US2791651A - Electrical switches - Google Patents

Description

May 7, 1957 Filed March 21, 1956 T. B. ORTWIG 2,791,651

ELECTRICAL SWITCHES 3 Sheets-Sheet 1 Mun/rag 771 0244: .8. Oerw A Tron/v: v

May 7, 1957 T. a. ORTWlG ELECTRICAL SWITCHES 3 Sheets-Sheet 2 Filed March 21, 1956 Wvewraz THOMAS E. OErW/ 5 /Zwml 44 A TTORNEY May 7, 1957 T. B. ORTWIG ELECTRICAL SWITCHES 3 Sheets-Sheet 5 FiledMarch 21, 1956 OETW/G fivwg w HTfOIF/ EY United States Patent ELECTRICAL SWITCHES Thomas Byrne Ortwig, Florissant, Mo., assignor to James R. Kearney Corporation, St. Louis, Mo., a corporation of Missouri Application March 21, 1956, Serial No. 572,950

3 Claims. (Cl. 200-48) This invention relates generally to electrical switches which are intended particularly for use as units of gang switches and more specifically to such a switch which is of the side-opening type of the character frequently used in the control of electric power distribution circuits. Switches of the character referred to are operated infrequently and are customarily mounted where they are exposed to the atmosphere and in other contaminated areas and, consequently, after remaining in the opened or closed positions for a period of time are difficult to operate. Moreover, in the construction of such switches and because they have such infrequent operation, the tendency has been to manufacture them as cheaply as possible which tends to militate against ease of operation.

The predominant object of the invention is to provide a switch of the type referred to which is easy to operate after long periods of remaining in one position and exposed to the elements.

A more specific object of the invention is to improve the supporting structure for the movable parts of such switches so as to facilitate operation under adverse conditions.

Another object of the invention is to provide an arcing tip arrangement for such switches which is cheap to manufacture, yet positive in its operation.

The present invention contemplates generally a switch of the character referred to having a blade movable about a normally vertical axis between a closed circuit position where the end of the blade remote from its vertical axis is received between contact jaws and an open circuit position where the blade is removed from such contact jaws. In accordance with the present invention, the vertical axis on which the switch blade is mounted is provided with upper and lower metallic journals intervened by an insulating structure; and the journals are provided with bearings of a character such as to insure smooth operation of the structure rotatable within them, in spite of the adverse effect of atmospheric conditions to which such bearings may have been exposed. The bearing structure is particularly characterized by the feature that, at positions where the vertical load of the rotatable structure is sustained by a fixed part, bearing members of dissimilar materials, such as sintered bronze and stainless steel plates, are used in cooperation one with the other and the assembly provided with a protective closure. The invention further contemplates arcing tips between the switch blade and the stationary contacts therefor, which are so constructed and arranged as to remain in contact until the operating contacts are separated but to impose but negligible drag on the operation of the switch.

Other objects and advantages of the present invention will become apparent to those skilled in the art when the following description is read in conjunction with the accompanying drawings, in which:

Figure 1 is a side elevation of the improved electrical switch of this invention with some parts thereof shown partially in section;

Patented May 7, 1957 Figure 2 is a top, plan view of the switch shown in Figure 1;

Figure 3 is an enlarged section taken on line 3-3 of Figure 1;

Figure 4 is a fragmentary elevation of a portion of the electrical switch looking toward the stationary contact end thereof;

Figure 5 is an enlarged vertical section taken on line 5--5 of Figure 1; and

Figure 6 is an enlarged horizontal section taken on line 66 of Figure 1.

In the embodiment shown in drawings, the switch is mounted upon a base member 1 having the cross section illustrated in Figure 5 including outwardly projected lower flanges 1:! extending in opposite directions from a central channel shaped section having vertical walls interconnected by top wall 10. Adjacent one end of the member 1 the top wall 1c is provided with an opening 2 through which extends the lower end of a cylindrical member 3. The member 3 is provided at its lower end with an annular shoulder which rests upon the upper surface of top wall 1c of the base member 1, adjacent the edges of opening 2.

The cylindrical member 3, at the location of the annular shoulder 4 is provided with flanges 5 which cxtend longitudinally of the base member 1 in opposite directions as shown in Figure l and bolts 6 are extended through openings formed through said flanges 5 and through openings formed through the top wall of the base member 3 for securing said cylindrical member in place with respect to base member.

The cylindrical member 3 constitutes a hub through which is extended a shaft 7, said shaft being screwthrcaded at its upper end, as indicated by the reference character 8 and the lower portion of said shaft being of slightly reduced diameter, and said reduced lower portion 9 being externally screwthreaded at its upper end, as indicated at 10 in Figure 5. Mounted on the screwthreaded portion 10 of the shaft 7 is a nut 11. Between nut 11 and the lower end of member 3, there is arranged a pair of bearing washers 12 and 12a, the lower one 12 of which is preferably formed of sintered bronze or other good bearing material, whereas the upper one 12a is formed of stainless steel or other relatively hard smooth material. Likewise, at the upper end of cylindrical member 3 a collar 13 is in screwthreaded engagement with the threads at the upper end of the shaft 7. The collar 13 is provided with ears 14 for connecting it with an insulator support later to be described. Between collar 13 and the upper end of member 3 there is interposed a pair of bearing washers 15 and 150, the upper one, 15 of which, is formed of sintered bronze or other good bearing material while the lower one 15a is formed of stainless steel or other relatively hard smooth material. Thus, at each end of member 3 there is provided a stainless steel washer whereas between the stainless steel washer and the adjacent member which is in screwthreaded engagement with shaft 7, there is provided a sintered bronze washer. The bearing provided by this arrangement of washers at the opposite ends of member 3 not only assures adequate support for the end thrust which must be sustained by member 3 but also insures that there will at all times be smooth interface between the washers 12 and 12a and between washers 15 and 15a which may move relatively during turning of the shaft 7 relative to member 3 and base 1. This arrangement eliminates the necessity for meticulous surfacing operations on either end of member 3 and permits member 3 to be a relatively rough casting. In order to protect the assemblies of washers 12-12a and 1515a from deterioration of their contiguous surfaces, which must slide relatively during operation of the switch, each of the assemblies is protected by the provision thereabout of a ring 16 of rubber-like material as shown clearly in Figure 5.

The rings 16 are accommodated between shoulders formed respectively on the ends of member 3 and the adjacent screwthrcaded parts 11 or 13, as the case may be, so that when the screwthreaded parts are drawn down tight, the rings 16 are compressed between the shoulders so as to form thereagainst a seal which will prevent the ingress of dust, dirt, and other foreign matter.

Collar 13 is secured against unintentional loosening of its scrcwthreaded engagement with shaft 7 by the provision of a spline key 17, while unintentional loosening of nut 11 is prevented by a cotter pin.

Arranged above the collar 13 is a member 18 which is of inverted, dish-shaped formation that is provided with cars 19, the cars 19 of the member 18 being alined with the ears of the collar 13 and said member 18 being secured to the collar 13 by bolt and nut assemblies 20, the shanks of the bolts of which extend through openings formed through said ears 19 and through ears 14.

The member 18 has formed thereon and extended therefrom an arm 21 having an opening at its outer end, and bolted to the arm 21 and extended downwardly therefrom is a pin 22 which serves as an abutment element. Secured to one of the flanges of the cylindrical member 3 is a bar 23, having an arcuate slot 25 through which extends one or more of the bolts 6, which secure member 3 to support 1. At opposite ends of the bar 23 upstanding ears 26 are provided, each of which has a screwthreaded opening in which the shank of a bolt 27 is received. The heads of the respective bolts 27 serve as abutmcnts to limit the movement of arm 21 about the axis of shaft 7. Each bolt 27 has a lock nut 28 related thereto to maintain the same in adjusted position.

Secured by bolt and nut assemblies 29 to the member 18 is a vertical pin 30 having a flange 31 at its lower end through which the shanks of the bolts extend, and suitably secured to th upper end of said pin is an insulator structure 32. Mounted at the top of said insulator structure and secured thereto by bolts 33 is a supporting member 34, said supporting member being elongated and having a cradle portion 35 formed at the forward end thereof. Also, the supporting member 34 includes the cradle portion 36 of a clamping means 37 that extends upwardly in line with shaft 7. A tubular switch blade 38 rests in the cradle portions 35 and 36 of the supporting member 34. The clamping means 37 includes an upper jaw 39 which is aligned vertically with the cradle portion 36, and is provided with a vertical shaft 40 in line with shaft 7. The shaft 40 has a lower portion 40 of reduced diameter whose lower end portion screwthrcadcd into cradle 36 as shown in Figure 3. The upper jaw 39 is recessed at the top, as indicated at 41 in Figure 3. said reduced lower portion of the vertical shul't extending through alined openings formed in the upper jaw 39, in opposite walls of the switch blade 38, and in the cradle 36, said shaft 40 being pinned into the latter by a pin 42. The shoulder 43 of the shaft 40 contacts with the face of recess 41 of the jaw 39 and thereby causes the switch blade 38 to be tightly gripped between the lower and upper portions of the clamping means 37.

Arranged to embrace the upper portion of the shaft 40 is a hub portion 44 of a terminal 45, said terminal 45 being provided with a web which is formed integral Valli] said hub portion and extends rearwardly therefrom. Also. the hub portion of the terminal 45 has an integral forwardly extended portion 46 to which is at tuchctl z: llcxiblc shunt 47, one end of the shunt 47 being secured to said forward portion 46 by a bolt and nut assembly 48 and the opposite end of said shunt se' cured by a bolt and nut assembly 49 to the switch blade 38. In addition to securing an end of the shunt 47 to the switch blade 38, the bolt and nut assembly 49 serves (ill to secure the switch blade 38 to the cradle 35 of the supporting member 34. The terminal is provided with a pair of suitable connectors which serve to connect mechanically and electrically an incoming electrical condoctor Ca to said terminal. By referring to Figure 3 it will be noted that the hub portion 44 is provided therein with hearing members 51 through which the upper portion of the shaft 40 extends and thus the hub 44 may turn on shaft 40. The bearing members 51 are preferably formed of sintered bronze or other good bearing material, and the lower one of the bearings 51 is arranged to ride upon a stainless steel washer 52 which rests upon the upper end of jaw 39 as shown in Figure 3. A cotter pin 53 is extended through an aperture formed through the upper portion of the shaft 40 to retain the terminal on said shaft 40.

The tubular switch blade 38 is closed at its rear end by a cup 54 and at its forward end by a cap 55. The cap 55 receives the root end of an elongated, upstanding rod 56, which at a position remote from cap 55 is bent back parallel with blade 38 to provide an arcing horn.

The free swinging end portion of the switch blade 38 moves into and out of engagement with respect to a stationary contact structure 57 which is supported by an insulator 58, said insulator being fixed to a pin 59 which i appropriately mounted on base member 1 remote from member 3.

The contact structure 57 comprises a lower member 66 which is provided with a bottom wall 66a, a rear vertical wall 66b, a short top wall 660, a front wall 66d and an angularly extended wall 66a, said rear Wall being provided with an outwardly extended flange 67 at its upper end which is strengthened by a rib 68. An ear 69 is extended from the rear wall 66c which supports a connector 70, an outgoing electrical conductor Cb being connected to the switch through the instrumentality of said connector 70. The top wall 660 and the angularly extending wall 66c is provided with a web 71 which is joined integrally with the rear wall 662, said web being provided with a shoulder 71 which serves a purpose to be hereinafter set forth, and said web having a facing of silver 72 for good electrical contact. The lower member 66 is secured to the insulator structure 58 by a pair of bolts 73. The contact structure 57 includes an upper member in. the form of a plate 74 which is secured at one end to the flange 67 by a pair of bolts 75, said plate possessing some resiliency toward its connected end and having an outwardly curved outer end portion 74'. The plate 74 is provided with a silver facing for contact purposes.

Upon one of the bolts 73 there is mounted an upstanding elongated rod 76 having a portion extending parallel with plate 74 but remote therefrom. The rod 76 is so bent as to make Contact with rod 56 when the switch is in or near its closed circuit position to draw arcs away from contact 57 and blade 38.

in the operation of a gang of switches of the type disclosed herein, the switches of the gang are connected together by phase bars (not shown) which are attached to the arms 21 of the several switches in the gang and force is applied to the lower portion 9 of the shaft 7 of one of the switches. Rotation of shaft 7 in the proper position will swing the switch blades 38 arcuately about shaft 7 as an axis and disconnect the outer ends thereof from their companion stationary contact structures 57, the outer end portion of the switch blades, when in Contact with the contact structures 57, engaging the silver facings of said 211 111.) 74 and said ribs 71 of the contact structures 57, The switch blade 38 is moved into contact with the contact structure 57 by rotating the shafts 7 in the reverse direction to the one just described.

When the switch is opened, the arcing horn 56 moves with the switch blade and remains in contact with the fixed arcing horn 76 until after the switch blade 38 is free of engagement with plate 74 and rib 71 of the stationary contact 57. As the switch blade continues t move in the opening direction, the arcing horns 56 and 76 slide on each other lengthwise of the hon'zontal portions until their divergent tips disengage and draw the are, which is broken by further movement of the switch. Thus, the length of the horizontal portions of the arcing horns is coordinated with the amplitude of movement of arm 21 to assure that the arcing horns will remain in contact, under their inherent resiliency, until blade 38 is free of stationary contacts 57, but that the arcing horns will break contact with each other before the limit of opening movement of arm 21 is reached.

The arrangement of bearing assemblies 12-12(1, 15-15a and 51-52. in which a member of sintered bronze or other good bearing material rides in thrust transmitting relation upon a member of stainless steel or other hard smooth material not only facilitates the operation of the switch but effects an economy in its construction. Such an arrangement of sintered bronze and stainless steel members eliminates the necessity for the performance of meticulous surfacing operations upon the end surfaces of the several parts between which the bearing assemblies mentioned are interposed. The arrangement of the arcing horns in the manner shown and described likewise facilitates the operation of the switch by reducing the drag which is normally imposed thereon by arcing tips. The latter is attributable to the inherent resilience of the arcing horns 56 and 76 due to their elongated character, and the fact that they are brought into contact with each other at a position remote from their anchorage, as well as to the fact that the contact between the arcing horns is substantially a point contact.

From the foregoing description, those skilled in the ant will readily understand that the invention accomplishes its objects and provides a switch of a character referred to which is capable of withstanding the exposure to the atmosphere and the weather, but is nonetheless easy to operate and sturdy in construction. While one complete embodiment of the invention has been disclosed in detail, it is to be understood that the embodiment described and shown in drawings is merely illustrative, and that the invention is not limited to that embodiment. On the contrary, it is contemplated that various changes in the structure described and shown may be made without departing from the spirit of the invention or the scope of the appended claims.

Having thus described the invention what is claimed and desired to be secured by Letters Patent is:

l. A switch of the character described comprising, a suppont, a stationary contact mounted upon said support and insulated therefrom, a movable contact mounted in insulated relation upon a vertical shaft, said shaft being mounted for rotation on said support at a. position horizontally remote from said stationary contact. said shaft having a radially extending part secured thereto for rotation therewith, and said support having a member secured thereto for receiving axial thrust from said part, and a pair of washers between said part and said member, one of said washers being of bearing material and the other of hard smooth material.

2. The switch of claim 1, in which said movable contact is provided with an upstanding shaft substantially aligned with the shaft upon which said movable contact is mounted, and a terminal having a hub mounted upon said upstanding shaft.

3. The switch of claim 1 wherein the edges of said washers are embraced by a ring of flexible material in sealing engagement with said part and said member.

References Cited in the file of this patent UNITED STATES PATENTS 2,707,732 Ortwig May 3, 1955

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