US 4,282,771 AGranted

Railroad hand brake with spring clutch

AssigneeMacLean-Fogg Company

InventorWilliam L. Grube

Life of this patent

Estimating the term…

Loading patent…

Abstract

A railroad hand brake includes a spring clutch interposed between an operating hand wheel and a gear drive for the chain drum. The clutch includes a spring cooperating with a control drum and with an output drum connected to the gear drive. An input element is rotated by the hand wheel in a forward direction to energize the spring so that the input element, the control drum and the output drum rotate as a unit to take up the brake load. A ratchet and pawl prevent reverse movement of the control drum in order to maintain the brake load applied when the hand wheel is released. When the hand wheel is rotated in the reverse direction, the input element tends to deenergize the spring, and the brake load is gradually released with a clutch action characterized by small input force and little wear. A quick release element operable with a small manual force abruptly uncouples the spring from the load drum in order to free the load quickly while the input element and hand wheel are stationary.

Claims27

Dependent claims

A load take up device of the type incorporating a spring clutch, and comprising in combination:

a housing;
an output drum having a cylindrical surface;
coupling means for interconnecting the output drum with the load;
a control drum having a cylindrical surface adjacent to and aligned with said output drum;
said output and control drums being mounted for rotation relative to said housing about a common axis;
rotation controlling means connected between the housing and the control drum and permitting rotation of the control drum in only one rotational direction;
a coil spring telescoped with said output and control drums, said spring being radially deformable in a first direction to engage said output and control drums and being radially deformable in a second direction to release said output and control drums;
an input element engageable with said spring at a region adjacent said control drum and remote from said output drum and movable in opposed rotational directions selectively to radially deform said spring in said first direction to interlock said input element and said control and output drums for rotation thereof in said one rotational direction for load take up, and to radially deform said spring in said second direction to release said output drum from said control drum to permit gradual movement of said output drum in the opposite rotational direction for gradual release of the load;
and
a quick release element engageable with said spring at a region said output drum and remote from said control drum, said quick release element being movable to radially deform said spring in said second direction abruptly to uncouple said output drum from said control drum for unrestricted release of the load.

7 more elements

Dependencies are inferred from the claim text.