US2428223A

US2428223A - Lift truck

Info

Publication number: US2428223A
Application number: US611347A
Authority: US
Inventors: George V Johnson
Original assignee: Hyster Co
Current assignee: Hyster Co
Priority date: 1943-12-31
Filing date: 1945-08-18
Publication date: 1947-09-30
Anticipated expiration: 1964-09-30

Description

G. v. JOHNSON Sept. 30, 1947.

LIFT TRUCK I Original Filed Dec. 31, 1943 5 Shuts-Sheet 1 [dderdor' Gear e Vfl/uworv p 4 G. I JOHNSON 2,428,223

LIFT TRUCK Original Filed Dec. 31. 1943 5 Sheets-Sheet 2 Rot vain)". (Zeqzye 1%.Jb/uzao7v Sept. 30, 194'".

Original Filed Dec. 31, 1943 G. v. JOHNSON LIFT TRUCK 5 Sheets-Sheet 3 Sept. 30, 1 947. g. v. JOHN-SON Y 3 32 LIFT TRUCK Origihal Filed D ec. :51, 1943 5 Sheets-Sheet 4 G. v. JOHNSON LIFT TRUCK Sept. 30, 1947.

Original Filed Deb. 31. 1943 5 Sheets-Sheet 5 -fraiezzibr (z'eazye LE/ZRSOIL Patented SepLBQ, 1941 I 1 UNITED STATES PATENT OFFICE George V. Johnson, Portland, reg., assignor to Hyster Company, Portland, 0reg., a corporation of Oregon 8 Claims.

The present invention relates to lift trucks and is particularly concerned with lift trucks of the type driven with an internal combustion engine and having at the forward end a pivotally mounted frame acting as a guide and a support for a carriage having a pair of forwardly extending lifting arms.

This application is a division of my prior application Serial No. 516,405, filed December 31, 1943, for Lift trucks, which is now issued as Patent No. 2,387,077, dated October 16, 1945.

One of the objects of the invention is the provision of an improved lift truck of the class described, the structure of which is more compact, sturdy, and makes more efiicient use of available space to permit the use of larger pneumatic tires and still retain general over-all dimensions consistent with trucks of equal capacity using smaller diameter solid tires.

Another object of the invention is the provision of a lift truck which is provided with an improved construction for the elevator or loadlifting device employed.

Another object of the invention is the provision of an improved lifting structure for trucks of the class described which permits a greater visibility for the operator, forwardly of the truck, through the elevator and its mechanism.

Another object of the invention is the provision of an improved arrangement of the mechanism of the lift truck upon its chassis by means of which the truck is adequately counter-balanced for supporting a load for which it may have been designed, and by means of which the truck is also made more compact than the devices of the prior art, so that it can he used within freight cars and tight places in warehouses even though tion showing a lift truck embodying the invention;

I Fig. 2 is a top plan view of the lift truck;

Fig. 3 is a fragmentary front elevational view showing the load carrying mechanism apart from thevehicle in front elevation and partial section;

Fig. 4 is a fragmentary sectional view taken on the plane of the line 44 of Fig. 3 looking in the direction of the arrows;

2 Fig. 5 is a fragmentary sectional view taken on the plane of the line 5-5 of Fig. 3 looking in the direction of the arrows;

Fig. 6 is a fragmentary sectional view taken on the plane of the line 6-6 of Fig. 3 looking in the direction of the arrows;

Fig.7 is a horizontal sectional view showing a plan of the combined transmission and differential housing and driving wheels and the mode of attachment of the load carrying mechanism to the chassis being shown in section;

Fig. 8 is a diagrammatic view in perspective of the hydraulic system by means of which the elevator frame is tilted and the load lifted;

Fig. 9 is a fragmentary elevational view in partial section showing the construction of the tilting cylinders and pistons and a spring which isutillzed to urge the elevator frame forward at the top and to urge the pistons inward foreffecting their return when hydraulic pressure is removed; and

Fig. 10 is a fragmentary sectional view taken on the plane of the line Ill-I0 of Fig. 3 looking in the direction of the arrows, showing the mode of attachment of the sheave at the top of the hydraulic ram. 1

The present vehicle preferably has its chassis in the form of an assembly of cast steel members which are also employed for housing and enclosing the mechanism and for providing the housings for a pair of laterally located mufflers.

Referring to Figs. 1, 2 and 7, the lift truck is there indicated in its entirety 'by the numeral 20 and its chassis frame by the numeral 2|. This chassis frame may comprise a pair of side panels 22 joined at the top under the feet of the operator by a transversely extending frame member 23 which also serves as a floor board, and joined at the rear by a vertically extending partially cylindrical end wall 24.

At the forward end of the vehicle each of the 2 side panels 22 is provided with a transversely extending wall 25, which is curved cylindrically and slightly spaced from each of the front Wheels 28, and which are provided with a pair of apertures for receiving the two legs of a U-shaped bolt 34 that embraces the axle housing and passes through the flanges 33 to secure the chassis fixedly to the axle housing 28. At the rear end of the chassis frame the side panels 32 also enclose a muiller chamber 35, which is formed by a top wall 35, bottom wall 31, side panel 22, inner wall 38, and two endwalls 38. 40 (Fig. 1).

This muiller has its top wall 38 provided with a threaded bore at H for receiving the tail pipe 42, which has a vertical portion threaded into the bore 4| and a horizontal rearwardly extending portion discharging at 43 rearwardly of the chassis frame.

The exhaust is brought to the muffler chamber 35 by an exhaust pipe 44 on each side of the vehicle. The exhaust pipes pass in at an aper ture 45 by means of a downwardly extending diagonal portion 45 and the pipes have a downwardly turned portion 41 in the chamber 35.

The top wall 36 of each muiiier chamber 35 may also have a threaded fllling opening which is closed by threaded plug 48 so that each muiller chamber may be filled with ordinary water to a level 49, which is slightly below the end 41 of pipe 44. The present muiiler may under certain conditions be used without water. 50 indicates diagrammatically in Fig. 1 the power unit comprising an internal combustion engine which may be of the V-type so that its cylinders are arranged in two series, one series having its exhaust connected to each of the muiliers on each side of the vehicle.

The operation of these muillers is as follows: The exhaust gases, sparks, carbon, etc., are dis charged from the end 41 to the pipe 44 at high velocity directly toward the free surface of the water 49 and any burning particles are driven into the water and extinguished. As the exhaust gases at high velocity pass out of the pipe end 41 into exhaust chamber 35 they are permitted to expand freely into the larger space provided and the velocity energy is dissipated in this chamber. Successive waves of pressure are created in the chamber which are discharged through the tail pipe 42 to atmosphere and noise of the explosion of the engine is substantially muilied by use of this structure.

Due to the use of water there is assurance that sparks will not pass out of the tail pipes, and the construction is so arranged that the water is not blown from the muffler, thus permitting their use for relatively long periods without refilling.

The side panels 22 are also preferably joined at the rear top by the upwardly extending diagonal walls 5|, 52 and at the rear by the frustoconical end wall 53.

The chassis is formed at its rear end with a centrally located and vertically extending bearing housing 55 provided with bearings for rotate ably supporting a vertical trunnion 65 that carries at itslower end a counter-weighted wheel supporting member 51 which rotatably supports the rear steered wheel 88. The structure of the wheel and its axle are preferably substantially as disclosed in my prior Patent No. 2,337,109, issued December 21, 1943, relating to industrial trucks.

The chassis supports at its rear top a circular member 92 which is mounted for rotation on substantially the same axis as the trunnion 65 and which supports a forwardly extending arm 9| that houses the steering mechanism and carries the seat 89 for the driver and also supports the 4 steering wheel 80 which directs the steered wheel 88.

The structure of this steering mechanism is covered by my prior application Serial No. 516,405, flied December 31, 1943, on Lift trucks, Patent No. 2,387,077, issued October 16, 1945, of which application this is a division.

Referring to Fig. l, the front of the vehicle is provided with an extensible elevator frame provided with a load carrying carriage, this assembly being indicated in its entirety by the-numeral I35.

The load carryingassembly I35 has a pair of vertical frames I38 and I31 mounted to telescope with respect to each other, the lower frame section being indicated at I38 and the extensible frame by I31. The lower frame section may consist of a pair of vertically extending channeled members I38, I39 which are joined at the bottom by the transverse frame member I40 and at the top by transverse frame member l4l. Each of the channeled members I38, I39 is substantially U-sh'aped having the side flanges I42, I43 joined by web I44 and the lower frame member I40 may fit within the side flanges I42, I43 to engage the web and may be welded to all three of these parts.

As the extensible section I31 only moves down to the lower frame member I40, this frame member may be placed inside the channels, but the upper transverse frame member I must be located outside of the channels I38, I39 to prevent interference between this frame member and the sliding frame I31. Therefore, the upper frame member I4I may consist of an angular member having a vertical flange I45 and a horizontal flange I45, and the horizontal flange frame extends around the outside of each channel I38, I39, as indicated on both sides of Fig. 3, where this horizontal flange is welded to the web I44. It is also welded to the rear side flange I42 of each vertical channel I38, I39, and in addition it holds the upper ends of the channels I38, I39 in proper spaced position. Frame member I serves as an anchor for one end of the sprocket chain I41, which may be secured to it by any suitable securing device, such as a terminal link having a screw bolt passing through the flange I48 and provided with lock nuts, as shown in Fig. 6, for the other end of the chain.

At its lower end the vertical frame I38 is also preferably provided with a pair of rearwardly extending arms I 48, I49, one of which is seen in Fig. 1, and both of which are seen in plan in Fig. 7.

These arms I48, I49 are'securely welded to the rear flange I42 of each channel I38, I39 and extend rearwardly at substantially right angles to these channels. Each of the arms 8, I49 may be pivotally mounted by means of a stub shaft or screw bolt I50 on a hanger I5I, Fig. 1, which is supported from the front axle housing 28 so that the load supporting assembly I35 is carried by the front axle housing, and is mounted for pivotal movement either on the axle housing or the hanger I5I.

One mode of support of the load carrying assembly I35 is to provide a transverse bar which is bolted to the lower side of'thetr'an's'mission housing, the ends of this bar being engaged by rubber torque bushings mounted in bores I52 in the arms I48, I49 to support the tilting frame.

Referring to Fig. 7, each of the arms I48, I 49 is formed with an inwardly turned diagonal flange I53 in order to clear the forwardl extendlngpart 3|, 32 of the chassis which is also attached to the axle housing 28.

At the rear end of each arm I48, I49 for the tilting frame, each arm is'pivotally connected by means of a rivet or screw bolt I54 to the piston rod I55 of a piston that is mounted for reciprocation in the cylinder I56, Fig, 1, Fig. 8. The cylinder itself is pivotally mounted on the chassis by means of a lug I51 having an aperture I58, Fig.

1, by means of a screw bolt I59 which passes through the bore I58 and is threaded into a threaded bore I60 in the chassis member 21.

The cylinder I56 has a hydraulic piston which is actuated by hydraulic fluid under pressure, as will be further described in detail, to effect a tiltin; of the frame I35 backward from the full line position in Fig. 1 to the dotted line position as shown at the right-hand of this figure.

The assembly I35 is urged counter-clockwise, Fig. l, by gravity since it is pivotally mounted at I50 at the right of its center of gravity. In order to assure the return of the titling assembly I35 to the forward dotted line position of Fig. l

and to assure the emptying of the hydraulic fluid from the cylinders I56 when hydraulic pressure is removed, the arms I48, I49 are also preferably engaged by a leaf spring assembly I6I which is carried by the transmission housing I62.

Leaf spring I6I may consist of an assembly of leaves I63, I68, each leaf being longer than the leaf below it and the leaves being symmetrically arranged between bolts I69 which are threaded into the tapped holesin the flywheel housing I62 and are used to clamp the spring in its proper position. The pistons I10 have a cylinder I56 which shows in Fig. 9, and they are provided with bifurcated lower ends having the spaced flanges I1 I, I12 for receiving the rivet I54.

Flange I12 may be made slightlylonger and may be curved at its lower end I13 to be received in a complementarily curved recess I14 formed in each end of the leaf spring I68. If desired, the engagement may be between a curved formation I15 on the lower side of the end of each arm I48, I49 and the leaf spring end I68, as shown in Fig. 8. The leaf spring assembly is under initial tension urging the pistons I10 upward into the cylinders I56 and the pressure of the spring combined with the weight of gravity of the forwardly extending load supporting assembly I15 is suflicient to drive the hydraulic fluid out of the cylinders I56 quickly when proper valve connections are effected by one of the levers I08, I09, as will be described in detail hereinafter.

Referring to Figs. 1 to '1, the upper extensible frame section I31 preferably comprises a pair of outwardly turned channel members I16, I11, these frame members being joined at the top by a channeled member I18. The channeled member I18 may have its side flanges I19, I80 of sufficient length to fit between the channels I16, I11 and may have its web I8I extended into the channels I16, I11 to eifect a close fit between these frame members I16, I11, I18, which may be welded together at all points of contact. Thus the extensible frame section I 38 has a rigid frame open at its lower end so that there is nothing to interfere with the central location of a cylinder I82 and piston I83 for actuating or lifting the upper frame section I31.

In order to support the cylinder I82, the lower fram section I36 is provided with an additional transverse frame member I84, Fig. 3, Fig.5, which is suitably attached to each of the side channels I38, I39 and its frame member I84 is widened at its central portion to be provided with a web I86 as well as two reinforcing flanges I86, I81. Web

I is substantially triangular and is adapted to receive cylinder I82 between its flanges with a clearance.

Adequate stabilization to the lifting frame 231 is provided by rollers 22 I224, and eliminates the need of employing two lifting chains'as found in the prior art. This permits the use of a single lifting chain I41 located ahead of the hydraulic ram I82-I83 so that there will be no lift chains obstructing the operator's visibility.

The lower end of cylinder I82 is provided with a partially spherical socket I88, Fig. 3, for receiving an upwardly extending lug I89 having a similarly shaped end for permitting a limited universal movement of the cylinder I82 on the frame member I84. In addition, a transverse-pin I90 may pass loosely in the cylinder I82 and may be riveted over in each of the flanges I86, I81 to make sure that the lug I89 will not get out of its socket I88,

The piston I83 engages at its upper end with a sheave assembly I9I. This cheave assembly comprises a pair of depending side plates I92, I93, Fig.

3, the side plates being integrally secured to a horizontal yoke I94 and also being welded at their upper ends to flanges I19, I8I of the upper frame spherical socket I99 for receiving the ball-shaped.

end of a headed member 200, which has its stein 203 mounted in the yoke I94.

The piston I83 has its upper end provided with two screw bolts 20I which pass loosely through large apertures in the yoke I94, and the screw bolts are fixedly mounted in threaded bores 202 in the piston I 83. The screw bolts 20I. are long enough, to provide a lost motion between the sheave assembly I9I and the piston I 83, and the sheave engages the piston I83 through the ball and socket I99, 200 which provides a limited universal movement. The bolts 20I in their enlarged apertures in the yoke I94 merely guide the sheave and define the limits of the pivotal movement of the sheave assembly I9I relative to the piston-I83.

The lower frame section I36 is preferably provided atits upper end with a roller 204 which is preferably formed with a crowned periphery 205 for engagement with the internal surfaces of the

flanges

206, 201 on the channels I16, I11. Roller 204 is rotatably mounted on a trunnion 208 carried by a block 209 which is shaped to fit in each channel I38, I39.- Block 209 may be secured in the channel by means of screw bolts. 2) which pass through apertures in the web I44 and are threaded into threaded apertures in block 209.

Block 209 may have at its lower end a pair of forwardly extending bearing flanges 2I I provided with apertures for supporting the pin 2I2, which pivotally supports a second roller 2I3 of substantially the same shape. Rollers 2 I3 are located to engage the web 2I4 of-each channel I 16, I 11 to guide the upper frame I31 against lateral movement in the lower frame I36 in the plane of these frames. Rollers 204 guide the inner and upper movable frame I31 against movement out of the plane of the frame I36,

r 7 a similar block 263 similarly secured and provided with the roller M for engaging the web I44 of each channel I36, I39 and with the roller 2I6 for engaging between the side flanges I42, I43 of each channel I36, I39.

It should be noted that these guiding rollers are located at the extreme lower end of the upwardly moving frame I31 and at the extreme upper end of the lower frame I36. Thus, the two frames are supported to be guided for telescoping movement with a minimum amount of strain because the spaced rollers are as far apart as possible in most of the positions of this frame, and the roller assemblies on each side only come close together when the frames are fully extended.

The upper movable frame section I31 supports a carriage indicated in its entirety by the numeral 220 which is guided on the upper movable frame I31 by a plurality of rollers 22I, 226,

The carriage 226 preferably comprises a rectangular frame which may consist of the hori-. zontal frame members 229, 236 and the vertical frame members 23I, 232 secured together at their corners to provide a rectangular frame. The horizontal frame members 229, 236 are preferably longer than the width of the tilting frame assembly I36, I31 so that they project beyond each sideof the tiltin frame assembly, and these frame members may be joined at the middle by an intermediate vertical frame member 233, which is provided with an enlargement 234 having a horizontal bore 235. As the carriage frame is widerthan the tilting frame assembly, the carriage frame is preferably provided with another pair of vertically extending

frame members

236, 231 for carrying the rollers 22I-228 which enage the movable frame section I31.

Rollers 225228 may be of substantially the same shape as rollers 204 but are carried by a stub shaft 238 which has a reduced threaded portion passing through the

frame members

231 or 236 and secured with a nut 23!, there being an annular shoulder 240 on each shaft on the opposite side of the

frame members

236 or 231.

The

frame members

236, 231 are provided with slots 24I adjacent the shafts 238 for passing the other rollers 22I224 which are also mounted upon shafts 242 that are suitably attached to the

frame members

236, 231 on each side of the shaft 2, Rollers 22I--224 engage the outside of the 'webs2I4 of the vertical channels I16, I11 and guide the carriage frame against tilting in the plane of the extensible frames I36, I31,

Rollers 225-228 keep the frame of the carriage substantially parallel and closely adjacent to the extensible frame I31 so that the carriage may move from the bottom end to the top end of the extensible frame I31 in lifting a load, or it may be moved from the bottom to the top or vice versa, to place the carriage in position to take on a load or to discharge a load.

Rollers

226, 228 are located in front of channels I16, I 11, while rollers 22B, 221 are located behind these channels.

The load supporting arms 243, 244, Fig, 3, are preferably adjustably mounted on the carriage 220, and each arm may comprise a vertically extending frame member 245 and a horizontally extending frame member 246. The vertically extending frame members 245 may be substantially as wide and as thick as the depth of the carriage frame, and they are provided with through bores 241 for receiving a rod or shaft 246 by means of which they are supported.

The shaft 248 is carried by the frame by being located in bores in the end frame members 8. 23I, 232 and the intermediate frame member 233. The shaft may be secured by a tight frictional fit or by cotter pins or any other convenient fastening means.

The load supporting arms 243, 244 have their bores 241 provided with a sliding fit on the shaft 246 so these may be moved laterally on the shaft 246 as desired to lift a wide or narrow load or to locate them centrally of the load when the vehicle is in a predetermined position. These load lifting arms are preferably spaced as widely as possible in order to provide a more stable support for the load which they carry, but they may be adjusted for various particular purposes.

The lower frame member 230 of the carriage frame is preferably located at the rear side of the frame members 23I, 232, so that the vertical frame members 235 of the load supporting arms 243, 244 may rest against the frame member 230 when they carry a load and still be located within the boundaries of the carriage frame.

Frame member 230 is preferably disposed with its flat side extending vertically so as to provide a wider bearing surface to engage the rear side of the vertical frame members 245 of the arms 243, 244.

The horizontally extending portions 246 of the load supporting arms may be tapered toward their outer ends 249 since they act as cantilevers and their depth may be proportioned to the moments imposed upon them at any point.

Also the thin tapered end 249 is thus adapted to he slid or wedged under some types of loads to take the load by its direct engagement with the floor or the ground.

The taper on these arms is preferably on the lower side, so that the tapered side may extend parallel to the floor or ground when the frames I36, I31 are tilted forward to take on a load.

The chain I41 which is anchored at its right end, Fig. 1, to the transverse frame member I of the lower frame section I36, passes through the sheave I31 from the back and passes down parallel to the piston I83 and cylinder I82 and has its other end anchored to the carriage 220. The form of anchorage is shown in Fig. 6 where the enlargement 234 on vertical frame member 233 has a rearwardly extending lug 256, provided with an aperture 25I for receiving the shank 252 of a special link 253. Shank 252 has a threaded end which is provided with a pair of nuts 254, so that the chain may be employed in lifting the carriage 220.

It should be noted that when the piston I63 is driven upward by hydraulic fluid under pressure in the cylinder I62, it engages the movable frame section I31 through the intermediary of the sheave assembly I9I and lifts the upper frame section I31 as well as the sheave. Since the rear end of the chain M1 is anchored to the lower section I36, the raising of the sheave withits pulley simultaneously extends both the forward and rearward bight of the chain, and the carriage 220 is raised twice as fast as the upper frame I31.

Referring to Fig. 8, this is a. diagrammatic illustration of the hydraulic system for controlling the raising and lowering of the carriage and the tilting of the load supporting elevator assembly. The system preferably includes a reservoir 255 for hydraulic fluid such as a suitable oil, and the reservoir 255 may comprise a cast metal container provided with a filling spout 256 having a cap 251,

A compressor pump 256 preferably of the gear type is located in the reservoir 255 and has its intake opening 266 downwardly turned at a point spaced from the bottom of the reservoir so as to utilize the supply of oil or other hydraulic fluid which is contained in the reservoir without actually taking the sediment which might collect on the bottom. Pump 258 is driven by a shaft 266 which projects from the reservoir at its forward wall and carries the drive pulley 26I preferably of the V-type. This pulley may be driven by means of a rubber V-belt 262 which also passes over a pulley 263 carried by a rearward extension of the motor drive shaft 264, or some other shaft driven by a motor 56.

The reservoir 255 may be pivotally supported for a limited pivotal movement by means of an angle bracket 265, bolt 286 and a bracket 261 car-- ried by the chassis. Another angle bracket may be fixedly secured to the chassis and to the reservoir 255 by bolt 269 in slot 216 so that the tension of the belt 262 may be adjusted by tilting the reservoir and securing it in place.

The pump 258 discharges through pipe 2" into a valve housing 212 which has a valve of the piston type 213 for controlling the flow of the hydraulic fluid under pressure to the tilting cylinders I56. Valve housing 212 is connected by p pes 214-216 to the upper ends of the cylinders I56 for this purpose.

The piston valve 213 is connected by a link 211 to a bell crank arm 218 by pivotal pins so that lever I69 may be used to open or close the valve 213. Thus a forward push on the lever I69 per- I mits hydraulic fluid under pressure to enter cylinders I56 to push the pistons I55 downward, pivoting the arms I48, H9 downward and tilting the load lifting assembly I35.backward. When the lever I69 is pulled backward, the valve 213 is closed against admission of further hydraulic fluid to the cylinders I56, and another port'is opened leading backward into the reservoir 255 so that the cylinders I56 are emptied.

The weight of the carriage 226, the load and the frames I36, I31 and the pressure of the spring assembly i6] cause the pistons to move into the cylinders I56 permitting the load carrying assembly I35, to tilt forward to desired position.

In the same way, the other lever I68 controls a similar valve which is adapted to admit hydraulic fluid from the pump 259 through the pipe 219 to the lifting cylinder I82 acting on piston I83, or the valve may be closed and the hydraulic fluid be'passed back to the reservoir by moving lever I68 to the rearward position.

The system is preferably provided with a spring-loaded bypass to relieve the hydraulic system of excessive pressure that might develop through any cause.

It will thus be observed that I have invented an improved construction for lift trucks which is simple, sturdy and capable of being manufactured at a low cost and adapted to handle relatively heavy loads for its size and to transport them at a greater speed than the devices of the prior art. The present elevator construction is very stable and flexible in its handling and provides a maximum degree of visibility for the operator since only a single chain is used which is disposed in alignment with the piston and cylinder.

The vehicle needs only a single power plant, and by means of the hydraulic pump, cylinders and pistons, the power derived from it is used not only for driving the vehicle in two speeds,

forward and reverse, but for tilting the elevator" ment of my invention, many modifications may be made without departing from the spirit of the invention, and I do not wish to be limited to the precise details of construction set forth, but desire to avail myself of all changes within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

1. In an industrial truck, the combination of a chassis supported upon steering and drive wheels with an upwardly extending frame having at its lower end a pair of rearwardly extending supporting arms pivotally mounted with respect to such chassis, hydraulic means carried by said chassis and engaging each of said arms and adapted to urge the arms downward to tilt the upwardly extending frame backward, and spring means carried by said chassis and urging said arms upward to return the hydraulic means to its initial position, the said upwardly extending frame being provided with an extensible section movably mounted with respect to said frame and a load carryingmeans adapted to travel upward or downward on said movable section, and hydraulic means for simultaneously extending said extensible section and lifting said load carrying means, said hydraulic means comprising a ram having a sheave engaging a cable anchored on the frame at one end and passing over the sheave and secured at its opposite end to the load carrying means.

2. In an industrial truck, the combination of a chassis provided 'with front drive wheel means and rear steering wheel means, a tiltable vertically extending frame having a pair of rear- 46 wardly' extending supporting arms pivotally mounted with respect to said chassis, a pair of hydraulic cylinders, each cylinder having its closed end pivotally mounted on said chassis and having'a piston projecting from its other end pivotally connected to each of said arms beyond the point of support of the arms on said chassis, and spring means comprising a leaf spring having a plurality of leaves symmetrically arranged,

and secured together at a central point, said 50 leaf spring being fixedly secured with respect to said chassis and having its free ends arranged to urge said pistons into said cylinders for tilting the upper end of said frame forward when hydraulic pressure isreleased from said cylinders, said truck including a driving engine having a housing, and said leaf spring having its central portion secured to said latter housing.

3. In a lift truck, the combination of a wheel supported chassis with a vertically extending load supporting frame carried by the front end of said chassis and arranged for tilting about a horizontal axis, said vertically extending frame comprising a pair of inwardly turned channelled mem-- bers, each having a web and two side flanges, 55 upper and lower frame members for securing said two channelled members together, said upper frame member being located outside of the channels, a second movable frame member comprising a second pair of outwardly facing channels rigidly joined together by an upper transverse frame member, roller means carried by the lower end of said second frame for engaging inside the firstmentioned channels against the two flanges and web thereof, roller means carried by the upper 76 ends of the first two mentioned channels for en- 11 gaging inside the channels of the second frame against the web and two flanges of the channels thereof, whereby the second frame is guided for vertical movement with respect to the first frame, a load carrying means adapted to run upward 'or downward on said second frame, a hydraulic supporting frame carried by the front end of said chassis and arranged for tilting about a horizontal axis, said vertically extending frame com-- prising a. pair of inwardly turned channelled members, each having a web and two side flanges, upper and lower frame members for securin said two channelled members together, said upper frame member being located outside of the channels, a second movable frame member comprising a second pair of outwardly facing channels rigidly joined together by an upper transverse frame member, roller means carried by the lower end of 'said second frame for engaging inside the first-mentioned channels against the two flanges and web thereof, and roller means carried by the upper ends of the first two mentioned channels for engaging inside the channels of the second frame against the web and two flanges of the channels thereof, whereby the second frame is guided for vertical movement with respect to the first frame, a hydraulic cylinder carried by the first frame and extending upwardly from a transverse frame member adjacent the bottom of the first frame, said cylinder having a piston enga ing a part carried by the second, whereby the second fram may be raised hydraulically, said part comprising a U-shaped bracket carried by the upper frame member of the second frame, and said piston having a predetermined universal movement with respect to said bracket,

5. In a lift truck, the combination of a wheel supported chassis with a vertically extending load supporting frame carried by the front end of said chassis and arranged for tilting about a horizontal axis, said vertically extending frame comprising a pair of inwardly turned channelled members, each having a web and two side flanges, upper and lower frame members for securing said two channelled members together, said upper frame member being located outside of the channels, a second movable frame member comprising a second pair of outwardly facing channels rigidly joined together by an upper transverse frame member, roller means carried by the lower end of said second frame for engaging inside the firstmentioned channels against the two flanges and web thereof, and roller means carried by the upper ends of the first two mentioned channels for engaging inside the channels of the second frame against the web and two flanges of the channels thereof, whereby the second frame is guided for vertical movement with respect to the first frame, a hydraulic cylinder carried by the first frame and extending upwardly from a transverse frame member adjacent the bottom of the first frame, said cylinder having a piston engaging a part carried by the second, whereby the second frame may be raised hydraulically, said piston being mounted on said first frame at its lower end for a limited universal movement.

6. In a lift truck, the combination of a wheel supported chassis with a vertically extending load supporting frame carried by the front end of said chassis and arranged for tilting about a horizontal axis, said vertically extending frame comprising a pair of inwardly turned channelled members, each having a web and two side flanges, upper and lower frame members for securing said two channelled members together, said upper frame member 'being located outside of the channels, a second movable frame member comprising a second pair of outwardly facing channels rigidly joined together by an upper transverse frame member, roller means carried by the lower end of said second frame for engaging inside the first-mentioned channels against the two flanges and web thereof, and roller means carried by the upper ends of the first two mentioned channels for engaging inside the channels of the second frame against the web and two flanges of the channels thereof, whereby the second frame is guided for vertical movement with respect to the first frame, a hydraulic cylinder carried by the first frame and extending upwardly from a transverse frame member adjacent the bottom of the first frame, said cylinder having a piston engaging a part carried by the second, whereby the second frame may be raised hydraulically, said part comprisinga U-shaped bracket carried by the upper frame member of the second frame, and said piston having a predetermined universal movement with respect to said bracket, said U- shaped bracket carrying a sheave pulley upon a shaft, a load carriage movably mounted upon said second frame, and a tension member extending over said pulley and having one end anchored to the'first frame, the other end being secured to said carriage.

7. In a lift truck, the combination of a tiltable vertically extending load supporting frame with a carriage guided for movement longitudinally of said frame, said carriage comprising a pair of horizontal and a pair of vertical frame members, and said vertical frame members being each provided with a pair of rollers, one of said rollers being located at the top behind said tiltable frame, and the other of said rollers being located at the 'bottom in front of said tiltable frame, a transverse shaft carried by the upper part of said carriage frame, a pair of load carrying arms, each load carry ng arm having a downwardly extending portion with a bore slidably mounted on said shaft and having a forwardly projecting load carrying arm at the lower end of said downwardly extending portion, said frame also having an auxiliary pair of end frame members-and a centrally located frame member for supporting said shaft, and a single tension member for operating said carriage frame.

8. In a lift truck, the combination of a tiltable vertically extending load supporting frame with a carriage guided for movement longitudinally of said frame, said carriage comprising a pair of horizontal and a pair of vertical frame members, and said vertical frame members being each provided with a pair of rollers, one of said rollers 'being located at the top behind said tiltable frame, and the other of said rollers being located at the bottom in front of said tiltable frame, a transverse shaft carried by the upper part of said carriage frame, and a pair of load carrying arms, each load carrying arm having a downwardly 13 extending portion with a bore slidably mounted on said shaft and having a forwardly P jecting load carrying arm at the lower end of said downwardly extending portion, said frame also having rollers extending through apertures in its vertical frame members for engaging said tiltable frame to guide the carriage thereon, and a sinzle tension member for operating said carriase frame.

GEORGE v. JOHNSON,

REFERENCES CITED The following references are of record in the file of this patent:

Number Schreck Feb. 19, 1946