US3356238A

US3356238A - Box loader

Info

Publication number: US3356238A
Application number: US506976A
Authority: US
Inventors: John L Aldred
Original assignee: FWD WAGNER Inc
Current assignee: Caterpillar Paving Products Inc; FWD WAGNER Inc
Priority date: 1965-11-09
Filing date: 1965-11-09
Publication date: 1967-12-05
Anticipated expiration: 1984-12-05

Description

DeC- 5, 1967 J. L. ALDRED 3,356,238

BOX LOADER Filed Nov. 9, 1965 s Sheets-sheet 1 f V@ i 20 O f4 2 F76. 4 /F/G.

J. L. ALDRED Dec. 5, 1967 BOX LOADER 3 Sheets-Sheet i Filed Nov. 9, 1965 Arrazvzrs Dec. 5, 1967 J. ALDRED 3,356,238

BOX LOADER Filed Nov. 9, 1965 3 Sheets-Sheet .'5

Mm, am zum United States Patent O 3,356,238 BOX LOADER .lohn L. Aldred, Portland, Greg., assigner to FWD Wagner, Inc., Portland, Oreg., a corporation of Oregon Filed Nov. 9, 1965, Ser. No. 506,976 7 Claims. (Cl. 214-147) This application relates to a box loader.

For handling large boxes and particularly for lifting the box portion of a semi-trailer to and from the wheels and supporting structure of such trailers, my device has flexibility and ease of handling far superior to any device known to me.

My device consists of a lifting unit having inner and outer lifting arms, each of which is provided with small lift fork portions extending toward each other. The arms are connected by an upper bridge unit, which permits the outer arm to swing with respect to the bridge unit and permits the bridge unit to `swing with respect to the inner arm to disengage the lifting unit from the box to be lifted. Positive signals are provided to inform the operator of the degree of engagement of the arms with the box. The entire lifting mechanism is able to tilt with respect to a vertical plane and is able to move laterally to position the box longitudinally. In addition the entire unit may move longitudinally to position the box laterally. The entire structure is carried on an elevatable boom mounted on a tricycle tractor, which is steered by means of a single wheel at the other end of the tractor from the lifting unit for further exibility. The tilting capability compensates for tilt induced by elevating the boom and for non-parallelism between a surface on which the box is to be placed and the surface on which the tractor is operating.

FIG. l is a front quarter perspective view of the device of my invention.

FIG. 2 is a side elevational View 4of the device of my invention, omitting most of the tractor, and with portions of the boom broken away to a longitudinal cross-section to show the internal structure. v

FIG. 3 is -a view on line 3 3 of FIG. 2 with portions broken away to show the internal structure of the inner lift arm.

FIG. 4 is an enlarged fragmentary cross-sectional view on line 4-4 of FIG. 3.

FIG. 5 is an enlarged fragmentary cross-sectional view on line 5 5 of FIG. 3.

FIG. 6 is an enlarged fragmentary cross-sectional view on line 6*6 of FIG. 3.

My device consists of a three-wheeled tractor 10 provided with a boom 11 extending longitudinally from a pivot 12 between and beyond the pair of wheels 13 at one end of tractor 10. Wheel 14 is steerable and is at the opposite end of the tractor from boom 11. Boom 11 is elevated about pivot 12 by cylinders 15. Carried at the end of the boom 11 by supporting structure to be described later is an inner lift arm 20 provided with lower lift fork portions 21, and an outer lift arm 30 provided with lower lift fork portion 31. The outer lift arm 30 is spaced from the inner lift arm 20 by a bridge member 40. Bridge 40 is pivoted at 41 to the inner lift arm and at 42 to the outer lift arm. A hydraulic cylinder 43 controls the pivoting of bridge 40 about inner lift arm 20, while a hydraulic cylinder 44 controls the pivoting of outer lift arm 30 about pivot 42 with respect to bridge 40.

Bridge 40 is also provided with a generally hook-shaped stop member 45 extending upwardly at an angle from the bridge member to engage the back of a cross member 22 which is part of inner lift arm 20. The engagement of hook 45 with cross member 22 when bridge 40 is in its horizontal position provides assurance against lowering 3,356,238 Patented Dec. 5, 1967 ice bridge 40 below the horizontal position and carries the load imposed on lift arm 30 to beam 22. Bridge 40 is also provided with `a stop 46 which engages a complementary stop surface 28 on inner arm 20, to restrict the lifting movement of bridge 40 to the maximum desired position.

As best shown in FIGS. 2, 3, 4 and 6, the device of my invention is provided with a series of indicator flags to inform the operator when inner arm 20, bridge 40, and outer arm 30 are in their proper positions with respect to a box 16. The indicator for outer arm 30 may conveniently consist of a plunger 32 pivotally connected to a bell-crank 33 which is in turn pivotally connected to a push rod 34 extending the full height of outer arm 30 where it is pivotally connected to a flag 35, above the pivot point 36 between the Hag and outer lift arm 30. The weight of rod 34 causes flag 35 to be normally retained in a horizontal position, at the same time urging plunger 32 outwardly. If plunger 32 is engaged by the side of a box 16 it will be pushed inwardly, thereby rotating bell crank 33, raising rod 34, and erecting flag 35 to a position where it will be visible to the operator of the tractor. In this manner the operator is informed that lift arm 30 is against the side of box 16 although he cannot see it directly. In the same manner, inner arm 20 is provided with a plunger 23 having a stem 24 which bears on a tab 25 of flag 26, so that when box 16 engages plunger 23 the flag 26 is carried to an erect position about pivot 27, indicating that the box is in full engagement with inner lift arm 20 (FIG. 4). The flag is normally biased by gravity to a horizontal position. As best shown in FIG. 6, the stop hook 45 has a tab 47 which engages a plunger 23a having a stem 24a. Plunger 24a is shown in FIG. 6 in the position in which it has been urged inwardly against tab 25a of flag 26a to erect the flag about pivot 27a, showing that hook 45 is in full engagement with cross beam 22 and consequently forms a firm support to maintain bridge 4-0 in a horizontal position against the Weight carried by outer lifting arm 30. Flag 26a is also normally biased by gravity to a horizontal position.

When all three

ags

35, 26, and 26a are raised, the operator knows that the box 16 is firmly engaged with both

lift arms

20 and 30, and that the bridge 40 is in loadcarrying position. He is thus free to proceed to lift and maneuver box 16, which may advantageously be the box portion of a semi-trailer.

A feature of my invention is the unusual flexibility with which the operator can maneuver a box 16 carried by

lift arms

20 and 30. Such maneuverability is extremely important in placing a box 16 on a trailer under-carriage and is also of considerable assistance in removing such a box from an undercarriage and placing it on a railroad car.

Inner lift arm 20 has an outer box-like lower portion 29 containing

roller tracks

50, 51, 52, 53, 54 and 55. An inner box structure 29a is provided with pairs of

rollers

56, 57 and 58 to carry the entire vertical and sideload forces imposed by inner arm 20, outer arm 30, bridge 40 and box 16, while these structures are moving laterally with respect to the inner box 29a. Lateral movement is accomplished by a hydraulic cylinder 59 which is pivotally attached at 60 to an ear 61 attached to inner box 29a.

Box 29a is pivoted on shaft 62 which extends through sleeve 63. Sleeve 63 is a part of boom extension 70.

Boom extension 70 comprises a downwardly and forwardly extending portion 71 which is fixed to sleeve 63 and a generally rearwardly extending section 72 which extends through an opening 17 in boom 11 and serves to stabilize the box lifting portions of the structure against side sway, `since portion 72 is wide enough to substantially lill the width of boom 11 between the side plates 1S.

A cylinder '73 is pivotally connected at 74 to inner box 29a of inner lift arm 20 and controls tilting movement of the

lift structure

20, 30 and 40 about shaft 62.

Boom extension 70 is also provided with a generally horizontal sliding support member 75 which carries at least one rear upwardly projecting roller 76, which rolls on a track 76a secured to the side plates 18 of boom 11. Extension 75 rests on a roller 77 below it at the outer end of boom 11. Boom extension cylinder 78 is attached to boom 11 at one end and to slide 75 at the other end to urge slide 75 longitudinally in or out with respect to boom 11, carrying boom extension 7% and the

entire lift structure

20, 30 and 40 with it. This allows the box 16 held between

lift arms

20 and 30 to be moved longitudinally with respect to the tractor 10 (which will usually be laterally with respect to box).

Thus it will be seen that my device is capable of shifting a semi-trailer sized load in two dimensions horizontally, and is capable of lifting said load and of tilting the load, either to compensate for the slight tilt induced by lifting or to set the load on a surface which is not parallel with that upon which the tractor rests. The system is further provided with warning devices to inform the operator when all parts of the unit are in iirm engagement with the load, to permit safe lifting. These systems are both eicient and simple. All of these functions may be carried out without moving the tractor, and the movements thus provided are augmented by the use of a tricycle tractor with rear steering so that the tractor can turn in a radius substantially equal to the wheel base if desired. This gives the capability of adjusting the angle of the box 16 with regard to the place where it is to be set down, such as a semi-trailer under-carriage.

I claim:

1. A box loading device comprising an inner carrying arm having horizontally projecting lifting means, an outer carrying arm having horizontally projecting lifting means, a bridge pivotally linked to said inner arm and to said outer arm, motor means adapted to swing said outer arm outwardly with respect to said bridge, motor means adapted to swing said bridge upwardly with respect to said inner arm, a tractor, and means mounting `said inner arm on said tractor for longitudinal, lateral, vertical and tilting movement with respect to said tractor.

2. The device of claim 1 in which said means include a longitudinal boom mounted on said tractor to pivot about a point located generally centrally of said tractor, motor means adapted to raise said boom with respect to said tractor about said pivot point, and motor means between said boom and said inner arm adapted to tilt said inner arm with respect to said boom.

3. The device of claim 1 in which said inner arm is comprised of an inner box and an outer box, said inner box being narrower than said outer box, and rollers interconnecting said inner and outer boxes for lateral movement of said outer box with respect to said inner box, and motor adapted to move said outer box laterally With respect to said inner box, said boxes, rollers and motor constituting said means for moving said inner arm laterally with respect to said tractor,

4. The device of claim 1 in which said means include a boom and a boom extension, said boom extension being longitudinally slidably mounted within said boom, said inner arm being supported on said tractor by means of said boom extension.

5. The device of claim 4 in which said boom extension is provided with a generally horizontally extending member within said boom, a roller mounted on said member and having a portion of its periphery above the upper surface of said member, a track within said boom, said roller being engaged with said track, a second roller at the end of said boom, said horizontally extending member resting upon said second roller, and a motor mounted to move said extension longitudinally with respect to said boom.

6. The device of claim 1 in which the inner lift arm is provided with a plunger, a flag pivotally mounted on said inner arm in a position visible to the operator, said ag being biased to a normally horizontal position, said plunger being mounted for axial movement with respect to said inner arm and having an end positioned to be moved axially by an object as the object is positioned on said inner lift arm, said plunger being adapted in one position of axial movement to raise said flag to a vertical position and being adapted in a second position of axial movement to permit said ag to drop to a horizontal position under the influence of said bias, a second ag pivotally mounted on said outer lift arm in a position visible to an operator, said second flag being mounted on a pivot and being gravity biased to a horizontal position, a second plunger mounted for axial movement in said outer lift arm, a linkage connecting said second plunger to said second flag and adapted to raise said second flag to a vertical position in one axial position of movement and to permit said second flag to drop to a horizontal position in another axial position of movement, a third flag pivotally mounted on said inner litt arm, said third flag being gravity biased to a horizontal position, a third plunger mounted for axial movement and engagable with said third ag to move said third Hag to a vertical position in one axial position of movement and to permit said third ag to drop to a horizontal position in another axial position of movement, and means mounted on said bridge adapted to move said plunger axially to its flag erecting position when said bridge is horizontally disposed.

7. The device of claim 1 in which said bridge is provided with a stop engagablev with a portion of said inner lift arm and adapted to prevent downward movement of said bridge under the entire weight of said bridge, said outer lift arm, and a load on said outer lift arm.

References Cited UNITED STATES PATENTS 2,920,917 l/l960 Sheeham 214-147 X 3,052,366 9/1962 Duncan 214-147 3,057,490 10/1962 Sauer 214-147 X HUGO O. SCHULZ, Primary Examiner.l

Claims

1. A BOX LOADING DEVICE COMPRISING AN INNER CARRYING ARM HAVING HORIZONTALLY PROJECTING LIFTING MEANS, AN OUTER CARRYING ARM HAVING HORIZONTALLY PROJECTING LIFTING MEANS, A BRIDGE PIVOTALLY LINKED TO SAID INNER ARM AND TO SAID OUTER ARM, MOTOR MEANS ADAPTED TO SWING SAID OUTER ARM OUTWARDLY WITH RESPECT TO SAID BRIDGE, MOTOR MEANS ADAPTED TO SWING SAID BRIDGE UPWARDLY WITH RESPECT TO SAID INNER ARM, A TRACTOR, AND MEANS MOUNTING SAID INNER ARM ON SAID TRACTOR FOR LONGITUDINAL, LATERAL, VERTICAL AND TILTING MOVEMENT WITH RESPECT TO SAID TRACTOR.