US3207087A

US3207087A - Railway car having a vertically movable load support platform

Info

Publication number: US3207087A
Application number: US245786A
Authority: US
Inventors: Clifford S Goby
Original assignee: Individual
Current assignee: Individual
Priority date: 1962-12-19
Filing date: 1962-12-19
Publication date: 1965-09-21
Anticipated expiration: 1982-09-21

Description

Sept. 21, 1965 c. s. GOBY 3,207,087

RAILWAY CAR HAVING A VERTICALLY MOVABLE LOAD SUPPORT PLATFORM Filed Dec. 19. 1962 3 Sheets-Sheet l ATT YS.

Sept. 21, 1965 c. s. GOBY 3, ,08

RAILWAY CAR HAVING A VERTICALLY MOVABLE LOAD SUPPORT PLATFORM Filed Dec. 19, 1962 3 SheetsSheet 2 FIG.6

INVENTOR. CLIFFQRD s. GO BY BY ZJ C-QX AQ fl QAZZ ATTYS.

Sept. 21, 1965 c. s. GOBY 3,207,087

RAILWAY CAR HAVING A VERTICALLY MOVABLE LOAD SUPPORT PLATFORM Filed Dec. 19, 1962 s Sheets-Shee t 3 FIG. 4

F|G.5 1 Add INVENTOR. CLIFFORD S. GOBY ATTYS.

United States Patent 3,207,087 RAILWAY CAR HAVING A VERTFCALLY MOVABLE LOAD SUPPORT PLATFORM Clifford S. Goby, 10308 Wilbur Ave., Cleveland, Ohio Filed Dec. 19, 1962, Ser. No. 245,786 7 Claims. (Cl. 105-455) The present invention relates to railway cars, especially to railway cars having a vertically movable load support platform adapted to receive thereon removable freight containers, freight trucks, trailers, or the like.

At the present time, there is an increasing use of various types of special railway cars adapted for hauling large freight containers thereon, or which cars may receive truck trailers thereon for hauling the truck trailers or freight containers specified distances and permitting their removal as units for delivery, or further shipping In all events, insofar as I am aware, nearly all of the constructions proposed heretofore and in use at this time involve relatively tedious, costly loading and unloading operations, or the use of costly equipment for the loading action. One improved type of a railway car is shown FIG. 2 is a plan view of the railway car of FIG. 1 with portions thereof broken away;

FIG. 3 is an enlarged vertical cross section of the cam type lift means of FIG. 1;

FIFIG. 4 is a fragmentary enlarged vertical section of FIG. 5 is a fragmentary vertical section taken on line 5--5 of FIG. 3; and

FIG. 6 is an enlarged horizontal section taken on line 6-6 of FIG. 1.

When referring to corresponding members shown in the drawings and referred to in the specification, corresponding numerals are used to facilitate comparison therebetween.

The present invention relates to a railway car, which in one embodiment of the invention, includes a frame including a pair of side sills having open centers and top portions, a load platform supported on the frame, a pair of spaced parallel support members for the load platform extending longitudinally thereof below the load platform with each support member being telescopically received in a side sill for only vertical movement therein, a pair of parallel, longitudinally inclined cam plates secured to each of the support members with one plate adjacent each end of such support member, roller means operatively engaging the cam plates to provide vertical movement of in my copending application, Serial No. 834,487, filed Aug. 18, 1959 now Patent No. 3,075,479.

It is a general object of the present invention to provide a novel and improved freight car characterized by the provision of a vertically movable and rotatable load carrying body therein whereby side loading of the cars with freight trailers, or freight carrying containers is facilitated.

Another object of the invention is to provide improved cam-type means for raising and lowering a freight carrying platform provided in a railway car.

Further objects of the invention are to provide a plurality of unitary acting hydraulic means for lift action in a railway car of the type described wherein a load support platform can be readily raised and lowered in the freight railway car and be carried in a recessed center portion of the car for freight transit action; to provide novel roll means for furnishing easy turning and support action between a movable load platform in the railway car and support means provided therefor so that the load platform can be rotated about a center support trunnion therefor; to provide effective guide means in combination with the side sills of the car so that special lift members received therein can be raised and lowered in a vertical plane only for controlling the position of the load platform; to provide special members on portions of the railway car and lift members to prevent longitudinal movement of the lift members or load platform; to provide a plurality of heavy duty lift means for engaging corner portions of a load platform; and to couple together several novel cam roller means in the railway car to obtain unitary, uniform lift action for the load support platform.

The foregoing and other objects and advantages of the present invention will be made more apparent as the specification proceeds.

Particular attention is now directed to the accompanying drawings, wherein:

FIG. 1 is a side elevation of a novel railway car embodying the principles of the invention, with portions of the car being broken away and with portions of the car being shown in vertical section;

' the support members relative to the frame by longitudinal movement of the roller means, which roller means are adapted to deposit a load platform on the frame for normal load carrying action and to raise the load platform by the support members by cam action of the roller means engaging the cam plates, and unitary acting control means carried by the frame and engaging the roller means to move them longitudinally of the frame simultaneously and lift the load platform by forces applied to corner portions thereof.

Having particular reference now to the details of the structure shown in the accompanying drawings, a railway car is indicated as a whole by the numeral 1. This railway car embodies the principles of the present invention and has included therein a set of conventional railway trucks 2, 2 at each end of the car 1, which trucks 2 are secured by conventional means to the load carrying, or frame portion of the railway car 1. The railway car 1 has ends or load carrying decks 3 provided at the ends of the railway car and which ends 3, 3 are of a fixed vertical height, or position. The railway car 1 has a recessed portion 4a in its railway car frame means 4 whereby a reduced height load support platform can be positioned intermediate the

ends

3, 3 of the railway car for reduced overall height load carrying action.

The railway car frame means 4 normally extend the length of the car and comprise a center sill 5 made, for example, from a pair of channels, or beams 6, 6 placed in spaced, parallel relation, and a pair of side sills 7, 7 each of which is made, for example, of L-shape in section and has an open center and top. The center sill 5 and side sills 7, 7 can be made from I-beams, channel members, shaped plates, or equivalents, that normally would have portions cut therefrom on the lower surfaces thereof at the ends of the railway car to contour the sills over the trucks 2, 2 and which may have portions cut, or otherwise removed therefrom at the tops thereof, if necessary, at the center portion of the railway car to provide for the reduced height portion 4a therein. Or, these center and side sills can be made from members of different contours and heights at the ends and center portion of the railway original parts of the beams cut therefrom and resecured thereto to different portions thereof. Or, the side sills and/ or center sill may be made from a plurality of vertically superimposed channels the adjacent flanges of which are welded or riveted together. A bottom plate 8 usually is welded to and extends between the center sill and side sills 7, 7.

A load, or support platform 9 is provided at the cen ter of the railway car 1 and extends the width thereof between the

ends

3, 3 of the car. This load platform 9 includes a plurality of transversely extending channels or beams 10 that have members, such as a cover plate, or runner strips 11, 11 secured to the upper surface thereof. Longitudinally extending parallel tie beams 12 extend the length of the load platform on the upper surface thereof and are secured to the cover plate 11 and cross beams 10 to complete the load carrying portion of the load platform 9. Edge beams 12a may also be secured to the cover plate 11.

Normally the load platform 9 is pivotally and vertically movably carried on the railway car 1 and to this end, trunnion means, such as a trunnion sleeve 13, is secured to and extends between the channels 6, 6 at the center of the recessed center portion of the railway car 1, usually at the longitudinal center thereof. This trunnion sleeve 13 extends above the center sill 5 and is adapted to receive a suitable trunnion spindle 14 therein. This trunnion spindle 14 has a trunnion bracket, or flange 15 secured thereto and extending therefrom for engagement with members such as the tie beams 12 forming a part of the load platform 9 by connecting T-beams 15a to transmit load from the load platform 9 onto the trunnion spindle 14 for support action in the trunnion sleeve 13. The trunnion sleeve 13 and trunnion spindle 14 are operatively connected to provide and permit pivotal and vertical movement of the trunnion spindle 14 in the receiving and positioning sleeve 13. The trunnion spindle 14 preferably has some conventional motion limiting means associated therewith to limit vertical upward movement of the trunnion spindle 14 in the trunnion sleeve 13.

An important feature of the present invention relates to the special plurality of lift means that are provided for engaging corner portions of the load platform 9 for elevating such platform from the recessed center portion of the frame 4, when desired. These lift or support means for the load platform 9 are adapted to raise the support platform until the upper surface thereof is at least level with the

ends

3,3 of the railway car, but at the same time the load platform 9 can be dropped down to an appreciably lower position from the height of the plane defined by the ends 3 of the car so that the overall height of a container, freight receptacle, or trailer carried by the load platform is reduced, which position normally is provided for the load platform when the railway car is being transported from place to place. The load platform 9, when at rest, is supported by the side sills 7, 7 of the car, as best indicated in FIG.6, but a pair of support members 16 and 17 are provided and extend longitudinally of the railway car 1 adjacent each side thereof below the load platform 9. Such support members, or beams 16 and 17 usually are of generally H-shape in vertical section and with each of such beams being individually telescopically received in one of the side sills 7, 7 for only relative vertical movement in such side sills.

FIG. 5 of the drawings best shows that guide sections, or members 7a are suitably secured to the side sills 7, 7 usually at longitudinally spaced portions thereof, .to complete an enclosure with the side sills and aid in providing vertically directed movement only for the beams 16 and 17 received in the side sills for load support action. These guide plates or members 7a usually are of a shape complementary to the vertical section of the side sills 7 to aid in forming substantially U-shaped means with the side sills, as shown in the vertical sections of these side sills at different longitudinal sections or portions thereof.

Each of the beams 16 and 17 have a pair of parallel, longitudinally inclined cam plates 18 and 19 suitably secured thereto, as by welding, adjacent the ends thereof, as best shown in FIGS. 1 and 3 of the drawings. These cam plates are secured to the flanges, and/or vertically extending side portions of the beams 16 and 17, and at that section of the beams, portions of the horizontally directed webs 20 thereof are removed. Hence, the cam plates 18 and 19 extend the width of these beams 16 and 17 and usually extend the major portion, or all of the height of the beams to provide the desired vertical lift action in the apparatus of the invention for elevating the beams 16 and 17 and thus the load platform 9 in the railway car, as hereinafter described in detail.

The actual lift action for the beams 16 and 17 and load carried thereby is provided by a plurality of cam means, or units, FIG. 5, indicated as a whole by the numeral 21. These cam means or units each comprise a frame 22 on which a plurality of lower supports or rolls 23 are journalled on positioning shafts 24 carried by the frame, while upper support rolls or cams 25 are likewise journalled on the frame 22 by means of a support shaft 26. The individual cam means 21 is each positioned immediately adjacent and below the lower surface of the inclined cam plates 18 and 19 so that the upper rolls 25 of the cam means engage with such cam plates for lifting action when the cam means 21 is moved longitudinally of the railway car. Means, such as as a pair of connecting links or

bars

27 and 28 extend longitudinally of the railway car in each of the side sills 7, 7 and are connected to each of the pair of cam means 21 received in the individual side sills, as by engaging the support shafts 24 for the lower rolls 23. The

links

27 and 28 extend through suitable slots 29 provided in the cam plates 18 and 19.

In order to obtain unitary actuation of the pair of cam means 21 engaging each of the beams 16 and 17, a control cylinder 30 is received in each one of the side sills 7 in the car. These cylinders 30 can be actuated by remote control means, and normally are double acting hydraulic cylinders with piston rods 31 extending therefrom. The piston rods 31 are secured to the pair of

links

27 and 28 in each side sill by suitable members, such as rods or shafts 32. Other means (not shown) are provided to connect the cylinders 30 to each other, as by a pressure supply pipe 33, whereby hydraulic fluid would be supplied to the cylinders 30 simultaneously and equal pressures would be set up in both of these cylinders. Hence, simultaneous action of the plurality of individual cam units 21 in the car would 'be provided to obtain a uniform force lifting action at all four corners of the beams .16 and 17 adjacent the ends thereof to supply the desired uniform lifting action to corner portions of the load platform 9.

As another part of the invention, a plurality of support rolls 40, 40 are provided in the railway car 1 of the invention, and these support rolls 40 are journalled on, or carried by suitable support shafts 41, and such shafts 41 themselves are supported on or journalled in a support bracket 42 of substantially U-shape in vertical section. FIGS. 3 and 4 of the drawings show that these support brackets 42 have vertically downwardly extending positioning stub shafts 43 suitably provided thereon, or secured thereto. These support pins 43 are received in apertures 44 provided in the horizontally extending webs 20 of the support beams 16 and 17 whereby the brackets 42 are pivotally positioned on the web for pivotal movement on a vertical axis. Hence, as the rolls 40 extend above the vertical margins or upper edges of the support beams 16 and 17, these rolls 40 will engage members, such as support plates or strips 45 that are operatively secured to the lower surface of the load platform 9. As best indicated in FIG. 1, preferably these support strips 45 are of slightly arcuate shape, with the arcs for these strips or plates being centered on the center of the trunnion means provided in the railway car whereby a minimum amount of material is used in forming or providing the support strips 45. Yet such strips will provide good support engagement between the rolls 40 and the load platform 9 when such load platform is turned arcuately about us trunnion means, which action may occur at any time when the beams 16 and 17 have been elevated above the top surfaces of the side sills in the railway car. The rolls 40 thus can oscillate on the vertical axis of the support pins 43 with the arcuate movement of the load platform to maintain .good rolling engagement therewith at all times.

It should be realized that the use of one common control cylinder for each of the pair of cam units, or means 21, 21 located in each of the side sills of a railway car is desirable, but in some instances, a separate control cylinder for each of the cam means 21 may be used. Hence, a piston rod, for example, from an individual control cylinder could be directly secured to each of the frame means 22 for the cam means unit, and then have pressure supply lines extending from a common pressure reservoir connect to the individual control cylinders for unitary and simultaneous actuation of the four individual control cylinders provided adjacent the corners of the load support platform 9. With individual control means for the cam units, the cam plates used may be oppositely inclined. However, by the use of just a pair of double acting hydraulic control cylinders as shown in the drawing, an improved, safer, simultaneous actuation can be obtained and the mechanical tie extending between the pair of support or cam means provided in each of the side sills will aid in insuring simultaneous load support and lifting action in the railway car of the invention.

The provision of only relative vertical movement be tween the load platform and its support means and the remainder of the railway car is insured by a member, such as a roll 50, that is journalled on suitable support arms 51 that extend longitudinally from the support beams 16 and 17 at corresponding ends of the support beams 16 and 17. These rolls 50 will engage a flat, vertically extending, surface such as a plate 52 provided on the frame 4 of the railway car at one end 3 thereof adjacent the recessed center portion 4a of the railway car.

It should be realized that the frame, the depressed or lowered height portion in the frame of the railway car, and the load platform itself may be formed in any known manner by suitable means, but that controlled vertical movement of the support means 16 and 17 is provided in the car frame.

From the foregoing, it is believed to be evident that the railway car of the invention has desirable and improved properties and that a very effective load support action can be obtained thereby. By the provision of the longitudinally extending tie beams 12, 12 provided in the railway car, these tie beams can be so adjusted as to be at the normal height of the flat portions of the

ends

3, 3 of the railway car when the load support platform 9 is at its lowered, or load carrying position. Hence, if desired, load containers can be slid onto the load platform at that time, and be suitably secured to the load platform for transport action. Should the upper ends of these tie beams 12 not be at a desired vertical height for load receiving action, then the load platform can be raised within the limits of its travel to locate such tie beams at a proper elevation for ready load receipt thereon. Hence, heavy containers can be relatively easily slid onto these tie beams 12 if, for example, the load support platform 9 has been turned to any desired angle with relation to the longitudinal axis of the railway car. Naturally the ends of the load support platform 9 are arcuate and the associated surfaces of the elevated ends 3 of the railway car can likewise be formed to an are complementary to that of the load support platform, or not, as desired.

The drawings show that fiat walls or flanges of the side sills 7 and support beams 16 lie adjacent each other in parallel relation to aid in obtaining controlled vertical movement of the support beams.

It has been found that effective lift action of the support beams is obtained with reasonable length movement of the cam units 21 when the cam plates 18 are inclined at an angle of about 23 to the horizontal.

The load platform 9 may be spaced the necessary clearance distance from the ends 3 of the car, rather than be of arcuate end contour. Or, the corners of the load platform could be cut off on angles or arcs to reduce the required clearance for the load platform.

Preferably the cylinders 30 are positioned adjacent the cam plate 19 where a pushing thrust is applied to the

links

27 and 28. One end of each of the cylinders 30 is preferably pivotally secured to its receiving side sill 7 and the opposite end of the cylinder has its piston rod extending therefrom to engage the

links

27 and 28.

Any suitable bearings (not shown) may be used in positioning the brackets 42.

Slots 60 are provided in the ends of the tie beams 12 to receive retractible spur means secured to a truck frame. Such spur means would be aligned and then engaged with the load platform slots 60 by adjustment of the position of the load platform to lock the truck and load platform in alignment for load transfer therebetween.

In all events, a very efiicient, practical and sturdy load support and load elevating and lowering mechanism has been provided by the apparatus of the invention. Hence, it is believed that the objects of the invention have been achieved by the practical, sturdy, but relatively uncomplicated railway car of the invention.

While one complete embodiment of the invention has been disclosed herein, it will be appreciated that modification of this particular embodiment of the invention may be resorted to without departing from the scope of the invention as defined in the appended claims.

What is claimed is:

1. In a railway car,

a frame including side sills of generally U-shape in section at some portions thereof and having open centers and top portions, said side sills extending substantially the length of the car and having a depressed center portion,

a load platform supported on said frame center portion,

trunnion means operatively secured to said frame and said load platform to provide vertical and arcuate movement of said load platform on said trunnion means axis relative to said frame,

a support member for said load platform extending longitudinally of the car adjacent each side thereof below said load platform, each said support member being telescopically received in a said side sill for vertical movement therein,

roller means operatively carried by said support members and engaging portions of said frame to aid in positioning said support members in said side sills for only relative vertical movement therebetween,

a pair of parallel inclined cam plates operatively secured to each of said support members adjacent the ends thereof to provide vertical movement of said support members relative to said frame,

a plurality of support roll means in each of said side sills individually and operatively engaging each of said cam plates,

rigid link means operatively journalling said support roll means thereon and connecting the pair of said support roll means in each of said side sills together for unitary movement of such pairs of support roll means,

a control cylinder in each of said side sills engaging the said link means therein to move it and said support roll means longitudinally of said frame in the same direction, and

means connecting to said cylinders for unitary actuation thereof,

said cam plates and support roll means being capable of depositing said load platform on said frame for normal load carrying action and to raise said support members up into engagement with said load platform to lift it above said frame.

2. In a railway car,

a frame including side sills having open centers and top portions, said side sills extending substantially the length of the car and having a depressed center portion,

a load platform,

trunnion means operatively secured to said frame and said load platform to provide vertical and arcuate movement of said load platform relative to said frame,

a support member for said load platform extending longitudinally of the car adjacent each side thereof below said load platform, each said support member being telescopically received in a said side sill for vertical movement therein to be lifted up and engage and lift said load platform,

means operatively engaging said support members and said frame to position said support members in said side sills for only relative vertical movement therebetween,

a pair of parallel longitudinally inclined cam plates I operatively secured to said support members adjacent the ends thereof to provide vertical movement of said support members relative to said frame,

a plurality of cam roll means carried by said side sills and individually engaging said cam plates,

link means connecting the pair of said cam roll means in each of said side sills together for unitary movement thereof,

a control cylinder and piston in each of said side sills operatively engaging said link means to move it longitudinally of said frame, and

means connecting to said cylinders for unitary actuation thereof to raise and lower said load platform by said cam plates and support members.

3. In a railway car,

a frame including side sills of generally U-shape in section in at least some portions thereof and having open centers and top portions, said side sills extending substantially the length of the car and having a reduced height center portion,

a load platform associated with said frame center portion,

trunnion means operatively secured to said frame and said load platform to provide vertical and arcuate movement of said load platform on said trunnion means relative to said (frame,

an H-shaped in vertical section support member for said load platform extending longitudinally of the 'car adjacent each side thereof below said load platform, each said support member being telescopically received in a said side sill for vertical movement therein,

roller means carried by said support members and extending thereabove to engage said load platform when said support members are raised to support said load platform for arcuate movement,

swivel means securing said roller means on said support members to provide oscillation of said roller means in a horizontal plane on arcuate movement of said load platform,

a plurality of parallel inclined cam plates operatively secured to said support members adjacent the ends thereof for providing vertical movement of the support members relative to the frame,

a plurality of support roll means in each of said side sills for individually engaging the lower surface of said cam plates to engage and lift said cam plates,

link means positioning and connecting a pair of said support r-oll means in each of said side sills together for unitary movement thereof,

a control cylinder in each of said side sills operatively engaging the said link means therein to move it longitudinally of said frame, and

means connecting to said cylinders for unitary actuation thereof.

4. In a railway car,

a frame including a pair of side sills having open centers and top portions,

a load platform adapted to be supported on said frame,

trunnion means operatively secured to said frame and said load platform to provide arcuate and vertical movement of said load platform relative to said frame on said trunnion means axis,

a pair of spaced parallel support members for said load platform extending longitudinally thereof below said load platform,

each said support member being telescopically received in a said side sill for vertical movement therein,

a pair of parallel inclined cam plates secured to each of said support members with one plate being adjacent each end thereof,

cam means including roller means operatively engaging said cam plates to provide vertical movement of said support members relative to said frame upon longitudinal movement of such roller means, said roller means being adapted to deposit said load platform on said frame for normal load carrying action and to raise said load platform by said support members for arcuate movement on said trunnion means, and

unitary acting control means carried by said frame and engaging said roller means to move them longitudinally of said frame in the same direction and lift said load platform.

5. In a railway car,

a frame including a pair of side sills having open centers and top portions,

aload platform supported on said frame,

trunnion means operatively secured between said frame and said load platform to permit controlled arcuate and vertical movement of said load platform relative to said frame,

a pair of longitudinally inclined cam plates secured to each of said support members with one plate being adjacent each end thereof,

a plurality of roller means in said side sills operatively and individually engaging said cam plates for movement longitudinally of said frame to provide vertical movement of said support members relative to said frame, said roll-er means being adapted to deposit said load platform on said frame for normal load carrying action and to raise said load platform by verticl movement of said support members, and

control means including link means and control movement means therefor carried by said frame and engaging said roller means to move them longitudinally of said frame and lift said load platform.

6. In a railway car,

a frame including a pair of side sills having open centers and top portions,

a load platform supported on said frame,

each said support member being telescopically received in a said side sill for only vertical movement therein,

a pair of parallel longitudinally inclined cam plate means provided on each of said support members with one plate being adjacent each end thereof,

roller means operatively engaging said cam plate means to provide vertical movement of said support members relative to said frame by longitudinal movement of said roller means, said roller means being adapted to deposit said load platform on said frame 1 for normal load carrying action and to raise said load platform by said support members by cam action of said roller means engaging said cam plate means, and

unitary acting control means -carried by said frame and operatively engaging said roller means to move them longitudinally of said frame simultaneously and lift said load platform.

7. In a railway car,

a frame having a reduced height center section and having a pair of side sills with open centers and top portions,

a load platform supported on the reduced height center section of said frame,

a pair of spaced parallel support members for said load platform extending longitudinally thereof be low said load platform,

a pair of parallel longitudinally directed cam plate means provided on each of said support members with one plate being adjacent each end thereof, said cam plate means being inclined to the horizontal at about 23,

roller means carried by said side sills and operatively engaging said cam plate means to provide vertical movement of said support members relative to said frame by longitudinal movement of said roller means, said roller means being adapted to deposit said load platform on said frame for normal load carrying action and to raise said load platform by said support members by cam action of said roller 1 means engaging said cam plate means, and

control means carried by said frame and operatively engaging said roller means to move them longitudinally of said frame simultaneously and lift said load platform by forces applied to said support members adjacent ea'ch end thereof.

References Cited by the Examiner UNITED STATES PATENTS 1,826,116 10/31 Andrews 254 5 2,021,503 11/35 Fildes 366 2,058,891 10/36 Kellett 105366 2,782,733 2/57 Ewing 105-368 2,821,936 2/58 Weissrnan 105368 2,970,550 2/61 'Petterson 105366 3,074,691 1/63 Knapp et al. 254 5.6 3,075,479 1/63 Goby 105-455 MILTON BUCHLER, Primary Examiner.

LEO QUACKENB-USH, Examiner.

Claims

6. IN A RAILWAY CAR, A FRAME INCLUDING A PAIR OF SIDE SILLS HAVING OPEN CENTERS AND TOP PORTIONS, A LOAD PLATFORM SUPPORTED ON SAID FRAME, TRUNNION MEANS OPERATIVELY SECURED BETWEEN SAID FRAME AND SAID LOAD PLATFORM TO PERMIT CONTROLLED ARCUATE AND VERTICAL MOVEMENT OF SAID LOAD PLATFORM RELATIVE TO SAID FRAME, A PAIR OF SPACED PARALLEL SUPPORT MEMBERS FOR SAID LOAD PLATFORM EXTENDING LONGITUDINALLY THEREOF BELOW SAID LOAD PLATFORM, EACH SAID SUPPORT MEMBER BEING TELESCOPICALLY RECEIVED IN A SAID SIDE SILL FOR ONLY VERTICAL MOVEMENT THEREIN, A PAIR OF PARALLEL LONGITUDINALLY INCLINED CAM PLATE MEANS PROVIDED ON EACH OF SAID SUPPORT MEMBERS WITH ONE PLATE BEING ADJACENT EACH END THEREOF, ROLLER MEANS OPERATIVELY ENGAGING SAID CAM PLATES MEANS TO PROVIDE VERTICAL MOVEMENT OF SAID SUPPORT MEMBERS RELATIVE TO SAID FRAME BY LONGITUDINAL MOVEMENT OF SAID ROLLER MEANS, SAID ROLLER MEANS BEING ADAPTED TO DEPOSIT SAID LOAD PLATFORM ON SAID FRAME FOR NORMAL LOAD CARRYING ACTION AND TO RAISE SAID LOAD PLATFORM BY SAID SUPPORT MEMBERS BY CAM ACTION OF SAID ROLLER MEANS ENGAGING SAID CAM PLATES MEANS, AND UNITARY ACTING CONTROL MEANS CARRIED BY SAID FRAME AND OPERATIVELY ENGAGING SAID ROLLER MEANS TO MOVE THEM LONGITUDINALLY OF SAID FRAME SIMULTANEOUSLY AND LIFT SAID LOAD PLATFORM.