US2690271A

US2690271A - Attachment for lift trucks

Info

Publication number: US2690271A
Application number: US122763A
Authority: US
Inventors: Carl B Marietta
Original assignee: Clark Equipment Co
Current assignee: Doosan Bobcat North America Inc
Priority date: 1949-10-21
Filing date: 1949-10-21
Publication date: 1954-09-28
Anticipated expiration: 1971-09-28

Description

Sept. 28, 1954 C. B, MARlETTA 2,690,271

ATTACHMENT FOR LIFT TRUCKS Filed Oct. 2l, 1949 3 Sheets-Sheet'l l INVENTOR. CARL B. MARIETTA ATTY.

SePt- 28, 1954 c. B. MARIETTA ATTACHMENT FOR LIFT TRUCKS 3 Sheets-Sheet 2 Filed Oct. 21, 1949 FIG. 2

INVENTOR. CARL', B. MARIETTA ATTY.

Sept 28, 1954 c. B. MARIETTA ATTACHMENT FOR LIFT TRUCKS 3 Sheets-Sheet 3 .Filed 001'.. 2l, 1949 WIIIIIIIII VIIIIIA"/IM lzes ATTY.

Patented Sept. 28,'k 1954 ATTACHMENT FOR LIFT TRUCKS Carl B. Marietta, Battle Creek, Mich., assignor to Clark Equipment Company, Buchanan, Mich., a corporation of Michigan Application October 21, 1949, Serial No. 122,763

2 Claims.

This invention relates to an attachment for lift trucks but, more particularly, is directed to an attachment provided for use on the forks of the lift truck in gripping rounded objects such as barrels, drums, or the like, for the purpose of transporting, stacking, or tiering the same.

Primarily, the present invention contemplates taking a lift truck of the type using the standard L-shaped lift fork elements and attaching to such fork elements suitable mechanism whereby one or more cylindrical objects may be grasped therebetween, lifted and stacked, or transported. In connection with this operation, it is necessary that the lift fork elements be so mounted upon the fork truck that they can be moved laterally toward and away from each other to provide the necessary gripping action.

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 particular1 construction and operation of the present invention.

In the drawings,

Figure 1 is a side elevational View of a fork truck embodying the present invention.

Figure 2 is a top plan View, partly diagrammatic, showing the lift fork mechanism and the adapting members.

Figure 3 is an isometric view of the construction shown in Figures 1 and 2 insofar as the clamp and fork arrangement is concerned.

Figure 4 is a sectional View taken substantially on line ll--Ll of Figure 3. v

Figure 5 is a sectional view taken substantially on line 5 5 of Figure 3; and

Figure 6 is a sectional view taken substantially on line 6 6 of Figure 3.

Referring now in detail to the drawings, an industrial truck is indicated generally at 5, including the drive Wheels 6, the steering wheels 'I, and the vertical mast or upright assembly 8 upon which is mounted a load supporting carriage 9, guided and arranged for vertical movement within the mast 8 in any conventional or well-known manner.

The carriage 9 includes a box-like structure, shown in more detail in Figure 3, having a backing plate portion I and suitable guideways formed therein for receiving slidable members I2 and I3 mounted at the upper and lower ends of vertically extending members I4, which members are adapted to have secured to the forward faces thereof the lift fork elements I as by means of cap screws, bolts, or the like. The forwardly projecting linger portions I6 of the lift forks are of conventional design and, in normal operation, are adapted to be disposed underneath a load for picking the same up and transporting it.

There is a forward plate Il mounted upon the assembly 3 for closing the guideways within which the guides i2 and i3 slide and which also forms a closure confining therebetween the clamp cylinders I3 and is which are mounted in opposed relationship and have

piston rods

26 and 22 connected respectively with the vehicle members It, whereby upon introduction of fluid under pressure into the cylinders, the piston rods tend to move the members lli toward or away from each other, thereby moving the fork portions I6 toward or away from each other. This clamping mechanism is only one of a number of well-known ways in which to provide a gripping action between the fork members and need not be described in any further detail.

As shown in detail in Figures 2 and 3 and the sectional views of Figures 4, 5 and 6, each of the fork portions I6 is adapted to receive channelshaped members 25, which members have the web portions 26 thereof in facing relation on the inner longitudinal edges of the finger portions i6 of the forks. The channel sections of the members 26 overlie and embrace the finger portions of the forks and are adapted to be pivotally mounted or hinged thereto by means of the pivot pins 2l, shown more in detail in Figure 6, these pins having the head portion on one of the anges of the channel-shaped members 25 and being threaded into the lower flange portion thereof, with the bushings 28 forming a bearing for the pivotal connection.

Preferably a suitable spacer member 29 is provided for limiting relative vertical movement between the fork I6 and the members 25.

Adjacent the forward and rear ends of the members 25, there are provided additional spacing members 29, as shown in Figure 4, which serve as pilots or friction reducing elements to accommodate relative swinging movement of the members 25 within a limited range with respect to the fork portions I6.

Immediately to the rear of the pivots 21, which are substantially centrally located intermediate the ends of the members 25, there is provided spring means, indicated at 30 in Figure 5, biased between a recessed portion of the fork I6 and web 26 of the members 25, normally urging the rear portions of the members 25 toward each other or inwardly with respect to the space between the forks. This, due to the hinging action provided by the pins 27, moves the forwardly proiecting ends of the members Z5 outwardly or away from each other, thereby opening up the space between the forks when no load to be lifted. This gives additional clearance so that if the fork truck is moved into a position approach ing the load7 the outer ends of the menti:I rs 2li will be spaced apart as far as possible to accommodate entry of the load therebetween.

While the present invention is designed marily for picking up barrels, drums, or t'ne like, it can be used for picking up any cylindrical object, such as rolls of newsprint, paper, rcoing material, or the like.

In Figure 2 I have shown two cylindrical drum men'ibers diagrammatically at A anc D be noted that the web portions of the are provided With arcuate inde-rrtatic cesses 32, disposed in longitudinally spa ing relationship. These indentations a to receive the peripheral surface of a roi object, such as the objects A and an' 'the clamp mechanism is actuated to inf; i

toward each other, these arcuate i tions will receive the load and clamp tl firmly between the forks. The frictions. sure imposed by this clamping action s allow the elevating carriage to then piclr .ip the load and transport it, tier or str-.cli

Reverse operation of the clamping mechanism itilo course, release the load and alloy] it to be sposed upon the i'ioor or upon the of similar load it is to be stacked or pivotal action provided by the pins 2l is of im ',:icrtance in accommodating the fork so that the pressure is evenly applied to ibotli of the members 4 and E by the clamping i', thereby insuring equalized frictional gripping on both ci the members. 1t is of further importance, i combination with the springs to open up une forward ends of the forlrs as far as possible ior entry about the sides of the cylindrical members to be lifted.

l.' am aware that various changes be made in the conguration and relative sizes of the members with respect to the forks it and in the mounting of the same upon the forks, and ii 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 of ior- Wardly projecting relatively movable lift fori-z elements and means carried by the truck for moving the fork elements toward and away from each other, means for adapting the fori; elements as gripping elements comprising a pair of channel-shaped members embracing respectively the opposed inner longitudinal edges of the fork ele-- ments, the said channel-shaped members and the respective lift fork elements being approximately respectively between the said inner edges (1o-extensive and the said members being pivotally connected about substantially vertical axes located centrally intermediate their ends to the respective fork. elements, a plurality of arcuate ndentations in the web portions of the said channel-shaped members for gripping cylindrical objects between the said members, each oi the said members having at least one such indentation on each side o' its said centrally located pivot and a pair of springs positioned respectively between the said inner edges of the fork elements and the reverse surfaces of the said web portions for biasing the forward ends of the said channelshaped members outwardly aw ay from each other. 2. In an industrial lift truck having a pair of forwardly projecting relatively movable lift fork elements and means carried by the truck for moving the forli elements toward and away from each other, means for adapting the forl; elements as gripping elements comprising a pair oi members ci channel-shaped section embracing respectively the opposed inner longitudinal edges of the forli elements, the said channel-shaped members and the respective lil't fork elements being approximately co-extensive and the said channel-shaped members being pivotally connected about substantially vertical axes located centrally intermediate their ends to the respective fork elem a pair of arcuate indcntations in the web por ons of the said channel-shaped members for gripping cylindrical objects between the channel-shaped members, each of the said channel-shaped members having at least one such indentation on each side of its said centrally located vertical pivot asis, and a pair or compression springs ,oo tioned oi the forli elements and the reverse surfaces of the said web portions of the channel-shaped members and rearwardly of the said pivot axes for biasing t'ne forward ends of the said channel-shaped members outwardly away from each other.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,918,260 Myrholm Feb. 20, 1912 1,862,299 Ciccone June 7, 1932 1,884,861 Remde Oct. 25, 1932 1,900,569 Laderer Mar. 7, i933 2,385,512 Heath Sept. 25, 194e 2,469,812 Breslav lvlay 10, 1949 2,475,367 Avery July 5, i949 2,490,772 Benner Dec. 13, 1949 2,497,118 Ferrario et al. Feb. 14, 1953 2,509,023 Vogel et al May 23, 1950 2,517,938 Stevenson Aug. 8, 1950 2,536,151 Backofen et al. Jan. 1951 2,554,433 Warren May 22, i951 2,574,857 Ball Nov. 13, i951 2,604,220 Frischinann July 22, 1952