US3214557A - Motion translating means - Google Patents

Description

Oct. 26, 1965 H. M. PFLANZ 4,

MOTION TRANSLATING MEANS Filed Feb. 11, 1965 2 Sheets-Sheet l Oct. 26, 1965 H. M. PFLANZ ,2

MOTION TRANSLATING MEANS Filed Feb. 11, 1965 2 Sheets-Sheet 2 @klsoRm/Zg United States Patent Wis.

Filed Feb. 11, 1963, Ser. No. 257,726 2 Claims. (Cl. 2001'53) This invention relates to means for actuating switches or the like, particularly to actuating means that reciprocally actuate the contacts of switches.

With the development of the vacuum switch, the trend in switch actuating mechanisms has been to smaller and lighter structures. This may appear simple to attain, but in practice many difficulties are present. For example, one problem is to provide means that will move contacts of switch modules positively to make and break the contact without an elaborate structure that will dwarf the vacuum switches themselves.

In accordance with this invention, a means is provided that positively translates reciprocal motion in both directions to open and close contacts. By utilizing such positive translation no biasing means directly controlling the movement of the contacts is required. The particular means also provides for limited movement without affecting the contact position so that minor movement or oscillations will not partially open or close the contacts. Also, 'with the use of this invention it is possible to individually adjust the gaps of each of the contacts without affecting the adjustment of other contacts. This adjustment may be simply made without any dismantling of complicated structure.

An object of this invention is to provide new and improved means for reciprocally moving contacts of a switch, especially a vacuum switch.

' Another object is to provide means for moving contacts of a vacuum type circuit breaker or switch that is small,"light, and uncomplicated.

Another object is to provide switch actuating mecha nisms that are reliable in operation, simple to install, and inexpensive to manufacture.

Another object is to provide switch actuating mechanisms that are readily adaptable for operating either vacuum switches or modules of vacuum switches or circuit breakers.

Another object is to provide a switch actuating mechanism that positively moves contacts from one position to another without excessive rebound or recoil.

Another object is to provide a contact moving means and linkage that provides for simple adjustment of the gap between switch contacts.

Another object is to provide a switch actuating mechanism for modules of switches that enables independent adjustment of contact gaps.

Another object is to provide a switch moving means that has a determinable mechanical advantage between the mechanism powering the movement of the contacts and the contacts themselves.

7 Another object is to provide a switch moving means for switches that maintains the contact position even with spurious limited movement of the contact actuating mechanism.

Other objects and advantages of this invention will be apparent from the following detailed description.

FIG. 1 is a cross section view, including vacuum switches, of a switch actuating mechanism embodying this invention;

relative to its associated cam follower.

3,214,557 Patented Oct. 26, 1965 FIG. 4 is a top view of the linkage mechanism shown in FIG. 3 with the top cover portion removed;

FIG. 5 is a view of the linkage mechanism taken along lines VV of FIG. 3; and

FIG. 6 is a view of a portion of the linkage mechanism shown in FIG. 3 showing the cam in another position.

FIG. 1 illustrates a circuit breaker or switch actuating mechanism having vacuum switches 10 and 10' and a contact actuating means 12. Vacuum switches 10 and 10 operate similarly and like parts are provided with similar reference characters.

The vacuum switches are mounted on a linkage housing 14 which is mounted on top of a support column 15.

One of the vacuum switches, switch 10, is shown in FIG. 1 in cross section. Each switch may comprise a cylindrical casing 18 closed at one end by a cover 19 and secured to linkage housing 14 at the other end by suitable means such as bolts 20 and a flange 21. Cover 19 also serves as a means for receiving and positioning one end of a stationary vacuum switch contact 22 within cylindrical casing 18 and as an electrical contact for interconnecting the vacuum switches or connecting them to a load or electrical source.

Vacuum switch 10 further comprises a cylindrical envelope 23 which may be formed, for example, of a suitable vitreous material. One end of envelope 23 is sealed to a cap 24 in vacuum tight relationship. Cap 24 supports stationary contact 22 which is arranged to extend along the longitudinal axis of envelope 23.

At the opposite end of envelope 23 a tube or retainer 25 is sealed in a vacuum tight connection to envelope 23. A metallic, cylindrically shaped bellows 26 is cylindrically secured in a vacuum tight connection to one end of tube 25. The other end of bellows 26 surrounds and is fixedly attached in a vacuum tight connection to a movable contact 27 which is arranged to extend through retainer 25 into envelope 23 and to move in cooperating relationship with contact 22.

Movable contact 27 and stationary contact 22 may be made of any suitable material such as tungsten or copper.

In order to control the arcing product emitted upon separation of the engaging surfaces of contacts 22 and 27, a cylindrically shaped, tubular shield 28 is provided around and spaced from contact 27. Shield 28 is arranged to extend beyond the adjacent ends of the contacts so as to surround at least a part of contacts 22 and 27 when the contacts are in contact engaging position.

Movable contact 27 and its counterpart 27 extend into linkage housing 14. Connecting means 33 and 33 are provided for connecting the movable contacts 27 and 27' to cam followers 31 and 31', respectively. Connecting means 33 may comprise a connecting cylinder 29, connecting rod 62, flanges 61 and 66 held together by bolts 60, and cam follower connector 63. A means 67 is provided for independently adjusting the location of each contact relative to the axis of movement of cam 42 or Means 67 is used to adjust the contacts to the optimum opening and closing position to insure proper closing and opening of the contacts. Washers 59 or similar elements may be inserted between flanges 61 and 66 to adjust the separation between cam follower 31 and connecting rod 62 to thereby space the contacts from the axis of movement. In this manner, each contact may be separately adjusted without dismantling any large structural components or affecting other contacts. To accomplish this it is only necessary to remove bolts 66 and insert the appropriate thickness of washer between flanges 66 and 61.

The movable contacts are actuated through the cam followers and connecting means by the movement of cam 42 substantially simultaneously in opposite directions so that both move inwardly and outwardly of their respective envelopes at the same time, that is, they are reciprocally actuated.

As shown more clearly in FIGS. 3, 4 and 5, particularly FIG. 3, connecting rod 62 is connected to move within an end 30 of connecting cylinder 29 and is connected to camfollower 31 at connecting flanges 61 and 66. Another end 35 of connecting cylinder 29 is rigidly connected to movable contact 27 through a retaining sleeve 64. A shunt 36 is electrically connected to contact 27 through retaining sleeve 64 with a bolt 65, and in this embodiment provides an electrical path between contacts 27 and 27' to place the contacts in series. A pin 32 is rigidly connected to connecting rod 62 and moves within a slot or hole 34 in cylinder 29. A spring 37 is in a precompressed condition between pin 32 and sleeve 64 when the contacts are open. As cam follower 31 is moved outwardly, it moves the pin to further compress spring 37 thereby pressing with sufficient force against the sleeve to move contact 27 to the closed position and thereby further charge spring 37. The predetermined compression of spring 37 serves to provide a given force at contact make to prevent contact rebound and overtravel. When the pin is moved in the opposite direction, pin 32 pushes against the sleeve at its slot to open the contacts, as shown in FIG. 6.

Contact actuating means 12 moves the contacts through a shaft 17 and a linkage mechanism 11. Shaft 17 is connected to the linkage mechanism at cam 42. As shown in FIG. 3, cam 42 has surfaces or slots 54 and 54 each of which form a middle slot portion 81) and 80 with extending slot end portions 68 and 68, respectively, at one end, and 69 and 69', respectively, at the other end. Cam followers 31 and 31 ride in, and are guided by, their respective slots 54 and 54' as shown. The cam is reciprocally movable along an axis to two positions and moves the cam followers along the axis of the contacts to move the contacts inwardly and outwardly from envelopes 23 and 23 to open and close the contacts. Retaining bars 55 and 55' maintain the position of the cam followers relative to the axis of the contacts. Rollers 56 retain the position of cam 42 so that it moves in the proper direction without wobbling.

Slots 54 and 54' have geometric configurations whereby cam followers 31 and 31 are pushed in one direction when the cam moves from one position to the other, and are pushed in another direction when the cam returns to the original position, thus making both movements mechanically positive. For example, as cam 42 moves from the position shown in FIG. 3 to the position shown in FIG. 6, a cam surface section 57 of the slot pushes against cam follower 31 to move it outwardly of the envelopes to open the contacts. As the cam moves from the position shown in FIG. 6 to the position shown in FIG. 3, a cam surface section 58 of the slot pushes against the cam follower to move it inwardly of the envelopes to close the contacts. Thus, no biasing means is relied upon to directly move the contacts in either direction. Instead, each movement is accomplished by a positive mechanical linkage between cam 42 and movable contacts 27 and 27'.

The position of movable contact 27 is maintained by slot end portion-s 68 and 69 if cam 42 should move or oscillate along its axis of movement within the limits of the length of the end portions. This results because the slot end portions are elongated along a line parallel to the axis of movement of cam 42 and the open and closed position of the contact is achieved when the cam followers are in these slot end portions. Therefore, these slot end portions effectively provide a lost motion mechanism between contacts 27 and 27 and cam 42 when the contacts are at the open and closed position.

The configuration of the middle slot portion can be selected to obtain the preferable mechanical advantage between the operating mechanism and the contacts. That is, if a desired mechanical advantage is necessary to properly operate the contacts as to speed and force, the angle of the slots to the axis of movement of the cam 42 may be calculated and appropriately determined for the mechanism. The slots are formed by he elongated along lines parallel to one line or, for example, with one slot being elongated parallel to one line and the other slot parallel to another line. These lines may be appropriately curved or straight (as shown) and are positioned to form an acute angle with the axis of movement of cam 42. The size of this acute angle, particularly when the elongation is along straight lines, determines the mechanical advantage between the operating mechanism and the contact. The movement of the cam is preferably as shown, i.e., along a line bisecting the angle between the lines and in the plane of the lines so that the resulting movement of the contacts are equal.

A means for reciprocally moving shaft 17 and thereby cam 42 is provided and comprises a motor 47 for rotating a drive shaft 45 through a gear box 79, a sleeve 70 mounted around shaft 45 and rotatable thereon, an eccentric cam 44 rigidly connected to sleeve 70, a tension spring 78 connected to rotate cam 44 and biasing springs 40 and 41 (FIG. 5) connected to bias a cam roller 01 follower 43 against the surface of cam 44. Shaft 17 is connected to transfer the reciprocal motion from cam follower 43 to cam 42 and to transmit the tension from biasing springs 40 and 41 to the cam follower to maintain it against the surface of cam 44.

Referring to FIGS. 1 and 2, to close the contacts in the vacuum switches, shaft 17 is actuated downwardly by cam 44 and biased upwardly by biasing springs 40 and 41. Shaft 17 extends through column 15 into housing 13 where it is connected to cam follower 43 through a cam follower structure 46.

Cam 44 is mounted on sleeve 70 and is rotated clockwise to where a pin 71, which extends radially outward from drive shaft 45, engages a pawl 72 extending axially outward from sleeve 70. Upon such engagement, starting with the position shown in FIG. 1, cam 44 is rotated clockwise and cam roller 43 rolls off the high portion of the surface of cam 44 and is pulled upward by biasing springs 40 and 41. This moves cam 42 to its upper position, as shown in FIG. 6, to open the contacts. The motor may be automatically turned off by any known means (not shown) in response to the opening of the switches.

To close the switches, the motor turns the shaft, sleeve, and cam 44 further clockwise to the point where an arm 49 is just slightly more than from the position shown in FIG. 1. At this point, tension spring 78, which is connected to arm 49 at a pin 50 and to housing 13 at an ear 51, compresses to pull the arm to rotate the sleeve (which will rotate freely in this direction because of the pin 71 and pawl 72 arrangement) and stop cam 44 at the position shown. This position, shown in FIGS. 1, 3, 4 and 5, closes the contacts. Any known means (not shown) may be provided for automatically stopping the motor when the switches are closed.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Motion translating means for moving a pair of movable contacts to a contact open and a contact closed position, said means comprising: a cam movable along an axis and having two slots each having a middle portion elongated in a direction along a first and second line, respectively, said lines positioned to each form an acute angle to said axis and said slots having end portions at each end elongated along a line parallel to the axis; means for reciprocally moving the cam along said axis; two cam followers each supported to ride in cooperative relationship with a different slot; means for connecting one of the cam followers to one of the movable contacts and the other cam follower to the other of the movable contacts; and said slots having a configuration adapted to move the contacts through the cam followers to the contact open position and to the contact closed position in response to movement of the cam, and means for moving the cam.

2. Motion translating means for moving a pair of contacts along a first axis to a contact open and a contact closed position, said means comprising: a cam reciprocally movable along a second axis substantially perpendicular to the first axis and having one slot having a center portion elongated in a direction parallel to a first line and an end portion at each end elongated in a direction parallel to the second axis and another slot having a center portion elongated in a direction parallel to a second line and an end portion at each end elongated in a direction parallel to the second axis; said lines positioned to form equal and opposite acute angles to said second axis; a pair of cam followers each supported to ride within and in cooperative relationship with a different slot and to be movable only in a direction parallel to the first axis; and means for connecting each of the cam followers to a different one of the movable contacts, and means for reciprocally moving the cam along said first axis to place each of the cam followers in one end portion of its respective slot at contact open position and to place each of the cam followers in the other end portion of its respective slot at contact closed position.

References Cited by the Examiner UNITED STATES PATENTS 2,128,427 8/38 Means 200--144 Re. 24,343 8/57 Korsmo 74110 2,981,817 4/61 Frentzel 200144 3,106,848 10/63 Brewer et al 74110 BERNARD A. GILHEANY, Primary Examiner.

Claims (1)

1. MOTION TRANSLATING MEANS FOR MOVING A PAIR OF MOVABLE CONTACTS TO A CONTACT OPEN AND A CONTACT CLOSED POSITION, SAID MEANS COMPRISING: A CAM MOVABLE ALONG AN AXIS AND HAVING TWO SLOTS EACH HAVING A MIDDLE PORTION ELONGATED IN A DIRECTION ALONG A FIRST AND SECOND LINE, RESPECTIVELY, SAID LINES POSITIONED TO EACH FORM AN ACUTE ANGLE TO SAID AXIS AND SAID SLOTS HAVING END PORTIONS AT EACH END ELONGATED ALONG A LINE PARALLEL TO THE AXIS; MEANS FOR RECIPROCALLY MOVING THE CAM ALONG SAID AXIS; TWO CAM FOLLOWERS EACH SUPPORTED TO RIDE IN COOPERATIVE RELATIONSHIP WITH A DIFFERENT SLOT; MEANS FOR CONNECTING ONE OF THE CAM FOLLOWERS TO ONE OF THE MOVABLE CONTACTS AND THE OTHER CAM FOLLOWER TO THE OTHER OF THE MOVABLE CONTACTS; AND SAID SLOTS HAVING A CONFIGURATION ADAPTED TO MOVE THE CONTACTS THROUGH THE CAM FOLLOWERS TO THE CONTACT OPEN POSITION AND TO THE CONTACT CLOSED POSITION IN RESPONSE TO MOVEMENT OF THE CAM, AND MEANS FOR MOVING THE CAM.

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