Title:
AMBULATORY ELEVATOR WITH FOLDING PLATFORM
United States Patent 3749201
Abstract:
A portable lift has a frame with a vertical mast. The mast defines two ways, one of which is closed on the front and back side while the other is closed only on the back side. A platform has upper wheels in the first ways and lower wheels in the second ways so that the platform is pivotal about the axis of the upper wheels, with the lower wheels moving away from the mast during pivoting. When horizontal the platform is too large to go through a doorway, but when pivoted, the frame and platform will go through a doorway. Within the mast is a hydrualic cylinder, the piston of which extends downwardly and is attached at its lower end to the frame. The cylinder is attached to the platform at a pivotal axis coincident with the axis of the upper wheels. Cables are provided to connect between the top of the mast and the middle of the platform when the platform is in the raised position so that when the hydraulic cylinder is lowered from the raised position, the cables will pull the platform into the hold position. The frame is mounted on wheels, one of which is dirigible. The dirigible wheel is attached to a vertical rod which has a cam eccentrically connected thereto. The cam bears against an abutment which is above it and forms a part of the frame. The steering handle is connected to the cam so that the handle may be used to rotate the cam and force the wheel downwardly, or it may be used to turn the rod about its vertical axis so as to steer the wheel.
US Patent References:
Lifting unit
Kappen - July 1963 - 3096895
FOLDABLE,ADJUSTABLE HEIGHT PLATFORM ASSEMBLY MOUNTABLE ON A VEHICLE
Dudschus - February 1970 - 3493079
/1082160.html
Kurowski - December 1913 - 1082160
Lifting unit
Kappen - July 1963 - 3096895
FOLDABLE,ADJUSTABLE HEIGHT PLATFORM ASSEMBLY MOUNTABLE ON A VEHICLE
Dudschus - February 1970 - 3493079
/1082160.html
Kurowski - December 1913 - 1082160
Application Number:
05/222846
Publication Date:
07/31/1973
Filing Date:
02/02/1972
View Patent Images:
Export Citation:
Assignee:
Autoquip Corporation (Chicago, IL)
Primary Class:
Other Classes:
187/235, 182/16, 280/43.240, 182/141, 182/69.600, 187/403, 187/237, 187/232
International Classes:
B66F9/04; B66F9/00; B66B9/20
Field of Search:
187/9 182/16,63,141 214/620,706 280/43.24
Primary Examiner:
Blunk, Evon C.
Assistant Examiner:
Maffei, Merle F.
Claims:
I claim
1. In an ambulatory lift apparatus comprising a frame having a vertical mast, wheel means for supporting said frame so that it can be moved about, a loading platform, means connecting the platform to the mast for vertical movement up and down the mast, power means operatively connecting the frame and platform for moving the platform vertically, the improvement comprising:
2. In an apparatus as set forth in claim 1, including releasably connectable means between the upper end of the mast and a portion of said platform spaced from said mast when said platform is adjacent the upper end of its movement, whereby when the power means is thereafter actuated in a direction to lower said platform, said platform will pivot about said axis from a horizontal position toward a vertical position.
3. In an apparatus as set forth in claim 2, wherein said power means includes a hydraulic linear motor comprising a cylinder member and piston member in said cylinder member, one of said members being attached at the bottom end to said frame, the other member being pivotally attached to said connecting means at said axis.
4. In an apparatus as set forth in claim 3, including a rod vertically movable in said frame, a curvilinear cam eccentrically attached to said rod for rotation about a horizontal axis, said frame including an abutment above said cam and in contact therewith, means attached to said cam to rotate said cam about said horizontal axis whereby rotation in one direction forces said rod downwardly and rotation in the other direction permits said rod to move upwardly with respect to the frame, and means connecting one of said wheel means to the lower end of said rod.
5. In an ambulatory lift apparatus comprising a frame having a vertical mast, wheel means for supporting said frame so that it can be moved about, a loading platform, means connecting the platform to the mast for vertical movement up and down the mast, power means operatively connecting the frame and platform for moving the platform vertically, the improvement comprising:
6. In an apparatus as set forth in claim 5, wherein said rod is cylindrical and is rotatable about a vertical axis with respect to said frame, said last mentioned means including a steering handle secured to said cam to permit a user to rotate said cam about said horizontal axis and rotate said rod about said vertical axis.
7. In an ambulatory lift apparatus comprising a frame having a vertical mast, wheel means for supporting said frame so that it can be moved about, a loading platform, means connecting the platform to the mast for vertical movement up and down the mast, power means operatively connecting the frame and platform for moving the platform vertically, the improvement comprising:
8. In an apparatus as set forth in claim 7, wherein said mast includes two ways, one of said ways having a front and a back side, the second way having a back side only, said connecting means including a wheel rotatable about said axis and located in the first way whereby it is restrained against horizontal movement and a wheel in the second way whereby it may be moved away from said mast, said second wheel being vertically spaced from said first wheel.
9. In a portable lift apparatus comprising a frame having a vertical mast, wheel means for supporting said frame so that it can be moved about, a loading platform, means connecting the platform to the mast for vertical movement up and down the mast, power means operatively connecting the frame and platform for moving the platform vertically. the improvement comprising:
10. In an apparatus as set forth in claim 9, wherein said rod is cylindrical and is rotatable about a vertical axis with respect to said frame, said last mentioned means including a steering handle secured to said cam to permit a user to rotate said cam about said horizontal axis and rotate said rod about said vertical axis.
1. In an ambulatory lift apparatus comprising a frame having a vertical mast, wheel means for supporting said frame so that it can be moved about, a loading platform, means connecting the platform to the mast for vertical movement up and down the mast, power means operatively connecting the frame and platform for moving the platform vertically, the improvement comprising:
2. In an apparatus as set forth in claim 1, including releasably connectable means between the upper end of the mast and a portion of said platform spaced from said mast when said platform is adjacent the upper end of its movement, whereby when the power means is thereafter actuated in a direction to lower said platform, said platform will pivot about said axis from a horizontal position toward a vertical position.
3. In an apparatus as set forth in claim 2, wherein said power means includes a hydraulic linear motor comprising a cylinder member and piston member in said cylinder member, one of said members being attached at the bottom end to said frame, the other member being pivotally attached to said connecting means at said axis.
4. In an apparatus as set forth in claim 3, including a rod vertically movable in said frame, a curvilinear cam eccentrically attached to said rod for rotation about a horizontal axis, said frame including an abutment above said cam and in contact therewith, means attached to said cam to rotate said cam about said horizontal axis whereby rotation in one direction forces said rod downwardly and rotation in the other direction permits said rod to move upwardly with respect to the frame, and means connecting one of said wheel means to the lower end of said rod.
5. In an ambulatory lift apparatus comprising a frame having a vertical mast, wheel means for supporting said frame so that it can be moved about, a loading platform, means connecting the platform to the mast for vertical movement up and down the mast, power means operatively connecting the frame and platform for moving the platform vertically, the improvement comprising:
6. In an apparatus as set forth in claim 5, wherein said rod is cylindrical and is rotatable about a vertical axis with respect to said frame, said last mentioned means including a steering handle secured to said cam to permit a user to rotate said cam about said horizontal axis and rotate said rod about said vertical axis.
7. In an ambulatory lift apparatus comprising a frame having a vertical mast, wheel means for supporting said frame so that it can be moved about, a loading platform, means connecting the platform to the mast for vertical movement up and down the mast, power means operatively connecting the frame and platform for moving the platform vertically, the improvement comprising:
8. In an apparatus as set forth in claim 7, wherein said mast includes two ways, one of said ways having a front and a back side, the second way having a back side only, said connecting means including a wheel rotatable about said axis and located in the first way whereby it is restrained against horizontal movement and a wheel in the second way whereby it may be moved away from said mast, said second wheel being vertically spaced from said first wheel.
9. In a portable lift apparatus comprising a frame having a vertical mast, wheel means for supporting said frame so that it can be moved about, a loading platform, means connecting the platform to the mast for vertical movement up and down the mast, power means operatively connecting the frame and platform for moving the platform vertically. the improvement comprising:
10. In an apparatus as set forth in claim 9, wherein said rod is cylindrical and is rotatable about a vertical axis with respect to said frame, said last mentioned means including a steering handle secured to said cam to permit a user to rotate said cam about said horizontal axis and rotate said rod about said vertical axis.
Description:
BACKGROUND AND SUMMARY OF THE INVENTION
There are many locations at which a vertically moving platform, non-permanently installed, is a requisite piece of equipment. For example, a factory does not have a loading dock, but occasionally receives heavy shipments on a truck which must be moved from the truck into the factory. The frequency of such deliveries does not justify a permanent installation, or, for other reasons, a permanent installation is not desirable or feasible. The solution is a platform apparatus which can be moved about the floor or ground area to the desired location and then the platform raised and lowered to enable the objects to be withdrawn from the truck and transported to where they are required. In order to handle fairly bulky objects, however, the platform must have a substantial horizontal size. In many locations, however, this horizontal size is so great that it impairs the ability to move the apparatus to and from the various locations at which it is to be used. For example, the apparatus will not go through an ordinary doorway, but must move through a doorway of the size of a garage door. Even after it has gone through the door, it may not be able to move through the aisles of the manufacturing plant, for example, because it has a width substantially greater than that of the average of such aisles. Furthermore, when stored, it occupies a significant amount of floor space, which prevents that floor space from being used for other purposes.
The principal object of the present invention is to provide a lift apparatus of the type described which is more easily moved about, primarily because of the ability to fold the platform in toward the vertical mast and thereby reduce the floor area covered by the apparatus. This, for example, permits the apparatus to be moved through an ordinary doorway or down the aisles of a manufacturing plant. The folding and unfolding is accomplished by the actuation of the apparatus that is normally employed to raise and lower the platform, thus it can easily be done by a single individual without the exertion of great effort in lifting or lowering heavy pieces of equipment. Other features are provided to facilitate the movability of the apparatus and its stability when in use. These and other objects and advantages will be apparent from the following description.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an embodiment of the invention when folded for movement;
FIG. 2 is a perspective view of the embodiment employed in the unloading of a truck;
FIG. 3 is a side view with the platform extended;
FIG. 4 is a fragmentary view of the apparatus for raising and lowering the dirigible wheel;
FIG. 5 is a fragmentary view as seen at line 5--5 of FIG. 3;
FIG. 6 is a perspective view of the wheels on which the platform moves vertically; and
FIG. 7 is an end view illustrating the manner of folding the platform.
DESCRIPTION OF SPECIFIC EMBODIMENT
The following disclosure is offered for public dissemination in return for the grant of a patent. Although it is detailed to ensure adequacy and aid understanding, this is not intended to prejudice that purpose of a patent which is to cover each new inventive concept therein no matter how others may later disguise it by variations in form or additions or further improvements.
The enclosed embodiment comprises a frame, generally 10. The frame includes a mast, generally 11. The rear of the frame is mounted on wheels 12 which are rotatable on axles 13. At the front of the frame is a dirigible wheel 14 which can be raised or lowered. When the wheel is raised, the front of the frame rests on a support 15. When lowered, the wheel 14 carries the load and raises the support 15 above the ground or floor.
Wheel 14 is journaled on an axle 17 secured to a yoke 18. A vertical shaft or rod 19 is secured to yoke 18 and journaled in the front frame portion 20. An inverted L-shaped member 21 is welded to frame portion 20 and has an opening in which the shaft 19 also is journaled. At each side of shaft 19 are cylindrical cams 22. A pin 23 extends through and is journaled in shaft 19. The cams 22 are secured to this pin eccentrically with respect to the cylindrical axis of the cams. A bifurcated member 24 is welded to the cams and also to handle 25.
When the handle is in the full line position illustrated in FIGS. 3 and 4, the cams 22 are lowered which permits wheel 14 to move upwardly so that the load is on the support 15. When the handle is rotated to the dot-dash line positions illustrated in FIGS. 3 and 4, the cams are rotated (clockwise in FIG. 3). This causes the cams to bear against the abutment thereabove formed by L-shaped member 21. As they do so, they force the shaft 19 downwardly, with the parts moving to the dot-dash line position illustrated in FIG. 4. This moves the wheel 14 downwardly a corresponding amount so that the wheel now is carrying the load and the support 15 is raised off the floor 26. With the structure illustrated, there can be a rotation of the cam 22 of about 165°. This is more than adequate to obtain the required movement of the wheel 14. At the same time, this substantial amount of cam movement (as compared to prior art configurations) makes it easier for an individual to perform the operation. When the handle is in the dot-dash line position illustrated in FIG. 3, it may be moved from side to side thereby rotating shaft 19 about its vertical axis so that there is a steering of wheel 14.
The frame also includes an outrigger 28. At its proximal end the outrigger is secured to the frame by a vertical pin (not shown) so that it may be pivoted from an extended to a retracted position. At its distal end the outrigger 28 has a boss 29 which is threaded to receive a screw 30. A floor pad 31 is at the bottom end of the screw. The outrigger has an arm 32 which contacts the actuating member of a valve 33. When the outrigger 28 is folded in towards the remainder of the frame, the actuating member of the valve 33 is not in contact with arm 32. Valve 33 is connected into the hydraulic system so that the hydraulic apparatus cannot be raised except when the outrigger 28 is out and the valve 33 actuated thereby.
The platform, generally 35, includes a floor plate 36, a subframe 37, uprights 38 and a cross-member 39. At each end of the platform is a dock board, 40 and 41 respectively. The dock boards are hinged about horizontal axes so that they can be moved between the positions illustrated in FIG. 3. The platform frame includes upright posts 42 having sockets at the upper ends. These sockets receive dowel pins 43 of a guard rail assembly 44. As seen in FIG. 1, the floor plate 36 has an opening 45 which may be closed by a removable cover 46. Below opening 45 is an enclosure to hold cables 47 having hooks 48 at the distal ends thereof. the proximal ends of the cables are secured to the platform frame below opening 45.
At the rear of uprights 38 are a pair of blocks 51 which are bolted to the top of the uprights respectively. Plus 52 on each of these blocks rotatably supports a wheel 53. Wheels 53 are rotatable about an axis 54. Wheels 53 are rotatable respectively within an enclosed way 55; that is, there is a plate 56 forming the rearwardly side of way 55 and a plate 57 forming the forwardly side of the way. The forwardly side of plate 57 also forms the rearwardly side of a way 58, which way has only the one side. Wheels 59 rotatably mounted on the platform frame 37 move in the two ways 58 respectively; that is, normally they bear against the front of plates 57. Wheels 59 have flanges 59a which bear against the outer edges of plates 57.
A linear hydraulic motor serves as the power drive for moving the platform up and down. This motor comprises a cylinder or barrel 62 within which is a piston 63. The bottom end of the piston is fastened to the frame as by means of a bolt 64 (FIG. 3). An electrically driven hydraulic pump 65 supplies hydraulic fluid from a sump tank in the column 11; only the fill spout 66 of the tank can be seen. The hydraulic fluid is delivered to the motor through a control 67, a hose 68 and a pipe 69. The linear motor is a single acting cylinder, the weight of the platform, etc., supplying the force for movement in a collapsing direction.
Referring particularly to FIG. 5, the barrel 62 has some plates welded thereto to define a boss 72. This boss is journaled to receive a pin 73. The pin is coaxial with axis 54 of the rollers 53. At each side of the boss 72 are bearing plates 74. These plates hold pin 73. A mounting plate 75 extends across the two bearing plates 74 and is welded thereto. Bolts 76 secure cross-member 39 of the platform frame to the mounting plate 75. This assembly provides the support for the platform, while permitting the platform to pivot about axis 54 with respect to the barrel 62 of the linear motor.
Assuming that the platform is extended, as it would be during use, and it is desired to fold it up for storage or movement, initially the guard rail 44 is lifted out of place and set to one side. With the platform raised as high as it will go, the cover plate 46 is removed to provide access to the cables 47. The cables are withdrawn and the hooks 48 thereon are secured to eyes 78 at the top of mast 11. The control 67 is now actuated in a direction to permit the platform to descend. As it does so, the cables 47 prevent the outer end of the platform from descending to any significant extent. The result is that the platform pivots about axis 54. As it does so, the wheels 59 move away from the mast. The platform moves into the position illustrated in dot-dash lines in FIG. 7 and in full lines in FIG. 1. The guard rail 44 now may be inserted to rest on the platform posts 38, as illustrated in those Figures.
The bolt 30 is raised and the outrigger 28 is folded in against the frame 10. Now by pivoting the handle 25 from the full line to the dot-dash line position in FIG. 3, the wheel 14 is lowered to support the front of the frame and the apparatus may be rolled to a new location for use or for storage.
When folded, as illustrated in FIG. 1, the apparatus has a total height of less than 7 feet and a total width (as measured in the direction of between wheels 12) of a little over 34 inches. Thus it can easily be moved through a door that is 36 inches wide by 7 feet high.
When it is to be put back into use, it is wheeled to the desired location and an electric cord 79 (FIG. 2) is plugged into an electric socket to supply power to the electric motor of the motor pump combination 65. The handle 25 is returned to the full line position of FIG. 3 thereby allowing pad 15 of frame 10 to rest on the ground or floor 26. The outrigger 28 is extended to the position illustrated in FIG. 7, thus actuating safety valve 33, and the pad 31 moved against the floor. The control 67 is now operated to extend the linear motor (i.e., raise the cylinder 62 to its full height). This returns the platform to the full line position of FIG. 7. This permits the cables 47 to be unhooked and replaced in opening 45. The cover 46 is then put back in place. The dock boards 40 and 41 are folded down as required. The guard rail 44 is replaced with dowels 43 being inserted into the sockets at the top of posts 42.
With the platform fully lowered, the dock board 40 will rest on the ground. Thus a wheel cart 80 can be moved onto the platform, and the platform then raised to the level of the truck body. After dock board 41 is lowered onto the truck body floor, the cart 80 can be wheeled into the truck body to be loaded and wheeled back onto the platform. The platform is then lowered to allow the cart to be wheeled off the platform over dock board 40.
There are many locations at which a vertically moving platform, non-permanently installed, is a requisite piece of equipment. For example, a factory does not have a loading dock, but occasionally receives heavy shipments on a truck which must be moved from the truck into the factory. The frequency of such deliveries does not justify a permanent installation, or, for other reasons, a permanent installation is not desirable or feasible. The solution is a platform apparatus which can be moved about the floor or ground area to the desired location and then the platform raised and lowered to enable the objects to be withdrawn from the truck and transported to where they are required. In order to handle fairly bulky objects, however, the platform must have a substantial horizontal size. In many locations, however, this horizontal size is so great that it impairs the ability to move the apparatus to and from the various locations at which it is to be used. For example, the apparatus will not go through an ordinary doorway, but must move through a doorway of the size of a garage door. Even after it has gone through the door, it may not be able to move through the aisles of the manufacturing plant, for example, because it has a width substantially greater than that of the average of such aisles. Furthermore, when stored, it occupies a significant amount of floor space, which prevents that floor space from being used for other purposes.
The principal object of the present invention is to provide a lift apparatus of the type described which is more easily moved about, primarily because of the ability to fold the platform in toward the vertical mast and thereby reduce the floor area covered by the apparatus. This, for example, permits the apparatus to be moved through an ordinary doorway or down the aisles of a manufacturing plant. The folding and unfolding is accomplished by the actuation of the apparatus that is normally employed to raise and lower the platform, thus it can easily be done by a single individual without the exertion of great effort in lifting or lowering heavy pieces of equipment. Other features are provided to facilitate the movability of the apparatus and its stability when in use. These and other objects and advantages will be apparent from the following description.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an embodiment of the invention when folded for movement;
FIG. 2 is a perspective view of the embodiment employed in the unloading of a truck;
FIG. 3 is a side view with the platform extended;
FIG. 4 is a fragmentary view of the apparatus for raising and lowering the dirigible wheel;
FIG. 5 is a fragmentary view as seen at line 5--5 of FIG. 3;
FIG. 6 is a perspective view of the wheels on which the platform moves vertically; and
FIG. 7 is an end view illustrating the manner of folding the platform.
DESCRIPTION OF SPECIFIC EMBODIMENT
The following disclosure is offered for public dissemination in return for the grant of a patent. Although it is detailed to ensure adequacy and aid understanding, this is not intended to prejudice that purpose of a patent which is to cover each new inventive concept therein no matter how others may later disguise it by variations in form or additions or further improvements.
The enclosed embodiment comprises a frame, generally 10. The frame includes a mast, generally 11. The rear of the frame is mounted on wheels 12 which are rotatable on axles 13. At the front of the frame is a dirigible wheel 14 which can be raised or lowered. When the wheel is raised, the front of the frame rests on a support 15. When lowered, the wheel 14 carries the load and raises the support 15 above the ground or floor.
Wheel 14 is journaled on an axle 17 secured to a yoke 18. A vertical shaft or rod 19 is secured to yoke 18 and journaled in the front frame portion 20. An inverted L-shaped member 21 is welded to frame portion 20 and has an opening in which the shaft 19 also is journaled. At each side of shaft 19 are cylindrical cams 22. A pin 23 extends through and is journaled in shaft 19. The cams 22 are secured to this pin eccentrically with respect to the cylindrical axis of the cams. A bifurcated member 24 is welded to the cams and also to handle 25.
When the handle is in the full line position illustrated in FIGS. 3 and 4, the cams 22 are lowered which permits wheel 14 to move upwardly so that the load is on the support 15. When the handle is rotated to the dot-dash line positions illustrated in FIGS. 3 and 4, the cams are rotated (clockwise in FIG. 3). This causes the cams to bear against the abutment thereabove formed by L-shaped member 21. As they do so, they force the shaft 19 downwardly, with the parts moving to the dot-dash line position illustrated in FIG. 4. This moves the wheel 14 downwardly a corresponding amount so that the wheel now is carrying the load and the support 15 is raised off the floor 26. With the structure illustrated, there can be a rotation of the cam 22 of about 165°. This is more than adequate to obtain the required movement of the wheel 14. At the same time, this substantial amount of cam movement (as compared to prior art configurations) makes it easier for an individual to perform the operation. When the handle is in the dot-dash line position illustrated in FIG. 3, it may be moved from side to side thereby rotating shaft 19 about its vertical axis so that there is a steering of wheel 14.
The frame also includes an outrigger 28. At its proximal end the outrigger is secured to the frame by a vertical pin (not shown) so that it may be pivoted from an extended to a retracted position. At its distal end the outrigger 28 has a boss 29 which is threaded to receive a screw 30. A floor pad 31 is at the bottom end of the screw. The outrigger has an arm 32 which contacts the actuating member of a valve 33. When the outrigger 28 is folded in towards the remainder of the frame, the actuating member of the valve 33 is not in contact with arm 32. Valve 33 is connected into the hydraulic system so that the hydraulic apparatus cannot be raised except when the outrigger 28 is out and the valve 33 actuated thereby.
The platform, generally 35, includes a floor plate 36, a subframe 37, uprights 38 and a cross-member 39. At each end of the platform is a dock board, 40 and 41 respectively. The dock boards are hinged about horizontal axes so that they can be moved between the positions illustrated in FIG. 3. The platform frame includes upright posts 42 having sockets at the upper ends. These sockets receive dowel pins 43 of a guard rail assembly 44. As seen in FIG. 1, the floor plate 36 has an opening 45 which may be closed by a removable cover 46. Below opening 45 is an enclosure to hold cables 47 having hooks 48 at the distal ends thereof. the proximal ends of the cables are secured to the platform frame below opening 45.
At the rear of uprights 38 are a pair of blocks 51 which are bolted to the top of the uprights respectively. Plus 52 on each of these blocks rotatably supports a wheel 53. Wheels 53 are rotatable about an axis 54. Wheels 53 are rotatable respectively within an enclosed way 55; that is, there is a plate 56 forming the rearwardly side of way 55 and a plate 57 forming the forwardly side of the way. The forwardly side of plate 57 also forms the rearwardly side of a way 58, which way has only the one side. Wheels 59 rotatably mounted on the platform frame 37 move in the two ways 58 respectively; that is, normally they bear against the front of plates 57. Wheels 59 have flanges 59a which bear against the outer edges of plates 57.
A linear hydraulic motor serves as the power drive for moving the platform up and down. This motor comprises a cylinder or barrel 62 within which is a piston 63. The bottom end of the piston is fastened to the frame as by means of a bolt 64 (FIG. 3). An electrically driven hydraulic pump 65 supplies hydraulic fluid from a sump tank in the column 11; only the fill spout 66 of the tank can be seen. The hydraulic fluid is delivered to the motor through a control 67, a hose 68 and a pipe 69. The linear motor is a single acting cylinder, the weight of the platform, etc., supplying the force for movement in a collapsing direction.
Referring particularly to FIG. 5, the barrel 62 has some plates welded thereto to define a boss 72. This boss is journaled to receive a pin 73. The pin is coaxial with axis 54 of the rollers 53. At each side of the boss 72 are bearing plates 74. These plates hold pin 73. A mounting plate 75 extends across the two bearing plates 74 and is welded thereto. Bolts 76 secure cross-member 39 of the platform frame to the mounting plate 75. This assembly provides the support for the platform, while permitting the platform to pivot about axis 54 with respect to the barrel 62 of the linear motor.
Assuming that the platform is extended, as it would be during use, and it is desired to fold it up for storage or movement, initially the guard rail 44 is lifted out of place and set to one side. With the platform raised as high as it will go, the cover plate 46 is removed to provide access to the cables 47. The cables are withdrawn and the hooks 48 thereon are secured to eyes 78 at the top of mast 11. The control 67 is now actuated in a direction to permit the platform to descend. As it does so, the cables 47 prevent the outer end of the platform from descending to any significant extent. The result is that the platform pivots about axis 54. As it does so, the wheels 59 move away from the mast. The platform moves into the position illustrated in dot-dash lines in FIG. 7 and in full lines in FIG. 1. The guard rail 44 now may be inserted to rest on the platform posts 38, as illustrated in those Figures.
The bolt 30 is raised and the outrigger 28 is folded in against the frame 10. Now by pivoting the handle 25 from the full line to the dot-dash line position in FIG. 3, the wheel 14 is lowered to support the front of the frame and the apparatus may be rolled to a new location for use or for storage.
When folded, as illustrated in FIG. 1, the apparatus has a total height of less than 7 feet and a total width (as measured in the direction of between wheels 12) of a little over 34 inches. Thus it can easily be moved through a door that is 36 inches wide by 7 feet high.
When it is to be put back into use, it is wheeled to the desired location and an electric cord 79 (FIG. 2) is plugged into an electric socket to supply power to the electric motor of the motor pump combination 65. The handle 25 is returned to the full line position of FIG. 3 thereby allowing pad 15 of frame 10 to rest on the ground or floor 26. The outrigger 28 is extended to the position illustrated in FIG. 7, thus actuating safety valve 33, and the pad 31 moved against the floor. The control 67 is now operated to extend the linear motor (i.e., raise the cylinder 62 to its full height). This returns the platform to the full line position of FIG. 7. This permits the cables 47 to be unhooked and replaced in opening 45. The cover 46 is then put back in place. The dock boards 40 and 41 are folded down as required. The guard rail 44 is replaced with dowels 43 being inserted into the sockets at the top of posts 42.
With the platform fully lowered, the dock board 40 will rest on the ground. Thus a wheel cart 80 can be moved onto the platform, and the platform then raised to the level of the truck body. After dock board 41 is lowered onto the truck body floor, the cart 80 can be wheeled into the truck body to be loaded and wheeled back onto the platform. The platform is then lowered to allow the cart to be wheeled off the platform over dock board 40.