US1813595A - Industrial truck - Google Patents

Description

July 7, 1931. l E. J. ABBE INDUSTRIAL TRUCK Filed Sept. 19, 1927 3 Sheets-Sheet l gne wkn awn/M4 am wmwwwzw y 1931. E. J. ABBE I 1,813,595

INDUSTRIAL TRUCK Filed Sept. 19, 1927 s Sheets-Sheet 2 alikoznew July 7, 1931. i E. J. ABBE 1,813,595

INDUSTRIAL TRUCK Filed Sept. 19, 1927 3 Sheets-Sheet s $460M M I 1 @a/Zw, MMAMM'JS. 41W

Patented July 7, 1931 UNITED STATES EQE - EDWARD J. ABBE, OF CLEVELAND, OI-ITO, ASSIGNOR TO THE ELWELL PARKER ELECTRIC COMPANY, or cnnvnnnnn, 01110, A conroianrron or cure INDUSTRIAL TRUCK Application filed September 19, 1927. Serial No. 220,486.

This invention relates particularly to an improvement in industrial trucks. The essential objectis to provide a practical and eflicient safety mechanism in connection with a load lifting carriage on a trackway, which mechanism will operate to check downward movement of thecarriage in the event of breakage or temporary disability of the lifting mechanism.

A more specific object is the provision of a simple and efficient friction brake safety device on the load lifting carriage of an industrial truck.

In the use of industrial trucks having a cablehoist and load carrier adapted to raise a load from the ground and place it upon a platform or shelving, it often happens that the operatorafter placing the load on such platform pays outthe cable to some extent before withdrawing the load carrier from contact with the platform. Also, in removing a load from such platform or shelving, he sometimes pays out the cable before the load carrier is clear of the shelf or platform. The net result in either case is to allow the carrier and sometimes the load to drop for a considerable distance before the slack in the cable is taken up. This sometimes snaps the cable and if there is no mechanism to stop the downward movement of the carrier, the load falls clear to the ground and considerable damage may re, sult, both to the load and to the truck mechanism. My invention contemplates in part the elimination of such possibilities.

Further objects and features of the in vention will become apparent from the fol.- lowing description relating to the accompany drawings wherein I have shown my preferred form. The essential characteristics are summarized in the claims.

In the drawings, Fig. 1 is a side elevation of an industrial truck showing a vertical trackway and a load lifting carriage mounted thereon for up and down movement; Fig. 2'is a sectional rear elevation through portions of the load lifting carriage and showing the safety device in active position, the section being indicated by the line 22 on Fig. 1; Fig. 3 is a view similar to Fig. 2 but showing the safety mechanism in inactive POSltlOD; Fig. 4 is a longitudmal central cross sectional view through the safety mech- I anism and showing part of thetrackway, as indicated by theline 4-l on Fig. 2; Fig. 5' 1s a cross sectlonalview taken along the line 5-5 on Fig. 3;and Fig. 6 is a transverse sectional view as indicated by the line 6-6 on Fig. 2. p

The embodimentshown comprises a pair of pivoted brake shoes adapted to bear against flanges, or the like, on a trackway, for supporting a load liftingfcarriagathe shoes being pivoted to the carriage. Each of the shoes has a connection to the lifting mechanism properthrough the block of a pulley, the: connection comprising arms on the shoes and links connecting the arms to the block. A single hoisting cable is shown, which is anchored at one end nearthe top of the trackway, then passes under the pulley, thence over a sheave near the top of the 'traclrway, and finally to thedrum of a hoisting unit. The hoistingunit may be, of any suitable form, and may be mounted in any convenlent position on the truck.

Referring in detail to the drawing, and

first to Fig. 1, an industrial truck body is indicated at 1, provided ,with a sub-frame 2 for supporting the body, pairs of driving wheels 8, and steering wheels 4:, one wheel of each pair being shown. Mechanism for driving the truck may be mounted adjacent the driving wheels 3 and may be suitably carried on the frame after the manner shown in the prior patent to Clyde E. Cochran No. 1,399,543 issued December 6th, 1921. The body 1 includes a casing for electric storage batteries to furnish power for the truck drive, etc, and at the rear side of the body are mounted control members consisting as shown of a steering arm 5, electric controller arm 6 and sectional platform members, one section of which is shown at 7 The driver stands on the platform 7 i and shifts his weight from one section of the platform to the other in operating the truck driving mechanism. Standing in this position he is able to manipulate other control members such as 5 and 6. Suitably secured to the front end of the sub-frame 2 is a trackway or frame 10 comprising side members 11 and 12 preferably channels, joined together by a cross member 13 at the top. Other suitable cross members are, of course, provided at the bottom. The trackway is supported in upright position by struts 15 (one being shown), extending over the top of the body l nd, r p ctiv y jo ning he m mb ll and 12 as by gusset plates 16. It is to be understood that the details of the truck on which my safety device is to be used may be varied within wide limits, since the truck construction so far described was well known prior to the present invention.

The load lifting carriage is mounted to run up and down on the frame members 11 and 12 which latter members serve as guides.

, The carriage comprises a main frame 20 provided with upper and lower sets of rollers 21 and 22, the set 21 bearing against the rear faces of flanges 23 ofthe upright frame members, and the latter rollers, namely 22, hearing against rails 24 mounted on the members 11 and 12.

The main frame has a lower bearing bracket 31 for supporting the shaft 32 on which the rollers 22 are mounted, and spaced apart bearing brackets 33 for carrying a fillitft 34 on which the rollers 21 are mounted.

For. engaging the load, L-shaped carriers 25 are pivoted as at 26 to brackets 27 secured to the member 20. The legs of the'carriers 25 rest against an apron 29 on the carriage and the load engaging arms 28 of the carriers extend forwardly of the truck in posi-' tion to engage beneath a load to lift it when the carriage is drawn upwardly along the trackway. Usually such loads are placed on stringers, and the arms are adapted to pass the stringers when carried under the load by manipulation of the truck.

The carriage may be raised and lowered by a cable from a hoisting unit 40 which may be of any suitable form. Preferably this unit consists of an electric motor, the position of which is indicated herein at 41, suitable gearing (not shown), and a hoisting drum, the, position of which is indicated at 42. Secured to the hoisting drum is a cable 48 which extends over a sheave 44 carried by a bracket 45 depending from the cross member 13 of the frame 10. The cable then extends downwardly to a pulley 46, connected to the carriage as will be presently shown, and then upward-1y to an anchor 47 on the cross member 13-.

The primary elements of the safety mechanism will now be described; The main frame member 20 of the carriage supports a cross plate 50, and between this cross plate and the member 20. are pivotally mounted two brake shoe members 51 and 52, the pivots comprisin bolts 54 extending through the cross-plate and into the member 20. The

arms in a straight line.

shoes comprise arcuate portions 56, the outer surfaces 57 of which gradually recede from the pivots 54 to provide an increasing ripping eflect once the surfaces 57 contact with the trackway. The opposite sides of the shoes have socketed portions 58 which loosely receive the ends of a guide bar 59 for a compression spring 60. The ends of the spring rests directly on the members 58 to normally press the $11 .65 Qutwardly into engagement with the webs of respective channels 11 and 12. The block of the pulley 46 comprises a pair of triangularly-shaped plates 61 62. The plates are connected by the axle 63 of the pulley 46 and by bolts 65. The bolts 65 support the upper ends of links 66 as spacers for the plates, and the lower ends of the links are pivotally connected as by pins 67 to upwardly extending arms 68 rigid with the brake shoe members.

In operation, when the carriage is being hauled upwardly 0r gradually lowered by the cable 43, the supporting bolts 65 forthe links, the connecting pins 67 between the links and arms 68 of the shoes 51 and 52, and the pivot bolts 54 of the respective brake shoes lie in straight lines by reason of slightly compressing the spring 60. This is because the weight of the carriage alone is sufiicient to overcome the compressive strength of the spring. When, however, the pull of the cable is suddenly released as by reason of the cable breaking, or when the carriage is suddenly free to. move downwardly as by being moved off a platform with the cable slack, then the arms 68 and the links 66 will assume the relative position shown in Fig. 2 with the shoes in contact with the trackway by reason of the fact that there is no longer any force acting against the spring 60 and tending to hold the links and Because the single spring 60 acts on both shoes their action will be substantially simultaneous and uniform. Once the end portions of the brake surfaces 57 are thus brought into engagement with respective websof the channels 11 and 12, the frictional engagement increases due to the increasing eccentricity of the shoe surfaces 57. The load carried on the. arms 28 will, therefore, be arrested and suspended, and will not drop to the ground in case the cable has been broken, and will not snap the cable in case it has been, temporarily slack and as above-mentioned, when the cable is mended or the slack taken up, the initial pull on the cable will cause the pairs. of links 66 and? arms 68 to again assume straight lines as. in Fig. 3, and; the parts will; then remain in this position with,- out further attention until again needed. To, release theshoes no.- excessive pull; is necessarybecause the shoes simply act as rollers for a little. distance, the bite of the shoes decreasing from the first until the shoes are entirely disengaged.

I claim:

1. In a device of the class described, a carriage adapted to sustain a load, a trackway for the carriage, a pair of members pivoted to the carriage and adapted to engage and disengage respective sides of the trackway, resilient means physically interposed between and acting in opposite directions on the pivoted members and tending to force the members into engagement with the trackway, and means to raise and lower the carriage, the last-named means being connected to the carriage through the pivoted members, and the connection being arranged to oppose the action of the resilient means to normally hold the pivoted members in inactive position.

2. In a device of the class described, a frame having parallel spaced members, a carriage mounted to traverse the frame, a pair of brake members pivoted to the carriage and arranged to engage the said frame members, a horizontally disposed compression spring constantly acting directly on both brake members and tending to force the members into engaging position, and means to raise and lower the carriage, said means being connected to the carriage through the brake members and acting against the spring to normally maintain the brake members in disengaging position.

3. In a device of the class described, upright means for sustaining a load, load engaging means mounted to traverse the upright means, a pair of pivoted members carried on the load engaging means and having surfaces arranged to frictionally engage the upright means to prevent downward movement of the load engaging means, a cable for raising and lowering the load engaging means, and means connecting the cable thereto including a floating block and links freely pivoted to the block and respectively pivoted to the said pivoted members for holding the pivoted members out of contact with the upright means when the block is lifted by the cable, there being resilient means tending to force the pivoted members into contact with the upright means.

4. In an industrial power driven truck, a substantially upright trackway forming frame .at one end thereof, a load lifting carriage comprising a movable frame with upper and lower reaction members, upper and lower sets of rollers on the respective reaction members arranged to guide the carriage on the trackway, means to raise and lower the carriage, and a safety braking mechanism supported by the carriage and on which the raising means acts to raise the carriage and said braking mechanism including means to engage the trackway in the event the raising and lowering means fails to sustain the weight of the carriage, said last named means being disposed, and acting on the trackway, in a horizontal plane between the reaction members.

5. In an industrial power driven truck, a substantially upright trackway forming frame at one end thereof, a carriage mounted to be raised and lowered on the trackway, said carriage comprising upper and lower reaction members and anti-friction members carried thereby respectively and guidingly engaging the trackway, means to raise and lower the carriage, and a safety braking mechanism interposed between and connected to said last named means and said carriage normally held inactive by the raising means, said braking mechanismrbeing arranged to engage the trackway in the event saidraising and lowering means fails to sustain the weight of the carriage, and being disposed in a horizontal plane between the reaction members. r

In testimony whereof, I hereunto afiix my signature.

- EDWARD J. ABBE.

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