invention provides
a lift system that includes a plurality of lifting mechanisms that communicate
with each other using wireless signals to raise or lower a vehicle in a coordinated
fashion. The use of wireless communication between the lifting mechanisms allows
for a coordinated lift while preventing the possibility of injury from tripping
over wires that typically extend across the working area in prior art systems.
The lift system also provides for increased mobility and convenience due to the
rechargeable power source that is used to raise and lower the vehicle from the surface.
While particular embodiments of the invention have been shown, it will be understood,
of course, that the invention is not limited thereto, since modifications may be
made by those skilled in the art, particularly in light of the foregoing teachings.
Reasonable variation and modification are possible within the scope of the foregoing
disclosure of the invention without departing from the spirit of the invention.
*
