US2297095A - Switch - Google Patents

Description

P 1942- RE. BASSETT, JR 2,297,095

SWITCH Original Filed April 19, 1937 INVENTOR EEK AEL (SASSETTJ):

Patented Sept. 29,1942

SWITCH Rex Earl Bassett, In, Miami Beach, is,

to Bendix Home Appliances, Inc., Ind., a corporation of Delaware assignor South Bend,

Original application April 19, 1937, Serial No.

137,662. bet 6,

This invention relates to actuated switch. e g

It is the object of this invention to provide a switch which will be initially operated, preferably released, by excessive vibration of the device to which the switch is attached, the release of the a restoring vibrationswitch serving to effect an electric circuit tov The subject matter of this application isa' division of my. application for United States Let-- ters Patent Serial No. 137,662, filed April 19, v 1937, and entitled "Cleaning Machines.

My invention is illustrated in the accompanying side-elevation drawing in which the switch case is shown in section and in which an external electric circuit, including a source of current and a magnetic device, is diagrammatically illustrated.

' The invention is preferably enclosed in a box or container I having a backplate 2 suitably attached to a machine, not shown, the excessive left and right vibration of which is to be checked. Mounted on the backplate 2 is a support 3 upon which a pendulum or inertia member 4 is pivoted at 5 to swing through an are limited by the shoulders 6 and l at the ends of a slot through the lower wall of the container i. The upper arm of the pendulum 4 is-provided with a forwardly-extending offset portion 9 which is arcuately formed about the pivot point 5, the

lower face of the forwardly-extending portion 9 being substantially perpendicular to the plane in which the pendulumswings. A contact spring l0, having an end ll arcuatelyformed about the pendulum pivot point 5, normally engages the under side of the forwardly-extending ofl'set portion 9 to hold the contacts H and IS in engagement with one another.

' Mounted above the contact spring III is a bimetal strip I 6 having an end I! adapted to move into operative engagement with the contact spring [0 when the bimetal strip i8 is heated .for a predetermined length of time by the heating coil l8, which lies near but preferably out of contact with the bimetal strip! 6. The heating coil I I is of high resistance and is connected, in parallel, with the contacts I! and I! so that,

in normal condition, current from the source 20 Divided and this application Septem- 1941, SerialNo. 409,863

6 Claims. (01. 200-52) and through the electromagnet 2! is shunted away from the heating coil [8 by the low-resistance path through the contacts l4 and I5. The resistance of the electromagnet 2| is low compared with the resistance of the heating element l8 so that the amount of current passing through the electromagnet 2|, when the contacts I4 and I5 are opened, is insuflicient to energize the electromagnet M to an operative extent, but is suflicient to heat the high-resistance heating element l8 to such 'an extent that it causes the downward deflectionof the bimetal strip [6, the engagement of the part IT with the contact spring l0 and the forcing of the end H of the contact spring l0 past the projecting point of the forwardly-extending offset portion 9 of the pendulum lever by moving the pendulum lever in a counterclockwise direction about its pivot point 5.

In operation, the backplate 2 will be attached to a machine or structure adapted to be started a or to have its speed increased by the energlzation of the electromagnet 2|.

If a condition within the machine to which the backplate 2 is attached is such that excessive vibration to the right and left takes place, the pendulum 4 will swing until the end ll of contact spring in is released from the point of the forwardly-extending offset portion 8, thus breaking the operating circuit of the electromagnet 2| and permitting current to pass through the heating element I 8 sufficiently gradually to heat the bimetal strip IS. The space be tween the heating element l8 and the bimetal strip l6 may be adjusted to provide any desired lapse of time for the machine to which the backplate 2 is attached to come to rest or to decrease its speed to a point where the out-of-balance condition, which was the cause of vibration. has been rectified. After the requisite predetermined time has elapsed, the bimetal strip l6 bends downwardly and pushes the end ll of contact spring l0 past the point of the forwardlyextending offset portion 9, resetting the switch, closing the contacts I4 and I5, shunting the heating coil l8 and magnetizing the electromagnet 2! to again start or increase the speed of the machine to which the backplate 2 is attached.

During the restarting period, the bimetal'strip l6 cools sufliciently that if the machine is still or again in unbalanced condition, so that vibration again occurs, the end I! and the contact spring l0 will have had time to become separated, so that contacts 14 and I5 may again open the operative circuit of the electromagnet 2|. Al-

While I have shown and described my inven,

tion with respect to specific details of construction, it is to be understood that modifications may be made within the skill of the art without departing from the spirit or scope of my invention.

What I claim is:

1. A machine control comprising a switch having contacts yieldingly urged apart, means for holding said contacts together, inertia means for releasing said holding means in case of excessive vibration, and heat-responsive means actuated upon release of said holding means for automatically reengaging said holding means after a time interval.

2. A machine control comprising a switch hav'- ing contacts yieldingly urged apart, means for holding said contacts together, inertia means for releasing said holding means in case of excessive vibration, a circuit energized by the release of said holding means, and heat-responsive means operated by the energizing of said circuit for reengaging said holding means.

3. A machine control comprising a switch having contacts yieldingly urged apart, means for holding said contacts together, inertia means for releasing said holding means in case of excessive vibration, a circuit energized by the release of said holding means, a heat-generating device energized by said? circuit when energized, and a thermally-responsive member deflected by heat from said device to reengage said holding means.-

4. A machinecontrol comprising a pair of normally-closed switch spring contacts, a 'pivotally supported inertia member, a pair of surfaces in normal engagement with one another, one of said surfaces being movable with one of said switch spring contacts and the other of said surfaces being movable with said inertia member,

the surface movable with the inertia member being substantially arcuate about the pivotal support for the inertiamember, whereby the movement of the inertia member within predetermined limits does not cause movement of the associated switch spring contact, the said engaging surfaces of the inertia member and the switch spring contact being separable by excessive oscillation of the inertia member about its pivotal support, whereby the switch spring contacts become separated, and a heat-operated member adapted to engage the said movable switch spring contact member to force the said surfaces into reengagement with one another after the excessive oscillation of the inertia member has subsided.

Y 5. A machine control comprising a pair of contacts normally biased away from one another, an inertia-controlled latch normally holding said contacts together against the said normal bias, a bimetal strip having a portion for operative engagement with one of said contact members for pressing said contact members together in opposition to the said bias, the movement of said bimetal strip in forcing said contacts together serving simultaneously to reset said inertia-controlled latch.

6. For use upon a vibrating machine and in Q series with a source of current and an electromagnetic device the actuation of which may cause the vibration of said machine, a machine control comprising a pair of switch contacts, one of said contacts being normally under tension tending to separate said contacts, a pair of latch members normally holding said contacts in engage-' ment with one another, a pivoted inertia. member connected with on of said latch members for separating the latch members upon excessive oscillation of the inertia member, a bimetallic heat-controlled member positioned to engage one of said latch members to press the latch members into relatched position upon the application of heat to said heat-controlled member, an electric heating element connected in parallel with said' pair of contacts and normally shunted thereby, the resistance of said heating element being high relative to the resistance across said contacts when the latter are closed.

: REX EARL BASSE'I'I', JR.

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