US2178367A

US2178367A - Industrial truck

Info

Publication number: US2178367A
Application number: US179273A
Authority: US
Inventors: Elmer J Dunham
Original assignee: Clark Equipment Co
Current assignee: Doosan Bobcat North America Inc
Priority date: 1937-12-11
Filing date: 1937-12-11
Publication date: 1939-10-31
Anticipated expiration: 1956-10-31

Description

Qct. 31, 1939.

E J. DUNHAM INDUSTRIAL TRUCK 9 Sheets-Sheet 1 Filed Dec. 11, 1957 Oct. 31, 1939. E. J. DUNHAM INDUSTRIAL TRUCK Filed Dec. 11, 1937 Q-SheetS-Sheet 2 wk 9% 9 y 5 v v Q? f 3 g N\ ,9 g5 h g H I v 8 Si H w gm w\ m m g. g H H U H U H H H H Q w QQ g NS MN \mmN m:

Oct. '31, 1939. E. J. DUNHAM INDUSTRIAL TRUCK Filed Dec. 11, 1937 9 Sheets-Sheet 3 Oct. 31, 1939. E J. DUNHAM INDUSTRIAL wnucx Filed Dec. 11, 1937 9 Sheets-Sheet 4 E. J. DUNHAM INDUSTRIAL TRUCK 9 Sheets-Sheet 5 Filed Dec. 11, 1937 jwenor Flmardflan/mm. lia/ Filed Dec. 11, 1937 9 Sheets-Sheet 6 Oct. 31, 1939. E. J. DUNHAM INDUSTRIAL TRUCK Filed Dec. 11, 1957 9 sheets-shes; 7

Jvuenor: Q [Zmer zfjun/Mzm Get. 31, 1939.

E, J. DUNHAM.

INDUSTRIAL TRUCK Filed Dec. 11 19:57 9 Sheets-Sheet ajvvenfor Emmi/7447 562772. 226W 5 Oct. 31, 1939. E. J. DUNHAM INDUSTRIAL TRUCK Filed Dec. 11, 1937 9 Sheets-Sheet 9 j Patented Oct. 3i, 1939 UNITED STATES INDUSTRIAL TRUCK Elmer J. Dunham, Battle Creek, Mich assignor to Clark Equipment Company,

Mich a corporation of Michigan Application December 11, 1937, Serial No. 179,273

12 Claims. (01. 214-113) This invention relates to industrial trucks, and more particularly is directed to industrial trucks of the high lift type for use in shops, warehouses, loading docks and the like. This type of truck 6 is especially adapted for material handling service, and for storing and tiering material or stock in industrial and mercantile establishments.

In the preferred form of the present invention I employ a gasoline powered tractor or truck unit 10 capable of rendering continuous service without the necessity of recharging batteries or the like, as is the case with the electrically powered units.

One of the main advantages of the present construction is the provision of a standard power plant, chassis and frame with means for converting the unit into either a straight lifting and tiering unit, or a tilting and tiering unit, or telescoping tiering unit for extremely high lifting, which latter unit can be either of the tilting or nontilting type.

In connection with the present invention, I preferably provide hydraulicmechanism for raising and lowering the load supporting means, which is operated from the power plant of the unit, and is under the direct control of the operato'r who is so disposed as to have a clear view of all operations and movements of the unit.

One of the features of the present invention is the disposition of the power unit and the oper- 'ators platform at the rear end of the frame whereby an effective counter-balance of considerable weight may be provided with a relatively long lever arm with respect to the fulcrum point of the load. This, in connection with suitable bracing members pivotally mounted on the rear portion of the frame and connected to the top' of the upright members which form the guides and supports for the load-carrying means, provides a construction having a large factor of safety and 40 protecting the operator from any possible hazards incident to overloading of the unit.

I have found that the placing of the drive wheels at the forward end of the frame adjacent the load supporting uprights serves to increase the tractive power of the unit, and also materially assists in controlling the movements of the unit when under full load. This arrangement also enables the uprights to be secured to the axle housing enclosing the drive transmitting means in such a manner that it may be removed with facility for repair or replacement of the upright structure or the load supporting means without necessitating the dismantling of any portion of the frame or chassis of the vehicle. Thus,

possible damage or breakage of any of the tiering mechanism requires only the replacement of such mechanism without in any manner affecting the frame and power unit of the vehicle.

Preferably, the dirigible steering wheels are located at the rear of the truck beneath the power 5 unit, facilitating steering action at slow speeds under full load, and also allowing for close operations and for moving of the truck into positions so that the load can be discharged from a center aisle to machines or storage bins without requir- 10 ing the truck itself to be moved completely out of the aisle. I

Another distinct advantage arising from this location of the steering means resides in the ability to obtain a greater turning angle, thus 15 reducing the turning radius of the truck without any loss of tractive effort. Thus the truck is able to turn at intersecting aisles which have a width less than the actual turning radius of the truck itself. I 20 While the truck unit of the present invention is adapted to'have any type of load supporting means mounted thereon for tiering movement, the present construction discloses the type of load-carrying means known to the trade as 25 finger or forklift unit. This type of unit has forwardly projecting finger members which can be lowered to the ground level for insertion under boxes'or crates resting on the floor, or for movement under skids or other similar bins or con- 30 tainers. By using such a finger lift, odd shaped packages or skids having varying widths and rack arrangements can be conveniently handled. In connection with such load-supporting means, I

also provide for lateral adjustment of the fingers 35' position until such time ,as the control lever is 45 again manually actuated by. the operator. Automatic stop means of this type insures that the load-supporting means will not be forced beyond its limiting positions even if the operator should leave the truck unattended with the control lever 50 in one of its operative positions. It is to be pointed out, however, that the control mechanism is so arranged that the load may be raised or lowered from any intermediate position. and no predetermined sequence of movement is necessary. This 5,;

Buchanan,

places the load under the direct and instantanesides in the provision of a brake mechanism which operates on the output shaft which transmits torque from the transmission to the drive axle. This takes the place of the usual brake mechanism at the driving wheels. In a preferred form of the invention this brake is of the type which is normally urged into braking position by heavy springs, and is released or moved into inoperative position by hydraulic means controlled by a foot treadle upon which the operator stands when it is desired to move the truck. If the operator shouldleave the truck, or for any reason be prevented from controlling the same due to an accident or the like, the release of this foot treadle immediately causes the setting of the brake, thereby locking the truck against any further movement.

Another advantage of the present invention resides in the provision of means on the uprights whereby the same are clamped in fixed laterally spaced position on the stub shafts of the axle assembly by means of brackets, whereby the entire upright structure and load supporting means can be moved forwardly away from the frame when the brackets are unclamped without dismantling any part of the frame. In this connection, I also provide a suitable cross bracing member between the uprights at the lower end thereof which is independent of the frame and which has means formed therein providing a rigid support for the hydraulic cylinder containing the actuating piston for raising and lowering the platform. If the truck is of the tilting type, th s cross member will provide for conjoint tilting movement of the cylinder with the uprights in order to maintain the piston in alinement between the uprights so that the maximum effective lifting force on the load-supporting carriage is provided.

Other objects and advantages of the present invention will appear more fully from the following detailed description which, taken in conjunction with the accompanying drawings, will disclose to those skilled in the art the particular construction and operation of a preferred form of the present invention.

In the drawings:

Figure 1 is a perspective view of the truck unit of the present invention with the load-supporting means in lowered position;

Figure2 is a corresponding view showing the load-supporting means in upper raised position;

Figure 3 is a perspective view of the truck unit' showing in more detail the load-supporting mechanism;

Figure 4 is a diagrammatic view illustrating the turning radius available with a unit of this type;

Figure 5 is 'a top plan view of the dirigible steering means of the vehicle;

Figure 6 is a front elevational view, partly in section, of the steering mechanism shown in Figure 5;

Figure '7 is a perspective view of the steering mechanism in one of its operating positions;

Figure 8 is an enlarged view taken substantially on line 8-8 of Figure 9;

Figure .9 is a top plan view partly in section, showing the arrangement of the'uprights at the forward portion of the frame;

Figure 10 is a diagrammatic view illustrating the hydraulic connections for the lifting mechanism;

Figure 11 is a diagrammatic view of'the control mechanism for operating the hydraulic lifting means; and

Figure 12 is partial elevational view of the upright structure taken substantially on line i2--| 2 of Figure 8.

Referring now in detail to the drawings, I have provided a truck unit indicated generally at l0, having a power unit comprising an internal combustion engine or the like mounted on the rear portion i2 of the frame of the unit and enclosed within a suitable hood I3.

'A suitable dash board it is provided at the rear of the power unit, and forms a rear enclosure for the hood I 3. This dash unit has suitable means for supporting the radiator |5 of the power unit, and provides for mounting of the steering wheel i6 thereon which operates the rear dirigible wheels II. On the opposite side of the radiator i5 from the steering mechanism It there is provided a change speed control member I8 which is moved longitudinally to select the particular driving speed desired. Disposed below the member I R is the shift member I 9 which operates a suitable clutch mechanism for controlling the forward or reverse movement of the vehicle, and which is provided with a throttle control portion for controlling the speed of the power unit in the usual manner. Disposed laterally of the control members 18 and i 9 I provide the lift control arm 22, which is shown in Figure 1 in its neutral position. The member 22 is raised upwardly in the slot 23 to raise the load-carrying platform indicated generally at 24, and is lowered in the slot 23 when it is desired to lower the platform.

In order to form an effective counter-balance for the load carried upon the supporting means 24, I provide a relatively heavy counterweight portion 25 bolted to the rear of the hood l3 on the face of the dash-board, and which extends down to the lower end of the frame. Extending rearwardly from this counterweight 25 are a pair of arcuately curved side members 26 formed of cast metal or the like and of heavy section, which also serve as suitable counterweight means and in addition, afford protection means for the operator against injury due to hitting against stationary objects. The platform upon which the operator stands is indicated generally at 21, and is also a relatively heavy cast member serving as an additional counterweight. A brake actuating treadle 28 is pivotally mounted on the platform 21, and suitable spring mechanism at the brake itself which normally setsthe brake, also serves to raise the treadle 28 to the positions shown in Figures 1 and 2. When the operator steps upon the treadle 28 and forces the same to the floor of the platform 21, the brake is released, allowing free transmission of torque from the transmission to the driving axle.

The details of construction of the operating members i6, i8, i9, 20 and 22 will be found in my copending application, Serial No. 94,926, filed August 8, 1936, which discloses a lift truck of the platform type which has incorporated thereinto the same power unit and control mechanism as provided in the present unit.

The frame itself is of the locomotive type and has an upwardly arched rear portion which accommodates the axle assembly and steering mechanism for the rear wheels ll. This mechanism is shown more in detail in Figures 5 to 7,

the spindle 33, as shown in Figure 6, which has 7 a tapered fit in the portion 32, and which at opposite ends is received in suitable bearing sleeves 34 and 35 carried by the trunnions 36 and 31 of the wheel spindle 33. The upper trunnion 31 of each of the wheel spindles 38 has a rearwardly extending portion 39 which, at its outer end, has a ball and socket connection 40 to the connecting member 42. The opposite end of the member. 42 is connected through the turn buckle coupling 43 to a suitable connection member 44 apex thereof is provided with the collar portion 49 secured to the pin 50 carried in suitable bearings 52 disposed in the center bearing support portion 53 of the axle member 30. The axle member 36 is also provided with an apertured portion 54 through which extends an actuating arm 5%; connected at one end by means of the ball and socket connection 56 to a crank arm 51 secured to the lower end of the pin 56 as by means of the nut 58. The opposite end of the arm is connected in any suitable manner to a crank arm 60 keyed for conjoint rotation with the shaft 62 which extends vertically upwardly through the truck at one side of the power unit,

and just forwardly of the dash-board 14. At its 'upper end the shaft 62 is connected through suitable reduction gearing to the shaft 63 of the steering wheel l6 whereby rotation of the wheel l6 causes predetermined rotation of the shaft 62 for rotating the crank 60. This in turn moves the arm 55 longitudinally to rotate the crank 51, thereby rotating the pin 50. Rotation of the pin 50 results in corresponding rotation of the crank plate 41, which produces longitudinal swinging, movement of the members 44, and consequently of the associated members 42, for rotating the arms 39 about the pins 33 as a center. This in turn produces rotation of the wheel spindles 39 in the same direction about the pins 33 to produce the desired turning movement. It will be noted that by reason of the overlapping arrangement of the portions 44 of the steering arms and the relationship of the balls 46 and 48 with respect to the axis of rotation of the plat 41, a

differential steering movement is provided, which results in conjoint turning movement of the wheels 11 as shown diagrammatically in Figure 4. This differential movement causes the inside wheel to turn through a greater are than the outside wheel of the truck, and consequently produces a sharper turning angle than could be provided by the conventional steering mechanism in which the two steering spindles are cross connected in the customary manner.

This steering action is under the directcontrol of the operator standing upon the platform 21 so that he may guide the vehicle along aisles and around corners with the greatest facility. This also allows the vehicle to discharge its load at right angles to the aisle by reason of the. fact that the rear end of the truck is capable of swinging movement about a. center that is disposed adjacent to one of the front wheels of the truck.

This action can be better considered in connection with Figure 4 in which an intersecting aisle is indicated at 10. The truck in turning about the aisle swings about a center located at the point X. which is adjacent to and in line with the axis of the front driving wheels 12 of the truck. From this view it will be apparent that the truck can turn about an intersecting aisle which is of smaller width than the overall length of the truck by a considerable amount. forward portion of the truck including the load carrying means 24 can be turned at right angles to an aisle or passageway by the steering movement produced by the wheels l1, whereby the truck pivots about a point adjacent one of its front wheels and consequently any load carried upon the means 24 can be discharged at substantially right angles to the aisle or passageway.

The axle 30 is supported from the frame of the vehicle by means of the transverse leaf springs 14 which are connected at their ends through suitable shackles to the frame of the truck and intermediate the ends are clamped to the axle member 30 by spring clamping plates 15 secured over the top of suitable recesses 16 in which the springs seat by means of bolts 11. Thus, the springs are rigidly secured to the axle 30 to support the same, and are pivotally connected at their ends to the truck frame whereby the weight of the truck is resiliently supported upon the axle member 30 and the wheels to provide for the desired riding characteristics for the operator standing on the platform 21.

Considering now the structure for guiding and supporting the load carrying mechanism 24, reference is made to Figures 8, 9 and 12. The forward portion of the frame ID of the truck comprises twoforwardly extending arm members which are banded together at their forward ends by means of the cross portion 82. Suitable laterally extending flange portions 83 on the frame members 30 serve to support an axle housing assembly indicated generally at 84.

Th s assembly consists of a differential case 85 in which is housed the differential gear mechanism connected to the power unit I3 of the truck through a change speed transmission of the type disclosed in my aforesaid copending application, and a forwardly extending power transmitting shaft which enters the drive axle assembly through the housing 96.

Bolted to opposite sides of the differential housing 85 are a pair of axle housing arms 81 which, at their outer ends are provided with circumferential flange portions 88 bolted to plates 89 carried by the wheel assembly shown in Figure '9. The arms 81 are provided with mounting portions 90 which have flanges aligned with the flanges 83 and bolted thereto by means of the bolts 92. Forwardly of the arms 31 the mounting portions 90 for receiving the stub shaft sections 93 which are rigidly secured therein and which extend through the plate 89 into the wheel assembly. The stub shafts 93 serve as hearing supports for the hub portions of the wheel discs 94 so that the wheels 12 are rotatably mounted upon the shafts 93. The discs 94 on their inner faces carry suitable intemal ring gears 95 which are driven from pinions 96 carried by shaft sections 91 extending through the arms 91 and into the side gears of the diflerentlal mechanism within the housin 35. Suitable sealing means 98 is provided on a closure plate 99 secured to the mounting plates Also, the

disc 94 and the plate 99 for lubricating the gears 95 and '96. .It will thus be apparent that the wheels 12 are driven through an internal gear reduction from the axle shafts, which in turn are driven from the power unit through the differential mechanism in the housing 35.

The mechanism for supporting the load consists generally of a pair of upright members I which are preferably of channel shape and are so mounted as to face each other on opposite sides of the forward portion of the frame. At their upper ends, the channel members I00 are tied together by a cross member I02 which has means for receiving the upper ends of the members I00 and is rigidly secured thereto as by means of the rivets I03. At their lower ends the members I00 are provided with rearwardly offset bracket portions I04 as shown more in detail in Figure 8, the lower portion of the bracket member I04 having a semi-cylindrical recess I05 therein which fits about a bronze bearing sleeve I06 secured on an enlarged portion I01 of the spindle shaft 93. In order to secure the uprights on the shaft portion I01 9. suitable bearing cap I03 is provided, which fits about the other half of the sleeve I06 and is rigidly secured to the portion I04 of the members I00 by means of thebap bolts II 0. Above the portion I04 at the rear of the upright members I00 there is provided a flange II2 which extends rearwardly from the members I00 above the frame members 30, and which is adapted to receive suitable bolts for securing thereto a cross head member III shown in more detail in Figures 9 and 12. A series of bolts II4 extend through the flanges H2 and through lateral flange portions of the cross member II3 whereby the cross member is rigidly secure'dto the uprights I00, but is out of engagew ment with the frame 80 and any portion of the axle assembly 84. The cross member I I3 has a forwardly extending portion II5 which projects into the space between the lower ends of the uprights and is provided with a suitable cylindrical recess or flange portion 6 adapted to receive the lower end of a hydraulic cylinder I I1 which forms the actuating means for the loadsupporting mechanism.

The members I00 as stated heretofore are channel-shaped in cross section, thereby form-- ing a pair of opposite facing guide surfaces III which arespaced apart a distance such as to receive the rollers I I0 of the load supporting carriage. This carriage consists of frame members I having upper and lower Journal supports I22 and I23 which carry suitable pins or stub shaft sections I24 upon which the rollers I I9 are rotatably mounted. The journal sections I22 and I23 are preferably formed as split clamped sec tions forced together as by means of the bolts I25. At its forward end the frame portions are tied together by means of a cross plate I26 which is secured to coplanar flange faces I21 carried upon each of the frame portions. The flange sections I 21 terminate at their outer lateral edges in outwardly extending portions I28, thereby serving to hold the plate in fixed position therebetween, and to secure the frame portions I20 in properly spaced position. Suitable countersunk bolts I30 serve to secure the plate I26 to the forward flanged portions of the frame portions.

Extending transversely between the flanges I23 indicated at I50.

of the frame portions is across shaft member I32 which, as more clearly shown in Figure 3, is provided with a central bearing supporting bracket I33 riveted or otherwise suitably secured to the face of the plate I26. The shaft I32 serves as a guiding means for the L-shaped finger members I34 which have their vertical portions extending upwardly on the plate I26; and are provided with suitable elongated openings I35 for providing limited relative movement between the fingers and the cross shaft I32. Disposedbelow the shaft I32 and rigidly secured to the face plate I 26 is a transverse bar I36 of rectangular cross section, which serves as a load supporting means for transferring the load from the finger members I34 to the plate I26, and hence to the frame portions I20. The rear faces of the vertical portions of the fingers I34 are provided with elongated rectangular cutouts I3l whereby the fingers may have slight relative movement with respect thereto. When a load is disposed upon the forwardly extending portions I38 of the fingers I34, the fingers move downwardly until the upper edges of the cutouts I31 engage the top surface of the bar I36. This transfers the load to the plate I26 and because of the relatively long bearing engagement below the bar I36 of the fingers I34 against the face of the plate I26, no tendency toward cocking movement of the upper end of a plurality of spaced' openings I42, and the upper edges of the fingers I34 are provided with corresponding recesses I43. By the provision of this structure, the fingers I34 can be adjusted transver'sely along the shaft I32 and held in adjusted positionby means of pins I44 which extend down through the flange I 40 and engage in the recesses I43 to align the fingers beneath the respective openings I42. The pins are connected to the plate I26 by means of chains I45 secured at one end to the pins 444 and at the opposite end to suitable securing means I46 mounted on the plate I26. By this lateral adjustment of the fingers I44 it is possible to space the fingers so tdlzat they will fit under skids of varying dimen- By reason of the vertical spacing of the rollers I I! and their mounting within the guide surfaces III of the members I00, no cocking, or binding of the load supporting means is possible within the members I00, and smooth vertical movement of the load-supporting carriage formed by the frame portions I20 and the plate I 26 is assured.

In full 'lowered position, the load-supporting carriage is in a position relative to the members I00 as showndn Figures 1 and.8. In such position, the forward portions I38 of the finger members I34 restupon the ground surface or floor This positions the fingers so that they may be readily inserted under skids, crates, or other containing means whereby forward movement of the truck will move the forward portions I38 of the-fingers into position to support the load thereon.

The frame portions I20 are each provided with a re-enforced portion I52 shown in Figure 9, which portions are apertured as at I53 to receive suitable means for securing the tension members I54 thereto. These members may be secured to the portions I52 of the frame by means of the tie bolts I55 and the nuts I 56, as clearly shown in Figure 8.

The tension members preferably comprise chains of the sprocket type which have their intermediate portions trained over sprocket wheels I58, as clearly shown in Figure 3. The opposite ends of the chains I54 are-secured to a cross member I60 which is bolted, riveted or otherwise rigidly secured to the rear face of the members I intermediate their ends, as indicated in Figures 1 and 2. The member I60 is provided with re-enforced portions I62 and the ends of the chain are provided with suitable tie bolts extending throughthe portions I62 and secured thereto by means of suitable nuts. Thus, upon vertical movement of the sprocket wheels I58 the chains I54 are tensioned to lift the frames I20, and consequently the plate and finger assembly or load-supporting means 24, to raise the load along the uprights I00.

Considering now in detail the upright construction in relation to the load-actuating means, the cylinder H1 at its lower end is provided with the inlet connection I10 which is connected to a suitable boss I12 formed at the bottom of the cross member I I3. This inlet connection supplies fluid under pressure to the lower end of the cylinder through the port I13, as will be described in detail hereinafter. Disposed within the cylinder H1 is a piston member I14 which is adapted to have reciprocating movement therein, and which is provided with a connecting rod I15 extending centrally upwardly through the cylinder H1, and having at its upper end a suitable cross head I16 which is provided with oppositely extending shaft portions I11 upon which the sprocket wheels I58 are mounted. Bolted to the upper surface of the cross head I16 is a plate member I80 having laterally extending wing portions I82 which extend into the channel formed in the uprights I00, and move upwardly therein upon upward movement of the piston to a position such as shown in dotted lines in Figure 12. This limits the upward'movement of the piston by engagement of the wings I82 with the under surface of the cross member- I02 at the upper end of the uprights I00.

The upper end of the cylinder H1 is held in flxed position between the uprights I00 by means of a clamping yoke I83 extending about the cylinder and secured to the cross member I60 whereby the cylinder is rigidly positioned between the uprights and rotates conjointly therewith about the spindle shaft sections I01. The cylinder is closed at its upper end by a cap plate I84 bolted, welded, or otherwise secured thereto, which plate also forms a guide for the upper end of the piston rod I15.

It will thus be apparent that by the admission of fluid under pressure through the port "3 to the lower end of the cylinder, the piston I14 will be raised, which in turn will raise the cross head I16 and cause the shortening of the tension chains I54 between the frames I20 and the sprocket wheels I58 resulting in raising of the load-supporting .flngers I34 at a rate substantially twice the rate of movement of the piston.

Adjacent its upper end the cylinder H1 is provided with an outlet port I86 which is connected through the coupling I81 to the upper end of a reservoir I88 secured by means of a suitable bracket I89 and yoke I90 to the rear of the cylinder I I1 The reservoir I88 has an outlet connection I92 which leads thru the flexible conduit I93 to the exhaust side of the oil pump I94 secured to and supported at one side of the motor or power unit within the hood I3. A suitable T connection I95 is provided intermediate the ends of the exhaust line I93. and is connected to the outlet side ofa control valve assembly I96 through the elbow I91. The high pressure outlet I98 of the pump assembly I94 is connected through the flexible conduit I99 to the inlet port 200 of the control valve I96. From the control valve I96 an outlet connection 202 is provided for conducting fluid under high pressure through the line 203 to the inlet connection I leading to the inlet I12 at the lower end of the cylinder I I1.

The valve I96 is controlled by means of the control lever 22 mounted on the dash-board of the vehicle and having the forwardly extending motion transmitting rod 224 which is connected to a suitable rock shaft 204 supported on the side of the frame I0 of the truck by means of the bracket 222. A suitable crank arm 206 also secured to the rock shaft 204 has a motion transmitting rod 201 which extends forwardly to the crank arm 208 mounted on ashaft 209 secured to the front axle assembly 84.

The crank 208 is in the form of a bell crank having the forwardly extending arm 2 I 0 which is provided with a slotted portion in which is carried a pin 2I2 extending transversely across the lower end of a rod 2I3. The rod 2l3 is guided for vertical movement at its lower end in a suitable opening M4 in the cross member I I3, and extends upwardly through the member I60 to an adjusting coupling 2 I 5 disposed above the member I60 adjacent the rear portion of one of the uprights I00. A second rod 2I6 is rigidly connected to the coupling 2 I 5, and at its upper end is guided for vertical movement in an offset portion 2I1 formed at the rear of the cross member I02 between the upper ends of the uprights. The rod 2 I6 is threaded for aconsiderablc distance adjacent its ends and carries thereon adjustable nuts 2 I8 and 2I9 which may be moved longitudinally with respect to the rod 2 I 6 by threading the same upwardly or downwardly. The nuts 2 l8 and 2I9 form automatic stop means for limiting the movement, of the cross head I16.

The operation of this stop means is produced by means of a fork 220 carried on the rearface of one of the ,wings I82 of the member I80 secured to the upper portion of the cross head I16. '--When the cross head moves to its upper limiting position the fork 220 engages beneath the nut 2I8 on the rod 2I6 and raises the rod vertically with respect to the guides I60 and 2I1.

This results in counter clockwise rotation of arm 2I0 and shaft 209, which in turn moves the rod 201 rearwardly rotating the shaft 204 mounted on bracket 222. As a result, the arm 225 is rotated in a counter clockwise direction which forces the-control valve plunger 223 for the valve I96 into position to by-pass the fluid back into the inlet side of thefluid pump, and thereby maintain the fluid within the cylinder II1 from escaping. This rotation of arm 225 also-results in rearward movement of rod 224 which is connected at its opposite end to a bell crank 226 carried by the bracket 221 bolted to the dash board I4 adjacent the forward end of the operators platform. The opposite end of the bell crank 226 is connected through the motion transmitting rod' 228 to the pivot 229 of the lever 22.

This lever is mounted at its forward end on a pivot shaft 230 carried by a bracket 232 mounted on the inner face of the dash-board I4 in alignment with the braket 23 which provides the slot in which the lever 22 reciprocates. The rearward movement of the rod 224 results in downward movement of rod 228, moving the lever 22 in a clockwise direction about its pivot 230 into the neutral position shown in Figure ll.

When it is desired to lower the load-supporting mechanism, the .lever 22 is rotated in a counter-clockwise direction from its neutral position to its lowered position, which results in rearward movement of the rod 224 from the neutral position into a position to connect the end of the lift cylinder with the inlet side of the fluid pump. This allows the load supporting mechanism to move downwardly under the influence of gravity to a point where the fork220 engages the nut 2I9. This moves the shaft 2i 3 downwardly which rotates the arm 208 in a clockwise direction, moving the rod 201 forwardly and thereby producing clockwise rotation of shaft 204. As a result, the arm 225 moves the plunger 223 of the valve I96 back to neutral position, and prevents further escape of fluid from beneath the piston in the lift cylinder. At the same time, this arm produces a forward motion of rod 224 .which, through bell crank 226, raises the rod 228, and consequently raises the lever 22 to its neutral position about pivot 230.

It is thus apparent that if the operator should move the control lever 22 into either of its operative positions and then leave the truck unattended, the mechanism will not be subjected to any damage due to the foot that the automatic stops controlled by rods M3 and 2I6 will provide for shifting of the control lever back to neutral position when the load-supporting means moves I into either of its limiting positions. It is also possible in the present construction for the operator to raise, stop or lower the load-supporting means 24 during any part of its movement by means of .the control member 22 which is instantly available for this purpose.

It will be noted that the uprights I00, mounted n the manner shown in Figures 8 and 9, are freely rotatable with respect to the truck frame and axle assembly about the portions I01 of the shaft sections 03. In some cases it is desirable that these uprights be rotatable as, for example, in a tilting and tiering mechanism such as disclosed and described in my co-pending application, Serial No. 190,714, filed February 16, 1938,

i which is directed more particularly to a tilting truck of this type. For a straight lift truck or tiering truck, however, it is desirable that the uprights be maintained in fixed vertical position in order that the load may be carried properly when no tilting action is required. Since it is impractical for purposes of standardization of the chassis of this type of truck for various types of tiering mechanisms to provide forrigid connection of the lower ends of the uprights to the truck frame or axle, I preferably employ other means for maintaining the uprights in fixed position. It will .be apparent that with the construction provided, as shown clearly in Figure 8, all that is necessary for removal of the entire load-supporting and guiding mechanism is the removal of bearing caps I09 from the portions I04 of the uprights I00. When this has been accomplished, the entire assembly can be taken off from the front end of the truck without any other adjustments outside of the disconnection of they hydraulic parts by which fluid is supplied to and conducted from the hydraulic actuating mechanism carried by the uprights. This is of distinct advantage where a large variety of tiering and tilting mechanisms are required for various operating conditions and it is not desired to provide a special chassis for each mechanism. In other words. the standardization of the frame, chassis, power unit and control assembly for trucks of this general type results in the lowering of the cost of the unit due to the mass production of these standardized. parts and the specialized productionof only a small portion of the complete assembly.

In order to provide for positive support for the uprights I provide suitable bracing members 240 which extend rearwardly from the upper ends of the uprights I00 and are secured at their lower ends to the rear portion of the frame I0 of the unit. These members 240 may comprise cylindrical rods of adequate cross section which, at their lower ends, are pivotally connected to the frame on opposite sides of the power unit and extend through suitable slots 242 formed in the hood I3 of the vehicle upwardly toward the upper ends of the uprights I00; At their upper ends the members 240 are secured in suitable arms 233 which are rotatably mounted upon a transverse shaft 234. The shaft 234 is mounted in suitable brackets 235 extending rearwardly from the rear face "of the uprights I00 and secured thereto in any suitable manner, such as by welding, riveting, bolts or the like. The rods 240 may be adjustable in length or may be threaded into and out of the arms 233 in order to insure positive control of the position of the urights I 00. It will thus be apparent that the uprights aze supported both laterally and vertically in fixed position, the vertical support being formed by the mounting of the uprights about the shaft sections I01 and the lateral support of the uprights being obtained by the cross members I02 and I60 and arms 240. This insures that the load carried upon the load-supporting means 24 will never have any possibility of throwing the uprights either forwardly or rearwardly,

which might endanger the operator or produce possible damaging of the truck.

It is therefore apparent that I have provided a truck structure of the disclosed type in which a standardized chassis and frame may be employed, and which is so designed that any desired type of load-supporting means may be mounted at the forward "end thereof without I am aware that a number of the details of a construction illustrated in the present disclosure may be varied slightly without in any way departing from the underlying principles disclosed in the present invention, and I therefore do not intend to be limited except as defined by the scope and spirit of the. appended claims.

I claim:

1. In an industrial truck having a frame provided with an internal gear driving axle assembly at its forward end including drive wheels journalled on dead stub shafts, a pair of upright members rotatably mounted at their lower ends on said stub shafts inwardly of the wheels, a cross head between said members at their upper ends, and bracing means pivotally connected at one end to the rear of said frame and at the opposite end to said upright members intermediate their ends for controlling the vertical position of said members.

2. In an industrial truck having a frame provided with a driving axle assembly at its forward end including driving wheels and a power unit at its rear end, a pair of guide members, means rotatably supporting said members at their lower ends on said assembly coaxially of said wheels, said means including split bearing journals providing for forward removal of said guide members from said assembly, load actuating means supported between said members and rotatable therewith, a load supporting carriage movable vertically in said members and controlled by said actuating means, and brace means connected between the rear portion of said frame and the upper portion of said guide members.

3. In an industrial truck of the class described, a frame, a front driving axle under said frame including a pair of wheels supporting stub shafts, a pair of channel-shaped uprights secured to said shafts, bracing means betweenthe upper end of said uprights and the rear portion of said frame, a hydraulic cylinder supported at its lower end between said uprights, a load supporting carriage comprising vertically spaced rollers engaging in trackways in said uprights and including a vertical plate disposed in a plane forwardly of said uprights, L-shaped fingers adjustably secured to said plate and having the forwardly extending portions thereof engage'able with the floor in lowered position of said carriage, means allowing limited, vertical movement of said fingers relative to-said plate, and means reciprocatory in said cylinder and connected to said carriage for raising the same upon admission of fluid under pressure to said cylinder.

4. In an industrial truck of the class described having a frame, a front driving axle secured to the front end of said frame and having two dead axle spindles, driving wheels freely joumalled on said spindles, drive shafts extending from said axle into said wheels including internal gear means for driving the same, a pair if load supporting and guiding members rotatably secured at their lower ends about said spindles inwardly of said wheels in such manner as to be removed forwardly of the axle, and bracing means pivotally connected between the upper end of said members and the rear portion of said frame.

5. In an industrial truck of the class described, a frame, an axle housing supported at one end of said frame, stub shafts carried by said housing, drive means in said housing, wheels mounted on the stub shafts of said housing for supporting said frame and adapted to be driven from said drive means, a pair of channel-shaped uprights, and means for detachably securing said uprights to said stub shafts inwardly of and adjacent said wheels, said securing means being so arranged that said uprights are attached to and removed from the outer side of said housing.

I 6. In an industrial truck, a frame, a power unit supported on said frame, a drive axle mechanism at one end of said frame driven from said unit and including an axle housing having dead axle shafts and driving wheels mounted at the extremities of said shafts, a pair of channel-shaped uprights, means for clamping the rear faces of said uprights to said shafts-adjacent said wheels,

and means secured between said frame and said uprights for maintaining said uprights in prehousing assembly secured to the forward portion of said frame including a stub shaft having means for rotatably maintaining-driving wheels thereon,

" forwardly extending front portion and an upward ly arched rear portion, a front axle assembly including a differential housing having drive shafts extending outwardly thereof above said frame, a pair of stub shafts on said frame forwardlyof and parallel to said drive shafts, wheels rotatably mounted on the outer ends of said stub shafts and having enclosed gear means driven from said drive shafts, a pair of channel-shaped uprights disposed on opposite sides of 'the front end of said frame, and detachable means for rotatably securing the rear edges said uprights adjacent their lower ends to said stub shafts in such manner that said uprights may be removed forwardly of the axle assembly.

9. In an industrial truck, a frame having a low forwardly extending front portion and an upwardly arched rear portion, a front axle assembly including a differential housing having drive shafts extending outwardly thereof above said frame, a pair of stub shafts on said frame forwardly of and parallel to said drive shafts, wheels rotatably mounted on the outer ends of said stub shafts and having enclosed gear means driven from said drive shafts, a pair of channel-shaped uprights disposed on opposite sides of the front end of said frame, means for rotatably securing said uprights adjacent their lower ends to said stub shafts, and a load supporting means mounted for vertical movement in said uprights.

10. In an industrial truck, a frame having a low forwardly extending front portion and an upwardly arched rear portion, a front axle assembly including a differential housing having drive shafts extending outwardly thereof above said frame, a pair of stub shafts on said frame forwardly of and parallel to said drive shafts, wheels rotatably mounted on the outer ends of said stub shafts and having enclosed gear means driven from said drive shafts, a pair of channel-shaped uprights. disposed on opposite sides of the front end of said frame, means for rotatably securing said uprights adjacent their lower ends to said stub shafts, and hydraulic liftmeans supported between said uprights above the front end of said frame. 11. In an industrial truck, a frame having a low forwardly extending front portion and'an said stub shafts and having enclosed gear means 4 driven'from said drive shafts, a pair of channelshaped uprights disposed on opposite sides of the front end of said frame, means for rotatably securing said uprights adjacent their lower ends to said stub shafts, and means connected between the upper end of said uprights and said arched portion of said frame for holding said uprights in predetermined position on said stub shafts.

12. In an industrial truck having a frame, an internal gear drive axle assembly at one end thereof, a pair of uprights having their lower ends rotatably mounted on said assembly, a load supporting carriage guided for vertical movement in said uprights and including a vertical plate disposed in a plane forwardly of the upadjustable laterally thereof, and means in the fingers receiving said bar and adapted to abut thereagainst to transmit the load from said fingers to said carriage.

ELMER. J. DUNHAM.