US3129833A - Industrial truck attachment - Google Patents

Description

A ril 21, 1964 w. J. TOWNSEND 3,129,833

INDUSTRIAL TRUCK ATTACHMENT Filed Dec. 29, 1960 4 Shets-Sheet 1 INV EN TOR.

WALTER J. TOWNSEND BY ATTORNEY April 1964 w. J. TOWNSEND 3,129,833

INDUSTRIAL TRUCK ATTACHMENT Filed Dec. 29, 1960 4 Sheets-Sheet 2 FIG. 2 '04 v mmvron WALTER J. TOWNSEND ATTORNEY April 1964 w. J. TOWNSEND 3,129,833

INDUSTRIAL TRUCK ATTACHMENT Filed Dec. 29, 1960 4 Sheets-Sheet 3 FIG. 6 7

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SH N 1 L INVENTOR. WALTER J. TOWNSEND BY ATTORNEY United States Patent 3,129,333 INDUSTRIAL TRUCK ATTACHMENT Walter J. Townsend, Delton, Mich, assignor to Clark Equipment Company, a corporation of Michigan Filed Dec. 29, 1960, Ser. No. 79,200 2 Claims. (Cl. 214-317) My present invention relates generally to a load elevating and dumping mechanism, and more specifically is directed to a lift dump attachment particularly adapted for emptying tote trays and the like.

It is an object of the present invention to provide an improved lift dump attachment construction which is well suited for use with industrial lift trucks, for example.

Another object of the invention is to provide a lift dump attachment which is of simple and economical construction, relatively free of service and maintenance costs, and economical and eflicient in operation.

A further object of the invention is to provide a lift dump attachment for lift trucks in which a tote tray or other material handling dump box is continuously engaged during elevation thereof on the upright of the truck and which is actuatable to a dump position from an elevated position on the upright by the combined use of means adapted to connect a portion of the tote tray to a telescoping portion of the upright and load engaging means of the truck which effect dumping of the tote tray as it is lowered in the upright at a rate greater than the lowering of the telescoping portion of the upright.

The lift dump attachment of my present invention comprises a frame means which is adapted to be secured to the load supporting fork carriage of a lift truck in which the fork carriage is supported in the usual manner for elevating movement in a telescoping upright construction of the truck. An inner sliding frame member of the frame means carries a tote tray engaging element adjacent the bottom thereof and is mounted for sliding movement in the frame means. The inner sliding member includes an opening therethrough at a predetermined location and is preferably located on the fork carriage intermediate a pair of fork tines which are also carried thereby. A latch mechanism is mounted atop the telescoping portion of the upright construction, and upon elevation of the fork carriage and attachment in the upright to a predetermined height the latch is actuatable to engage the opening in the inner sliding member of the frame means which causes the fork tines to move downwardly away from the inner sliding member upon lowering of the upright. Such lowering movement causes the fork tines to be lowered at a 2:1 ratio relative to the upright in the embodiment disclosed herein, which causes the tote tray to tip to a dump position as the inner sliding member telescopes outwardly of the frame means. Following dumping of the tote tray the fork tines may then be re-elevated to re-engage fully the tote tray, whereupon the latch mechanism is actuated to disengage the inner sliding member, and the attachment and fork tines may thereupon be lowered to floor level to repeat the aforesaid operation.

Other objects, advantages and features of the invention will become readily apparent from the following detailed description taken in conjunction with the drawings, wherein:

FIGURE 1 is a view in side elevation showing the lift dump attachment mounted upon an upright mast of an industrial lift truck preparatory to engaging a tote tray;

FIGURE 2 is a front elevational view of FIGURE 1 with the tote tray removed;

FIGURE 3 is an enlarged partial plan view of FIG- UM 2;

FIGURE 4 is a side view in elevation showing the attachment in maximum elevated position on the mast preparatory to dumping the tote tray;

3,129,833 Patented Apr. 21, 1964 FIGURE 5 is a View similar to FIGURE 4 with the attachment actuated to a dumping position;

FIGURE 6 is a side view in elevation of the latching mechanism; and

FIGURE 7 is a front view of FIGURE 6.

Referring now to the drawings in detail and first to FIGURES 1-3, the front chassis portion of an industrial lift truck is indicated generally at numeral lid; it includes a body portion 12 mounted on an axle of a pair of front drive wheels 14 and having a steering post 16 extending upwardly into an operators compartment from an instrument panel and cowl section 18. A vertically disposed telescopic mast structure 29 is mounted in known manner on the drive axle and is adapted to be pivoted thereon in either direction by hydraulic tilt motors, not shown, which are connected to the mast 21) by brackets, one of which is shown at 21.

Mast structures of the type indicated are known and need not be described in detail herein. Generally the mast structure includes an outer guideway formed by a pair of laterally spaced channel members 22 and an inner slide structure which telescopes within the outer guide structure and which is formed by a pair of laterally spaced channel beams 24 nested within the outer guide structure. Transverse plate means 25 connects beams 24 together at the upper end thereof and a bracket 27 (FIGURE 3) connects together outer channel members 22 intermediate the ends thereof.

The attachment of my invention, indicated generally at numeral 26, along with a pair of fork tines 23, is supported for vertical movement within the inner slide structure 24 by means of a known bracket, roller and load carriage assembly 30. The load carriage assembly 30 is supported in the inner slide structure 24 for elevating movement along the mast in known manner and is operatively connected to a hydraulic hoist cylinder and piston motor means 32 by means of lifting chains 34 which are anchored relative to the truck it) at the one end and are connected to the carriage 30 at the other ends, being reeved over sprockets 35 which are secured to a crosshead 36 of motor means 32. The cross-head 36 is mounted at the upper end of the piston rod and is secured by bolts 33 to plate means 25 of the inner slide structure 24. Extension and retraction of the piston rod raises and lowers the load carriage 3i? relative to the inner slide 24 by means of chains 34 and the inner slide relative to the outer channel members 22 in a Well-known manner. The attachment 26 is supported upon the load carriage 3% by a plurality of bolts 4-2 and extends upwardly therefrom intermediate the fork tines 28.

The lift dump attachment 26 comprises a built-up channel construction 44 which includes a transverse, vertically extending rear plate member 46, and a pair of transversely spaced, vertically extending plates 48 connected to the transverse plate 46 by intermediate plates 50. A downwardly extending slot 52 is formed in the back plate 46. A slide plate 54 is nested in channel assembly 44 and extends a short distance below the channel assembly when fully nested therein. Slide plate 54 has secured to the forward surface thereof a pair of upper and lower transversely spaced slide bars 56, a C-shaped hook member 58 mounted at the lower end of the slide plate, and a rectangular opening 60 formed centrally of the slide plate and at a predetermined distance from the upper end thereof. The opposite side edges of slide plate 54 each has an elongated recess 62, the length of which determines the distance which the slide plate can move outwardly of channel assembly 44, pins 64 being provided which extend through the channel assembly for supporting the slide plate fully nested Within the channel assembly when in abutment with the upper shoulders of recesses 62 and limiting the extent of outward movement of the slide plate relative to the channel assembly when in contact with the lower shoulders of recesses 62.

A manually actuatable latch assembly 76 (FIGURES 6 and 7) is mounted on upper plate means 25 of inner slide 24 by means of a bracket assembly '72 which comprises a pair of upright support members 74 supporting a longitudinally extending, foursided box-like assembly having side plates 76 and upper and lower plates 78 forming an opening 80 in which is mounted for reciprocation an elongated bar $2. A plate 84 is located at the forward end of bar 82 and projects slightly above the upper side of bar 82. A manually actuated lever 86 extends through an opening %8 in the upper plate 78 and into a vertical slot t of sliding bar $2 for connection with a pin 92 which is supported in a transverse opening 94 of the sliding bar 82. The lever arm 86 is supported pivotally from a pin 96 which is supported in a pair of transversely spaced support blocks 98 located on upper plate '78, the lever arm being normally held in the position illustrated in FIGURES 1 and 6 by means of a tension spring 100 which is connected to the lever arm and to an anchor block 162 on upper plate 78. A crank arm 104 is connected to lever arm $6 and extends rearwardly therefrom, having a pull cable 1% extending downwardly thereof for actuation by the operator of the truck when it is desired to actuate the slide bar 32 forwardly from the FIGURE 6 position thereof to the position thereof in FIGURES 4 and for a purpose to be explained.

A tote tray shown generally at numeral 119 may be of any suitable construction; as shown it comprises a lower inverted U-shaped floor section 112 adapted to receive in the pocket thereof the fork tines 28. A three-sided plate construction comprising a rear vertical plate 116, a lower horizontal plate 11% and a forwardly biased plate 120 is secured to floor section 112. Tote tray 110 is adapted to handle various types of material, such as bar stock 122. Extending rearwardly of each side of the tote tray is a bracket member 124. A bar 126 extends transversely and rearwardly of the tote tray and is secured to the ends of brackets 124. The bar 126 is adapted to be engaged by the lower hook section of C-shaped member 58 during elevation of carriage St) in mast prior to a damp operation, and by the upper hook section during elevation following a dumping operation, as will be explained.

In operation, the industrial truck 10 is driven into position endwise of tote tray 11% until fork tines 28 are projected fully beneath the floor section 112 of the tote tray, whereupon the hydraulic hoist motor 32 is energized to elevate the inner slide structure 24 outwardly of outer guides 22 and to elevate attachment 26 and fork tines 28 with load carriage 30 in inner slide structure 24. It will be noted that C-shaped member 58 is located at floor level when the forks are so located, and the C-shaped member will first engage bar 126 of the tote tray as the fork tines come into abutment with the lower surface of floor section 112. Continued energization of the hydraulic hoist motor 32 elevates the attachment and tote tray with the load carriage 34) in inner slide structure 24 at a 2:1 ratio relative to the inner slide until a predetermined elevation is reached such as is shown in FIGURE 4. At this predetermined elevation the opening 60 of slide plate 54 is in alignment with slide bar 82 of latch mechanism 70, whereupon the operator, without moving from his seat on the lift truck, can actuate pull cable 106 and lever arm 86 to move slide bar 82 forwardly into registry and through opening 60, as shown in FIGURE 4. With the attachment and latching mechanism so located, the hydraulic hoist motor may then be de-energized permitting the load carriage, fork tines and channel assembly 44 to be lowered a predetermined amount by chains 34 relative to inner slide structure 24, while the slide plate 54, C-member 58 and tote tray bar 126 are lowered with the slide bar 82 and plate of inner slide structure 24. It will be noted that face plate 84 of slide bar 82 projects slightly above the upper boundary of opening 60 thereby positively retaining slide plate 54 in fixed relation to the inner slide during such lowering movement. Inasmuch as the load carriage 30 is lowered at a 2:1 speed ratio relative to the inner slide, the forward end of the tote box, being supported on the fork tines, will be lowered away from the bar 126 thereof which is supported by the C-member 58, thus causing the tote tray 110 to be actuated from the FIGURE 4 position to a dump position as shown in FIG- URE 5. During such relative downward movement of the fork tines relative to O-member 58 it will be understood, of course, that the inner slide plate 54 is actuated upwardly out of channel assembly 44 as in FIGURE 5. It will be noted that pins 64 limit the maximum elevation of slide plate 54 outwardly of channel assembly 44 at the position in which pins 64 contact the lower ends of recesses 62 in the slide plate. The lift truck has in the meantime been driven to a location wherein it is desired to discharge the load 122 from the tote tray, which is accomplished when the parts of the construction are located as illustrated in FIGURE 5 with the mast 20 tilted slightly forwardly by the tilt cylinders and brackets 21.

Subsequent to discharge of the load from the tote tray the hoist motor 32 is re-energized to again elevate the load carriage and fork tines to the FIGURE 4 position wherein the fork tines are again in full engagement with the floor section 112 of the tote tray. During such upward movement of the fork tines relative to C-mernber 58, bar 126 of the tote tray tends to be elevated with the rear section of the tray in relation to the G-member. The upper hook section of C-member 58 prevents any such substantial upward relative movement of the rear section of the tray. When the attachment has been re-elevated to the FIGURE 4 position, the pull cable is released by the operator which permits spring to return slide bar 82 to its original position in the latching mechanism 70 and out of registry with opening 6% and the slide plate 54 is again fully nested within channel assembly 44. The hoist motor is then again de-energized whereupon the load carriage, fork tines, attachment 26 and tote tray are lowered together at a 2:1 ratio in the inner slide to floor level position, at which the lift truck may disengage itself from the tote tray and re-engage a second loaded tote tray to repeat the above operation. Throughout the operation of my invention it will be noted that C-member 58 is continuously engaging support bar 126 of the tote tray, thereby assuring that the tote tray will be stably supported against movement longitudinally of the fork tines.

It will now be appreciated that I have provided a novel lift truck dump attachment construction which is relatively simple, economical in manufacture, operation and maintenance, and extremely efiicient and safe in operation.

Now, while I have shown and described what I believe to be the preferred embodiment of my present invention, it will be understood that various modifications and rearrangements may be made therein without departing from the spirit and scope of my invention.

I claim:

1. In an industrial truck having an outer fixed upright mounted at one end of the truck, an inner movable upright telescopical within the outer fixed upright, motor means for elevating the movable upright in the fixed upright and a load supporting carriage mounted in the movable upright for raising and lowering movement relative thereto, the combination comprising a latching mechanism mounted on the movable upright having a manually actuatable lever and a movable member adapted to be reciprocated thereby, a pair of transversely spaced fork tines mounted upon the load supporting carriage and adapted to be lowered to floor level in the movable upright, and an auxiliary upright mounted on said load supporting carriage intermediate said fork tines having a fixed portion secured to the load supporting carriage, a slidable portion mounted in the fixed portion and elevatable relative thereto, an opening in the slidable portion and a load engaging member secured on said slidable portion and located continuously horizontally adjacent said fork tines during upward and downward movement of the load supporting carriage in the upright except during downward movement of the load engaging means from an elevated position wherein said latching mechanism engages said opening, said load supporting carriage, fork tines and auxiliary upright being elevatable in said movable upright to a height at which the reciprocable member of said latching mechanism is registrable with said openmg.

2. In an industrial truck having an outer fixed upright mounted at one end of the truck, an inner movable upright telescopical within the outer fixed upright, motor means for elevating the movable upright in the fixed upright and a load supporting carriage mounted in the movable upright for raising and lowering movement relative thereto, the combination comprising latching means secured to the movable upright, load engaging means projecting from the load supporting carriage, and an auxiliary upright assembly mounted on the load supporting carriage and extending upwardly therefrom including an outer fixed assembly, an inner slide assembly having means engageable with said latching means and a load engaging member projecting therefrom in normally horizontal adjacent relation to said load engaging means, said auxiliary upright assembly being of substantially less collapsed height than said outer and inner uprights and being elevatable in the inner movable upright to a location wherein said latching means is actuatable to engage said inner slide assembly, whereupon said load supporting carriage may be lowered in the movable upright for causing the load engaging means to be actuated downwardly away from the load engaging member.

References Cited in the file of this patent UNITED STATES PATENTS 1,768,149 Remde June 24, 1930 2,702,645 Dempster et a1. Feb. 22, 1955 2,708,043 Streb et al May 10, 1955 2,921,703 Dempster et a1. Ian. 19, 1960

Claims (1)

1. 2. IN AN INDUSTRIAL TRUCK HAVING AN OUTER FIXED UPRIGHT MOUNTED AT ONE END OF THE TRUCK, AN INNER MOVABLE UPRIGHT TELESCOPICAL WITHIN THE OUTER FIXED UPRIGHT, MOTOR MEANS FOR ELEVATING THE MOVABLE UPRIGHT IN THE FIXED UPRIGHT AND A LOAD SUPPORTING CARRIAGE MOUNTED IN THE MOVABLE UPRIGHT FOR RAISING AND LOWERING MOVEMENT RELATIVE THERETO, THE COMBINATION COMPRISING LATCHING MEANS SECURED TO THE MOVABLE UPRIGHT, LOAD ENGAGING MEANS PROJECTING FROM THE LOAD SUPPORTING CARRIAGE, AND AN AUXILIARY UPRIGHT ASSEMBLY MOUNTED ON THE LOAD SUPPORTING CARRIAGE AND EXTENDING UPWARDLY THEREFROM INCLUDING AN OUTER FIXED ASSEMBLY, AN INNER SLIDE ASSEMBLY HAVING MEANS ENGAGEABLE WITH SAID LATCHING MEANS AND A LOAD ENGAGING MEMBER PROJECTING THEREFROM IN NORMALLY HORIZONTAL ADJACENT RELATION TO SAID LOAD ENGAGING MEANS, SAID AUXILIARY UPRIGHT ASSEMBLY BEING OF SUBSTANTIALLY LESS COLLAPSED HEIGHT THAN SAID OUTER AND INNER UPRIGHTS AND BEING ELEVATABLE IN THE INNER MOVABLE UPRIGHT TO A LOCATION WHEREIN SAID LATCHING MEANS IS ACTUATABLE TO ENGAGE SAID INNER SLIDE ASSEMBLY, WHEREUPON SAID LOAD SUPPORTING CARRIAGE MAY BE LOWERED IN THE MOVABLE UPRIGHT FOR CAUSING THE LOAD ENGAGING MEANS TO BE ACTUATED DOWNWARDLY AWAY FROM THE LOAD ENGAGING MEMBER.

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