Lift for truck gate

• US 4,076,310 A
• Filed: 01/24/1977
• Issued: 02/28/1978
• Est. Priority Date: 01/24/1977
• Status: Expired due to Term

• Current Assignee: Donna Schwalm
• Original Assignee: Howard G. Schwalm
• Inventors: Schwalm, Howard G.
• Primary Examiner(s): Werner, Frank E.
• Application Number:
  US05/762,199
• Time in Patent Office: 400 Days
• Field of Search: 298/23 R, 298/23 MD, 298/23 M, 298/23 S, 298/23 D, 298/23 DF, 298/22 R, 298/18, 298/17.5, 298/17.6, 298/17.7, 298/7, 105/240, 105/263, 105/274, 105/275, 105/286, 105/308 P, 296/57 R, 49/340
• US Class Current: 298/23.0MD
• CPC Class Codes: B60P 1/26 Means for controlling movement of tailboards or sideboards open loading compartments with movable sideboards or tailgates B62D33/027

Abstract

The invention is a lift for the gate of a truck, and especially a gate at the side of the truck. An L-shaped lift arm has base bars pivotally connected to an actuator mechanism beneath the bed of a truck. These arms swing to the side of the truck when extended and a lift bar on the base bars extends therefrom to engage the outside of a truck gate and the lift bar is angled from the base bars to push the gate upwardly to its closed position when the base bars are rotated to their extended position. The actuator mechanism includes two chain connected sprockets: a smaller sprocket at the base bar pivot and a larger sprocket connecting with the piston of a cylinder. The sprocket pitch diameter ratios are such that rotation of approximately 90° by the larger sprocket will effect an 180° rotation of the smaller sprocket, permitting the lift arm to swing from a fully retracted position underneath the body of the truck to a fully extended position where the lift bar closes the gate.

Claims

1. A mechanism for lifting the hinged gate of a truck or trailer body and the like, comprising:

an actuator means carried underneath the body of the truck alongside the gate;

a lift arm pivotally mounted upon said actuator means below the hinge area of said gate, to be pivoted upwardly by the actuator means to move said gate from a lower open position to an upper closed position;

said actuator means including;

a smaller sprocket means connected to the pivotal mounting of said lift arm;

a larger sprocket means connected with the smaller sprocket means having a greater pitch diameter than said smaller sprocket means; and

thrust means for pivoting said larger sprocket means through a predetermined arc, thereby moving said smaller sprocket through a greater arc which is sufficient to move said lift arm from underneath the body of the truck into engagement with said gate and thence moving said gate upwardly to an upper closed position.

2. A mechanism as defined in claim 1, wherein:

said thrust means comprises a fluid cylinder and piston rod crank-connected with said larger sprocket means.

3. A mechanism as defined in claim 2, wherein:

said crank connection of said piston rod is below the horizontal center line of said larger sprocket means.

4. A mechanism as defined in claim 2, wherein:

fluid under pressure is supplied to the end of said cylinder opposite said piston rod to cause said arm to move said gate upwardly;

said fluid pressure is released to permit said arm to move upwardly; and

resilient means assists in moving said arm downwardly.

5. A mechanism as defined in claim 2, wherein:

said cylinder is provided with means for receiving fluid under pressure at each end thereof.

6. A mechanism as defined in claim 1, wherein said lift arm is L-shaped and includes:

a base bar attached to the pivotal mounting at said actuator means; and

a lift bar angularly extending from the base bar, the proportions thereof being generally such that the base bar will swing to an extended position a short distance beyond the edge of the truck with the lift bar being extended upwardly to the gate closing position.

7. The mechanism defined in claim 6, wherein:

the angular configuration of the lift arm is approximately 90°

.

8. The mechanism defined in claim 6, wherein:

the angular configuration of the lift arm is obtuse.

9. A mechanism as defined in claim 6 wherein:

said gate is hinged above said bed at the upper edge of an upright panel attached to said bed; and

an intermediate arm is pivoted on said panel for engagement with said gate and by said lift arm in lifting said side gate.

10. A mechanism as defined in claim 9, including:

resilient means for moving said arm downwardly to a lower position;

resilient means for moving said latch to a gate engaging position; and

the pressure of fluid in said end of each said cylinder is released to permit said gate to move downwardly and said latch to move to its gate engaging position.

11. A mechanism as defined in claim 1, wherein:

said sprocket means are chain connected.

12. A mechanism as defined in claim 1, including:

latch means for holding said gate in an upper position; and

a second thrust means for moving said latch means to release said gate and permit downward movement of said gate.

13. A mechanism as defined in claim 12, wherein:

each of said thrust means comprises a cylinder and piston rod; and

each cylinder is supplied with fluid under pressure to the end opposite said piston rod to cause the respective piston rod to extend said gate to move upwardly and said latch to be released, respectively.