Disk brake for elevator

Abstract

A caliper brake set engages a disk on the machine shaft or drive sheave to hold the elevator car in place at a landing. The brake set is biased by one or a pair of springs to a "brake-on" condition, and a solenoid assembly is provided to hold the brake set in a "brake off" condition when power is supplied to the solenoid. Camming levers are used in conjunction with the solenoid to provide a mechanical advantage which allows use of smaller solenoids. The brake shoes are spring biased for improved operation on the disk.

Claims

1. An elevator caliper disk brake assembly comprising:

(a) a pair of brake shoes pivotally mounted on vertical pins on an associated pair of horizontal brake arms, said brake shoes having opposed planar vertical braking surfaces and said brake shoes having a pair of horizontal lugs straddling said brake arms above and below the latter;

(b) horizontal spring means disposed between said brake arms for engaging said brake arms to bias said brake shoes toward each other;

(c) a brake disk interposed between said brake shoes, said brake disk having parallel opposite vertical side surfaces facing respective ones of said braking surfaces;

(d) stop means on each of said brake arms for engagement with a respective one of said brake shoes to limit pivotal movement of said brake shoes on said brake arms in one direction;

(e) springs on each of said brake arms for biasing each of said brake shoes against its respective stop means, said stop means and said springs being operable to retain said braking surfaces substantially parallel to said side surfaces of said brake disk; and

(f) latching means including:

(i) a pair of horizontal pivotally mounted levers for engagement with said brake arms to hold the latter against the bias of said spring means; and

(ii) solenoid latch actuating means including a cylindrical solenoid plunger operably engaging said levers to selectively hold the latter against said brake arms, said plunger being reciprocally vertically movable between latch-on and latch-off positions to selectively latch and release said brake arms said solenoid plunger having a constant diameter and being telescoped into a conforming cylindrical passage in the solenoid whereby said solenoid plunger is freely slidable in said passage and can be freely lifted out of said passage after disengagement from said levers.

2. The brake assembly of claim 1 wherein said spring means comprises a pair of coil springs each engaging one of said brake arms to independently bias said brake shoes toward each other.

3. The brake assembly of claim 1 wherein said solenoid plunger is connected to adjacent ends of said levers with a common connecting pin.

4. The brake assembly of claim 3 wherein said adjacent ends of said levers are overlapped.

5. The brake assembly of claim 1 further comprising contact means for providing operating contact between said brake arms and said levers, said contact means comprising contact pins slideably mounted on ends of said brake arms distal of said brake shoes, and arranged for engagement with said levers, and means for adjustably moving said contact pins toward and away from said levers to modify the positioning of said levers.

6. The brake assembly of claim 5 wherein said contact pins are provided with rounded ends engaging said levers for providing point contact between said brake arms and levers.

7. The brake assembly of claim 1 wherein said stop means is adjustable whereby the pivotal position of said brake shoes on said brake arms can be varied..Iadd.8. A brake unit for an elevator hoist apparatus for use with an electric motor output shaft, comprising:

a brake disc having two braking surfaces and connected to the motor output shaft for rotation therewith;

a pair of brake arm assemblies each having a movable brake arm having a first end and second end and a brake shoe mounted on the first end of the brake arm, each of the brake arm assemblies being movably disposed in the vicinity of the brake disc for selective braking engagement of the brake shoes with the braking surfaces of the brake disc;

brake spring means for biasing the brake shoes on the brake arms toward the braking surfaces;

a pair of levers, each of which is pivotally supported on an axis perpendicular to the axis of the output shaft, each of the levers having a first end and second end engageable with the second end of one of the brake arms; and

actuator means for engaging with the first ends of the levers and pivoting the levers about their respective axis, thereby separating the brake shoes from the brake disc against the force of the brake spring means..Iaddend.