US 4,639,561 A · Mechanical time delay mechanism

Abstract

A mechanical time delay mechanism is shown which provides a predetermined time delay between the movement of the moving contact blade on a circuit breaker and the activation of a switch. The control circuit design of the circuit breaker provides for tripping at one level when the breaker is in the closed position and at a second lower fault level when the circuit breaker is closing and for a predetermined number of cycles thereafter. The subject time delay mechanism activates a switch to change the tripping level from the second level to the first level at the appropriate time. The mechanism includes a pivot link assembly connected directly to the moving contact arm, a ratchet assembly, and a pivot link connecting the two. The pivot link assembly includes a set of springs to delay the movement of the link with respect to the movement of the pivot link in response to an opposing pull on the link. The pull on the link comes from the ratchet wheel which is slowed by a weighted rocker which rocks over several ratchet teeth. The switch is activated by a pin mounted on the ratchet wheel after the ratchet wheel has rotated through a predetermined angle.

Claims13

Dependent claims

A time delay mechanism displacing a second member after a predeterined time delay and in response to the displacement of a first member being located adjacent said mechanism, the second member also being located adjacent said mechanism, said mechanism comprising:

a link having a first end and a second end, said first end connected with the first member;
delay means for delaying movement of the link in response to displacement of the first member;
a wheel rotatably mounted about an axle, said wheel having a point spaced apart from said axle, said wheel connected at said point to the second end of said link, said wheel rotating in response to movement of said link;
slow means for slowing the rotation of said wheel;
and
a pin mounted on said wheel, said pin being adapted to displace the second member upon the rotation of the wheel through a predetermined angle.

3 more elements

A time delay mechanism mechanically coupling a first member (13) to a second member (72) which introduces a predetermined delay in the movement of the second member in response to the movement of the first member from a starting position to a specified position, said mechanism comprising:

a pivot link (12) connected fixedly to said first member;
a moving pin (26) carried by said pivot link and movable between a first position and a second position relative to said pivot link;
a connecting link (40) having a first end pivotally connected to said moving pin and an opposite end;
a ratchet support (56) connected to the second member,
a ratchet wheel (48) rotatably connected to said ratchet support and having a plurality of teeth (49) along at least a portion of the periphery of said wheel,
a rocker (66) having a groove (67), said rocker operably associated with said wheel such that a predetermined number of said teeth are received within said groove and rotation of said wheel causes rocking of said rocker to accommodate succeeding teeth as a part of said predetermined number whereby the speed of rotation of said wheel is limited by the movement of the rocker,
said opposite end of said connecting link connected to said ratchet wheel,
an actuating pin (52) connected to said ratchet wheel and movable in response to rotation of said wheel between a first position away from engagement with said second member and a second position in engagement with said second member;
and
biasing means for biasing said moving pin toward said first position and delaying movement of said moving pin to said second position in response to the movement of said first member to said specified position.

7 more elements

Dependencies are inferred from the claim text.

Mechanical time delay mechanism

Life of this patent

Mechanical time delay mechanism

Life of this patent

Abstract

Claims13