US1449708A - Automatic stop mechanism - Google Patents

Description

Mar. 27, 1923 1,449,708

J. TOUCH ET AL AUTOMATIC STOP MECHANISM Filed 001;. 18, 1921 awe/who;

Jab/z 7 0x06. RF". 72666/2.

Patented Mar. 27, 1923.

UNITED STATES PATENT OFFIQE.

JOHN TOUCH AND DOMINIC F. TOUCH, OF ARCHBALD, PENNSYLVANIA.

AUTOMATIC STOP MECHANISM.

Application filed October 18, 1921. Serial No. 508,585.

., provements in Automatic Stop Mechanism,

of which the following is a specification.

This invention relates to automatic stop mechanism and more particularly to a mechanism designed to stop the operation of an electric motor in the event of slipping or breakage of a belt or chain driven by said motor, or a breakage of any piece of machinery indirectly driven by the motor.

Generally speaking the object of the present invention is to provide in connection with a line shaft or similar driven part, and an electric motor for driving said part, means for automatically breaking the motor circuit in the event the speed of rotation of the shaft is decreased beyond a predetermined limit.

The figure of the accompanying drawing represents a view partly in elevation and artl dia rammatic illustratin the mecha-' p y b b wire 14 leads to a fixed contact member 17 nism embodying the invention.

In the drawing the numeral 1 indicates an electric motor of any type and the numeral 2 indicates a line shaft which is driven 'as for example by a belt 3 and pulleys 4 from the shaft of the motor 1. The shaft 2 is designed to transmit power to any desired number of machines, and the present invention has as its object the provision of means for breaking the circuit to the motor 1 in the event of breakage or slipping of the belt 3 or stopping of any of the machines, driven from the line shaft 2, through any accidental cause. The motor circuit is indicated in general bv the numeral 5 and embraces a knife switch 6 provided with the usual handle 7 whereby it may be conveniently thrown. This switch is preferably mounted upon a base block which is indicated by the numeral 8 and there is also mounted upon this block an electric motor indicated by the numeral 9 which motor may be of small size and is provided with the usual shaft 10. A cam 11 is'fixed upon the shaft and, in the rotation of the shaft, is designed to ride against one end of a rock lever which is indicated by the numeral 12 and which is pivotally supported as at 13 upon the base block 8. The other end of the lever 12 projects beneath the handle 7 of the knife switch 6 i and when the parts areat rest and in normal positions the cam 11 will be out of engagement with the said rock lever 12 and the lever will be tilted to about the position shown in the drawing, the switch 6 being closed and the handle 7 of the switch resting in engagement with the last mentioned end of the said rock lever. However, it will be evident that when the motor 9 is energized, the rotation of the shaft 10 of the motor will result in the cam 11 bein brought into engagement with the end of the rock lever 12 thus rocking this lever upon its fulcrum and elevatingits end which is engaged beneath the switch handle 7. This movement of the rock lever will serve to throw the switch to open position and it will remain in this position until again manually closed, at which time, of course, the rock lever 12 will be restored to normal position illustrated in the drawing.

The circuit in which the electric motor 9 is located embraces conductor wires 14 and 15, and the wire 15 leads to one terminal of a battery or other source of electric current supply indicated by the numeral 16. The

which is mounted upon some suitable fixed support located in proximity to the shaft 2. A wire 18 leads from the other terminal of the battery 16 to a bracket 19 which is also fixed in proximity-to the shaft 2 and suitably spaced from the contact 17. The numeral 20 indicates in general a governor which is associated with the shaft 2 and this governor comprises a head 21, which is fixed with relation to the bracket 19 and in electrical circuit therewith, and a head 22 which is slidable upon the shaft 2, these heads being connected by the usual spring arms 23 carrying the centrifugal balls 24.

When the shaft 2 is at rest the head 22 of the governor 20 will be in electrical contact with the contact member 17 and the circuit will be closed through the motor 9. When the shaft is rotating, however, at a proper rate of speed, the centrifugal action of the balls 24 of the governor will draw the head 22 out of engagement with the contact 17 and no current will flow through the motor 9. Under these conditions, which are normal, the switch 6 will remain closed to close the circuit through the motor 1, but should the belt 3 slip or break or should the speed of rotation of the shaft 2 for any other reason be retarded below a predetermined limit. the head 22 of the governor 20 will come into engagement with the contact member 17 thus immediately closing the circuit through the motor 9 and effecting a rocking movement of the lever 12 to throw the switch 6 to open position thus breaking; the circuit through the motor 1.

It may at times be desirable to close the circuit through the motor 9 from a distant point and with this object in view an elec tric pushbutton switch or a switch of any other suitable type indicated by the numeral 25 is placed in a shunt circuit 26 with the motor circuit.

It is also preferable that a bell or other signal 27 be placed in ashunt circuit 28- with the motor circuit so as to give warning at the time the circuit is closed through the motor 9.

Having thus described the invention,what is claimed as new is:

1. In mechanism of the class described,the combination with a motor circuit, a motor in said circuit, a switch in said circuit, and an element driven from the motor, of means operable automatically to throw the switch to break the motor circuit upon variation in speed of the said driven element beyond a predetermined rate, the said means comprising a rock lever arranged when rocked in one direction to throw the switch to break the motor circuit. an electric motor, means operated through said second-mentioned motor for coaction with the rock lever to so move the same, a clrcuitin which the last' mentioned motor is located, a fixed contact element in the second mentioned circuit, and a contact element also in said second mentioned circuit adapted to be moved with relation to the first mentioned contact element in accordance with variation in speed of the said driven element.

2. In mechanism of the class described, the combination with a motor circuit, a motor in said circuit, a switch in said circuit, and an element driven from the motor, of means operable automatically to throw the switch to break the motor circuit upon variation in speed. of the said driven element beyond a predetermined rate, the said tion in speed of the said driven element,

and a manually operable switch in the last mentioned circuit for closing the same in dependently of the contact element.

3. In mechanism of the class described, the combination with a motor circuit, a motor in said circuit. a switch in said circuit, and an element driven from the motor, of means operable automatically to throw the switch to break the motor circuit upon variation in speed of the said driven element beyond a predetermined rate, the said means comprising a rock lever arranged when rocked in one direction to throw the switch to break the motor circuit, an electric motor including a shaft, a cam upon the shaft rotatable therewith and ositioned for coaction with the said rock lever to rock the same when the second mentioned motor is energized, a circuit in which the lastmentioned motor is located, a fixed contact element in the second mentioned circuit, and a contact element also in said second mentioned circuit adapted to be moved with relation to the first-mentioned contact element in accordance with variation in speed of the said driven element.

In testimony whereof we aflix our signatures.

JOHN TOUCH. DOMINIO F. TOUGH.

Images