US2493750A

US2493750A - Fork lift truck with boom

Info

Publication number: US2493750A
Application number: US6570A
Authority: US
Inventors: Bucksath Grace
Original assignee: Individual
Current assignee: Individual
Priority date: 1948-02-06
Filing date: 1948-02-06
Publication date: 1950-01-10
Anticipated expiration: 1967-01-10

Description

Jan. l0, 1950 R, BUCKSATH 2,493,750

FORK LIFT TRUCK WITH BOOM Filed Feb. e, 1948 IN V EN TOR.

WWM

Patented Jan. 10, 1950 amaro l ronx mer 'nwcx wrrn nooM Russell Bucksath, deceased, late of Long Beach, Calif., by Grace Bncksath, administran-ix, Long Beach, Calif.

Application February c, 194s, serial No. 6,510

e calms. (ci. 214-95) (Granted under the act oi' March 3,1883, as amended April 30, 1928: 370 0. G. 757) The invention described herein, if patented. may be manufactured and used by or for the Government for governmental purposes, without the payment of any royalty thereon.

This invention relates to a fork lift truck with a boom', and more particularly, to a lift truck of conventional commercial design, convertible into a derrick or crane by a removable boom or outrigger.

Fork lift trucks have found wide acceptance in warehousing operations; and it is possible, by employing them, to stack, load, or otherwise move great quantities of matriel in a comparatively small amount of time and with a great saving in man power. However, the type of matriel which can be processed by means of the conventional fork lift truck is limited to articles of comparatively small or medium size, as the forks of the lift truck are unable to support a large article, e. g., an article twice the size of the forks. Also.

. the operational range of a conventional fork lift truck is limited to removal of matriel from floor level to an elevated level and vice versa, but does not reach levels below the floor level; for instance, it is not possible to load or unload a barge with a fork lift truck standing on an elevated pier.

It has been proposed to remedy these shortcomings of a conventional lift truck by mounting on its forks or other load-supporting means a boom or outrigger, carrying at its free end a hook or other load-supporting means, whereby the fork lift truck is converted into a wheeled derrick or crane. Examples of such industrial trucks are shown in U. S. Patent No. 2,364,493, Ulinski, and French4 Patent No. 748,739, Fenwick S. A. These devices consist of conventional industrial lift trucks, and removably mounted at or near the free end of the load-supporting surface a pivoted Outrigger terminating in a hook. Although well adapted to accomplish the objects for which they are intended, these devices possess certain disad- 2 industrial fork lift truck in enabling the operator of the lift truck to install the same without help or tools.

Still another object of this invention is a combined industrial lift truck and boom, which can in a small parking space without the need of revantages which this invention overcomes, and

which are readily apparent by comparing them with the preferred embodiment of this invention.

Accordingly, it is an object of this invention to provide an attachment for an industrial lift truck of strong and lightweight construction, and without movable parts, capable of converting the moving the attachment.

These and other objects and advantages of the present invention, not present in the prior art, will become more readily apparent through the following description of a preferred embodiment of the invention, illustrated in the appended drawing.

In a fork lift truck with boom, according to the present invention, a conventional industrial fork lift truck is equipped with a boom having a loadsupporting device such as a hook at one end and carrying a pair of spaced brackets at its other end, which are threadable over the free ends of the forks and slidable over substantially the entire horizontal length of the forks.

In the appended drawing, which illustrates a preferred em?. udiment of the invention, y

Figure l is a schematic view of a fork lift truck with boom in operative position and engaged in the loading of a barge from a raised pier;

Figure 2 is a perspective view of a fork lift truck and boom in assembled relation, the truck being shown in part only;

Figure 3 is a front elevation of a boom attachment in accordance with my invention; and

Figure 4 is a side elevation of the boom attachi ment corresponding to Fig. 3, and showing the attachment in inoperative (full lines) and in operative (broken lines) position.

More particularly, reference numeral I0 indicates the body of an industrial lift truck, equipped with an upright Il, whereon is mounted in verti cally slidable relation a load-supporting device I2, comprising in the illustrated device a pair of substantially L-shaped forks I3, I3', the horizontal tines of which extend forwardly of the truck body I0. It will, of course, be understood that such a lift truck is conventional and well known to the art, and is not claimed by me as such, other than in combination with the boom attachment plished by the aforementioned attachment of an hereafter described. The said boom attachment,

apex of the triangle is provided a hook I1 adapted to support a load I8 by means of a sling I9 or equivalent means; the hook Il may be fixed in place (as shown in the drawings) or conventionally supported from a horizontal shaft or trolley (not shown) associated with the free ends of the boom at the apex of the triangle. At the base of the boom is a pair of

brackets

20, 20".

asmuch as equivalents of specific details described parts will readily occur to the expert, which equivalents are thus desired to be embraced within the scope of the present invention, the latter is intended to be limited only by the appended claims.

Itis claimed:

l. In combination with a lift truck of the type comprising a vehicle, an upright extending from said vehicle, and projecting load-supporting means slidably associated with said upright: a

spaced from each other for distance equal to the space between fork tines Il, I3'. Each bracket is of sumcient width to permit the insertion of a tine (I3, or I3') into the bracket and to permit a pivotal or rocking motion of the boom relative to the fork, when the boom rests on the fork, while at the same time holding the boom against lateral displacement from the fork. Cable means 2l extend from the apex of the triangle to the vertically slidable load-supporting means I2 at a point or points above the horizontal portion of fork I3, I3', so as to hold the boom in angular relation to the upright I I of truck I0.

When it is desired to assemble lift truck and boom, the following steps are performed: The fork of the lift truck is lowered, cable means 2I extending from the apex of the boom are fastened in place to the vertically sliding portion I2 of the truck by suitable means e. g., snap hooks 22, and the free ends of tines I3, I3' are inserted into brackets 20, of the base I6 of the boom. Finally, the base of the boom is slid towards the body I0 of the truck until base I6 abuts on the ends of the tines I3, I3' proximate the upright I I. In this manner, a iirmly braced Outrigger structure is obtained, which is able to support loads of .considerable magnitude. As load I8 exerts a downward pull at the apex of the boom triangle, it tends to urge the base end of the boom to a direction opposite the free ends of the tines I3, I3' of the lift fork; thus, as base I6 of the boom acts as a bearing surface at or near the base of the fork, it eliminates the undesirable shearing effect on the tines which would result if the boom were supported on the fork at or near the-free ends of the tines. By selecting cable means 2l of suitable length, the angle between the boom and the upright can-be adjusted so as to elevate or depress the boom to the desired position.

When it is desired, after assembling lift truck and boom, to use the forks of the truck rather than the boom itself, it is not necessary to remove the boom. In such a case', the boom is tilted upwardly to ayertical or nearly vertical position (as shown in Fig. 4 in full lines) and held in place by appropriate means, e. g., by insertion of bolt 22 associated with sliding portion I2 intoeye 23 on boom Il. This leaves the horizontal portions of the fork unobstructed and permits them to engage loads in the same manner as if `the boom were removed from the truck.

-In the foregoing description of a fork truck with boom in accordancewith the present invention has been illustrated the construction and operation of a preferred embodiment of the same. However, it will be understood, of course, that it is not intended to limit the scope of the invention to any specic structural details, as for instance, the triangular shape of the boom or other details desirable but not essential for its operation. In-

boom adapted to support a load from one end, a

bearing surface proximate the other end of said boom for pivotal abutment on said load-supporting means, means removably positionable on said load-supporting means and adapted to hold said bearing surface in pivotally abutting engagement with said load-supporting m'eans proximate said upright and preventing lateral displacement of said boom, and means for holding said boom in angular relation relative to said upright.

2. In combination with a fork lift truck of the type comprising a vehicle, an upright extending from said vehicle, and a projecting load-supporting fork having spaced tines, said fork being slidably associated with said upright: a boom adapt ed to support a load from one end, a bearing surface proximate the other end of said boom adapted to pivotally abut on said tines, spaced bracket means loosely interiitting with and removably positionable on said tines to hold said boom proximate said upright and against lateral displacement, and means for holding said boom in angular relation relative to s aid upright.

I 3. A boom removably positionable on projecting load-supporting means of a lift truck, said boom comprising an isosceles triangle, means proximate the apex of said triangle for supporting a load, and means opposite the apex of said triangle for removably positioning said boom on said loadsupporting means, said means comprising a bearing surface at the base of said triangle pivotally abutting on said load-supporting means, and bracket means associated with said bearing surface and loosely interiitting with said load-supporting means.

4. A boom removably positionable on the projecting tines of a fork lift truck, said boom comprising an isosceles triangle, means proximate the apex of said triangle for supporting a load, and means proximate the base of said triangle for removably positioning said boom on said tines, saidl means comprising spaced brackets loosely interiitting with said tines.

5. A boom removably positionable on the projecting tines of a fork lift truck, said boom comprising an isosceles triangle, means proximate the apex of said triangle for supporting a load, a bearing surface at the base of said triangle adapted to pivotally abut on said tines, and spaced means at said base removably positionable on and loosely interiitting with said tines to prevent lateral displacement of said boom relative to said tines.

6. In combination: A fork lift truck of the type comprising a vehicle; an upright extending from said vehicle; a projecting load-supporting fork slidably associated with said upright and having spaced tines; a boom comprising a pair of convergent beams, load-supporting means at the apex of said boom, and spaced bracket means on the opposite end of said boom, said bracket means interiitting. loosely with said tines and removably'and pivotably supporting said boom on said tines proximate said upright; and means for 5 holding said boom in angular relation to ldd u r ht.

p is Number UNITED sTATms PATENTS GRACE BUcxsATH. Name Date Adminmratrix of the Estan of Rama Buck- ,1.837.486 Remde Dec- 22. 1931 ,am Deemed, 5 ,2.381.744 Clapp oct. so, 1945 2,433,584 Turner Dec. so, 1947 REFERENCES ,CITED v FOREIGN PATENTS The followin references are of record in the Number Country Da me of ms wint: 1 '148,139 mm Apr. 25, 1m