EMPTY-LOAD BRAKING APPARATUS

• US 3,794,146 A
• Filed: 08/03/1972
• Issued: 02/26/1974
• Est. Priority Date: 01/07/1970
• Status: Expired due to Term

• Current Assignee: Robert L. Ludington, Robert M. Holloway
• Original Assignee: Robert L. Ludington, Robert M. Holloway
• Inventors: Ludington, Robert L., Holloway, Robert M.
• Primary Examiner(s): Reger, Duane A.
• Application Number:
  US05/277,811
• Time in Patent Office: 572 Days
• Field of Search: 188/195,153R 303/22R
• US Class Current: 188/195
• CPC Class Codes: B60T 8/1812 characterised by the means for pressure reduction
• CPC Class Codes: B60T 8/185 Arrangements for detecting vehicle level
• CPC Class Codes: B60T 8/1893 especially adapted for railway vehicles

Abstract

Empty-load braking apparatus for a railway car in which the cylinder of the fluid operable cylinder and piston means which actuates the brakes is slidably mounted and movement of the cylinder upon actuation of the brakes is opposed by a spring with a lightly loaded car. With a heavily loaded car, a pawl controlled by load responsive means on the car limits the movement of the cylinder so that a greater braking force is applied.

Claims

1. Apparatus for operating the brakes of a railway car comprising fluid operable means having a pair of members movable relative to each other with the supply of fluid under pressure thereto, means for movably mounting one of said members on said car, spring means opposing movement of said one member in a predetermined direction, means for connecting the other of said members to said brakes, and control means for alternately limiting said movement of said one member to a first predetermined distance less than that permitted by said spring means and permitting movement of said one memeber in said direction by a second predetermined distance greater than said first predetermined distance.

2. Apparatus as set forth in claim 1, wherein said members are a cylinder and a piston therein having a piston rod extending from said cylinder.

3. Apparatus as set forth in claim 2, wherein said cylinder is said one member which is movably mounted.

4. Apparatus for operating the brakes of a railway car comprising fluid operable means having a cylinder and piston movable relative to each other with the supply of fluid under pressure thereto, said piston having a piston rod extending from said cylinder, means for movably and slidably mounting said cylinder on said car, spring means opposing movement of said cylinder, and means for limiting said movement of said one member to less than that permitted by said spring means, comprising means engageable with the slidable portion of said mounting means for locking the latter in a predetermined position.

5. Apparatus as set forth in claim 4, wherein said means engageable with the slidable portion of said mounting means comprises a pawl and further comprising cable means secured to said pawl for moving said pawl into and out of engagement with said slidable portion.

6. Apparatus for operating the brakes of a railway car comprising a mounting plate adapted to be secured to said car, a shear plate slidably mounted on said mounting plate, a fluid cylinder mounted on said shear plate for movement therewith, a piston within said cylinder and movable with respect to said cylinder by fluid under pressure in said cylinder and between said piston and said cylinder, a piston rod mounted on said piston and extending from one end of said cylinder, stop means extending from mounting plate in spaced relation to the other end of said cylinder, spring means mounted between said other end of said cylinder and said stop means for opposing movement of said cylinder, and control means on said mounting plate selectively engageable with and disengageable fRom said shear plate for limiting movement of said cylinder in the direction of said spring when said control means is in engagement with said shear plate.

7. Apparatus as set forth in claim 6, wherein said control means comprises a pawl.

8. Apparatus as set forth in claim 6, further comprising a cable connected to said pawl in series with a conical, helical spring having frictionally engaging turns.

9. In braking apparatus for a railway car comprising brakes and brake rigging for actuating said brakes, the combination therewith of load means on said car responsive to the load on said car, fluid operable means on said car comprising piston and cylinder members for actuating said rigging, means connecting one of said members to said rigging, mounting means movably mounting the other of said members on said car, spring means acting between said other member and said car for opposing movement of said other member upon the supply of fluid to said fluid operable means for actuating said rigging, and control means connected to and responsive to said load responsive means and engageable with one of said mounting means and said other member for limiting movement of said other member when the load on said car reaches a predetermined value, whereby a predetermined braking force is applied to said brakes when said load reaches said predetermined value and a lesser braking force is applied to said brakes when said load is less than said predetermined value.

10. Apparatus as set forth in claim 9, wherein said mounting means comprises a mounting plate secured to said car and a shear plate slidably mounted on said mounting plate, said cylinder member is mounted on said shear plate, said piston member has a rod extending from one end of said cylinder which is connected to said rigging, said mounting plate has stop means thereon spaced from the other end of said cylinder and said spring means extends between said stop means and said cylinder.

11. Apparatus as set forth in claim 10, wherein said mounting plate comprises second stop means for limiting movement of said cylinder in the direction in which it is urged by said spring means whereby said cylinder is limited in movement in said last-mentioned direction by said spring means to less than that which would occur in the absence of said second stop means.

12. Apparatus as set forth in claim 10, wherein said control means comprises a pawl engageable with said shear plate.

13. Apparatus as set forth in claim 12, wherein said railway car has a frame and a bolster, the relative positions of said frame and said bolster being dependent upon the load on said car, and wherein said load responsive means comprises means responsive to the relative positions of said frame and said bolster.

14. Apparatus as set forth in claim 13, wherein said means responsive to the relative positions of said frame and said bolster comprises a cable connected at one end to one of said frame and said bolster and movable thereby in accordance with the spacing between said frame and said bolster and means connecting said cable to said pawl for engaging said pawl with said shear plate when said spacing between said frame and said bolster is less than a predetermined amount.

15. Apparatus as set forth in claim 14, wherein said means for connecting said cable to said pawl comprises a conical, helical spring having frictionally engaging turns.