US2226818A

US2226818A - Electrical switch

Info

Publication number: US2226818A
Application number: US299602A
Authority: US
Inventors: Walter A Heinrich
Original assignee: James R Kearney Corp
Current assignee: James R Kearney Corp
Priority date: 1939-10-16
Filing date: 1939-10-16
Publication date: 1940-12-31
Anticipated expiration: 1957-12-31

Description

Dec. 31, 1940. w. A. HEINRICH y ELECTRICAL SWITCH Filed Oct, 16, 1959 v'4 Sheets-Sheet 1 fmwm .LQ/Ggf( .o

Afro/Niv M 31, 1940. w. A. HEINRICH ELECTRICAL SWITCH f' Y Filed 001:/ 16, 1939 4 Sheets-Sheet 2 zzgaz' liga' Dec. 3l, i940. w. A. HEINRICH 2,226,818

' ELECTRICAL SWITCH Filed oct. 16, 1939 4 s'heetslsheet :s

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Armen/fr Dec. 31 1940. w. A. Hl-:sNRlcH I ELECTRICAL SWITCH 4 Sheelzs--SheeetI 4 Filed oct. 16'.` 1939 /m/i/Yroe/ W42 ri A. #HNE/CH A fr0/Ew; Y

Patented Dec. 3l, 1940 UNITED STATES PATENT OFFICE ELECTRICAL SWITCH Application October 16, 1939, Serial No. 299,602'

7 Claims.

This invention relates generally to electrical switches of the type employed in systems for transmitting electrical energy for power, lighting, and other purposes, and more specifically to such switches which generally comprise spaced terminals and associated contact means into and out oi contact with which contact means an.

move corrosion which forms at the point of con- A tact of said movable element and said contact means.

Switches of the type to which this invention relates are frequently susceptible to the format'on of corrosion at the points where the movable elements of the switches contact with the contact means thereof, and as a result of such formation of corrosion the eiiciency of the switches is very materially affected. In other words, it has been found that the presence of corrosion at the points mentioned effects the current-carrying capacities of the switches to the extent that they are reduced far below the rated capacities of the switches, whereby the capab'lities of the switches to function in the desired eiilcient manner is very greatly interferred with and the switches are subjected to overheating.

The predominant feature of the present invention resides in the fact that the improved switch is so constructed and arranged that the movable element of the switch is capable of slight movement relative to the contact means of the switch while said movable element remains in electrical contact with said contact means. This slight movement is suicient to break loose any corrosion that has formed and reestablish clean contactingsurfaces between the movable element and the contact means which will return the switch to its rated current-carrying capacity.

Also an mpcrtant feature of the present inven- 50 tion is that the movement of the movable element of the switch relative to the contact means thereof which serves .to break loose any corrosion which has formed at said switch parts is produced whle the switch is in a closed condi- 65 tion and without interrupting the circuit. This (Cl. 20o-162) is important because in most cases interruption vof the circuit for the purpose of freeing the switch parts from corrosion would be undesirable. f

Fig. 1 is a side elevation of one form of the improved switch disclosed herein.

Fig. 2 is a front elevation of the switch shown in Fig. 1, with a portion shown in section and a part broken away.

Fig. 3 is a horizontal section taken on line 3-3 lo of Fig. 1.

Fig. 4 is a horizontal section taken on line 4 4 of Fig. 1.

Fig. 5v is a fragmentary front elevation of another form of the improved switch disclosed 15 herein.4

Fig. 6 is a fragmentary side elevation of the switch shown in Fig. 5.

Fig. 7 is a fragmentary section of a lower portion of the switch shown in Figs. 5 and 6. 0

l Fig. 8 is a horizontal section taken on line 8-8 of Fig. 6.

Fig. 9 is a front elevation, with parts broken away, of still another form of the improved switch.

Fig. 10 is a side elevation of the switch shown in Fig. 9.

Fig. l1 is a horizontal section taken on line II-Il of Fig. 10.

Fig. 12 is a fragmentary front elevation of yet another form of the improved switch.

Fig. 13 is a side elevation of the switch shown in Fig. 12.

Fig. 14 is a horizontal section taken on line |4|4 of Fig. 13. 35

Referring now to the drawings, wherein are shown for the purpose of illustration, merely, several embodiments of the invention, and particularly to Figs. 1, 2, 3, and 4, thereof, A designates one form of the improved switch generally. The switch A of the Views mentioned includes a suitable supporting member l on which is rigidly mounted, by means of suitable fastening means I', a pair of vertically spaced insulators 2 and 3. 45 The upper insulator 2 has secured thereto by means of suitable fastening devices 4 a terminal 5, said terminal 5 comprising a terminal member 6 which is secured directly to the insulator 2 by means of the fastening devices 4, and a terminal member l which may be secured by bolts 1', or otherwise, to said terminal member 6. The terminal member 1 includes as a part thereof a conductor-clamping portion 8 which serves to mechanically and electrically secure to the ter- 5J minal 5 a conductor C which is a portion of the electrical circuit of which the switch A forms a art.

p In like manner the lower insulator 3 has secured thereto a terminal 9 which comprises a terminal member IIJ that is secured directly to said insulator 3 by means of suitable fastening devices II, and a terminal member I2 which may be secured by bolts III', or otherwise, to said terminal member I0. Also the terminal member I2 includes as a part thereof a conductor-clamping portion I3 which serves to mechanically and electrically secure to the terminal 9 a conductor C which constitutes a portion of the electrical circuit of which the switch A forms a part.

Forming a part of the terminal 9. associated with the Alower insulator 3 is a contact I4 which is comprised of a plurality of lengths of relatively heavy, resilient wire arranged in parallel relation, as shown in Figs. 1 and 2. The lengths of wire which produce the contact I4 are shaped, when viewed in plan, as shown in Figs. 3 and 4; that is to say, each length of wire includes a rear portion I 4a which is suitably anchored to the terminal member I of the terminal 9 and from the opposite ends of which opposed forwardly extended portions I4b are extended, the portions I4b at their outer ends being provided with portions I4c which are bent rearwardly with respect to said portions I4b in inwardly spaced relation with respect thereto and in spaced relation with respect to each other. The terminal 5 of the upper insulator 2 is provided with a contact I5 which is similar in construction and arrangement to the contact I4 just described, said contact I5 being suitably anchored to the terminal member 6 of said upper terminal 5.

Supported by the lower terminal 9 is the switch blade I6 of the switch A illustrated in Figs. 1 to 4, inclusive, which constitutes the movable element hereinbefore referred to. Obviously the switch blade I6 may be of any suitable type, the particular switch blade illustrated being in the form of a rod which is circular in cross-section as shown in Fig. 4. At its lower end the switch blade is provided with a portion I6a of reduced diameter, at the upper end of which a shoulder I6b is provided, and this reduced switch blade portion is disposed in a sleeve I1 for rotary movement with respect thereto with the shoulder I6b of the switch blade contacting with the top face of said sleeve I1.

The sleeve I1 is located between a pair of outstanding ears I8 that are formed on the terminal member I0 of the lower terminal 9, and in order to pivotally secure said sleeve, and the associated switch blade I6, to the pair of ears I8 a pair of trunnion elements I 9 are xed to the sleeve and extend into apertures I8 formed in the ears, as shown in Fig. 2. Preferably, though not necessarily, each trunnion element comprises a stud bolt which includes a screwthreaded portion of reduced diameter that is screwed into a screwthreaded opening formed in the sleeve I1, and a smooth portion of larger diameter that is disposed in the aperture I8' of one of the ears I8.

As will be presently explained in detail herein, the main portion of the switch blade is subjected to rotation with respect to the sleeve I1, and to limit said rotary movement of said switch blade a pin is xed to the switch blade so that it extends therefrom into an opening 2| formed in the sleeve as shown to the best advantage in Figs.

1, 2 and 3. Because oi this arrangement rotation of the switch blade is limited to a portion of a circle, merely, as rotary movement oi the switch blade is arrested at the opposite limits of its rotary movement by the pin 20 coming in contact with the opposite end walls of the opening 2| in the sleeve.

When the switch blade I6 is in the open switch position an extension 22 formed on the sleeve I1 contacts with a xed portion 22' to maintain said switch blade in a substantially horizontal position, and from this position the upper end of the switch blade is movable in an arc of a circle to the closed switch position in which said switch blade is shown in Fig. 1. When the switch blade I6 is 1 moved to the closed switch position it is forced between the inwardly turned portions of the contacts I4 and I5 (see portions I4c of Fig. 3) to bridge the space between said contacts and establish electrical connection between the terminals 5 and 9, and to maintain the switch blade in such closed switch position a latching mechanism 23 is provided.

The latching mechanism 23 includes a latch 24 which is pivoted by means of a pivotl pin 25 between a pair of ears 26 that extend forwardly from the terminal member 610i the upper terminal 5, said pivot pin having arranged thereabout a torsional coil spring 21 which coacts with the latch 24 in a manner to urge the outer end thereof downwardly. The latch 24 is provided with opposed lugs 28 which contact with extensions 29 formed on the ears 26 to limit downward movement of the outer` end portion of said latch, and said latch is provided, also, with lugs 30 which are adapted to contact with the extensions 29 of the ears 26 to limit upward movement of the outer portion of said latch. The latch 24 includes a downwardly extended portion 24 adjacent to its outer end which engages the upper end portion of the switch blade I6 to hold said switch blade in the closed switch position where it is in electrical connection with the contacts I4 and I5, there being an inclined face 3| formed at the outer end of said latch against which the upper end portion of the switch blade moves, when it is being moved to the closed switch position, to cam the outer portion of the latch upwardly so that said upper portion of said switch blade may move beneath the portion 24' of the latch so as to be latched by same when the torsional coil spring has restored the latch to its lowered latching position as shown in Fig. 1.

In order to provide for raising the outer portion of the latch to permit the switch blade I 6 to be withdrawn from the closed switch position a latch-operating member 32 is provided. This latch-operating member is pivotally supported on the switch blade I6 by a pivot pin 33, and said latch-operating member includes an extension 34 at its inner end which contacts with a lower face of the latch 24, and an eye 35 at its outer end adapted to receive a suitable tool. Also the latchoperating member 32 is provided with a downwardly projected extension 36 which, as will presently appear herein, is adapted to engage an extension 31 which is projected downwardly from a forwardly directed portion 38 of the terminal member 6 of the terminal 5. The latch-operating member 32 is provided with a pair of opposed lugs 39 which limit movement of said latch-operating member about its pivot 33 because of portions o f said lugs moving in contact with' the switch blade when opposite limits of movement of said latch-operating member are reached.

The switch blade has ilxed thereto an arm which extends outwardly therefrom. Preferably this arm is provided at its outer end with a tool-receiving portion 4I, an eye, for instance, which -may be engaged by a suitable tool for the purpose of subjecting the switch blade to slight rotary movement with respect to the contacts i4 and I5.

- In the operation of the switch illustrated in Figs. 1 to 4, inclusive, the switch blade is moved from the open switch position to the closed switch position with the aid of a switch stick, 0r other suitable tool, a portion of which is introduced into the eye portion 35 oi.' the latch-operating member 82, the upper end portion of the switch blade being moved until said upper end of said switch blade has contacted the inclined face 3l of the latch 24 and has raised said latch so as to permit the upper end oi' the switch blade to ride thereunder, after which the torsional coil springv 21 moves the outer end of the latch 24 downwardly to latch the switch blade in the closed switch position. If, after the switch has been in use for some time, corrosion forms at the points where the switch blade I6 and the contacts I4 and i5 contact, a suitable tool, a switch stick, for ini stance, is engaged with the eye portion 4i of the arm 46, and while the switch blade remains in the closed switch position, the switch blade is rotated back and forth several times through an arc of a circle to the extent permitted by travel of the pin 20. This will break loose the corrosion and will clean the contacting points of the switch blade and contacts whereby clean, intimate, and good electrical contact will again be provided between said parts of the switch.

When it is desired to move the switch blade 40 from the closed switch position to the open switch position, a switch stick, or other suitable tool, is engaged with the eye portion 35 of the latch-operating member 32 and said eye portion is pulled downwardly. This will raise the outer portion of the laten 2a end w111 move the extension 3650i? the latch-operating member against the extension 31 of the terminal member 6. Continued downward and outward pull on the eye portion of the latch-operating member 32 will draw the upper end portion of the switch blade of the improved switch is illustrated. The switch of Figs. 5, 6, '7, and 8 includes a switch blade 45 that comprises an inner rod 46 which is secured to a member 41 that is pivotally supported between a pair of ears 48 by a pivot pin 59, said ears being extended from a lowerterminal 50. Surrounding the rod 46 is a tubular element 5| which contacts at one end with a shoulder 41 of the member 41, and at its opposite end said tubular element contacts with a shoulder 52 formed on the top portion 53 of the switch blade. The switch blade is movable to the closed switch position where the tubular -ele. ment 5i thereof is forced between opposedportions of .

contacts

54 and 55 which are suitably anchored respectively to the lower terminal 56 and the upper terminal 66, and the switch of Figs. 5 and 6 is provided with suitable latching means 51, which, because it resembles the latching means of the switch illustrated in Figs. 1

and 2 need not be described in detail herein.v The tubular element 5I has pinned or otherwise formed on the member 41 is projected.

4When the switch illustrated in Figs. 5, 6, 7, and 8 is in the closed switch position, as shown in Figs. 5 and 6. and it is desired to break loose and remove corrosion which has formed at the points where the tubular element 5I makes contact with the

contacts

54 and 55, a suitable tool, a switch stick, for instance, is introduced into the eye 63 of the arm 6I and the upper end portion of said arm is moved rapidly backwardly and forwardly several times. Such movement of the arm 6I, because of the connection provided by the pin 59, will rotate the tubular element through short rotary movements in opposite directions about the rod 46 and with respect to the

contacts

54 and 55, whereby the corrosion will be effectively removed and clean contacting points between the switch blade and the contacts will be restored. The rotary movement vaway portion 64 into which an extension 65 of the tubular element 5I in response to movel ment of the arm 6I is limited by the opposite walls of the cutaway portion 64 of the member 56 coming in contact with the iixed extension 65.

In Figs. 9, 10, and l1l is illustrated still another form of the improved switch wherein the switch blade 66 is moved inwardly arid outwardly relative to the

contacts

61 and 66 in order to remove corrosion from the contacting points of said switch blade and contacts. In this form of the invention the lower portion of the switch blade has formed therein an opening 69 which extends through said ,lower portion of the switch blade 4 from side to side and which is elongated from front to back of said blade portionyas shown in Figs. 10 and l1. Extended through said opening' 69 is a pivot pin 10 which is,supported by spaced, outwardly extended ears 10' which form parts of the lower terminal 1i, and supported on said pivot pin for rotary movement with respect thereto is an arm 12 which is provided with an eye portion at its outer end. The arm 12 is provided with

elongated bars

13 and 14 between which the switch blade is extended, said elongated' bars at the ends thereof opposite to the location of the arm 12 being joined by a hub portion 15 which is mounted for rotation on the pivot pin 10 as shown in Fig. 11.

Adjacent to the upper end of the switch illustrated in Figs. 9, 10, and 1l, an element 16, which includes an eye portion at its outer end, is pivoted to the upper portion of the switch blade 66 through the instrumentality of a pivot pin 11. This element 16 includes also a rearwardly and downwardly projected extension 18 which is disposed in close proximity to a switch portion 19 which is fixed to the upper terminal of the switch. Also the element 16 has formed on its opposite faces lugs 8|, portions of which are adapted to contact with the outer face portion of the switch blade 66.

'I'he switch illustrated in Figs. 9, 10, and 11, includes latching means 62 for securing the switch blade 66 in the closed switch position as shown in Figs. 9 and 10. However, because this latching mechanism closely resembles the latching mechanism illustrated in Figs. 1 and 2, which has already been described herein, it will not be necessary to describe the latching mechanism of Figs. 9 and 19 in detail.

When the switch illustrated in Figs. 9, 10, and 11 is in the closed switch position and it is desired to free the switch blade and the contacts from corrosion at the points where these parts make electrical contact, a switch stick, or other suitable tool is engaged with the eye portion of the arm 12 and the outer end portion of said arm is moved rapidly back and forth about its pivot 10. During such movement of the arm 12 one and then the other of the bars 13 and 'I4 will engage the lower portion of the `switch blade 66, said lower portion of the switch blade being moved inwardly by the bar 13 and being moved outwardly by the bar 14 and the elongated opening 69 in the lower portion of the switch blade permitting said inward and outward movement of the switch blade with respect to the pivot pin 10. As a result of the described inward and outward movement oi' the lower portion oi' the switch blade 68, the portion of said switch blade which makes contact with the contact 81 will be moved with respect to said contact 61 so as to break loose any corrosion which has formed between the switch blade and said contact whereby clean contact between said switch parts will be restored.

In like manner the eye portion of the element 16 will be engaged by a suitable tool and will be moved rapidly upwardly and downwardly in an arc about its pivot. On downward movement of the eye portion of the element 18 the portion 18 of said element moving against the fixed portion 19 will cam the upper portion outwardly with respect to the contact 68, while on upward movement of the eye portion oi.' said element 16 the lugs 8| will move into contact with the switch blade and continued upward movement of the eye portion of the element will move the upper portion of the switch blade inwardly with respect to the contact 68. Obviously, the outward and inward movement of the upper portion of the switch blade relative to the contact 68 will break loose corrosion formed at the points of contact between the switch blade and said contact 68 and restore clean, contacting points between said parts. It is to be noted that there is suilicient looseness between the latch element 83 and the opposite end portions of the pin 11 to permit the inward and outward movement of the upper portion of the switch blade 68 described above, yet said latch element 83 will prevent accidental movement of the switch blade out of the closed switch position.

In Figs. 12, 13, and 14, yet another form of the improved switch construction is illustrated in accordance with which the switch blade 84 is moved upwardly and downwardly with respect tothe

contacts

85 and 86 to free the contacting surfaces of the switch blade and contacts from corrosion. In accordance with the form of the invention shown in Figs. 12, 13, and 14, the switch blade is in the form bf a rod of circular cross-section whose lower end portion is disposed in a bearing member 81 for vertical sliding movement with respect thereto. The bearing member 81 is supported for pivotal movement between a pair oi ears 88 which extend outwardly from a lower terminal 89, such pivotal movement being obtained through the use oi trunnions 9D whose inner end portions are screwthreadedly seated in screwthreaded openings formed in the bearing member, and whose headed outer end portions are disposed in openings formed in the spaced ears 88.

Pivoted between a pair of ears 9| extended from the bearing member 81 by means of a pivot pin 92 is an arm 93 which is provided at its upper end with an eye portion 93'. Fixed to the switch blade 84 is a collar 94 which is provided with an outwardly projected extension, and pivotally attached to the extension 94' of the collar 94 and to the arm 93 is a link 95. 'Ihe bearing member 81 is provided with an upwardly extended portion 96 in which a vertical slot 96 is formed, as shown in Fig. 13, and extended into this slot is a pin S1 which is xed to the switch blade 84.

The switch illustrated in Figs. 12, 13, and 14, is provided with a suitable latching mechanism 98 ofthe general type of the latching mechanism shown in Figs. 1 and 2 and previously de scribed herein, and when it is desired to free the switch blade and contacts of corrosion while said switch blade is held in the closed switch position by said latching mechanism, as shown in Figs. 12 and 13, the eye portion of the arm '93 is engaged by a suitable tool and the upper portion of said arm is swung back and forth about its pivot. Because of such movement the switch blade will be subjected to upward and downward movement relative to the

contacts

85 and 88, the switch blade moving upwardly and downwardly within the bearing member 81 and being guided during such movement by the slot and pin connection 96-91 between the bearing member and said switch blade. Obviously the described upward and downward movement of the switch blade relative to the contacts of the switch will free the contacting surfaces of the switch blade and contacts of corrosion and will restore the contacting surfaces of said switch parts to their original clean condition.

I claim:

1. An electrical switch comprising a contact, an elongated movable element movable into and out of closed switch position with respect to said contact, a portion of said elongated movable element being supported for rotation relative to said elongated movable element and being adapted to contact mechanically and electrically with said contact when the elongated movable element is in closed switch position, and means for rotating said rotatable portion of said elongated movable elementin maintained electrical and mechanical contact with said contact and without removing said rotatable portion from electrical contact with said contact' throughout the entire rotary movement of said rotatable portion, said elongated movable element being adapted to be drawn out of closed switch position relative to said contact by movement thereof which is independent of the rotary movement of said rotatable portion of said elongated movable element.

2. An electrical switch comprising spaced contacts, an elongated movable element movable into and out of closed switch position with respect to said contacts, a portion of said elongated movable element being supported for rotation about the longitudinal axis of said elongatedmovable element and being adapted to contact mechanically and electrically with said contacts when the elongated movable element is in closed switch position, and means for rotating said rotatable portion of said elongated movable element in maintained electrical and mechanical contact with said contacts and without removing said rotatable portion from electrical contact with said contacts throughout the entire rotary movement of said rotatable portion, said elongated movable element being adapted to be drawn out of closed switch position relative to said spaced contacts by movement thereof which is independent of rotary movement of the rotatable portion of said elongated movable element.

3. An electrical switch comprising spaced contacts, an elongated pivotally movable element movable into and out of closed switch position with respect to said contacts, a portion of said elongated movable element being supported for rotation about the longitudinal axis of said elongated movable element and being adapted to contact mechanically and electrically with said contacts when the elongated movable element is in closed switch position, and means for rotating said rotatable portion of said elongated movable element in maintained electrical and mechanical contact with said contacts and without removing said rotatable portion from electrical contact with said contacts throughout the entire rotary movement of said rotatable portion, said elongated movable element being adapted to be drawn out of closed switch position relative to said spaced contacts by movement thereof which is independent of rotary movement of the rotatable portion of said elongated movable element.

4. An electrical switch comprising spaced contacts, an elongated pivotally movable element movable into and out of closed switch position with respect to said contacts, a portion of said elongated movable element being supported for rotation about the longitudinal axis of said elongated movable element and being adapted to contact mechanically and electrically with said contacts when the elongated movable element is in closed switch position, means for rotating said rotatable portion of said elongated movable element in maintained electrical and mechanical contact with said contacts and without removing said rotatable portion from electrical contact with said contacts throughout the entire rotary movement of said rotatable portion, said elongated movable element being adapted to be drawn out of closed switch position relative to said spaced contacts by movement thereof which is independent of rotary movement of the rotatable portion of said elongated movable element, and latch means for latching said elongated movable element in closed switch position relative to said contacts.

5. An electrical switch comprising spaced contacts, an elongated pivotally movable element movable into and out of closed switch position with respect to said contacts, a portion of said elongated movable element being supported for rotation about the longitudinal axis of said elongated movable element and being adapted to contact mechanically and electrically with said contacts when the elongated movable element is in closed switch position, means for rotating said rotatable portion of said elongated movable element in maintained electrical and mechanical contact with said contacts and without removing said rotatable portion from electrical contact with said contacts throughout the entire rotary movement of said rotatable portion, said elongated movable element being adapted to be drawn out of closed switch position relative tol said spaced contacts by movement thereof which is independent of rotary movement of the rotatable portion of said elongated movable element, and manually releasable latch means for latching said elongated movable element in closed switch position relative to said contacts.

6. An electrical switch comprising spaced contacts, an elongated pivotally movable element movable into and out of closed switch position with respect to said contacts, a portion of said elongated movable element being supported for rotation about the longitudinal axis of said elongated movable element and being adapted to contact mechanically and electrically with said contacts when the elongated movable element is in closed switch position, means for rotating said rotatable portion of said elongated movable element in maintained electrical and mechanical contact with said contacts and without removing said rotatable portion from electrical contact with said contacts throughout the entire rotary movement of said rotatable portion, said elongated movable element being adapted to be drawn out of closed switch position relative to said spaced contacts by movement thereof which is independent of rotary movement of the rotatable portion of said elongated movable element, and manually releasable latch means for latching said elongated movable element in closed switch position relative to said contacts, said latch means being adapted to retain said elongated movable element in latched closed switch position when said rotary portion of said elongated movable element is being rotated.

'7. An electrical switch comprising spaced contacts, an elongated movable element movable into and out of closed switch position with respect to said contacts, a portion of said elongated element being supported for rotation about the longitudinal axis of said elongated movable element and being adapted to contact mechanically and electrically with said contacts when the elongated movable element is in closed switch position, and means including an element adapted for rotary movement for rotating said rotatable portion of said elongated movable element in maintained electrical and mechanical contact with said contacts and without removing said rotatable portion from electrical contact with said contacts throughout the entire rotary movement of said rotatable portion, said elongated movable element being adapted to be drawn out of closed 'switch position relative to said spaced contacts by movement thereof which is independent of rotary movement of the rotatable portion of said elongated movable element.

WALTER A. HEINRICH.