US1795434A - Panel-board switch - Google Patents

Description

March 1- H. E. LEPPERTY 1,795,434

I PANEL BOARD SWITCH Filed Jan 18, 1928 4 Sheets-Sheet 3 INVENTOR- H enryE.L eppert, 1 g B iN'EY- March 10, 1931.

EQLEPPERT PANEL BOARD SWITCH Filed Jan. 18, 1928 14 Sheets-Sheet 4 INVEIQTOR H enry E. L ep /uert,

Patented Mar. 10, 1931 yumrsn 'sT s' PATENT OFFICE HENRY ELECTRIC MANUFACTURINGCOMPANY, OF PLAINVILLE, CONNECTICUT PANEL-BOARD SWITCH Application filed. January 18, 1928. Serial No. 247,611.

This inventionrelates generally to snap switches but more particularly to quick-make and quick-break switches adapted for panel board use.. v L

What is commonly known as a panel board is the combination, in a single construction, of bus bars, switches, fuses, wire connectors, etc. for the purpose of separately controlling .branch circuits. The construction is usually mounted in a suitable enclosing cabinet and is preferably provided with insulating means whereby the operator is protected from accidental contact with live parts.

Panel boards are usually installed in oflice buildings, apartment houses or other buildings having a' number of tenantsand are so arranged that each tenant may control his own'individual circuit. The average tenant has no electrical-knowledge beyond how to operate the switch or replace a blown fuse,

therefore it is of prime importance that all element's'of chance or danger be eliminated in the construction of a panel board and-that the construction be sturdy and dependable.

Standard fuses are made to standard dimensions and grouped according to capacity as, for instance, 0 to amp. 125 v., 0 to 30 amp. 250 v., 31 to 60 amp. 250 v., etc., and in each group the outside dimensions are identical, thus, in the first group for example, the fuses are of the plug type and all the casing dimensions are identical whether they enclose a one ampere fuse, a thirty ampere fuse or,

one of any other rating between the limits.

- Each branch circuit is provided with a receptacle or clips'for receiving standard fuses of either the plug of cartridge type and it is due to this fact that the requirements of a suitable operatingswitch are peculiar. The 40 small load to be operated 'from each branch circuit yet each circuit is provided with either a receptacle or clips which will receive fuses of full thirty amperes capacity and it natur-.

follows that the branch switches must be all ablYa-to break the full thirty ampereload inv case the circuit hasbeen overfused. It further follows that, in order to secure the underwriters approval, the switch must first undergo the regular tests which'include the .that practically underwriters will permit only 'a relatively successful operation under load of thirtysevenand one-half amperes at 250volts.

From the foregoing it will be clear that a panel board switch must be of a very substantial and dependable construction and must be 'ableto meet severe service conditions and yet it is very desirable that the switch becomparatively very small. v I

Because of the many difiiculties in provid-- ing a suitable and practical switch, it has been common practice to use switches of the knife blade type but this had the serious objection all of the live parts were eX-, posed. It is desirable that the switch be of the toggle type but such switches of this class as have been placed upon the market have been either too-large and cumbersome or have failed to meet the severe conditions of usage. Applicants main purpose has been to provide a switch having all of the desirable re quirements and which will meet with the fullapproval of the underwriters and yet be no larger 1n SIZB than an ordinary ten ampere switch.

Some of the novel features in the preferred form of my construction are as follows: All

of the switch parts except the operating handle, the spring and the rivets are made of die-blanked sheet stock which insures ab solute duplication and the parts are permanent-ly assembled upon the insulating-base as a unit and entirely without the use of screws. The rocker plate is a flat blank having shoulders which fulcrum oncooperating shoulders on the frame, and portions at both sides of the fulcrum shoulder whichcooper'ate with angular shoulders on the frame to form stops for the plate in both of it's positions and at both sides of the fulcrum shoulder. A central opening in the plate permits the passage of the, operating spring when passing the center lineof its operating movement.

bridge portion cooperates with cam shoulders on theoperating plate carried by the handle toform a simple knock-off for positively starting the operating 'movement of the rocker 'plate. This bridge portion also greatly strengthens the operating plate and adapts it for heavy duty service. A spring. positioning lug securely retains one end of extending lugs, the plate is finished andready for use as it comes from the blanking dies.

The operating lever or handle is provided with a fiat sheet metal operating plate having cam shoulders for engagement with the bridge portion of the rocker plate for easily yet positively starting the operating move ment of the rocker plate. '1 he operating plate is further provided with an extension having a slot the bottom of which forms a bear ing for the turned in end of the operating spring without the use of washers or additional fastening means.

The operating spring is of the compression type, one of its ends being open but bent or ground ofi so that the plane of the end coil is at right angles to the axis of the spring so as to allow it to fit over and rest perpendicularly upon a positioning lug carried by the rocker plateand the other end having the end of the coil bent so as to cross the center line of the coil and thus form a pivot bearing for thespring in the slot of the operating plate. No washers or other extra parts are required to position or guide the spring and it may easily be attached or detached by merely compressing the coils. This method allows for the maximum length of spring which is important because the space is limited and it also allows for a perfectly free rocking movement of the spring at its bearing points during its operating movement.

The stationary. and movable contacts are preferably made of copper and compressed at their contact making heads as per my former Patent No. 1,552,993 because it is found that such contacts will carry a much greater current than other forms of contacts and with comparatively very little heating eflect.

It is becoming general practice to fuse only one side of the circuit in a panel board branch circuit and full advantage has been taken of that fact by using two blades and two pairs of stationary contacts or terminals, each pair being formed from the same blank and being, in effect, a double terminal. The blades are arranged to make or break the circuit simultaneously, the circuit flow being divided between them and this construction makes Dill it possible to. properly carry the current through a switch of comparatively minute dimensions.

The switch is provided with an insulating cover having slots and barriers so arranged as to support the free ends of the terminals and to prevent arcing of the current to adjacent parts of the switch or to another adj acent switch or other metal parts.

- As the switch blades move away from the terminals, they are housed in narrow slots in the insulating cover and the slots tend to greatly minimize if not entirely dissipate thearc should one start to form.

This insulating cover may be secured to the switch proper by means of screws or other fastening-means if so desired but, as shown in the drawings, it does not require any fastening means because it is held in place by the outside cover plate.

It may be further noted that the frame of the switch is open at one side and also at the bottom to permit the rocker plate to be located upon its hearings in the sides of the frame and that the rocker plate is retained in operative position by the force of the compression spring. I

Fig. 1 is-a front view of a panel board cabinet or casing with switches embodying my invention but omitting the cover or door and showing the place for the insertion of two switches.

Fig. 2 is a vertical sectional View of the casing or panel board box showing the ends of the switch supporting units or panel sections. v

Fig. 3 is a horizontal sectional view of the casing showing a panel section.

Fig. 4 is a longitudinal sectional view and side. elevation of a switch embodying my invention.

Fig. 5 is a transverse sectional view of the same on the line 55 of Fig. 4..

Fig. 6 is a cross section and plan omitting the cover plate.

Fig. 7is an end view of a switch unit omitting the insulating housing.

Fig. 8 is a side view and section of one of the switch unit-s showing the parts in the open circuit position.

Fig. 9 is a similar view showing the parts in the closed circuit position.

' Fig. 10 is a similar view showing the spring compressed and about to close the circuit.

Fig. 11 is a bottom view of one of the switch units.

Fig. 12is a perspective view showing a modification.

Fig. 13 is an exploded perspective view of the various parts of a switch unit.

Fig. 14 is a detail sectional view of the ban dle and showing the operating plate.

The cabinet, box or receptacle 15, in which the parts are mounted, has a face plate 16 and a door 17 of any suitable character.

Each section of the panel consists of a sup port or base 18 and is preferably provided with two switch units including fuse sockets of any suitable type. Bus bars 19 are provided behind the panel sections and a bracket 20 is secured to each bus bar for connection with one of the switch terminals. The other lit) posts 28 connected by a cross bar 29, and contact arms 30. Thus the two posts are tied together as a unit and ieenforce each'other. The switch frame is preferably formed of sheet metal with side plates 31 which have lugs 32 adapted to be riveted to the insulatingbase 26. These side plates are preferably connected by integral cross pieces 33 which serve as stops for the oscillating oper atingmember. The operating member consists of a handle 34 of insulating material and a flat C-shaped operating plate having two arms 35 and 36'and is pivoted onpin 34'.

The movable switch members 37, preferably in pairs, are carried by a plate 38 which is detachably and pivotally su' ported in the frame. This plate has shoulders 39 which rest in the V-shaped notches 40 of the frame.

The notches 40 are rounded at the bottom to forma pivot bearing for the rocker plate 38. The spring 41 has one end seated on the lug 42 in the bottom of the plate 38 and at the other end the coil is bent so as to form a cross piece 43 which is hooked into the slot 44 at the rear end of the arm 36 to form a bearing for that end of the spring. This method of pivotally mounting the spring obviates the necessity for any washers or guiding means and allows for the complete operating movement of the spring without distortions 101' strains, in fact the operating pressure is exerted in a straight line between the bearing points of the spring at all times.

In the open circuit position shown in Fig. 8, this spring 41, pressing against the lug 42 and the arm 36, holds the arts so that the shoulder 45 abuts against t e under side of cross piece 33 of the frame. ,In this position the sides 46 of the plate 38 are pressed against the side 47 of the V-shaped notch 40. At-the-same time the side 48 of theplate 38 is pressed against the shoulder 49 'so as to afford an evenly balanced support for the plate 38. In the closed circuit position of Fig. 9 the spring 'holds the parts in position with the shoulder 50 pressing against the crosspiece 33 at the left. The sides 48 of the plate 38 are now pressed against the shoulder 51 while the sides 46 are pressed against the shoulder 52.

In order to break the circuit it is simply necessary to move the operating lever 34 from one position to the other.

Fig. 10 shows the beginning of this movement. I It will be seen that the arm 36 engages the top of the cross bar of the plate 38 so as to forcibly start the tilting of the plate 38 before the arm 36 carries the cross piece 43 of the spring '41 past the center line. .The r switch, therefore, does not rely upon the spring alone to start the snap action altho as soon as the snap action has started it is obvious that the movement cannot be interfered with by the operator.

It will be obvious that in moving from the open circuit to the closed circuit position the arms-35 will coact with the plate 38 in the same manner as above described with respect to the arm 36.

-Each of the movable switch contacts is preferably-made up as above described oftwo members 37 which are suitably secured to but insulated from the oscillating or tilting carrier plate 38. The method of attachmentis clearly shown inFig. 13, the plate 38 beingprovided with two small pin-like projections or lugs 53, adapted to pass thru washer plates 54 and 55 and be riveted over onthe outer ends.

" Insulating Washers 56 and 57 are interposed next to'the contact plates 37 and insulating bushings 58 mounted on the pins 53 extend thru the plates 56, 37 and 57 to insulate the contact members 57 from the carrier plate 38.

For convenience in installing the switch unit the feet 27 and 27 may be provided with notches suchas 59 and 60 adapted to be de-' tachably slipped under the heads of the attaching screws. I

Altho the switch above described has great utility for the various uses for which snap switches are commonly employed, I have found it possible to greatly increase the stability and carrying capacity of the switch by a peculiar form of housing illustrated in 4 to 7. Thishousing 62 may be of any suitable insulating material designed to enclose the'switch contacts. This housing is provided with a projection 63 which fits between the posts 28 and serves to position and support them.

The flanges 64 embrace the sides of the frame 31 and form narrow slots 65 for the contact arms 30. This provides very close quarters for the movable switch members 37 and serves to snuff out any are which tends to form. Flanges 66 are-designed to fit close to the shanks of the contact members 30 so as to definitely prevent displacing them from their proper positions. This housing 62 may convenlently be held'in place by the cover.

While some of the foregoing details may seem of little importance in themselves, yet the combination of the same in a single construction has resulted in a switch which is admirably adapted for its purpose and one which will properly control an electrical circuit of far greater capacity than could reasonably be expected of a switch of such comparativelysmall-dimensions. In fact in accurately calibrated tests, it has been found that a switch of this design and of approximately the same size as an ordinary ten ampere switch will safely and continuously op crate on a current of 75 amperes at 250 volts.

While the foregoing describes my construction more particularly as a panel board switch, it is obvious that the general ideas involved may be employed in the construction of a single blade switch, a double pole switch or, in fact, in any of the usual forms as are usually furnished by the regular trade.

I claim:

1. A snap switch including an insulating base, a switch contact member secured to said base, said contact member comprising a single stamping having a foot secured to said base and two projecting posts each post having a contact tip and a cross bar connecting said posts intermediate said tips and said foot.

2. A snap switch including an insulating base, a switchcontact member secured to each end of said base, each contact member comprising a single stamping having a foot secured to said base and two projecting posts terminating in contact tips and a cross bar connecting said posts intermediate said tips having a central perforation and having a.

spring positioning lug at one end of said perforation and a starting abutment at the other end of said perforation, bearing shoulders at the inner edges of the perforation and lugs projecting laterally from the outer edges of the plate and contact arms riveted on said lugs, said starting abutment extending entirely across the end of said plate and 0011- necting the side portions thereof to re-inforce said plate.

4.1/5 switch including a frame having open-sided bearings, a rocker plate having bearings extending toward each other and pivotally supported in said bearings of said frame and having a spring positioning lug at one end and a cross bar at the other end, said rocker plate having a central opening with closed sides and ends, an oscillating operating member supported in said frame and having two arms adapted to engage said i cross bar for starting saidplate, one arm being adapted to pass through said plate, and a compression spring interposed between said lug and one of said arms.

5. A switch including a frame having bearings, a flat rocker plate pivotally supported in said bearings and having a lug at its inner end and a central closed sided opening, an oscillating operating member supported in said frame and having stop shoulders to engage said frame and having an arm adapted to pass through said rocker plate, and a compression spring interposed between said lug and said arm.

6. A panel board switch including a base, stationary terminals supported on said base and having integral contact tip portions projecting from said base, a switch frame supported on said base, a movable switch member pivotally mounted on said frame for en gagement with said contact tips and a readily removable insulating housing for covering and for partially surrounding said stationary terminals and said housing having grooves for receiving and partially surrounding a portion of said stationary terminals to insulate said frame from the contact making portions of said terminals andsaid movable blade. 4

7. A panel board switch including a base, stationary terminals supported on said base and having contact tip portions projecting from said base, a switch frame supported on said base, a movable switch member mounted on said frame for engagement with the con tact tip portions of said terminals and a readily removable housing for covering said contact tip portions and for partially surrounding said stationary terminals, said housinghaving grooves for receiving and partially surrounding said stationary terminals to insulate said frame from the contact making portions of said terminals and said movable blades, the said housing having recesses to receive portions of said terminals at points adjacent to the respective contact tip portions for maintaining said contact tip portions in operable position.

8. A panel board switch including a base, switch terminals supported at opposite sides of each end of said base and having contact tips projecting from said base, a switch frame supported on said base, a movable switch blade mounted on said frame for engagement with said contact tips and a readily removable insulating housing for covering and for partially surrounding said switch terminals, said housing having barriers adapted to be interposed between the said frame and the contact making portions of the respective switch members, a cover plate for said housing and switch operating means accessible through said cover plate.

9. A panel board switch including a base,

oppositely disposed terminals supported on switch terminals, said housing having integral barriers adapted to be interposed between the respective contact tips and said frame, a cover plate for said housing and 5 switch operating means operable through said cover plate and said insulating housing having positioning recesses to receive a portion of said terminals at a point adjacent to the respective contact tips.

HENRY E.

LEPPERT.

Images