US2944689A - Lift truck with auxiliary truck pickup - Google Patents

Description

y v1960 A. E. R. ARINOT 2 ,944,689

. LIFT TRUCK WITH AUXILIARY TRUCK PICKUP Filed May 16, 1957 3 Sheets-Sheet 1 INVENTOR AT ORNEY July 12, 1960 A. E. R. ARNoT LIFT TRUCK WITH AUXILIARY TRUCK PICKUP s Sheets-Shet 2 Filed May 16, 1957 lNVENToR W 'JRM 7 f we ATTORNEY LIFT TRUCK WITH AUXILIARY TRUCK PICKUP Filed May 16, 1957 3 Sheets-Sheet 3 v \NVENTOR W Z M ATTORNEY United States Patent I LIFT WITH AUXILIARY TRUCK PICKUP Alfred E in Reginald Arnot, Basings'toke, England, as-

1 signers-to Emmanuel Kaye and John Reginald Sharp,

both of Basingstoke, Hampshire, England This invention comprises improvements in or relating to goods-carrying trucks. 1

In U.S.'patent"applicati0n No. 553,354, now Patent No. 2,796,186, there is described a'construction of lift truck comprisinga'mast and a vertically movable carriage thereon which is adapted to receive andsto hold the back of an auxiliary truck having forks. The auxiliary truck can be detached from the carriage of the lift truck when desireld, with its load uponait, and moved about independent y.

In .the aforesaid patentapplication,the carriage on the mast of thelifttruck had aspecially shaped front plate to cent-reand engage; a hooked. fixing on the auxiliary truck. Fork truckshowever are standard equipment, of whichthere is normally a. number in. a works, and the necessity for sucha specially shaped front plate prevents the use of the combination of fork lift truck and removable auxiliary truck exceptin caseswhere the standard fork lift truck has been specially modified. It is an object of thisinvention to provide a constructionwhich can beused with any standard truck.-

According to the present invention an attachment is provided which is capable of fitting the lifting carriage of a normal fork lift truck and constitutesv an intermediate member having projections to enter apertures in the auxiliary truck, and the 'auxilia-rytruck is modified'to'receive said projections instead of hooking over thefront plate of the lift truck carriage as heretofore.

' It will be appreciated that the auxiliary 'tru'ckihas' to be centralised with the lift truck when engaged and that this cannot be done exactly by manoeuvring the two' trucks over the ground; hence the use of the'spec'ially shaped cen: tering front plate on the prior truck". With the intermediate attachment used according to. this invention the hooked fixing on the auxiliary truck, whichwas'designed to-co-operate withthe specially shaped front plate'as-centering means, as well as lifting means; can no -longer con- Patented July 12,, .1960

plied when the steering handleof. the auxiliary truck. .is moved to a selected position in readiness for engagement. The following is adescription by way of exampleof one. construction in accordance'with the'invention,;refer- 'ence being made to the accompanying drawings in-which:

Figure 1 is a side elevation of part of a masted lift truck and of an auxiliary truck in accordancewith the present invention, shown in the positioninto-E which they are brought prior to engagement;

- Figure 2 is a rear view of the auxiliary truck; Figure 3 is aplanof'the same andof the intermediate attachment member;

Figure 4 is a front elevation of the attachment member;

Figure 5 is a side elevation of the same;

Figure 6 shows part of the internal mechanism of the auxiliary truck including the automatic-brake;

Figure 7 is a section taken in plane at right angles to Figure 6, of part of they automatiebrake mechanism;

Figure.8 is a plan of part of the auxiliary truck. to a larger scale than'that shown in Figure 3.; and

Figure 9 is asvertical section throughoneof .the fork arms to show its internal mechanism. I

Referring to Figure 1, thelift truck 11 is: a standard type of truck, comprising achassis 12 having front wheels 13, a fixed'mast 14,.a rising mast 15 and a carriage on the rising mast having a flat vertical front plate lfiiwhich, is of standard form, and when not required .for use according to the present invention carries the usual detachable fork members. According to the present, invention there .isan intermediate. attachment member 17 provided-for the vertical plate 16 of the lifting carriage,swhich is shown in greater detail in Figures 3, 4 and 5. The attachment consists 'oftwo lateral plate members 18, 19 at the side which are united together by a lighter plate member 20 in the centre. The front face of the, member 20 lies in the same plane as the front faces of the side membersls, 19 and is welded thereto; The light central plate 20 is narrower in widthat the top than the bottom and the side members18, 19' are therefore inclined inwardstoward the top. At their rear upper edges; they carry hook members 21,22 which'are notched at their undersides so as 'to hook over the top edge ofthe vertical plate 16 of the lifting carriage. On the front face ofthe side members 18, '19there are socured twoforwardly and upwardly, projecting inclined bracket members 23, 24'which form hooks to engage apertures in the-back of an auxiliary truck'25. The spacing of the two pick-up hook brackets 23, 24-is made'to suit veniently be employed and other-centering means is needed".

the back ofthe auidliary: truckhaving centering faces at their upper ends and the' projections on theintermediate 7 attachment member enter the apertures in-the back of the auxiliary truck and when teri'ng faces andce'ntre the auxiliary truck relative to the lifttruclg. i

Either of both trucks maybe motor propelled if desired, but normally the masted lift truck 7 pelled'and the auxiliary would be alian'd-truck. It is found moreover that with the known auxiliar ytrucks, whenthem'as tedlift truck approaches the auxiliary truck witha view to 'engagin'g 'ihthe auxiliary truck tends to move awayof its own accord inter engagem'entcorrectly; t According to thepres'ent' invention, the auxiliary truck in addition to int'er engaging 5 means is fitted. with a brake which is capablefofz-ho'lding and:;is:preferab1yrarranged so as to'bezautomatically ap.-

lifted they engage the cenwould bemotor proaudit is difficult to effect it 'duringthe: engaging period the size of the" auxiliary truck 25 which is in use; The lower'ends-of'thesidemembers 18, 19-of the intermediate attachment are wider apart than the upper portions thereof- 'and'they carry rearwardly projecting 'lugs- 26 which, when the attachment is in place on-the carriage plate 16, are capable 'of' fitting just outside the side edges of the plate 16.- These lug s are notched or drilled to permit pegs 27 to be passed through them, one fromeach 'side behind the plate 16 of the lifting truck and to thereby hold the attachment securely in place.

The auxiliary truck'25 is in general similarato. the corresponding truck described in. the aforesaid US. patent applicationNo. 553,354, but the rear upstanding. portion 25 of. the truck, which contains a steerablemounting 30 for a ground wheel 31, .is made. with a pair of apertures 32, 33 (Figure 2) which are large-enough tozreceive readilythe upwardly and forwardlyprojecting hooks or brackets 23, 24 on the intermediate attachment plate 18, 19, 20 already described. The apertures 32-, 33 in the back of the auxiliary truck are made quite largeand each hasinclined-shoulders or faces 34, 35 at its upper end which. areinclined inwardly and upwardly as shown. Theresult is that it isquite easy-to manoeuvre the lift truck 11 intoa position where the pick-up hook brackets 23,;24 can enterthe apertures 32, 33, and'whenithe lift.

' 41 between the side arms of carriage 16 on the mast 15 is raised the inclined upper faces 34, 35 centralise the auxiliary truck 25 relatively to the lift truck. To assist in this centralising action the upper edges of the p ick-up hook members 23, 24 are themselves chamfered as shown at 36. The chamfers 36 extend in a sloping upwardly direction asiviewed in side elevation, as can be seen from Figures 1 and 5, and also assists in making the back of the auxiliary truck 25 slide down the members 23, 24 uritil the back of the auxiliary truck is firmly seated against the front face of the intermediate member 17, V The auxiliary truck 25 not only comprises the hollow back portion in which is the mounting for the steering wheel 31, but also forwardly projecting parallel fork members 37, 38, the front ends of which are supported on rollers 39 so that the truck can be wheeled about on the ground. A bail handle 40 is provided for pushing where heavy force has to be exerted, but there is also a steering tiller arm 41 having a handle 42 at its upper end for guiding and pushing the truck about under normal conditions. a V V Figure 6 shows the internal mechanism connected with tiller arm 41, which is located inside the upright rear portion of the truck 25, the mechanism being shown removed from the truck in Figure 6. It comprises a fixed cross-member 45 which is secured to the interior of the hollow upright portion of the truck 25 and which is provided with two hydraulic cylinders 46, 47, having rams 48, 49 connected to a cross-head 58. The hydraulic cylinders 46, 47 are single acting and they act to push downwardly on the cross-head 50 and so raise the truck. Springs 51 bring about the return movement. On the cross-head 50 are downwardly depending cam members 52, 53 which operate mechanism in the forks 37, 38 for raising the forks relatively to the rollers 39 as shown in Figure 9. The return movement for retracting the rollers 39 into the fork arms is assisted by springs 78 (Figure 9) located within the fork arms in addition to the action of the springs 51 in raising the cross-head 58. Also mounted on the cross-head in the centre is a ring 54 containing a ball-race 55 which supports a fork 56 in which is carried an axle 57 for the steering ground wheel 31. Extension of the jacks 46, 47 therefore raises the cross-member 45 relatively to the ground wheel 31 and at the same time causes the cams 52, 53 to raise the front ends of the forks relative to the rollers 39. The fork 56 which carries the ground wheel 31 is keyed to a steering column 58 and the upper end of the steering column is guided in a bush 59 in a bracket 60 on the transverse member 45. Therefore when the body of the truck is raised by the jacks 46, 47, the bush 59 slides up on the steering column 58. The upper end of the steering column forms the fork member 30 already referred to, in which is a pin 61 on which the tiller arm 41 is pivoted by means of a hub 62 mounted on the pin the fork member 38. The hub 62 has in its centre a cam 63 which bears on a ball 64 carried on a tube 65 slidably within the steering column 58. The tube 65 rests on the spring 66 which in turn rests on a collar 67 secured to the inside of the seteering column. Therefore the ball is urged upwardly against the underside of the cam 63. The tube 65 which supports the ball 64 is fixed to a brake rod 68 which extends down through the steering column to just above the wheel 31 through a bush 69 and carries at its lower end a brake-shoe 70. The cam 63 is so shaped that if the tiller arm 41 is moved upwardly past the vertical position into the position indicated by the chain-line 71 in Figure 7, the brake-shoe 70 will be firmly pressed down on the ground wheel 31. It will be noted that the cam edge has an indent to hold the tiller arm in the chainline position. If the tiller arm is brought forward to the position of the lower chain-line 72, the brake is released and the truck can be pushed and steered by the handle'42. 'When the auxiliary truck is to be mounted t side of the roller 39 and are slotted on the mast truck 11, it is wheeled into a position such as is shown in Figure l, where its rear face is opposite to the upwardly inclined members 23, 24 on the intermediate attachment member 17, and the tiller arm is thrown upwardly to the chain line position 71 which puts the brake on the ground wheel 31. The mast lift truck is then moved forward to engage the members 23, 24- with the auxiliary truck and the carriage 16 israised. This automatically seats the upright back portion ofthe auxiliary truck against the intermediate attachment member 17 and at the same time centres the auxiliary truck relative to the lift truck by the action of the inclined faces 34, 35 of the apertures 32, 33 upon the inclined faces of the members 23, 24. Further lifting movement of the carriage -16 raises the auxiliary truck oh? the ground to any height desired, the two trucks can be moved as one. The auxiliary truck can be deposited upon an elevated floor or platform or upon the ground, as desired, and disengaged and 'used for moving any goods which'it carries to their ultimate position.

The plan view Figure 8 of the upright portioncf the truck 25 shows how the handle 40 and the steering tiller arm 42 are disposed so as not to interfere with the operation of a pump handle 75. The pump handle 75 operates a pump 76 (shown in. dotted lines) whichdraws hydraulic fluid through a reservoir 77 and delivers it to the jacks 46, 47 when the auxiliary truck is to be raised from the-ground for running about.

A relief valve 8%) permits the jacks to be retracted by springs 51 when desired. The relief valve 80 can also be opened after the auxiliary truck has been engaged and lifted by the masted truck. The action of springs 51 and the springs in the fork arms then retracts the ground wheel 31 and the rollers 39 and this permits the fork arms 37, 38 to be used like the fork arms of an ordinary masted lift truck whenever desired.

Figure 9 shows the internal mechanism for the fork arms 37, 38. The roller 39 of each fork arm is mounted on a lever 81 which is pivoted at 82 on a spindle which spans the space between the sides of the fork arm from side to side. The lever 81 is a double'lever, having a single pivot and two arms which extend one at each to engage the spindle 83 of the roller, which is held in the slots by screws passing through it.

The cam 53 has a vertical rear face 84 which is backed up by a bobbin-shaped roller 85 pivoted in the upright portion of the truck. The front face of the cam 53 engages a second bobbin-shaped roller 86 secured between the two sides of a double push rod 87 which extends forwardly within the box-shaped portion of the fork arm and is pivoted at its front end to the lever 81 by means of a pivot 88. This arrangement makes the lever 81 in efiect into a bell crank lever. A pair of springs 78 draw the push rod 87 rearwardly when the cam 53 is raised relatively to the rollers 85, 86. In order to guide the rear end of the push rod 87 it is provided with side rollers 89 which run along the lower inner surface of the box-shaped fork arm. It will be appreciated that the fork arm is welded to the vertical part of the truck 25. The parts are shown in Figure 9 in the position in which a truck body is lifted relatively to the ground wheel 31 and the roller 39, but when the cam 53 is raised, if the truck is resting on the ground the fork arm 38, or 37, as the casev may be, and the rear portion of the truck will descend to ground level. If the truck is mounted on the lifting carriage of a lift truck and the cam 53 is lifted by releasing the relief valve 80, the wheel 31 and the'rollers 39 will'rise into the body of the truck and into the fork arm respeetivelyunder the action of the springs. Auxiliary rollers 90, 91, 92, 93 and 94 are provided to guide the ends of the forks over the lower cross members or bottom deck of a pallet.

An alternative means of ensuring that the brake is on when the tillerhandle is moved to'the upright posh tion involves the employment of a Bowden cable for actuating the braking control. One end of the cable, between the caster wheel forks, is connected to a brake pad which is hinged to the forks and is urged into braking position by a strong spring. The cable, however, if tension is applied to it, is capable of pulling the brake pad off the wheel. The cable and itscasing is led up the steering column and along the tiller handle to a brake release lever which extends alongside the hand-grip on the handle. If the hand-grip is grasped by the operator he will grasp the brake release handle at the same time and pull the brake off. When he lets go the brake is automatically put on by the spring, and the truck is ready to be engaged by the attachment on the lifting truck.

I claim:

1. In combination, a lift-truck comprising a wheeled body, a mast thereon, a lifting carriage on the mast adapted to support normally removable fork members, an intermediate carrier member adapted to fit said carriage in place of the normally removable fork members and having hook-like projections extending forwardly and upwardly from a position near the top of the carriage when the carrier member is in place therein, and an auxiliary fork truck having a wheeled body with an upstanding back portion and forwardly extending fork arms for engaging pallets, crates and the like, said back portion having apertures therein substantially wider than the said hook-like projections and adapted to fit on said hooklike projections, said apertures having inclined centering faces at their upper ends to engage the projections and center the auxiliary truck relatively to the fork lift truck.

2. Apparatus as claimed in claim 1 wherein the auxiliary truck, in addition to the inter-engaging means provided on it is fitted with a brake for the purpose deg d M 3. Apparatus as claimed in claim 1 wherein the auxiliary truck has means for moving the body thereof up and down relating to its wheels and means are provided to enable said wheels to be retracted when the auxiliary truck is attached to the carriage of the lift truck.

4. Apparatus as claimed in claim 2 wherein thesteering handle of the auxiliary truck is operatively connected to the brake so as to be automatically applied when the steering handle is moved to a selected position.

5. Apparatus as claimed in claim 3 wherein the means for moving the body of the auxiliary truck up and down comprise a hydraulic jack device in the back portion of the body, a wheel mounting movable relatively to the back portion under the force exerted by said jack device, operative connections for said wheel mounting to rollers carried in the fork arms to move them when the wheel mounting is so moved, and a hydraulic pump device to operate the jack device.

6. Apparatus as claimed in claim 5 wherein the hydraulic jack is single acting and acts to extend the wheel mounting, retraction is effected by spring return means and the pump is provided with a relief valve to allow said spring return to act.

References Cited in the file of this patent UNITED STATES PATENTS 2,829,896 Swenson Apr. 8, 1958

Images