Adjustable shock absorbing tow bar

• US 6,679,185 B2
• Filed: 02/27/2002
• Issued: 01/20/2004
• Est. Priority Date: 02/27/2002
• Status: Expired due to Term

• Current Assignee: Automatic Systems, Inc. (George K. Baum Group, Inc.)
• Original Assignee: Automatic Systems, Inc. (George K. Baum Group, Inc.)
• Inventors: Sullivan, Michael Dennis, Land, Jaret Devin
• Primary Examiner(s): Morano, S. Joseph
• Assistant Examiner(s): Jules, Frantz F.
• Application Number:
  US10/083,834
• Publication Number:
  US 20030159614A1
• Time in Patent Office: 692 Days
• Field of Search: 104/172.3, 104/172.4, 104/172.2, 104/172.1, 213/1.R, 213/7, 213/62.R, 213/66, 213/69, 293/136, 267/196, 267/201, 188/129, 188/67, 188/268, 188/322.12, 188/381, 188/322.18
• US Class Current: 104/172.3
• CPC Class Codes: B61B 10/046 Impellers
• CPC Class Codes: B62D 65/18 Transportation, conveyor or haulage systems specially adapted for motor vehicle or trailer assembly lines conveyors and haulage in general B65G

Abstract

The trailing, load supporting component of a product conveyor is connected to a powered, leading component by a shock absorbing tow bar that employs relatively movable friction elements in a sandwich configuration to absorb the shock by sliding engagement at internal wear surfaces. A brake tongue slides between opposed brake pads of the sandwich which are placed under pressure against the tongue. A two-piece, telescoping tubular housing shields the brake assembly from contaminants and enhances the structural integrity of the unit.

Claims

1. In combination with a leading component and a trailing, load-supporting component of a product conveyor, a shock-absorbing tow bar for minimizing the effect of rapid acceleration or deceleration of the conveyor, said tow bar comprising:

a pair of elongated tubular housing members in longitudinally aligned relationship and presenting a forward end and a rearward end,

means for connecting said forward end to said leading component of the conveyor, and for connecting said trailing end to said load-supporting component of the conveyor,

an elongated brake tongue,

means for securing said tongue within one of said tubular housing members, said tongue extending longitudinally thereof,

a brake assembly secured within said other housing member and including at least a pair of spaced friction elements slidably receiving said tongue to present a sandwich configuration,

said friction elements presenting opposed wear surfaces in contact with said tongue, and

pressure means engaging said elements for selectively maintaining said wear surfaces against said tongue to cause a predetermined frictional resistance therebetween,

said tubular housing members being longitudinally movable relative to each other to cause corresponding relative movement of said tongue within said brake assembly,

whereby collision of said leading component with an object such as another conveyor, or engagement of said leading component by a powered driving component causes said tongue to slide longitudinally relative to said friction elements to absorb shock transmitted by the collision or engagement.

2. The combination as claimed in claim 1, wherein said tubular housing members are disposed in relatively telescoped relationship.

3. The combination as claimed in claim 1, further comprising means preventing separation of said tubular housing members upon longitudinal movement to an extended position caused by failure of said brake assembly in response to an extending shock.

4. The combination as claimed in claim 1, wherein said brake assembly includes spaced brake shoes having inwardly facing sides provided with said friction elements.

5. The combination as claimed in claim 1, wherein each of said friction elements is composed of a fiber-reinforced, heat and chemical resistant plastic.

6. The combination as claimed in claim 1, wherein each of said friction elements is composed of a glass-filled polytetrafluoroethylene.

7. The combination as claimed in claim 1, wherein each of said friction elements is composed of a carbon-filled polytetrafluoroethylene.

8. The combination as claimed in claim 1, wherein each of said friction elements comprises one or materials selected from the group consisting of carbon fiber, polytetrafluoroethylene, and fiberglass.

9. In combination with a leading component and a trailing, load-supporting component of a product conveyor, a shock-absorbing tow bar responsive to acceleration or deceleration of the conveyor, said tow bar comprising:

an elongated tubular brake housing member having an open end,

a friction brake assembly in said housing member secured thereto, and including a pair of spaced brake shoes and brake pads mounted on inwardly facing sides of said brake shoes,

an elongated tubular shaft housing member having an open end,

an elongated brake shaft within and secured to said shaft housing member, extending

longitudinally thereof and presenting a free end projecting from said open end of the shaft housing member,

a brake tongue slidably positioned between said brake pads in frictional contact therewith, said tongue being attached to said free end of the brake shaft,

means for slidably interengaging the open ends of said housing members to maintain the same in relatively telescoped relationship for movement relative to each other along a longitudinal axis,

means for selectively applying force to said brake shoes to cause a predetermined frictional resistance between said brake tongue and said brake pads,

said relatively telescoped brake and shaft housing members presenting forward and trailing ends, and

means for connecting said forward end to one of said components of the conveyor, and for connecting said trailing end to the other of said components of the conveyor,

whereby impact communicated to said tow bar shifts the housing members along said longitudinal axis to lengthen or shorten the tow bar in response to acceleration or deceleration, respectively of the conveyor, and causes corresponding movement of the brake tongue against the resistance of the brake pads to thereby absorb the shock of accelerating or decelerating impact.

10. The combination as claimed in claim 9, wherein each of said brake pads is composed of a fiber-reinforced, heat and chemical resistant plastic.

11. The combination as claimed in claim 9, wherein each of said brake pads is composed of a glass-filled polytetrafluoroethylene.

12. The combination as claimed in claim 9, wherein each of said brake pads is composed of a carbon-filled polytetrafluoroethylene.

13. The combination as claimed in claim 9 wherein each of said brake pads comprises one or materials selected from the group consisting of carbon fiber, polytetrafluoroethylene and fiberglass.

14. A method of minimizing the effects of acceleration or deceleration of a product conveyor comprising the steps of:

providing a leading component and a trailing, load-supporting component of a product conveyor;

providing an elongated tubular brake housing member,

providing, in said brake housing member, a friction brake assembly having a pair of spaced brake shoes with brake pads mounted on inwardly facing sides of said brake shoes,

slidably positioning a brake tongue between said brake shoes in contact with said brake pads,

attaching said tongue to a dampener shaft within an elongated shaft housing member,

relatively telescoping said brake housing member and said shaft housing member such that one of said housing members may slide longitudinally within the other to allow said tongue and brake assembly to concurrently move relative to each other,

selectively applying force to said brake shoes to cause frictional resistance between said tongue and said brake pads, and

connecting said housing members between said leading and trailing components to thereby provide a tow bar in which relative longitudinal movement of the members and lengthening or shortening of the tow bar occurs in response to acceleration or deceleration of the conveyor, thereby absorbing the shock thereof.