US923157A - Starting device for electromotors. - Google Patents

Description

K. VON-BERGER STARTING DEVICE FOR ELEGTROMOTORS,

' APPLICATION FILED MAY 23, 1908.

923, 157, Patented June 1,1909.

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KARL VON DREGER, OF BERLIN, GERMANY.

STARTING DEVICE FOR ELECTROMOTORS.

Application filed May 23, 1908.

Specification of Letters Patent.

Patented June 1, 1909.

Serial No. 434,458.

To all whom it may concern:

Be it known that I, KARL VON Dnnenn, a citizen of the Empire of Germany, residing at Berlin, in the Empire of Germany, have in vented a new and useful Starting Device for Electromotors, of which the following is a specification.

There are known starting devices for electromotors comprising a lever riding over the waved circumference of a segment or the like, which latter carries two contact springs and is elastically connected with the operating handle by means of a spiral spring. For starting the electromotor the operating handle is then turned in one direction and the lever serves for braking the segment or the like, so as to prevent it from following too rapidly the operating handle, so that the two contact springs may successively pass over various contact pieces arranged in two concentric arcs, and for stopping the electromotor the operatinghandle requires to be turned back to its initial position. Such starting devices present two serious defects. One defect is, that the two contact springs also lag behind the operating handle during the switcliing-oif operation, which under circumstances may create serious disturbances. The other defect is, that the resistance offered to the lever by the waved circumference of the segment or the like does not decrease in proportion to the diminishing tension of the strained spiral spring on the segment or the like with the two contact springs following the operating handle after the latter has been turned forward for starting the electromotor.

My invention relates to improvements in such starting devices for electromotors, whereby the said two defects are avoided.

Instead of the segment or the like I employ a ring loose on the periphery of a drum which is elastically connected with the operating handle by means of a spiral spring and I provide the ring on its outside with waved surfaces and notches. A lever is provided which is adapted to ride with its free end over the waved surfaces of the ring during the forward turn of the operating handle and to engage in the notches of the ring for stopping same during the return of the operating handle. lvleans are provided for coupling the ring with the drum during the forward turn and for disconnecting the former from the latter during the return. The operating handle is adapted to at once take along with it during its return the drum with the two contact levers. Thus the first defect named above is avoided. The waves in the waved surfaces of the ring are made irregular in such a manner, that in each series of waves the first wave is made the shortest and highest and the last wave is made the longest and lowest, while the intermediate waves successive y decrease in height and increase in length. Then the braking effect of the lever upon the ring will decrease in bout the same proportion as the tension of the spiral spring diminishes. Thus the second defect named above is avoided.

I will now proceed to describe my invention with reference to the accompanying drawing, in which Figure 1 is asection through a starting device on the line ccZ in Fig. 2, when looked at in the direction of the arrows, and Fig. 2 is another section through the same on the line al in Fig. 1., when looked at in the direction of the arrows. Fig. 3 is a view similar to Fig. 2, showing a slightly modified construction.

Similar characters of reference refer to similar parts in all the views.

In a casing or box 1 of any known construction a shaft 8 is provided, which may form a part of any known device not shown. This shaft 8 extends through a cover 30 of the box 1 and carries without a loose operating handle 23 and within a loose spring-d rum 6 and a loose lever 20. The lever 20 is shown as provided with two claws 25 which engage in corresponding recesses in the nave of the operating handle 23. Thereby the lever 20 is obliged to partake in the movement of the operating lever 23. On the periphery of the drum 6 a ring 9 is mounted to turn, while it is prevented from axially shifting by a collar 6 and an internally screw-threaded ring 31 or the like. In the race of the ring 9 there is provided a recess 11 (see Fig. 2) in the periphery of the drum 6, and. in this recess 11 a pawl 10 is mounted to rock on a suitable pin shown, while a leaf spring 12 serves for pressing the pawl 10 on the inner circumference of the ring 9. The latter is provided with three notches 13, into any of which the pawl 10 can engage. A. spiral spring 19 is provided within the drum 6 and is attached with its internal end to the nave of the lever 20 and with its external end to the inside of the drum 6, as is shown. The rim of the drum 6 is provided with a projection 24 on which the lever 20 normally rests under the action of a slight tension in the spring 19. The periphery of the ring 9 is provided with three series of waves 17 and three notches 14, 14 14 which latter are set at an angle of 12 0 from one another. The first .wave in each series 17 (when counting from any of the notches 14", 14 14 in a direction opposite to that of the hands of a clock) is made the shortest and the highest, while the following waves successively decrease in height and increase in length, as is clearly shown in Fig. 2. In the casing 1 a pin 15 is provided, on which a lever 14 is mounted to rock. The hooked free end of this lever 14 is adapted to ride over the waved periphery of the ring 9. Between the lever 14 and the inside of the casing 1 a helical spring 16 is inserted, which serves for pressing the hooked end of the lever 14 on the ring 9. The tension of the helical spring 16 can be regulated by means of an adjusting screw 32 in the lever 14. On

the side of the drum 6 and insulated therefrom are fastened two contact springs 4 and 5, which are electrically connected with one another. Sufficient play is left to the three parts 6, 20 and 23, which can longitudinally shift on the shaft 8 and are normally pressed together against a collar 33 on the shaft 8 by the two contact springs 4 and 5.

On the inside of the casing 1 and insulated therefrom are fastened for example a contact strip 2, six contact pieces 3, 3 and two insulating pieces 27, all of which are disposed in two concentric rows around the shaft 8 and are well known. The contact spring 4 is adapted to slide over one insulating piece 27 and the contact strip 2, while the other contact spring 5 is adapted to slide over the other insulating piece 27 and the series of contact pieces 3, 3 and to strike against a projection 28 of the last contact piece 3 whereby the turn of the drum 6 with the two contact springs 4 and 5 in the direction of the arrow 18 is limited. The angle through which the two contact springs 4 and 5 can be turned from their normal position shown in full lines in Fig. 2 to their other extreme position over the last contact piece 3 amounts to 120 like the angle between any two of the notches 14, 14 14 in the ring 9. The operating handle 23 normally occupies the same position as the two contact springs 4 and 5, which position is indicated by the dotted center line A8, and can be turned beyond the last contact piece 3 to the other extreme position indicated by the dotted center line B*8. In this extreme osition the operating handle 23 may be hell it bearing against some pin provided on the cover 30, or it may be secured by means of any known stopping, pinching or locking device.

The starting device operates as follows: For the normal position of the operating handle 23 in the dotted center lineA8 in l by hand, r

Fig. 2 the hooked end of the lever 14 engages in any of the three notches 14 (as shown), 14 14 and the pawl 10 engages in the corresponding notch 13 of the ring 9. When the operator is desirous of starting the electromotor, he turns the operating handle 23 in the direction of the arrow 18 to the other extreme position B8 with any speed he likes. Thereby of course the lever 20 is moved off from the projection 24 of the drum 6 and the spiral spring 19 is strained, so that its tension will pull the drum 6 with the two contact springs 4 and 5 forward in the direction of the arrow 18, and the .pawl 10 will take the ring 9 along with it, but the spring-pressed lever 14 will brake the ring 9 and prevent it together with the drum 6 and the two contact springs 4 and 5 from following too rapidly the operating lever 23. During this movement the tension of the spiral spring 19 will diminish, but as the waves 17 also decrease in height and increase in length, the diminishing tension of the spiral spring 19 will be still able to overcome the friction of the hooked end of the lever 14 on the periphery of the ring 9 and to move the contact springs 4, 5 to their extreme position in which one of them (5) strikes the projection 28 of the last contact piece 3 In this manner the two contact springs 4 and 5 are moved forward with a nearly uniform speed. The small tension still remaining in the spiral-spring 1-9 will suffice for pressing the contact spring 5 against the projection 28 and thus securing the two contact s rings in their extreme position, while the liboked end of the springpressed lever 14 engages in the following notch 14 of the ring 9. Of course the lever 20 will be at a small distance from the projection 24. In this manner the electromotor is gradually started in spite of any rapidity in the movement of the operating handle 23. When the operator wants to StQp tl16*6l6Ct1O motor, he turns the operating handle 23 back from the position B-8 to the initialposition A-S with any speed he likes. The lever 20 striking the projection 24 will thereby take along with it the drum 6 and the pawl 10 will slide on the inner circumference of the ring 9 until it engages in the following notch 13. Thus the two contact springs 4 and 5 are moved back as rapidly as the operating handle 23, as it should be. The ring 9 is of course prevented from returning by the hooked end of the lever 14 engaging its notch 14 The starting device described may be varied in many respects without departing from the spirit of my invention. For example the lever 14 may be weighted instead of spring-pressed. The ring 9 may be provided on its side with a waved groove, as is indicated in Fig. 3, it having on its inside nearer the shaft 8 substantially the same outline as the waved periphery of the ring 9 shown and described above with reference to Fig. 2. The free end of the lever M may have a pin or a pin with a roller for engaging in the waved groove. In this case the lever 14 is preferably not spring-pressed or weighted but is pivotally connected with the rod 34 of a piston fitting loosely in the cylinder 29 of an air-brake or liquid-brake of a known construction, as is indicated in Fig. 3.

I claim:

1. In a starting device for electromotors. the combination with an operating handle, of a drum, a spring connecting said operating handle with said drum for pulling the latter forward, a ring turnable on said drum, means forconnecting said ring with said drum during the forward turn of said operating handle for switching-on, means for stopping said ring during the return of said operating handle for switching-oil, contact pieces, two electrically connected contact springs on said drum and insulated therefrom and adapted to slide over said contact pieces, and means for braking said ring with a force decreasing in proportion to the diminishing tension of said spring so as to move said two contact springs with a nearly uniform speed, said operating handle being adapted during its re turn to take along with it said drum with said two contact springs.

2. In a starting device for eleotromotors, the combination with an operating handle, of a drum provided with a recess and a projection, a spring connecting said operating handle with said drum for pulling the latter forward, a ring turnable on said drum and provided with a notch, a spring-pressed pawl in the recess of said drum and adapted to engage in the notch of said ring for taking the latter along with it during the forward turn of said operating handle for switching-on, means for stopping said ring during the return of said operating handle for switchingoff, contact pieces, two electrically connected contact springs on said drum and insulated therefrom and adapted to slide over said contact pieces, and means for braking said ring with a force decreasing in proportion to the diminishing tension of said spring so as to move said two contact springs with a nearly uniform speed, said operating handle being adapted during its return to strike the projection of said drum and thereby take along with it the latter with said two contact springs.

3. In a starting device for electromotors, the combination with an operating handle, of a drum provided with a recess and a projection, a spring connecting said operating handle with said drum for pulling the latter forward, a ring turnable on said drum and provided on its inner circumference with a notch and on its outside with a waved surface and a notch, spring-pressed pawl in the recess of said drum and adapted to engage in the internal notch of said ring for taking the latter along with it during the forward turn of said operating handle for switchingon, a support, a lever mounted on said sup port to roclr and adapted to ride with its free end over the waved surface of said. ring and to engage the external notch of same for preventing it from returning during switching-oif, contact pieces, two electrically connected contact springs on said drum and insulated therefrom and adapted to slide over said contact pieces, and means for braking said ring by means of said lever, the waves in the waved surface of said ring successively decreasing in height and increasing in length for reducing the fi 'ction of said lever in proportion to the diminishing tension of said spring so as to move said two contact springs with a nearly uniform speed, and said operating handle being adapted during its return to strike the projection of said drum and thereby take along with it the latter with said two contact springs.

4. In a starting device for electroinotors, the combination with a plate, of a shaft at right angles to said plate, an operating handle on said shaft, a drum loose on said shaft, a spring connecting said operating handle with said drum for pul ing the latter forward, a ring turnable on said drum, means for connecting said ring with said drum during the forward turn of said operating handle for switching-on, means for stopping said ring during the return of said operating handle for switching-oil, contact pieces on said plate, two electrically connected contact springs on said drum and insulated therefrom and adapted to slide over said contact pieces, and means for braking said ring with a fo ce decreasing in proportion to the diminishing'tension of said spring so as to move said two contact springs with a nearly uni- .form speed, said operating handle being adapted during its return to take along with it said drum with said two contact springs.

5. In a starting device for electromotors, the combination with a plate, of a shaft at right angles to said plate, an operating handle on said shaft, drum loose on said shaft and provided with a recess and a projection,

a spring connecting said operating handle with said drum for pulling the latter forward, a ring turnable on said drum and provided with a notch, a spring-pressed pawl in the recess of said drum and adapted to engage in I the notch of said ring for taking the latteralong with it during the forward turn of said operating handle for switching-on, means for stopping said ring during the return of said operating handle for switching-oil, contact pieces on said plate, two electrically connected contact springs on said drum and insulated therefrom and adapted to slide over said contact pieces, and means for braking said ring with a force decreasing in proportion to the diminishing tension of said spring so as to move said two contact springs with a nearly uniform speed, said operating handle being adapted during its return to strike the projection of sale drum and thereby take along with it the latter with said two contact springs.

6. In a starting device for electromotors, the combination with a plate, of a shaft at ri ht angles to said plate, an operating handle on said shaft, a drum loose on said shaft and provided with a recess and a projection, a spring connecting said operating handle with said drum for pullin the latter forward,

5 a ring turnable on said drum and provided on its inner circumference with a notch and on its outside with a waved surface and a notch, a spring-pressed pawl in the recess of said drum and adapted to en age in the internal notch of said ring for taking the latter along with it during the forward turn of said operatinghandle for switching-on, a lever mounted on said plate to rock and adapted to ride with its free end over the waved surface of said ring and to engage the external notch of same for preventing it from returning during switching-off, contact pieces on said plate, two electrically connected contact springs on said drum and insulated therefrom and adapted to slide over said contact pieces, and means for braking said ring by means of said lever, the waves in the waved surface of said ring successively decreasing in height and increasing in length for reducing the friction of said lever in proportion to the diminishing tension of said spring so as to move said two contact springs with a nearly uniform speed, and said operating handle being adapted during its return to strike the projection of said drum and thereby take along with it the latter with said two contact springs.

7. In a starting device for electromotors, the combination with a plate, of a shaft at right angles to said plate, an operating handle on said shaft, a drum loose on said shaft, a spiral spring connecting said operating handle with said drum for pulling the latter forward, a ring turnable on said drum, means for connecting said ring with said drum during the forward turn of said operating handle for switching-on, means for stopping said ring during the return of said operating handle for switching-off, contact pieces on said plate, two electrically connected contact springs on said drum and insulated therefrom and adapted to slide over said contact pieces, and means for braking said ring with a force decreasing in proportion to the diminishing tension of said spiral spring so as to move said two contact springs with a nearly uniform speed, said operating handle being adapted during its return to take along with it said drum with said two contact springs.

8. In a starting device for electromotors, the combination with a plate, of a shaft at right angles to said plate, an operating handle on said shaft, a drum loose on said shaft and provided with a recess and a projection,

a spiral spring connecting said operating handle with said drum for pulling the latter forward, a ring turnable on said drum and provided with a notch, a spring-pressed pawl in the recess of said drum and adapted to engage in the notch of said ring for taking the latter along with it during the forward turn of said operating handle for switching-on, means for stopping said ring during the return of said operating handle for switchingoff, contact pieces on said plate, two electrically connected contact springs on said drum and insulated therefrom and adapted to slide over said contact pieces, and means for braking said ring with a force decreasing in proportion to the diminishing tension of said spiral spring so as to move said two contact springs with a nearly uniform speed, said operating handle being adapted during its return to strike the projection of said drum and thereby take along with it the latter with said two contact springs.

9. In a starting device for electromotors, the combination with a plate, of a shaft at right angles to said plate, an operating handle on said shaft, a drum loose on said shaft and provided with a recess and a projection, a spiral spring connecting said operating handle with said drum for pulling the latter forward, a ring turnable on said drum and provided on its inner circumference with a notch and on its outside with a waved surface and a notch, a spring-pressed pawl in the recess of said drum and adapted to engage in the internal notch of said ring for taking the latter along with it during the forward turn of said operating handle for switching-011, a lever mounted on said plate to rock and adapted to ride with its free end over the waved surface of said ring and to engage the external notch of same for preventing it from returning during switchingoff, contact pieces on said plate, two electrically connected contact springs on said drum and insulated therefrom and adapted to slide over said contact pieces, and means for braking said ring by means of said lever, the waves in the waved surface of said ring successively decreasing in height and increasing in length for reducing the friction of said lever in proportion to the diminishing tension of said spiral spring so as to move said two contact springs with a nearly uniform speed, and said operating handle being adapted during its return to strike the projection of said drum and thereby take along with it the latter with said two contact springs.

KARL VON DREGER.

Witnesses NOLDEMAR HAUPT, HENRY Hasrnn.

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