US1357249A - Controller - Google Patents

Description

I. S. PUKERUD.

CONTROLLER.

APPLICATION FILED OCT-9.1915. v 1,357,249, Patented Nov. 2, 1920.

2 SHEETS-SHEET 2- WITNESSES: INVENTOR ad T/mma 5 Puke/0d UNITED STATES PATENT OFFICE.

THOMAS S. PUKERUD, 0F WILKINSBURG, PENNSYLVANIA, ASSIGNOR To WESTINGg HOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENN- SYLVANIA.

CONTROLLER.

Application filed October 9, 1915.

To all whom it may concern Be it known that I, THOMAS S. PUKEBUD, a citizen of the United States, and a resident of VVilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Controllers, of which the following is a specification.

My invention relates to controllers for electric motors and particularly to controllers embodying a rotatable element and mechanism for returning it to an inoperative position.

My invention has for its object to provide a controller that is simple in construction and efiicient in operation and is arranged to be automatically returned to its inoperative position during a portion of its range of movement and to remain in the position to which it is actuated during a second portion of its range of movement.

A controller constructed in accordance with my invention is adapted for use in connection with electric motors having starting resistors that are gradually shunted and having, also, means for varying the operating speeds of the motors after the starting resistors have been entirely removed from circuit. In such arrangements, it is essential that the controller be always operated through each of the several starting positions in starting the motor. Otherwise, the motor may receive an excessive current as, for example, in case'a circuit breaker is closed while the controller is in an intermediate starting position. It is desirable, however, that the controller bearranged to remain in the running position in which it may be placed in order that the operator need not maintain physical force upon it during the normal operation of the motor.

In accordance with the above considerations, the controller is so arranged that it is biased to its inoperative position from each of the starting positions but is stable in each of its running positions. A single spring operates through a cam mechanism to return the controller handle to its off position from the starting positions and also actuates an accentuating device for retain ing the handle in either of the operating positions. The spring operates, also, as a buffer to yieldingly bring the controller to rest Specification of Letterslatent.

Patented Nov. 2, 1920. Serial No. 54,966. I

yvhen it is returned to its inoperative posi- 1on. The details of my invention will be described in connection with the accompanying drawings in which Figure l is a view, partiallyv 1n plan and partially in section, of a controller constructed in accordance with my invention. Fig. 2 is a view, partlally in elevation and partially in section, of a portion of the mechanism of Fig. 1. Figs. 3, 4, 5 and 6 are views similar to Fig. 1, showing the relation of the parts of the return mechanism when the controller is in various positions.

Referring particularly to Figs. 1 and 2, a controller 1 of the drum type comprises a casing 2 having a cover member 8 that is rigidly secured to vertically extending rods 4 and 5. A rotatable shaft 6, which carries the movable contact members 7 of the switching mechanism, only a part of which is shown, is provided, at its upper end, with the usual handle 8.

The return mechanism for the rotatable parts of the controller comprises a member 9 that is rigidly secured to the shaft 6. The

tion 12, according to the relative positions of the members 9 and 16. The member 16 is provided with a curved projecting arm 18 having a cam surface 19 at its outerextremity for engaging the roller 14. A spring 20 yieldingly retains the member 16 in its position illustrated in Fig. 1 to hold the member 9 and its connected parts in the positions shown.

It may be assumed that the various parts are in their respective positions illustrated in Figs. 1, 2 and 3. The controller handle is in its ofi' position. When the handle 8 is moved in a clockwise direction, as viewed in Fig. 3, the roller 14, which is in engagement with the cam surface 19 of the projecting member 18, actuates the members 16 about its pivot to place the spring 20 under tension. When the handle is in the first starting position, the various parts have assumed the relative positions illustrated in Fig. 4.

\Vhen the handle reaches the third starting position, as illustrated in Fig. 5, the member 18 has passed out of engagement with the roller 14, and the roller 17 is in engagement with the cam surface 10. The member 16 has been actuated further in a clockwise direction to store energy in the spring 20. It will be evident that, if the handle be released in either of the three starting positions, the spring 20 will operate, through the roller 17 and the cam surface 10 or the projecting member 18 andthe roller 14 to re urn the handle to its off position.

Further rotation of the controller handle brings the several parts intc their respective positions, as illustrated in Fig. 6. In this position of the controller, which is the first running position, the roller 17 engages one of the notches 11 to constitute an accen tuating device for retaining the controller handle and its connected parts in such position until the handle is again actuated by the operator. It will be noted that, in the running position of the controller, the spring 20 and the member in no longer tend to return the controller to its off position. The relations of the several parts in the succeeding running positions of the controller differ in no material respect from those of the position illustrated in Fig. ,6, except that the roller 17 occupies the notch corresponding to the position of the controller.

To return the controller to its off position, it is only necessary to actuate the controller handle in a counter-clockwise direction until it occupies approximately the position shown in Fig. 5. The spring 20 then operates, through the roller 17 and cam surface 10, to continue the movement of the controller drum until the projecting arm 18 engages the roller 1 The engagement of the latter parts then tends to actuate the drum to its off position, as illustrated in Figs. 1 and 3. In order to insure that the drum will come to rest in its proper position, the projection 12 is arranged to engage the roller 17, and the spring 20 is.

placed under tension if the inertia of the rotating parts tends to carry them beyond the off position.

It will be noted that I have provided a device of simple construction in which the operating mechanism is so arranged that, when the controller handle is released by the operator, it will be returned to its 01f position during a portion of its range of travel. During another portion of its range of travel, the mechanism will be yieldingly nes /34.9

vention as employed in connection with a drum controller having starting and run ning positions, it will be obvious that such use is illustrative only and that it may be applied to any mechanism embodying a rotatable element having a definite position to which it may be desirable to return the rotatable element when it has been actuated therefrom. It is immaterial, also, whether controllers constructed in accordance with any invention are employed in connection with direct current motors or alternatingcurrent motors.

I claim as myinvention:

1. In a controller, the combination with a shaft, and a member connected thereto having a cam surface and a series of notches, of a spring-pressed member for succesively engaging said cam surface to bias said shaft to an inoperative position and engaging said notches to retain said shaft in its operative positions.

2. In a controller, the combination with a shaft rotatable in opposite directions be tween its normal and operative positions and a member connected thereto having a cam surface and a series of notches corresponding to operative positions of said shaft, of a spring-controlled member for successively engaging said cam surface to bias said shaft to its normal position and engaging said notches to retain said shaft in the corresponding operative positions.

3. In a controller, the combination with a movable member having a plurality of successive positions, of means comprising a unitary cam mechanism and an accentuating device for returning said member to an inoperative position from certain of said positions, retaining said member in other of said positions, and yieldingly permitting the movement of said member in opposite direc: tions from said last-named positions.

l. In a controller, the combination with a movable member having a plurality of successive positions, of means comprising a unitary cam mechanism and an accentuating device for returning said member to an inoperative position from certain of said positions and for yieldingly retaining said member in other of said positions, and a single spring for actuating said mechanism and said device and for yieldingly bringing said member to rest in its inoperative position.

5. In a controller, the combination with a shaft, and a member connected thereto having a cam surface, a series of radially-extending notches and a projecting member, of a spring-pressed member which operates, upon the rotation of said shaft, to successively engage said projecting member and said cam surface to bias said shaft to its normal position and enga c said notches to yieldingly retain said sha in an operative position.

6. In a controller, the combination with a movable member having an operative position and an inoperative position, of resilient means for actuating said member to said inoperative osition and retaining said member in sai operative position, said means serving as a buffer during said actuation to said inoperative position.

7. In a controller, the combination with a movable member having a starting position and a running position, of means for returning said member to an inoperative position when it occupies said starting position, and a spring for actuating said means and serving as a buffer during said return to said inoperative position.

8. In a controller, the combination with a movable member having a cam surface and a recess, of a member having means for engaging said cam surface to actuate said movable member to an inoperative position and for engaging said recess to yieldingly retain said movable member in an operative position.

9. In a controller, the combination with a movable member having a plurality of starting positions and a running position, of a member having a plurality of means for engaging said first member in each of said starting positions, and means for returning said member to an inoperative position when it occupies any of said starting positions.

10. In a controller, the combination with a movable member having a recess and adapted to occupy a starting position and a running position, of a member having a curved projecting arm for engaging said movable member in the starting position to return said movable member to an inoperative position, and having means for engaging said recess to retain said movable member in said running position.

11. In a controller, the combination with a shaft, and a member connected thereto having a cam surface, a series of radiallyextending notches and a projecting member, of a spring-pressed member having an arm and a projection, said arm being adapted to engage said projecting member to bias said shaft to its normal position, and said projection being adapted to engage said cam surface to bias said shaft to its normal position and to engage said notches to yieldingly retain said shaft in an operative position.

In testimony whereof, I have hereunto subscribed my name this 24th day of Sept,

THOMAS S. PUKERUD.

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