US2474843A

US2474843A - Control mechanism

Info

Publication number: US2474843A
Application number: US698485A
Authority: US
Inventors: Knud J Helsing
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1946-09-21
Filing date: 1946-09-21
Publication date: 1949-07-05
Anticipated expiration: 1966-07-05

Description

July 5, 1949. K. J. HELSING 2,474,843

CONTROL MECHANISM Filed Sept. 21, 1946 WITNESSES: INVENTOR K/vua u? HELSING. 641i? 5% g V ATTORNEY Patenled'July 5, .1949

CONTROL MECHANISM Knud J. Helsing, Springfield, Mass., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application September 21, 1946, Serial No. 698,485

4 Claims. 1

This invention relates to control mechanism and particularly to mechanism which controls the operation of a device through a predetermined series of operations and then is rendered inoperative until an operator initiates operation of the mechanism by some predetermined means.

More specifically, an object of the invention is to provide a control mechanism, such as a coininitiated mechanism, which, upon the insertion of a suitable coin, will cause operation of a device, for example, a vending machine, through a predetermined cycle of operations and which is so constructed and arranged that no repeated cycle of the machine will occur in the event the coin becomes lodged on the cycle-initiating switch, or if, for any reason, this switch fails to open after the coin has passed it.

While reference has been made in the foregoing paragraph to a coin-operated switch for initiating the cyclic operation of the machine, that switch may equally well be closed manually or by some other means than a coin.

An object of the invention is to, provide a control mechanism having the aforesaid characteristics.

Another object is to provide a simple and emcient structure which may be applied to the shaft of, and is operated by the main timer motor.

Still another object is to provide a mechanism which automatically places the machine in normal operating condition when the fault has been cleared.

These and other objects are effected by the invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part of this application, in which the figure is a schematic perspective view of a timer mechanism embodying the invention.

The invention is here shown as applied to a timer comprising a shaft I0 driven by a motor M. The shaft will carry a plurality of cams (not shown) adapted to contact switches in sequential order to operate the machine controlled by the timer through a predetermined cycle when operation of the timer motor is initiated by a predetermined act. At the end of the cycle, the timer breaks its own motor circuit and leaves the timer in condition for operation through a succeeding similar cycle on the repetition of the predetermined act, which may be the insertion of a'coin in a slot or the operation of a push button.

The shaft I0 carries a cam II rotatable therewith which, at the end ofthe cycle, contacts switch member I2 to separate contacts I3, I4 and deenergize motor M. Thus when the machine is idle, contacts I3 and I4 are open and motor M is inactive. The motor is started by the momentary closing of switch I5 which is in parallel with switch member I2. The momentary closing of switch I 5 may be caused by the passage of a coin through a chute I5a or the pressing of a push button or by other means. This switch is closed only momentarily, but sufllciently long to rotate motor M far enough to release cam II from switch member I2, whereupon contacts I3 and I4 engage to complete a holding circuit for motor M until the shaft I0 has rotated far enough to again bring cam I I in contact with member I2 and thus separate contacts I 3. ll.

Under some conditions, momentary contact switch I5 may fail to open as intended, due to the lodging of a coin on the switch, the sticking together of the contacts or for other reasons. Under this condition, the machine controlled by the timer will continue to function, for example, to dispense articles, even though no additional coins are inserted.- It is to prevent this unauthorized repeated cycling that the present invention is directed.

To this end, the shaft It) carries a. disc member I6 rotatable therewith. A finger I1 is loosely mounted on the shaft and disc I6 and is permitted to move between the limits defined by spaced pins I8, I9 mounted on the disc. A solenoid relay comprising a coil 20 and an armature 2I pivoted at 2Ia are provided and disposed adjacent the disc I6. The armature 2| carries a pair of contacts 22, 23 which may be mounted on

leaf springs

24 and 25, respectively. The

springs

24, 25 are so disposed that the contacts 22, 23 are normally closed and these contacts in turn are in series with the circuit through motor M. The spring member 25 projects a sufiicient distance beyond spring member 24 so that it may be engaged by the finger I1 under certain conditions to separate the contacts 22, 23. The armature 2I also control the breaking of the primary circuitto the vending machine, or both. The armature 2| is normally biased away from the coil 20 about pivot 2| a by a spring 30 and is restrained by a stop 30a.

Coil to is disposed in series with momentary contact switch it and with switch member 12, and as these switches are connected in parallel, the coil is deenergized only when both those switches are open. The earn it and disc it are so disposed on the shaft that contacts 53, it are separated just before contacts 22, 23 are separated by finger ii. The latter condition prevails, of course, only if the coil 29 remains energized after the contacts i3, It are separated and due to the fact that, for some undesired reason, the switch it has not opened of its own accord.

The operation of the mechanism is believed apparent from the foregoing description. However, a brief resume will be given. In the inactive position of the vending machine, switches i2 and iii are open, contacts 22 and are engaged, and coil 26 is deenergized. The finger is in. the dotted line position of When. switch iii is closed, as by its momentary contact with coin, motor M is energized, as is relay coil Initial rotation of the motor suiIfici-ent to move cam beyond switch member so that contacts closed. and he motor con tinues to rotate thereby ca "se desired operation of trolled mac ie.

at the end of a si"gle revolution of shaft cam engages switch m mber to sepa contacts it, thus deenergizing motor M coil Thereupon the spring 3t pulls armature 2i out of the path of finger ill and the latter drops to its dotted line position against pin iii. for any reason, however, the momentary contact switch It] has failed to open as expected, the coil 26 will remain energized, and, contacts 22, 23 remaining closed, the motor will continue to cycle until finger l1 has engaged spring 25 to separate contacts 22, 23, thus deenergizing the motor and preventing further cycling of the machine until the source of trouble at switch l5 has been cleared up. When this has been done, the coil 20 becomes inactive and the machine is ready for normal operation. Likewise, when contacts 22, 23 are opened by finger IT, contacts 21, 28 are simultaneously closed to give a visual or audible signal of the condition of the machine and/or to also interrupt, through suitable circuits, the primary circuit to the machine.

While the invention has been shown in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof.

the convarious other cams car d t tl 'hat is claimed is:

1. In an electrically operated and controlled timing device, an electric motor, a rotatable shaft driven by the motor, said motor being adapted to be connected to a source of electric energy, switch means adapted to be momentarily closed for connecting the motor to the energy source, means associated with the rotatable shaft for maintaining the motor energized to rotate the driven shaft through a complete revolution after the motor has been initially energized by the momentarily closed switch means, a relay connected in series with the last-named switch means, a normally closed'switch disposed in series with the momentarily closed switch means, said n r mally closed switch being controlled by said rel and means responsive to the movement of sai rotatable shaft for causing said normally clo switch open and thereby break the c rcu event momentari electrically oi? tor, said mote e connec to a source c switch in to be for connec g the motor to t with the re maintaining the motor enero driven shaft through a complet a. l the motor has been initially energized by the momentarily closed switch means, a nected in series with the last-named switch means, a normally closed switch disposed in series with the momentarily closed switch means, said normally closed switch being controlled by said relay, and means carried by said rotatable shaft for causing said normally closed switch to open and thereby break the circuit to the motor in the event the momentarily closed switch has failed to open upon the completion of one revolution of the driven shaft.

3. Structure according to claim 2 in which the said relay is connected in parallel with the motor and is energized simultaneously therewith.

4. Construction according to claim 2, in which the relay comprises a stationary coil and a. movable armature, and contact members movable by said armature to a position adjacent the shaft when the aforesaid coil is energized.

mum J. memo. No references cited.