US2898417A - Automatic starting and reversing switch - Google Patents

Description

1959 E. E. WIECZOREK I 2,898,417

AUTOMATIC STARTING AND REVERSING SWITCH Filed Aug. 13, 1957 2 Sheets-Sheet l 1959 E. E. WIECZOREK 2,898,417

AUTOMATIC STARTING AND REVERSING SWITCH Filed Aug. 13, 1957 2 Sheets-Sheet 2 United States Patent AUTOMATIC STARTING AND REVERSING SWITCH Eugene E. Wieczorek, Racine, Wis., assignor to In-Sink- Erator Manufacturing Company, Racine, Wis, a corporation of Wisconsin Application August 13, 1957, Serial No. 677,962

'12 Claims. (Cl. 200-80) This invention relates to a combined speed and direction responsive switch mechanism for controlling the starting Winding on an induction motor. in the patent to Hammes 2,701,855 for Reversible Motor and Switch for Garbage Disposal Units, issued February 8, 1955, there is disclosed apparatus for causing the electric motor to alternate its direction of rotation with each successive starting cycle. The mechanism there disclosed comprises a switch plate actuated by a centrifugal mechanism to place the starting winding in and out of a circuit depending upon the speed of motor rotation. This switch plate is furthermore controlled by the motor shaft in accordance with its direction of rotation so that as the motor comes to rest or slows down, the connection to the starting winding is established for the reverse direction of rotation.

Mechanisms of this character are effectively utilized in apparatus such as garbage grinders, garage door openers and other devices to provide effective overload protection by arranging for prompt reversal of the motor whenever it tends to stall.

While the switch mechanism there disclosed has been widely used commercially with complete success, it in volves the use of rather expensive assembly procedures and requires certain flexible conductors which are undesirable if both low cost and long life are to be achieved.

It is an object of the present invention to provide an improved switch mechanism of the class described wherein the reliability over a long life may be enhanced.

A further object is to provide a switch mechanism of the character described which may be produced economically and which avoids the use of flexible conducting leads or pigtails.

A further object is to provide an improved friction driving mechanism for controlling switch operation in response to the direction of motor rotation.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred form of the present invention is illustrated.

In the drawings:

Fig. 1 is a side view of a motor shaft and switch assembly embodying a preferred form of the present invention.

Fig. 2 is a top view of the switch assembly shown in Fig. 1, showing the shaft in cross section on line 2-2 of Fig. 1.

Fig. 3 is an enlarged end view, looking from the left in Fig. 2, of the switch assembly shown in Fig. 1.

Figs. 4 and 5 are sectional views taken on line 4-4 of Fig. 1 and showing the parts in difierent operating positions.

Fig. 6 is a fragmentary sectional view taken longitudinally of the motor shaft, showing a portion of the switch operating mechanism.

Referring now to Fig. 1, a motor shaft 10 carries pressed thereon a plate 12 forming the base of a centrifugal mechanism generally designated 14-. This may ice comprise weighted arms 16 pivoted at 18 and urged inwardly by springs 20. The mechanism 14 may be of any desired form and the one in the drawings is similar to that shown in the Hammes patent previously referred to.

Mounted upon a stationary portion of the motor frame is a base plate 22 which forms the principal frame or base for a switch assembly. The plate 22 is preferably formed as a unitary molded piece of insulating material, for example, phenolic or other plastic compound. The base plate 22 carries a plurality of pairs of contact leaves for the purpose of controlling the starting Winding of an electric motor and also for controlling other auxiliary circuits as may be desired.

Mounted upon upstanding bosses 24 are a pair of main line contact leaves 26 which have terminal tabs 28. The leaves 26 have separate branches 30 and 32, each of which carries a contact point 34 which is one of a pair of co-operating contacts. Also secured to the base plate 22 are a pair of U-shaped contact leaves 36 and 38 and these carry at their tips a mating contact point forniing the other half of each contact pair.

The plate 22 may be provided with elongated openings as shown at 42, which provide for some free action of the tips of the leaves 36 and 33, While a raised arcuate cross bar 44 which is molded integrally with the plate 22 extends across the openings 42 to limit the upward movement of each leaf. The leaves 26 have auxiliary branches 46 and 48, each of which carries one of a pair of contact points 50 and 52 respectively. The opposite contact points 54 and 56 of each pair are carried by leaves 58 and 60 which are mounted upon plate An upstanding boss 62 provides an elevated mounting for the leaf 58 so that the contacts 50-54 are nor-malty closed. The leaf 60, however, is mounted upon a lower level boss 64 so that the contacts 2v56 are normaily open. An independent set of actuating contacts 66-60 are carried on leaves 70 and 72 respectively, which are secured to the plate 22 as shown in Fig. 3. The contacts 6668 are normally open.

For the purpose of actuating the various contactors mounted upon base plate 22, there is provided an actuator ring generally designated 74. This comprises a flange 76 having a central tubular neck 73 (see Fig. 6) which has an internal diameter to loosely fit upon the sh: ft 10. The plate 22 is provided with an aperture through which the neck 78 extends and below the plate 22 there is provided a snap ring or collar for limiting u .vard movement of the actuator ring.

A depending cylindrical portion is also formed on the lower face of flange 76 to serve as a stop for limiting the downward movement of the actuator ring "F4. A projecting pin 86 is formed on the bottom surface of portion 34 to engage in either one of two holes 38 (see Figs. 4 and 5) formed in the base plate Surrounding the neck 78 is a helical compression spring 550 for holding the ring 74 in its uppermost position.

The lower face of the flange 76 is provided with a plurality of contact operators which take the form of integral projections preferably molded in a single piece with the entire actuator ring 74. These contact actuators are so arranged that they engage with various of the contact leaves to depress them toward the plate 22 depending upon the angular position of the ring 74.

Referring to Figs. 4 and 5, it will be seen that there are two projections 92 and 94 which actuate one or the other of the pair of leaves 30 and 32 depending upon whether they occupy the position of Fig. 4- or that of Fig. 5 when the ring is depressed. Another projection 96 may selectively overlie the contact leaf 53 for the purpose of opening the contacts 50-54 when the ring is in position of Fig. 4 and then depressed toward the plate a) 22. A fourth operator 98 is arranged to overlie the end of leaf 48 to close the contacts 52-56 when the ring is in the position of Fig. 4 and depressed toward the plate 22. Another contact operator 100 is arranged to overlie the leaf 70 when in both positions of ring 74, for the purpose of closing contacts 66'68 whenever the ring is depressed.

If desired, the flange 76 may be provided with extra operators 102 and 104 in the event that extra leaves corresponding to leaves 58 and 60 are to be mounted on the extra bosses 106 and 108. The operators 96 and 102 may also serve as stops to limit the rotary motion of ring 74 by abutment with the bosses 24 at the top and bottom of Figs. 4 and 5.

In operation, the parts are shown in Fig. l in the position which they occupy when the motor shaft is rotating at a speed above critical, that is, the speed where'the starting winding is cut out. Thus, the centrifugal weights 16 have been swung outwardly by centrifugal force which overcomes the force of the springs 20. This enables the actuator ring 74 to be elevated by the spring 90. Thus the contacts which are normally open remain open and those normally closed remain closed, as for example contacts 50-54.

When the motor slows down under an excessive load imposed by the material in a garbage grinder, for example, or by a garage door operator reaching the end of its travel, centrifugal weights 16 swing inwardly and press the ring 74 downwardly in Fig. 1 until the stop ring 84 contacts the plate 22. If the direction of rotation of the motor shaft 10 had been in a clockwise direction, the contact operating projections would lie in the positions shown in Fig. 4, and actuate the respective contact leaves over which they lie.

Thus, if the main line contact leaves 26 be connected to the power source as shown in the Hammes patent above referred to, and the U-shaped leaves 36 and 38 are connected to the starting winding, a connection will be established for counter-clockwise starting of the motor. This causes the motor to pick up speed in a counterclockwise direction until other controls cut off the supply of current or until the motor stalls again while operating counter-clockwise.

The auxiliary contacts 50-54 and 52-56 may be utilized for controlling a holding relay or for other purposes and the contacts 66-68 may be utilized for controlling a garage light or for controlling certain auxiliary windings provided in the motor. Obviously, many other circuit controlling functions may be initiated and terminated in accordance with the opening and closing of these contacts.

The friction drive mechanism between the shaft 10 and the actuator ring 74 comprises a bore 110 extending diametrically through the shaft 10 and carries a pair of plungers 112 urged outwardly by a spring 114. The plungers 112 each carry a tip 116 preferably formed of leather or other suitable long wearing friction material so that they exert a constantly effective frictional drag between the shaft and the ring 74. Thus, whenever the motor shaft slows down, the ring 74 will have been rotated until one of the stop projections 96 or 102 is in contact with an upstanding boss 24 on the plate 22.

It will thus be seen that the present invention provides an improved and simplified switch mechanism in which all of the electric contacts are carried upon a single base plate which avoids the use of flexible pigtailed connections and that, furthermore, the operating parts of the switch assembly comprise but two unitary plastic molded pieces, one of which serves as the switch base and the other of which serves as a contact actuator which is responsive to both rotational and translatory movements to selectively actuate the contacts.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A switch assembly for association with a motor shaft and responsive to both speed and rotation thereof comprising a base plate carrying a plurality of pairs of leaf mounted contacts having connection terminals secured to the base plate, an actuating ring mountable on the shaft for relative rotation and axial translation and having a flange parallel with the base plate and a tubular neck extending through the base plate, a spring surrounding the neck and urging the flange away from the base plate, a stop collar on the neck for limiting the motion of the flange away from the base plate, and a plurality of bosses mounted on the flange in positions overlying the leaves of certain contacts to actuate the contacts upon axial motion of the flange relative to the base plate and selectively responsive to rotation of the flange for bringing at least one boss into and out of overlying relation to one of the leaves for actuation or non-actuation thereof.

2. A switch assembly for association with a motor shaft and responsive to both speed and rotation thereof comprising a base plate carrying a plurality of pairs of leaf mounted contacts having connection terminals secured to the base plate, an actuating ring mountable on the shaft for relative rotation and axial translation and having a flange parallel with the base plate and a tubular neck extending through the base plate, a spring surrounding the neck and urging the flange away from the base plate, a stop collar on the neck for limiting the motion of the flange away from the base plate, a plurality of bosses mounted on the flange in positions overlying the leaves of certain contacts to actuate the contacts upon axial motion of the flange relative to the base plate and selectively responsive to rotation of the flange for bringing at least one boss into and out of overlying relation to one of the leaves for actuation or non-actuation thereof, frictional means associated with the motor shaft and resiliently engaging the interior of the neck and centrifugal operating means carried by the shaft and arranged to actuate the flange in an axial direction.

3. A combined rotation responsive and translation responsive switch comprising a base plate, a plurality of pairs of contact leaves secured to the base plate, an actuator plate mounted on the base plate for both rotation and translation with respect thereto, spring means for normally holding the actuator plate in one position of translation, and a plurality of contact operators attached to the actuator plate, at least one of the operators and its associated contact leaf being positioned for engagement only when the actuator plate has been rotated to a predetermined angular position.

4. A combined rotation responsive and translation responsive switch comprising a base plate, a plurality of pairs of contact leaves secured to the base plate mounted on the base plate for both rotation and translation with respect thereto and, an actuator plate having a cylindrical neck portion extending through the base plate, spring means surrounding the neck for normally holding the actuator plate in one position of translation, and a plurality of contact operators attached to the actuator plate, at least one of the operators and its associated contact leaf being positioned for engagement only when the actuator plate has been rotated to a predetermined angular position.

5. A combined rotation responsive and translation responsive switch comprising a base plate, a plurality of pairs of contact leaves secured to the base plate, an actuator plate mounted on the base plate for both rotation and translation with respect thereto, spring means for normally holding the actuator plate in one position of translation, and a plurality of contact operators comprising raised bosses attached to the actuator plate, at least one of the operators and its associated contact leaf being positioned for engagement only when the actuator plate has been rotated to a predetermined angular position.

6. A combined rotation responsive and translation responsive switch comprising a base plate, a plurality of pairs of contact leaves secured to the base plate mounted on the base plate for both rotation and translation with respect thereto and, an actuator plate having a cylindrical neck portion extending through the base plate, spring means surrounding the neck for normally holding the actuator plate in one position of translation, and a plurality of contact operators comprising raised bosses attached to the actuator plate, at least one of the operators and its associated contact leaf being positioned for engagement only when the actuator plate has been rotated to a predetermined angular position.

7. A combined rotation responsive and translation responsive switch comprising a base plate, a plurality of pairs of contact leaves secured to the base plate, an actuator plate mounted on the base plate for both rotation and translation with respect thereto, spring means for normally holding the actuator plate in one position of translation, and a plurality of contact operators attached to the actuator plate, at least one of the operators and its associated contact leaf being positioned for engagement only when the actuator plate has been rotated to a predetermined angular position, said base plate and said actuator plate each consisting of a single piece of molded insulating material.

8. A combined rotation responsive and translation responsive switch comprising a base plate, a plurality of pairs of contact leaves secured to the base plate mounted on the base plate for both rotation and translation with respect thereto and, an actuator plate having a cylindrical neck portion extending through the base plate, spring means surrounding the neck for normally holding the actuator plate in one position of translation, and a plurality of contact operators attached to the actuator plate, at least one of the operators and its associated contact leaf being positioned for engagement only when the actuator plate has been rotated to a predetermined angular position, said base plate and said actuator plate each consisting of a single piece of molded insulating material.

9. A combined centrifugal and directional switch mechanism comprising a shaft, a base plate, an actuator plate, contacts controlled by the actuator plate, a centrifugal actuator on the shaft and arranged to push the actuator plate axially in response to changes in shaft speed, and a friction pad resiliently positioned to form a yielding rotary drive between the shaft and the actuator plate.

10. A combined centrifugal and directional switch mechanism comprising a shaft, a base plate, an actuator plate, contacts controlled by the actuator plate, a centrifugal actuator on the shaft and arranged to push the actuator plate axially in response to changes in shaft speed, and a friction pad of leather resiliently positioned to form a yielding rotary drive between the shaft and the actuator plate.

ll. A combined centrifugal and directional switch mechanism comprising a shaft, a base plate, an actuator plate, contacts controlled by the actuator plate, a cen trifugal actuator on the shaft and arranged to push the actuator plate axially in response to changes in shaft speed, and a friction pad resiliently positioned to form a yielding rotary drive between the shaft and the actuator plate, said pad being positioned radially in the shaft and arranged to contact an interior cylindrical surface formed on the actuator plate.

12. A combined centrifugal and directional switch mechanism comprising a shaft, a base plate, an actuator plate, contacts controlled by the actuator plate, a centrifugal actuator on the shaft and arranged to push the actuator plate axially in response to changes in shaft speed, and a friction pad of leather resiliently positioned to form a yielding rotary drive between the shaft and the actuator plate, said pad being positioned radially in the shaft and arranged to contact an interior cylindrical surface formed on the actuator plate.

References Cited in the file of this patent UNITED STATES PATENTS 2,701,855 Hammes Feb. 8, 1955 2,806,917 Hupp et a1 Sept. 17, 1957 2,831,153 Deming et al Apr. 15, 1958

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