US2754019A - Protective guard for lift trucks - Google Patents

Description

y 1956 N. B. WATSON 2,754,019

PROTECTIVE GUARD FOR LIFT TRUCKS Filed Jan. 8, 1953 2 Sheets-Sheet l .ZEVVEn far Mrman J3. Z'zfaison July 10, 1956 N. B. WATSON PROTECTIVE GUARD FOR LIFT TRUCKS 2 Sheets-Sheet 2 Filed Jan. 8, 1953 United States Patent PROTECTIVE GUARD FOR LIFT TRUCKS Norman B. Watson, Chicago, Ill., assignor to The Mercury Manufacturing Company, Chicago, Ill., a corporation of Illinois Application January 8, 1953, Serial No. 330,332

2 Claims. (Cl. 214-674) This invention relates generally to industrial materials handling equipment and more particularly to an overhead protective guard for a lift and tiering truck.

Heretofore lifting and tiering trucks of the type having a lifting mast assembly equipped with a fork lift or the like have been provided with some form of protective guard to insure an adequate measure of safety for the truck operator. For example, in one type of protective guard apparatus, the lift truck is equipped with an overhead canopy anchored directly to the front and rear portions of the truck frame by bolted connections or pipe sockets. Such type of protective guard is satisfactory for only such lift trucks as do not require frequent removal of the power unit or storage batteries. Where daily service of the truck power unit is required, such a protective guard is awkward, cumbersome and highly restrictive of a facile servicing operation.

In an effort to overcome such deficiencies, the protective guard apparatuses heretofore provided have contemplated the utilization of a hinged canopy section so that a portion of the canopy guard can be hingedly displaced in order to facilitate removal of batteries from a battery box. The utilization of a hinge structure, however, greatly increases the cost of the protective guard apparatus and the manipulation of the hinge section requires a more expensive and time-consuming servicing operation particularly where frequent battery changing is contemplated.

According to the principles of the present invention, an improved protective guard is provided for a lift truck of the type having a lifting mast assembly pivotally connected to the truck body. The protective guard is pivotally mounted on the forward portion of the truck frame and on the upper portion of the tiltable lifting mast. The protective guard forms an adequate canopy protection overhead so as to adequately insure a full measure of safety for the truck operator, however, overhead removal of batteries from the battery box can be conveniently effected without interference.

The pivotal mounting means provided between the protective guard and the tiltable lifting mast and also between the protective guard and the truck frame permits the maintenance of the protective guard canopy in a substantial horizontal position even though the lifting mast is moved forwardly and backwardly during a tilting operation.

The protective guard assembly of the present invention may be conveniently fabricated from a reduced number of highly simplified elements and is particularly efficient in practical operation.

It is an object of the present invention, therefore, to provide a protective guard apparatus which overcomes the deficiencies of the protective guard apparatus heretofore provided.

Another object of the present invention is to provide a protective guard canopy which is at least partially supported on the tilting mast assembly and which will remain substantially horizontal even though the tilting mast is moved forwardly and backwardly.

Another object of the present invention is to provide a protective guard apparatus for a battery-powered lifting truck which will not interfere with the servicing of the power unit or the removal of batteries from the battery box.

Another object of the present invention is to provide a protective guard apparatus which may be conveniently fabricated from a reduced number of simplified elements at a substantial reduction of cost.

Many other advantages, features and additional objects of the present invention will become manifest to those versed in the art upon making reference to the detailed description which follows and the accompanying sheets of drawings in which a preferred structural embodiment of a protective guard apparatus constructed in accordance with the principles of the present invention is shown by way of illustrative example.

On the drawings:

Figure l is an elevational view of a lift truck incorporating a protective guard apparatus according to the principles of the present invention;

Figure 2 is a plan elevational view of the lift truck shown in Figure 1;

Figure 3 is an enlarged fragmentary view showing addi-- tional details of construction of the protective guard apparatus and illustrating in phantom the various positions of the protective guard apparatus in relation to corresponding positions of the tiltable lifting mast assembly; and

Figure 4 is a fragmentary front elevational view of the structure shown in Figure 3 and showing additional details of construction of the protective guard apparatus provided in accordance with the principles of the present invention.

As shown on the drawings:

A lift truck is indicated generally by the reference numeral 10 and is provided with a truck body or frame 11 mounted on longitudinally spaced wheels 12 and-13, respectively.

The lift truck 10 is provided with an enclosed power unit 14 located on one end of the truck body 11. in the preferred embodiment herein illustrated, the power unit 14 comprises a battery energized prime mover and the enclosure takes the form of a battery box 16 closed by a cover 17 which can be raised by grasping the handles 18 and pivotally displacing the cover 17 about the axis of a hinge 19 By opening the cover 17, convenient access is afforded to the battery box 16 so that a servicing operation may be effected. For example, it may be desirable in the case of a battery energized prime mover to replace the batteries each day of operation.

At the other end of the truck body 11 is provided a lifting mast assembly indicated generally at 24), the lifting mast assembly 20 being pivotally connected to the truck body 11 by suitable pivot bracket means 21. The lifting mast assembly 20 includes, by way of illustrative example, a fork lift 22 which can be effectively utilized in the handling of industrial materials. The lifting mast assembly 20 is tiltable, that is, it can be moved forwardly and backwardly in a manner well known in the art by a hydraulic actuating means including a cylinder 23 housing a piston on the end of a piston rod 24 pivotally connected to a bracket 26 forming a part of the lifting mast assemblylil.

The lift truck 10 is fully dirigible and a steering control device 27 together with other control apparatus is carried on a portion of the truck body 11 forwardly of the power unit 14 so that an operator (not shown) standing in the space 28 may conveniently manipulate the various controls of the truck 10 in order to elfect the regulation thereof. An upright support member 29 forming a front portion of the truck body or frame 11 is provided to sup port the control apparatus and to rigidify and strengthen the frame structure of the truck 10.

According to the principles of the present invention, a protective guard canopy indicated generally by the reference numeral 30 is provided to extend horizontally superjacent the truck and particularly over the area normally occupied by the operator so as to insure an adequate measure of safety for the operator.

More particularly, the protective guard canopy 30 comprises a pair of generally parallel rail members 31 and 32 which are bent to assume an L-shaped configuration, thereby providing each rail member 31 and 32 with a long leg 31a or 32a, respectively, and a short leg 31b or 32b, respectviely.

The L-shaped rail members are inverted so that the long legs 31a and 32a are positioned generally horizontally and extend rearwardly from a position generally superjacent the lifting mast assembly 20, the ends of the rail members 31 terminating short of the end of the truck body or frame 11 on which the power unit 14 is mounted.

A plurality of cross bars 33 are extended between the long legs 32a and 31a of the rail members 31 and 32 and are placed in firm assembly therewith to provide a rigid frame structure. A foramionus screen 34 is firmly assembled to the frame structure thus provided and forms a protective covering over the head of the operator.

The rail members 31 and 32 being in parallel spaced alignment, the short legs 31b and 3212 form a yoke receiving an upper portion of the lifting mast assembly 20. The lifting mast assembly includes vertical side frames 36 which are provided with a bracket 37 each carrying a pivot rod 39 and receiving in pivotal support assembly the short legs 31b and 32b of the rail members 31 and 32. The protective guard canopy 30 is thus pivotally connected to the lifting mast assembly 20.

Along a medial portion of each of the long legs 31a and 32a of the rail members 31 and 32, a link arm 40 is pivotally connected by means of a pivot pin connection indicated generally at 41. The opposite end of each of the link arms 40 is pivotally connected to the truck body or frame 11. In order to effect such connection, a bracket 42 is connected on each side of the upright support member 29 and is provided with a yoke 43 holding a pivot pin 44. The link arm 40 is pivotally connected to the pin 44.

The spacing relationship between the pivot points established by the pivot pins 39, 41 and 44 insures that the protective guard canopy remains in substantial horizontal alignment even though the lifting mast assembly 20 is moved forwardly and backwardly by virtue of the tilting action thereof. This is illustrated graphically by the dotted line positioning of the various related components as shown in Figure 3. In the dotted line showing on the right hand side of Figure 3, the vertical frame members 36 are moved rearwardly so that the short legs 31b and 32b of the rail members 31 and 32 pivotally move with respect thereto. At the same time, the lever arm 40 forms a radius arm about the pivot axis 44 which is relatively stationary because it is on the truck body or frame 11. As a result, the protective guard canopy remains substantially horizontal.

The dotted line showing on the left hand side of Figure 3 depicts the lifting mast assembly 20 with its vertical frame members 36 positioned forwardly. In this position, too, the protective guard canopy 30 is substantially horizontal.

It will be noted that a particularly advantageous feature of the present invention resides in the fact that the protective guard assembly does not in any Way interfere with the convenient servicing access afiorded to the power unit 14 but at the same time a completely adequate measure of protection is provided for the operator of the truck.

Although various minor structural modifications might be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art.

I claim as my invention:

1. In combination, a lift truck having a body mounted on dirigible wheels, a battery powered motor unit on one end of said body including battery storage means, a tiltable lifting mast pivotally connected to the other end of said body, means forming an operator station between said motor unit and said lifting mast, a stationary upright support member on said body between said operator station and said lifting mast, manually operable control means adjacent said upright support member adapted to be manipulated by an operator carried on the truck at said operator station, an L shaped guard means having a horizontally extending protective covering for the operator superjacent the body and a vertically extending connecting portion, connecting means pivotally connecting said vertically extending portion of said L shaped guard means to said lifting mast, and link means between said guard means and said upright support member, whereby said guard means remain substantially hori zontal upon tilting of said mast, said guard means terminating short of a vertical plane erected at the said one end ofsaid body to facilitate removal of batteries from said battery storage means.

2. A lift truck comprising a frame, a power unit at one end of said frame, a cover on said power unit, hinge means for said cover to permit overhead service of said power unit when said cover is open, a tiltable lifting mast on the other end of said frame, a guard canopy pivotally connected at one end to said lifting mast, and link arm means pivotally connecting said guard canopy to a portion of said frame intermediate the lifting mast and the power unit, said guard canopy comprising a generally L-shaped screen member inverted to align the long leg generally horizontally, the short leg of said screen member being aligned generally vertically and being pivotally connected adjacent the end thereof to said lifting mast, and said link means being pivotally connected by means of said pivot connections at one of said opposite ends to said long leg at a medial portion thereof, said guard canopy terminating short of a vertical plane intersecting said one end of said frame so as to permit overhead service of said power unit without interference.

References Cited in the file of this patent UNITED STATES PATENTS 2,143,983 Howell Ian. 17, 1939 2,263,978 Branovic et al Nov. 25, 1941 2,263,981 Dalecke et al. Nov. 25, 1941 2,479,623 Johnson Aug. 23, 1949 2,494,651 Flynn Jan. 17, 1950 2,621,821 Melin Dec. 16, 1952

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