US1546354A - Electrically-controlled switch mechanism - Google Patents

Description

July 14, 1925. 1,546,354

E. B. TUPPEN ELECTRICALLY CONTROLLED SWITCH MECHANISM Filed Nov. 15, 1924 ln vent'orz' Edward BZL pen. by M His fittorney Patented July 14, 1925.

UNITED STATES PATENT OFFICE.

EDWARD B. TUPPEN, or ERDINGTON, BIRMINGHAM, ENGLAND, A-ssIGNoR To GENERAL ELECTRIC COMPANY, A CORPORATION on NEW YORK.

ELECTRICALLY-CONTROLLED SWITCH MECHANISM.

Application filed November 15, 1924. Serial No. 750,207.

To all whom it may concern:

Be it known that I, EDWARD B. TUPPEN, a subject of the British Empire, residing at Erdington, Birmingham, England, have invented certain new and useful Improvements in Electrically-Controlled Switch Mechanisms, of which the following is a specification.

This invention relates to electrically controlled switch mechanism, and more particularly to cam actuated controllers and other switching mechanism which are operated by electrically controlled means and are re quired to be brought to rest in definite angular positions.

When such switch mechanism is operated by an electric motor, it has been proposed heretofore to stop the switch mechanism at each angular position either by dynamic braking or by frictional braking or by a combination of dynamic and frictional braking in a manner such, for example, as is described in British Patent No. 204,105. However, with such braking arrangements, it is sometimes difficult to stop the switch. mechanism at the definite angular positions with the desired accuracy, owing chiefly to fluctuations in the supply voltage and to wear of the frictional brakes. Furthermore, when the cam actuated controller or other switch mechanism is operated by an electrically controlled air motor, a similar difliculty in accurately stopping the mechanism at the desired position is sometimes encountered.

The object of the present invention is to provide an improved electrically controlled arrangement whereby switch mechanism of the above character may be operated to and brought to rest in any predetermined angular position with great accuracy.

More specifically the invention provides an improved form of electrically operated stop mechanism which is arranged to cooperate with electrically controlled operating means to positively stop the switch mechanism when it has reached the predetermined definite angular position.

Although not necessarily limited thereto, the invention may be carried into effect in a cam actuated motor controller driven by a pilot motor as illustrated in the accompanying drawing, in which Fig. 1 is a distorted perspective view of a controller operating mechanism embodying the invention, and

5 Fig. 2 is a circuit diagram of theconnections for the pilot motor and the electrically operated stop mechanism. '1

Referring first to Fig. 1, the shaft of the pilot motor 11 carries a pinion 12, which engages with a gear wheel 13 mounted on the driving shaft14. A worm 15 on the driving shaft 14 gears with a worm wheel 16, which is mounted on thecam-shaft 17 of the controller. The electrically operated stop mechanism comprises a disk 18 formed with a plurality of notches 19 and a movable stop 20, which is pivoted at 21. The sto 20 carries a roller 22 which is biased into a utting engagement with the notches of disk 18 by means of a spring 23 mounted ona support 2t. An electromagnet 25 is capable, when energized, of lifting the stop 20 out of engagement with the disk 18.

The circuits of the pilot motor are shown diagrammatically in Fig. 2, in which 26 represents the pilot motor armature and 27 the series field winding. The positive and negative supply lines are indicated by 28 and 29 respectively. A switch 30 is arranged to open the pilot motor circuit and a switch 31 is adapted to control the energization of a relay 32 and the electromagnet 25. The relay 32 is arranged to short circuit the armature 26 through contacts 33 when the relay is deenergized.

In operation, assuming that switches 30 and 31 are open, switch 30 is first closed and current flows from the line 28 through series field winding 27, contacts 33, switch 30 to line 29. The field winding 27 is thus energized but the motor does not start since the armature 26 is short circuited by contacts 33. Switch 31 is then closed and current flows from line 28, through electromagnet 25, relay 32, switch 30 to line 29. .Relay 32 is thus energized to remove the short circuit and allow the motor to start. Since the electromagnet 25 is. connected to be controlled simultaneously with relay 32 by the switch 31, stop 20 is released and the motor drives shaft 14 and cam shaft 17 to another angular position. The shafts 10, 14 and 17 will rotate in the directions indicated by the arrows in Fig. 1 for the operation of turning the cam shaft from the off-to the full-on position. I

To stop the motor, switch 31 is opened, simultaneously deenergizing electromagnet 25 and relay 32 and thus short circuiting the motor armature 26 and allowing the stop 20 to be operated by the spring 23 into position to abuttingly engage with a notch on disk 18 when the cam shaft 17 reaches the desired angular position. A resistance may, if desired, be placed in the armature circuit whe short-circuited.

It is evident that the gear ratio between the worm l and worm wheel 16 must be such that one of the notches 19 is just approaching the roller 22 at the time that the controller cam shaft 17 is approaching an angular position at which it is desired that it should stop. For example, if the stopping positions of the controller cam shaft 17 are 30 apart and the notches, 19 on't-he cam '8 are 120 apart, then the ratio of the worm and wo rm wheel 16' may be eight revo-l-utions of the worm 15 to one revolution of wheel 6. In this case the cam 18 would revolve through 240 for each movement of the shaft 17, or if the ratio of worm 15 to wheel 16 is twelve to one, then cam 8' would revolve through 360. In either case one-of the notches 19 would be in av position to positively engage the roller 22 with the cam shaft 17 in each of a plurality of stopping positions.

In order toensure that the motor and consequently the cam shaft 17 are stopped, at the desired position it is necessary for the roller 22 to abut against a notch '19 and to effect this the adjustments of the braking means are such that the cam shaft 17 would be moved just past the desired position if it were not arrested by the roller 22 coming into engagement with the notch. Thus the employment of the disk 18 and the engaging stop '20 enables the cam shaft to be stopped at very definite positions irrespective of varying. conditions of service. The disk 18 may be yieldingly attached to driving shaft 1% in order to lessen the shock when engagement with stop 20 takes place.

It will be evident that an additional disk and stop'ma-y'be arranged to come into operationwhen the motor is returning the cam shaft to the off position if desired. Like wise, the intermediate driving shaft 14: may

be dispensed with, if desired, and the cam '18 mounted directly on the cam shaft 17, in

which case, however, the angular spacing of the notches '19 must be the same as the angular spacing of the desired stopping positions of the cam shaft. A series wound motor has been illustrated in the drawings but any suitably wound motor may be employed. Further, any suitable braking means may be employed with the positive locking; means such as dynamic braking, frictional braking, or a combination of the two. In accordance with the provisions of the patent statutes, I have described thegprinciple of operation of my invention together :with the apparatus which I now consider to represent the best embodiment thereof but I would have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means. lVhat I claim as new and desire to secure by Letters Patent of the United States, is 1. In an electrically controlled 7 switch mechanism, the combination of a shaft said shaft to said positions, and means for positively stopping said shaft in a. plurality of said angular positions comprising a member mechanically connected to be rotated responsively to the rotation of said shaft, an electrically operated stop operable into abutting engagement with said member when said shaft is in each of a plurality of said angular positions, and connections whereby the said stop is operated to release said shaft upon the operation of said means to rot-ate the shaft.

In an electrically controlled switch mechanism, the combination of a shaft adapted to be rotated to a plurality of angular positions for operating said mechanism, electrically controlled means for rotating said shaft to said positions, an electrically operated stop mechanism connected to be controlled simultaneously withsaid means to positively stop said shaft in each of a plurality of said angular positions and comprising a rotatable member connected to be rotated responsively to rotation of said shaft, a stop biased into abutting engagerent with said member when said shaft is in each of said positions, and an electromagnet for releasing said stop to permit rotation of said shaft'to other angular'positions.

4. In an electrically controlled switch mechanism, the combination of a shaft adapted to be rotated to a plurality of angular positions for operating said mechanisms, an electric motor for rotating said 11::

said cam shaft through speed reducing gearing, an electric motor operatively connected with said driving shaft, and an electrically operated stop mechanism connected to be operated upon the deenergization of said motor to positively stop said cam shaft in each of a plurality of said angular positions and comprising a rotatable member mounted upon said driving shaft, a stop biased into abutting engagement with said member when said cam shaft is in each of a plurality said angular positions, and an electromagnet for releasing said stop to permit rotation of said cam shaft to other angular positions.

6. In an electrically controlled switch mechanism, the combination of a shaft adapted to be rotated to a plurality of angular positions for operating said mechanism, an electric motor for rotating said shaft to said positions, control switch mechanism for starting and stopping said motor and electrically operated stop mechanism connected to be controlled by said control switch mechanism and arranged to positively stop said shaft in each of a plurality of said angular positions upon the operation of said control switch mechanism to stop the motor.

7. In a cam operated motor controller, the combination of a cam shaft, an electric motor for rotating said shaft to a plurality of angular positions, switch mechanism operable to one position for establishing power connections for the motor and to another position for establishing dynamic bra-king connections for the motor, and electrically operated stop mechanism connected to be controlled by said switch mechanism and arranged to positively stop said shaft in each of a plurality of said angular positions upon the operation of said switch mecha nism to establish the dynamic braking connoctions of the motor.

8. In a cam operated motor controller, the combination of a cam shaft, a driving shaft connected to said cam shaft through speed reducing gearing, an electric motor for driving said driving shaft to operate said cam shaft to a plurality of angular positions, stop mechanism associated with said driving shaft for positively stopping said cam shaft in a plurality of said angular positions and comprising a disc secured to said driving shaft and having a notch therein, a movable stop operable into abutting engagement with said notch when said cam shaft is in each of a plurality of said angular positions, and an electromagnet for controlling the operation of said stop and connected to be energized simultaneously with said motor. a

9. In a cam operated motor controller, the combination of a cam shaft, a driving shaft, speed reducing gearing operatively connecting said driving shaft with said cam shaft, an electric motor for driving said driving shaft, switch mechanism for controlling the motor and operable to one position to establish power connections therefor and to another position for establishing dynamic braking connections therefor, and means cooperating with said motor to positively stop said shaft in each of said angular positions comprising a disc secured to said driving shaft and having a plurality of notches therein, a movable stop biased into engagement with each of said notches when said cam shaft is in each of a plurality of said angular positions, and an electromagnet connected to be controlled by said switch mechanism and arranged to operate said stop out of engagement with said notches upon the operation of said switch mechanism to establish the power connections of the motor.

In witness whereof, I have hereunto set my hand this 25th day October 1924.

EDWARD B. TUPP'EN. Witnesses:

J. A. Fos'riin, MARION D. MANN.

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