US1128582A - Automatic stop. - Google Patents

Description

V. H. CARMAN.

AUTOMATIC STOP.

APPLICATION TILED AUG.4,1913.

Patented Feb. 16, 1915.

WITNESSES.

ATIORIVEV UNITED STATES PATENT omen.

VICTOR H. CABHAN, OI INDIANAPOLIS, INDIANA, ASSIGNOB TO Cm & ram A COPABTNERSHIP COMPOSED OF VICTOR H. CA BMAN AND DAVID L. FRY

AUTOMATIC STOP.

Specification of Letters Yatent.

. Patented Feb. 16, 1915.

Application filed August 4, 1913. Serial No. 782,817.

useful Automatic Stop, of which the following is a specification.

In the operation of certain moving devices, such as some electric switches, it is desirable that the device in its movement in one direction be stopped for a time in an intermediate position between the initial position and the linal position. Such is the case, for instance, in the star-delta switch shown in my prior Patent No. 1,009,061, issued Augusta, 1913.

It is the object of my present invention to provide automatic means for positively producing such stopping, especially in such star-delta switch.

The accompanying drawing illustratesinv invention as applied to the aforesaid stardelta switch. I

Figure 1 is a perspective view showing such a star-delta switch equipped with my invention, the switch being shown open in fulllines and completely closed, in position for delta connection, in dotted lines: Figs. '2, 3, and 4 are detail views showing the operation of the stopping means in successive positions of the switch in its movement: Fig. 5 is a section on the line 5.' of Fig. 2; Fig. 6 is a section on the line 6-43 of Fig. 3; and Figs. 7 and S are diagrams showing the connections produced by the stardelta switch in its intermediate position and in its full closed position, respectively.

In my aforesaid star-delta switch, there is an insulating base 10 on which are mounted a plurality of pivotal supports 11. 12, and 13, to which are pivoted the switch blades 14, 15, and 1G. The outer end of the-e switch blades are suitably fastened to an insulating cross bar 17. whereby they may be moved together by a common operarbing handle 18. The knife blades cooperate with two sets of contacts 19. .20, and 21. and '22. .23. and ll. each of which contacts has the two spring leaves usual in knife switch contacts. The contacts 19, 20, and 21 a re longer than the contacts '22, :2 and 24. so that they are engaged first by the respective knife blades as the latter are swung downwardly but remain in engagement with the knife blades after the latter engage the contacts '22, Q3, and 24. The contacts 22, 23, and 2% are provided with auxiliary contacts 23' and 23", and 2*, respectively, these auxiliary contacts,- which are conveniently though not necessarily separate pieces from the main contacts, extending upward and toward the auxiliary contacts of the adjacent main contacts, as shown in Fig. 1, 50

that auxiliary switch blade contacts 25 and 3 carried by insulating blocks 21' and 22S suitably ifnounted on the cross bar 17. may pass between and engage the contacts 2;! and 23', and :23" and 24 respectively, when the switch has been brought to its first closed (or intermediate) position, in which the switch blades respectively engage the contacts 19, 20, and ".21. as stated above. The contacts 12'. .20, and 21 are connected to the corresponding ends (the clockwise ends as illustrated) of Coils 30-. I31, and 23;, spectively; and the contacts '32., 23, and it are connected to the other (or counterclockwise) ends of coils 231, 212. and 25". respectively. Thus the two ends of each of said coils are connected to .non-corrcs louding contacts of the two sets of contacts. The coils 5H. :31, and 32 are illustrated as the primary windings of a three-phase induction motor 7- 1. but may be any other coils which it is desired to control in a similar inauncr.

\Vhen the switch above described is open (or 111 its initial position). the coils 30, 31, and t are entirely disconnected. 'hen the switch is moved to its tirst"cl'osed (or intermediate) position, the switch blades ll. 15, and 11' engage the contacts 1 9. '10, and :1. respectively. and the auxiliary switch blade contacts 25 and 2H engage the auxiliary contacts 2;! and 2 3. and 23" and :21. respectivcly, thus connecting the three windings 30, Sl, and 3; in star to the three-phase sup ply mains 33. 3!), and 37. When the switch is moved to its full closed (or Iinal) posi tion. the switch blades ll. 15. and 1" engage the contacts 19 and 22. i and 2 3. and 21 and 24. respectively. and the auxiliary switch blade contacts 3-3 and 26 pass out of engagement with. and the insulating blocks '17 and '28 pass between. the. auxiliary con tacts. thus breaking the star connection and connecting the three windings 3U. 31, and 32 to the supply mains in delta. This switch SllO.il(l be allowed to remain for a time in its intermediate position. to maintain the star connection while the motor,

gains speed. In order to insure this, my

pres'ent. invention, provides an automatic stop which positively stops the switch in its intermediate position as it is moved'from open to full closed position. To this end one of the set of contacts first engaged by the knife blades, say the contact 20, is provided near the top with a transverse opening'40 projecting through both leaves of the contact, and a stop 'pin 41 is carried by a leaf spring 42 so that it may move into such opening to block the path of the switch blade 15 or -out'of such opening to leave such path clear, the two positions being shown in Figs. 6 and 5 respectively. The pin 41 is preferably arranged so that when it is engaged on top by theswitch blade 15, as'shown in Fig. 6, the leaf spring 42 will yield sufficiently so that the'under side of the pin will be. supported by the'lowe'r parts of the opening 40, thereby relieving the strain on the leaf spring. This'leaf spring, which is conveniently fastened between the bottom of the contact 20' and the base 10,

normally stands in thelposition shown in Fig. 5, leaving the path clear between 'the two leaves of the contact 20. In order to movethe leaf spring 42 and the pin 41 to the other or stopping position, the knife blade has attachedto its side an operating plate 43, which cooperates with the upper end' of the spring 42. As the switch is moved .from open toward full closed position, and is approaching its intermediate position, an oblique finger 44 on the plate first engages afinger at the :top of the leaf spring 42, as shown in Fig. 2, and by a cam action forces the spring 42 toward the contact 20. As the switch blades continue their downward movement, the finger 45 asses smoothly from engagement with the i1 er 44 into engagement with the inclined main wall 46 of the plate 43, and is forced thereby farther toward the contact 20. The

uppereedge of the main wall 46 is the closest to the switchf'blade 1.5, at a suflicien't distance therefrom to allow room for a leaf of the contact 20 and the leaf spring 42. The pin 41 now fully occupies the opening 40. As the switch blade continues downward, the'wall 46 passesout of engagement with the finger 45, but engages a lower finger 47 on the spring 42, momentarily allowing the leaf spring 42 to spring out very slightly from the contact 20 so that the upper edge of the wall projects through a notch 48 between the fingers 45 and 47 to the inner side of the finger ,45; but this outward springing is not sufficient to allow the pin41 to clear the path for the knife blade 15 between the two leaves of the contact 20.v The switch is now in the position shown in The notch 48 is sufiiciently narrow so that the projecting pointed end of the wall 46 covers the finger 47 before it passes out of engagement with the finger 45. In

switch positively about this position of the switch, or very slightly thereafter, the switch blade 15 engages the upper surface of the pin 41 and is positively stopped thereby from continuing downward toward its final closed position, the wall 46 engaging the finger 47 to hold the'leaf spring 42 so closely against the contact 20 that the pin 41 fully occupies theopening 40. The windings 30, 31, and 32 are now connected in star. When it is the desire to move the switch beyond the inter mediate position to the full closed position, it is first moved slightly toward open position, in which movement the end of the inclined wall 46 passes through the notch 48 to the space between the finger 45 and the I are ready to serve their purpose to stop the in intermediate position upon the next closing. of the switch.

I claim as my invention 2-- 1. A switch comprising a pivoted knife blade, ardouble leaf contact which said knife blade engages as the switch is moved toward closed position, a second contact which the knife blade engages .after 'it engages the first contact, said first contact being provided with a transverse opening, a pin'movable into and out of such opening, and means carried by the switch blade for movingvsaid pin into said opening to block the path of the switchblade after the latter has been moved into engagement with the first contact but before it has moved into engagement with the second contact.

2. A switch comprising a pivoted 'knife blade, a double leaf contact which said knife blade engages as the switch is moved toward closed position, a second contact which the knife blade engages after it engages the first contact, said first contact being provided with a transverse opening, a pin movable into and out of such'opening, and means carried by the switch blade for moying said pin into said opening to block the path of .ions, a sto movable into and out of the path of saici movable switch member to stop it in its intermediate position, and means carried by said switch member for moving said stop into stopping position as the switch member approaches its intermediate position from its open position and holding said stop in said stopping position until the switch member has been stopped in such intermediate position.

4. In combination, a movable switch member having open, intermediate, and final positions, a stop movable into and out of the path of said switch member itself to stop it in its intermediate position, and means carried by said switch member for moving said stop into stopping position as the switch member approaches its intermediate position from its open position, said stop being spring mounted, and said means carried by t e switch member requiring said switch member to be moved slightly backward from its intermediate position in order to allow said stop to spring out of the path of the switch member, thereby allowing the switch member to be moved through the intermediate position to the final position.

5. In a knife switch, the combination of a pivoted knife blade having open, intermediate, and final positions, and means controlled by the movement of the switch blade from open position toward final position for positively stopping it in its intermediate position.

6. In a knife switch, the combination of a pivoted knife blade having open. intermediate. and final positions, and means controlled by the movement of the switch blade from open position toward final position for positively stopping it in its intermediate position and for ermitting the knife blade to move on to nal position after a preliminary slight backward movement from intermediate position.

7. In ijOITlbllltlClOIl. a member movable in a definite path and having initial. intermediate, and final positions. a spring-mounted stop normally out of such path. and means carried by said member for moving said stop into the path of said member positively to stop the latter in intermediate position as it is moved from initial position toward final position said means requiring a preliminary slight backward movement of the member from intermediate position in order to permit said stop to spring out of such path to allow the member to continue its movement from intermediate position to final position.

8. In combination, a member movable in a definite path and having initial, intermediate, and final positions, a stop normally out of such path, and means carried by said member for moving said stop into the ath of said member positively to stop the atter in intermediate position as it is moved from initial position toward final position and for holding said stop in the path of said member until said member has been stopped in intermediate position.

9. In combination, a switch member having initial, intermediate. and final positions, a stop movable into and out of the path of said switch member to stop it in its intermediate position as it is moved from initial position toward final position, and means carried by said switch member for moving said stop into stopping position as the switch member approaches its intermediate position from its initial position and for holding said stop in stopping position until the switch member is moved backward slightly from intermediate position after having reached such position.

10. In combination. a member movable in a definite path and having initial, intermediate, and final positions, a stop normally out of such path, and means carried by said member for moving said stop into such path to stop said member in intermediate position as it is moved from initial position toward final position and for holding said stop in such path to prevent movement of said member beyond intermediate position until said member is moved slightly backward from its intermediate position after having reached such position.

11. A switch comprising a pivoted knife blade. :1 double leaf contact with which said knife blade engages as the switch is moved toward closed position. a second contact which the knife blade engages after it engages the first contact. said first contact being provided with a transverse opening, a pin movable into and out of such opening in such close proximity to that wall thereof which is toward the closed position of the switch that such pin will be forced against such wall when the pin is engaged by the switch blade. and means carried by the switch blade for moving said pin into such opening to block the path of such blade after the latter has been moved into engagement with the first contact but before it has been brought into engagement with the second contact.

In witness whereof. I have hereunto set my hand at Indianapolis. Indiana, this second day of August. A. D. one thousand nine hundred and thirteen.

VICTOR H. CARMAN.

Witnesses:

Lou'isr. Bmmm'r, G. B. SCHLEY.

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