US3584897A

US3584897A - Protective guard for lift trucks

Info

Publication number: US3584897A
Application number: US882132A
Authority: US
Inventors: Robert J Frantz; Larry A George
Original assignee: Towmotor Corp
Current assignee: Caterpillar Industrial Inc
Priority date: 1969-12-04
Filing date: 1969-12-04
Publication date: 1971-06-15
Anticipated expiration: 1988-06-15

Abstract

An overhead guard for protecting the driver of a lift truck from falling objects with means to enable folding of the guard downwardly when vertical clearance is limited as by a doorway or other structures. The means for folding is constructed to enable folding with little physical effort by the operator as he sits in the operator''s station and to permit the lift truck to be driven in a normal manner from the operator''s station with the guard in its lowered position.

Description

United States Patent Robert J. Frantz Brooklyn;

Larry A. George, Willowick, both of, Ohio 882,132

Dec. 4, 1969 June 15, 1971 Towmotor Corporation Cleveland, Ohio Inventors AppL No. Filed Patented Assignee PROTECTIVE GUARD FOR LIFT TRUCKS 3 Claims, 6 Drawing Figs.

U.S. Cl 280/150C, 296/ l 02 Int. Cl B60r 27/00 Field of Search 296/ 1 02;

[56] References Cited UNlTED STATES PATENTS 3,289,871 12/1966 Tourneau et al.... 296/102 X 3,502,368 3/1970 Maxa 296/102 Primary Examiner- Leo Friaglia Assistant ExaminerWinston H. Douglas Attorney- Fryer, Tjensvold, Feix, Phillips & Lempio ABSTRACT: An overhead guard for protecting the driver of a lift truck from falling objects with means to enable folding of the guard downwardly when vertical clearance is limited as by a doorway or other structures. The means for folding is constructed to enable folding with little physical effort by the operator as he sits in the operators station and to permit the lift truck to be driven in a normal manner from the operators station with the guard in its lowered position.

PATENTEUJUM 5197! 3584.897

SHEET 1 or 2 INVENTORS ROBERT J. FRANTZ LARRY A. GEORGE A'I'T RNEYS PROTECTIVE GUARD FOR LIFT TRUCKS Fork-type lift trucks are commonly used for handling palleted material which is raised and lowered between the ground and a storage or a transport place such as stacks in a warehouse or-on a truck or other carrier. Sometimes the forks are not properly engaged with the palleted load and sometimes the load being handled strikes another load or part thereof causing it to fall which is very dangerous to the operator of the lift truck whose station is generally disposed a short distance to the rear of the lift mechanism and also quite close to the stacked material with which he is working.

Guards have been devised for the protection of operators of such lift trucks and generally comprise an overhead protective structure supported by vertical posts forwardly and rearwardly of the operator station and in some cases only forwardly. To afford satisfactory protection to the operator without unduly interfering with his view of the lift mechanism and materials being handled, these guards extend upwardly some distance aBove the truck and mast of the lift mechanism which otherwise is the tallest part of the structure. Since doorways and overhead structural members in warehouses sometimes present limited vertical clearance, various arrangements have been employed to enable the protective guards to be temporarily lowered. The present invention is directed to a guard of the type described which may be lowered and particularly to such a guard which may be very conveniently and easily lowered by the operator ofthe vehicle while he remains in his seat. The invention is also concerned with a guard which may be lowered to present a low overall vehicle profile without interfering with the normal operation of the vehicle by the operator in his usual station.

The invention is more fully described and will be readily understood upon reading the following specification wherein reference is made to the accompanying drawings.

In the drawings:

FIG. I is a schematic view ofa forklift truck equipped with an overhead guard embodying the present invention,

FIG. 2 is a fragmentary detail illustrating the height adjusting means and latch means employed on collapsible posts which form a portion ofthe guard,

FIG. 3 is a fragmentary view illustrating the detail of a modification of the latch means shown in FIG. 2;

. FIG. 4 shows a hinge'joint employed in collapsible posts which form a part of the guard and is taken from the line lV-IV ofFlG." 1;

FIG. 5 is an enlarged view in front elevation of the guard illustrated in FIG. I; and

FIG. 6 is a fragmentary view illustrating a hinge and spring means employed in connection with the forward posts of the guard shown in FIG. 5.

In FIG. I a tractor, schematically illustrated at 10, has a forklift assembly 12 disposed forwardly thereof and actuated by power in a manner well known to move vertically with respect to a mast 14 carried by the forward portion of the tractor. An operator's seat is shown at 16 and a steering wheel at 17. Controls for starting and stopping the tractor and for raising and lowering the forklift 12 on the mast 14 are conventional and not illustrated. The overhead protective guard of the present invention comprises a pair of forwardly disposed substantially vertical posts 18 (See also FIG. 5), the lower ends of which are supported with respect to a pair of spaced vertical stanchions 20 disposed just forwardly of the steering wheel of the tractor. At their upper ends the posts 18 are curved rearwardly and terminate in substantially horizontal spaced roof beams 22. A protective network is provided over the operators station by transverse members shown at 24 extending between the members 22 and spaced longitudinal bars 26 (FIG. 5) resting upon and preferably welded to the transverse members 24. A pair of rear posts, one of which is generally indicated at 27 in FIG. I, extend between the underside of the top members 22 and the body of the tractor. Both the forward posts 18 and rear posts 27 are collapsible to assume a position such as that illustrated in broken lines in FIG. 1 where the protective guard has been lowered and extends only slightly above the top of the mast [4 of the forklift mechanism.

The forward posts 18 are pivoted as at 28 to the stanchions 20 and, as best shown in FIGS. 5 and 6, pivot pins shown at 30 extend through a single hinge part 32 secured to and projecting from within the post 18 and opposed spaced hinge parts 34 secured to the inner walls ofthe stanchions which are of channel shape. An enlarged extension 36 of the hinge pin projects inwardly of the stanchion and supports a coil spring 38 which is anchored about a pin 40 at one end and extends behind the post 18 at its opposite end, as shown at 42, to resist swinging movement of the posts 18 about their pivots 28. The strength of the springs 38 is selected to effectively counterbalance the weight of the structure being raised and lowered so-that the weight is only partially borne by the operator in making the adjustments between the raised and lowered positions.

The rear posts 27 have an upper part 44 secured to and extending downwardly from the horizontal members 22 and braced with respect thereto by a gusset 46. The lower part of the posts are made of upper and lower portions 48 and 50 (See also FIG. 2) connected by a stud 52 which has both rightand left-hand threaded connections with the parts to enable adjustment of the links of the posts to accommodate for irregularities in the configuration of the lift truck. The upper and lower portions of the posts 27 are connected by a pivot pin best shown at 54 in FIG. 4 which extends through a bifurcated hinge part 56 depending from the upper portion and a single hinge portion 58 carried by the lower portion. A coil spring 60 is supported by an extension of the pin 54 and has ends which bear against both of the upper and lower portions of the post to afford a counterbalancing resistance to the bending of the leg portions about their hinged connections.

The rear posts 27 are held in vertical positions and retained against hinging by latch means connecting them with the lift truck adjacent their lower ends. One form of such latch means is shown in FIG. 2 wherein a bracket 62 extending upwardly from the lift truck is illustrated as carrying a pin 64 embraced by a recess in the end of a plate 66 carried by the end of the lower portion 50 of the post. The plate 66 has a second recess registering with a recess in the bracket 62 for the reception of a removable pin 68 which normally prevent forward swinging movement of the lower portion of the post about the pivot 54 and toward the position shown in broken lines at FIG. 1 which movement makes it possible for the posts 18 to swing rearwardly about their pivots 28 and toward the lowered position of FIG. 1. To move the guard from its raised to its lowered position, it is simply necessary for the operator to remove the pin 68 and urge the lower portions ofthe rear posts forwardly.

A modification of the latch mechanism shown in FIG. 2 is illustrated in FIG. 3 wherein a plate 70 of different configuration than the plate 66 in FIG. 2 depends from the lowermost end 50 of the rear post and has a notch for receiving a pin 64. The pin 64 is retained within the notch by a latch bolt 72 urged downwardly as by a spring 74 and capable of being raised to a release position by a small handle 76 at its upper end. In this case it is only necessary for the operator to raise both of the latch bolts 72 for an instant while he urges the posts forwardly. In both modifications the latch mechanisms are disposed in convenient positions adjacent opposite sides of the operator's seat and, as shown in FIG. 1, when the guard is lowered the foremost of the transverse members 24 is disposed behind the operators back so that he can retain his seat and continue to operate the vehicle. With the arrangement disclosed the protective guard need only be raised to its protecting position when the operator is engaged in manipulating loads overhead.

What we claim is:

I. An overhead protective guard for a lift truck which has lift means disposed forwardly of an operator's station comprising a pair of spaced vertical posts hinged to the truck between the lift means and operator's station and having beams extending rearwardly from their upper ends, a second pair of spaced 2. The guard of claim 1 having a protective network supported by and extending between the rearwardly extending beams, and positioned to pass over the operator's head as the guard is lowered.

3. The guard of claim 1 with spring means tending to counterbalance the weight of the parts as they move about the hinge connections.

Claims

1. An overhead protective guard for a lift truck which has lift means disposed forwardly of an operator''s station comprising a pair of spaced vertical posts hinged to the truck between the lift means and operator''s station and having beams extending rearwardly from their upper ends, a second pair of spaced posts adjacent the operator''s station each supporting one of said beams and hinges intermediate the ends of the second pair of posts and latch means at their lower ends to enable their lower portions to swing forwardly when said latch means are released and so as to enable the first pair of posts to swing rearwardly and downwardly to reduce the height of the guard and when said latch means are latched to maintain said guard rigid.

2. The guard of claim 1 having a protective network supported by and extending between the rearwardly extending beams, and positioned to pass over the operator''s head as the guard is lowered.