Brush wear indicator

Claim 2

A brush wear indicator system for an electric motor having a commutator and a brush slidably contained within a socketed carrier, with its leading edge extending therefrom to contact the commutator, said brush being resiliently biased to be moved from the carrier and against the commutator as it wears, and comprising in combination therewith: a circuit shunting the brush and a circuit component of the motor; a switch means in said circuit adapted to be tripped from a normal position and to thereby disrupt the circuit; a signal means actuated responsive to a disruption of the circuit; a holding pin mounted upon the carrier, biased towards the brush with one end bearing against a side of the brush when the brush is normally within the carrier socket and the other end holding said switch means in its normal position, said pin dropping behind a rearwardly disposed edge of the brush surface when the brush is moved toward the commutator and nearly worn out, and thereby tripping the switch means; and an insulation means, at the pin, to insulate the switch means from the brush.

Claim 3

In the organization set forth in claim 1, wherein the brush includes a hole in its side near its rearward end in alignment with the pin to constitute said rearwardly disposed edge so that the pin will drop into the hole.

Claim 4

In the organization set forth in claim 1, wherein: said switch means includes a resilient arm mounted upon the carrier having an end biased towards the socket therein; said pin is carried in a passageway extending through a hole in the wall of the carrier and into the socket with its inner end bearing against the side of the brush and its outward end holding the arm away from the carrier when the brush is in its normal position, but with said pin dropping over the edge of the brush and into the socket when the brush is moved close to its worn out position to thereby release the arm and permit it to move towards the carrier.

Claim 5

In the organization set forth in claim 3, wherein the pin is an insulator and said switch means includes an electrical contact on the carrier adjacent to the pin which is adapted to be contacted by the arm whenever the pin drops away from the brush.

Claim 6

In the organization set forth in claim 3, wherein said insulation means includes a pad at the arm at the location where the pin contacts the arm.

Claim 7

In the organization set forth in claim 5, wherein said pad is a short sleevelike member fitted about the arm.

Claim 8

In the organization set forth in claim 5, wherein said pad is a short, sleevelike member fitted about the arm, and a finger extending from the arm to contact the carrier to close the circuit thereof whenever the arm moves towards the carrier.

Claim 9

An artificial respiration apparatus including in combination: a. an electrical motor to operate the apparatus having a brush in a socketed carrier resiliently biased against the commutator of the motor; b. an indicator circuit including a switch means and a warning means adapted to actuate when the switch means is tripped from a normal position, said switch means including a spring member mounted upon the carrier and resiliently biased towards the brush within the carrier; c. a passageway through the carrier wall between the switch spring member and the brush; d. a switch-tripping means including a pin slidably carried in the passageway with its outer end contacting the aforesaid spring member and its inner end contacting a side of the brush when the brush is normally within the carrier, said pin being held against the brush by the spring Member but dropping from an edge of the brush when the brush approaches its wornout condition, whereby to permit the spring member to move towards the brush; and e. a means to actuate the switch means when the spring member moves toward the brush.

Claim 10

An artificial respiration apparatus including in combination: a. an electrical motor to operate the apparatus having a brush in a socketed carrier resiliently biased against the commutator of the motor; b. an indicator circuit including a switch means and a warning means adapted to actuate when the switch means is tripped from a normal position, said switch means including a spring member mounted upon the carrier and resiliently biased towards the brush within the carrier; c. a passageway through the carrier wall between the switch spring member and the brush; d. a switch-tripping means including a pin slidably carried in the passageway with its outer end contacting the aforesaid spring member and its inner end contacting a side of the brush when the brush is normally within the carrier, said pin being held against the brush by the spring Member but dropping from an edge of the brush when the brush approaches its wornout condition, whereby to permit the spring member to move towards the brush; and e. a means to actuate the switch means when the spring member moves toward the brush.

Claim 11

In the organization set forth in claim 8, wherein: the spring member is a conductor; the pin is an insulator member to hold the switch means normally open when inactuated; and a contact means is mounted on the carrier adapted to contact the resilient means and close the switch when the pin drops away from the brush.

Claim 12

In the organization set forth in claim 8, wherein: said switch means is normally open when inactuated; said spring member is a conductor arm attached to the carrier and cantilevered from its point of attachment and the extended end of this arm includes a finger adapted to engage a conductor component at the brush; and an insulation pad on the arm at the point of contact by the pin adapted to prevent an electrical contact between the arm and brush through the pin.