US1732181A - Switch interlock device - Google Patents

Description

Oct. 15, 1929. BURNS 1,732,181

I SWITCH INTERLOCK DEVICE Original Filed Feb. 27. 1 2 3 Sheets-Sheet 1 Oct. 15, 1929. J BURNS SWITCH INTERLOCK DEVICE Original Filed Feb. 27, 1 3 Sheets-Sheet Oct. 15, 1929. J. BURNS SWITCH INTERLOCK DEVICE 3 Sheets-Sheet 3 Original Filed Feb. 27, 1920 Patented Oct. 15, 1929 UNITED STATES PATENT OFFICE JAMES F. BURNS, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOB T V. V. FITTINGS COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF PENNSYL- VANIA SWITCH INTER-LOCK DEVICE Original application filed February 27, 1920, Serial No. 361,852. Divided and this application filed November 5, 1920.

One object of my invention is to provide a novel device for preventing opening of the door of a compartment such as that in which the fuse receptacles or other accessories removable or operative by hand and associated with an electric switch, may be mounted, until such switch is fully opened, and which will prevent the closure of the switch as long as said door remains open, the door being auto- 19 matically unlocked as soon as the switch is opened and the switch being automatically locked in its open position as long as the door is in any other position than fully closed.

I also desire to provide a novel form of 23 switch controlling mechanism in combination with door locking means of the type above indicated, whose parts shall be so arranged that the operation of looking or unlocking of the door shall not interfere with the quick and positive opening and closing of the switch.

These objects and other advantageous ends I attain as hereinafter set forth, reference being had to the accompanying drawings, in

Fig. 1 is a perspective view of a safety switch constructed in accordance with my invention, and having its casing in the closed position;

Fig. 2 is a plan of the switch shown in Fig. 1, with the covers removed to show the detail construction of the controlling mechanism Fig. 3 is a vertical section on the line 3-3, Fig. 2;

Figs. 4 and 5 are vertical sections on the line 4-4, Fig. 2, illustrating the switch in its open and closed positions;

Figs. 6 and 7 are elevations illustrating the operation of the controlling mechanism for 49 i the door of the fuse compartment; and

Fig. 8 is an elevation, partly in section, taken on the line 88, Fig. 2, showing the detail construction of the operating handle and its associated parts.

i In the above drawings 1 represents an elongated containing box or casing preferably of pressed sheet metal, having in the present instance a fuse compartment 2 and a switch compartment 3 separated by a transverse partition 4;there being a hinged cover 5 for r Ur)" Serial No. 421,863.

the fuse chamber or compartment 2 and a second hinged cover 6 for closing the switch compartment 3, which is preferably of greater depth than said former chamber. This latter cover 6 has a slot for a spring strip 7 projecting outwardly from the top of the partition 4 and formed with projecting shoulders 8 immediately above the level of the top surface of said cover when this is closed, so as to prevent its accidental opening.

The slot for the strip 7 is of such width that these shoulders will clear its edge when said strip is sprung in one direction from its normal position, thereby allowing the cover to be raised, and the end of the strip is preferably provided with an opening for the reception of a padlock 9 whereby the cover may be locked in its closed position.

A similar spring retaining strip 10 is mounted on the inside surface of the lower end of the casing 1 so that it extends through a slot in the cover 5 of the fuse compartment and it likewise is formed with laterally projecting shoulders 11 extending over the top surface of said cover to normally maintain it closed. It may be moved laterally in its slot to cause said shoulders to clear the edge thereof and to permit the cover to be opened, and it also is provided with an opening 12 for the reception of a suitable lock.

In accordance with my invention, an electric switch is mounted within the compartment 3 and a suitable fuse or fuses within the compartment 2. In the case illustrated this switch includes a base plate 13 fixed to the bottom or back of the casing 1 and having mounted upon it a pair of switch clips 14 to which are respectively pivoted two switch blades 15. These are designed to respectively coact with a second pair of clips 16 also mounted on the base 13 and each having a terminal screw or equivalent device 17 for the attachment of the terminals of a current supply circuit.

Within the compartment 2 is mounted a second base 18 of insulating material having fixed to it in the present instance two pairs of spring fuse clips 1919 of which one of each pair is connected to the adjacent switch clip 14 by a conductor in the form of a flat bar 20 extended through a suitable insulating bushing 21 in the transverse partition 4. The other clip 19 of each of said bars is provided with a screw or equivalent device 22 for the attachment of a terminal forming part of a circuit to be supplied with current and it is noted that the fuse clips 19 of each pair, as well as their associated switch clips 14 and 1G with the blade 15, are in a straight line extending longitudinally of the casing.

For operating the switch and controlling the door 5 of the fuse compartments, I provide ajspindleor shaft 23 journalled in the sides of the casing and so positioned as to. extend transversely through the switch compartment immediately under the-conducting bars 20, there being a sleeve 24 of insulating material mounted on this shaft to. prevent short circuiting with either of said bars. One end of the shaft 23 is extended beyond the outside surface of the casing and has, keyed onit a collar 25 (Fig. 8) providedwith a pro.-

jecting tooth 26 designed to cooperate with the opposite walls of a recess 27 extending longitudinally in the hub or base ofan operating handle 28 loosely mounted on said spindle. The latter is provided with fiat, oppositely extending wings 29 from which a series of pins or teeth 30 project toward the adjacent side of the casing 1 so as to mesh with the teeth of a segment 31 rotatably mountedon a headed stud 32 projecting from said casing.

This segment is rigidly connected to or formed integral with an intermediate member in the form of a plate 33having a convex circularly curved portion 35 designed to cooperate with a projecting arm 34 rigidly fixed to one side of the cover 5 of the fuse compartment from which it projects at a point adjaa tent its pivotal or hinge axis. Said arm has formed in one side a concave circularly curved recess 36 so positioned that when the cover 5 is closed it is concentric with the stud32 and its radius is slightly greater than that of the curved portion 35 of the plate 33. As a consequence the latter is free to rotate without interference from said arm 34 as long as this occupies the position shown in Figs. 6 and 7; ie., with the cover 5 in its. fully closed position. I

In addition the plate 33 likewise has a circularly curved concave portion 38 extending from one end of the convex portion 35 and so,

placed that when said plate occupies a definite definite position, i. e.,thatshown in Fig. 6,

it is concentric with the pivotal axis of the cover 5 and will permit passage of the arm 34 whose portion 39 is also concentric with said pivotal axis and of slightly less radius than the curve of the portion 38.

The teeth of the segment 31 are so engaged with the teeth or pins 30 of the handle28 that when the latter occupies one ofits extreme positions in engagement with a stop 40 mounted on one side of the casing 1, the plate 33 is in such a position as to permit the curved portion 39 of the arm 34 to freely pass into the recess defined by its curve 38, and the cover 5 may therefore be freely opened and closed. Vi hen on the other hand, the handle 28 occupies its other extreme position (Fig. 7) in engagement with a second stop 41 on the casing 1, the plate 33 is in a position in which its curved portion 35 lies within the recess defined by the portion 36', thus effectually preventing movement of the arm 35 and hence of the cover 5 to which it is rigidly connected. Moreover the plate 33 and arm 34 are so de signed that when the handle 28 is in any other position except in engagement with the stop 40, some portion of the curved portion 35 of said plate 33 extends under or interferes with the arm 34 so that the cover 5 cannot be moved on its pivot. Likewise when the cover occupies any but its fully closed position, its arm 34 effectually blocks movement of the plate 33 and hence also of the handle 28 with its associated mechanism.

Rigidly fixed to the shaft 23 adjacent opposite sides of the switch compartment 3 are two projecting quadrants 42 each of which is radially slotted at 46 for the reception of a'link 43 pivotally connected to it by a pin or rivet 44 adjacent its point of connection with said shaft. These two links project above their respective quadrants and are rigidly connected by a cross bar 45 so that they are necessarily moved in unison about the pivotal axis provided by said pins 44 with in the limits defined by the ends of the slots 46. r

The blades 15 of the switch are connected to move in unison, by a block 49 of insulating material for which purpose each of them has fixed in it a pin 50 which projects into one end of said block so that the latter is free to rotate independently of said blades about said pins as an axis. An eye bolt 51 engages the central portion of the cross bar 45 and extends therefrom through the middle of the connecting block or bar 49 to which it is adjustably held by two nuts 52 and 53.

l/Vith this construction it is obvious that the switch blades with their connecting block are free to move with the cross bar 45 and the arms 43 independently of the quadrants 42 which as before noted are fixed to the operating shaft 23, and each of these segmental A arms has pivot-ally connected to one end of its outer portion a link 55 having a longitudinally extending slot through which projects a pin 56 rigidly fixed to and extending inwardly from the adjacent side of the cas ing 1. Each link is connected to its quadrant 42 by a pivot 57 and has mounted on it a spring 58 confined between two cups 59 and 60, of which the latter abuts against a stop in the'form of a cotter pin 61 passing transversely through said link and the other abuts upon a pair of washers 62 mounted on the pin 56.

\Vith this arrangement of parts each of the quadrants 42 and its associated link 55 constitutes a toggle, which under the action of the spring 58 tends to remain either in the upwz rdly bowed position shown in Fig. i or in the downwardly bowed position shown in Fig. 5. In the former case that end of each quadrant distant from the link 55 abuts againstthe partition 4, while in the second case the opposite end of said quadrant engages the floor or bottom of the switch compartment 3. The various parts are so proportioned and arranged that with the operating shaft 23 and hence the toggles 42-55 associated therewith, in the positions shown in Fig. 4, the links 43 necessarily occupy such positions that the switch blades 15 are in their open positions and cannot engage the clips 16 or even approach dangerously near them even though said links be moved to the extreme limit allowed by the slots 46. On the other hand when the operating shaft 28 occupies the position shown in Fig. 5, with the toggles et2-55 in the downwardly bowed position, the switch blades are in engagement with their clips 16.

ith the above described mechanism if it be assumed that the switch blades are in en gagement with the clips 16, some part of the curved portion 35 of the plate 33 lies under or immediately adjacent the curved edge 36 of the arm 34 so that even though the lid or cover 5 of the fuse compartment be released from its spring holding strip 10, it cannot be opened. Under these conditions current is free to flow from conductors connected to the terminal screws 17 through the switch and the bars 20 to one setof the fuse clips 19 and if fuses are mounted in said clips, to pass through the latter to the terminal screws 22 and hence to the circuit which is to be supplied with the current. The fuse clips and their associated parts withinthe compare ment 2 are therefore alive, and access to this compartment is effectually prevented.

In order to open the cover 5 to inspect or replace the fuses in the clips 19, it is necessary to first move the handle 28 in a counter clockwise direction, and it is noted that as it is turned from a position in engagement with the stop 41 to and into its mid position, it does not rotate the operating shaft 28 nor affect the closed switch, although through ,he teeth 30, it turns the blade 33 so as to partially move its curved edge from under the arm 3% of the cover 5.

WVhen said handle reaches its mid position, one wall of its recess 27 comes into engagement with the tooth 26 of the collar 25 so that said shaft is thereafter turned with the handle toward the stop 40. As a consequence, the

, quadrants 42 are swung upwardly, likewise in a counterclockwise direction, until the II-J ootl of the latter are carried with said arms stantaneously disengaged from their clips 16, as they are swung on their pivots in counterclockwise direction. This movement of he various parts is finally arrested by the free or outer ends of the quadrants l2 striking the partition 4: and it is particularly to be noted that the shoe; due to such stoppage is not transmitted to nor permitted to affect any part of the switching mechanism.

lllereorer not only are the blades capable of moving independently of their actuating quadrants 12 but the latter turn are like wise so arranged as to move independently of the actuating handle 28, with the result that it is a physical impossibility to tease the switch; i. e.,-to partially open or close it or to so slowly open or close it that an arc would be maintained between its blades 15 and clips 16 On the contrary the blades are necessarily in their fully closed positions within the clips 16 or they are in their fully opened positions C istant from the clips without there being any possibility of the operator of the handle 28 causing them to remain in any intermediate position.

After such opening of the switch has occurred, the operating handle 28 may be brought into el'igagement with its final stop 40, at which time alone the plate 33 is clear of the arm 3%. thus permitting the cover 5 to be swung on its hinges to allow of access to the fuse compartment.

If when this cover is open it should be attempted to close the switch, any movement of the operating handle 28 or of the shaft 2?) is effectually prevented since the plate 38 at once comes into engagement with the curved portion 39 of the arm 3 which blocks it and it is not until the cover is moved to its fully closed position that said arm finally clears said plate, so that closure of the switch when the fuse compartment is open is an impossibility.

lVhen the handle 28 is moved in a cloc wise direction with a view to closing the switch, as soon as leaves the stop l0, a portion of the edge 35 of the plate 38 is inserted under the arm Thereafter said handle may be freely moved to its mid p tion with the result that said plate is further swung under the arm 84 until when the wall of the recess 2? comes into ei'igagement with the tooth of the collar 25 the shaft 23 with its quadrants 42 are moved in a clockwise direction. This causes a compression of the springs 58 until the toggles i255 pass the r neutral point when the expansion of said springs suddenly causes them to move into the position shown in Fig. 5, in which they are brought to rest by their engagement with the back of the casing 1. Such sudden movement causes the members l3 with the blades 15 to likewise be moved from the open to the fully closed positions altogether independently of the handle 28 and of said toggles and since the relatively violent movement of the latter is arrested by the casing, there is no resulting shock to or stress upon the switch proper. With the parts in the above noted positions (Fig. 5) the cover of the fuse compartment is immovably locked by the members heretofore described which occupy the positions shown in Fig. 7.

From the above description it will be noted that the parts are so arranged that when the switch is closed any force exerted upon the door of the fuse compartment has no effect upon the operating handle tending to cause this to actuate the switch, and vice verse, when the door is open, no force exerted upon the handle can have any effect upon said door tending to cause it to close.

Another important feature of my invention resides in the fact that the door of the fuse chamber can only be opened when the operating handle is in its fully off position, and is immediately locked from movement by any appreciable displacement of the handle in the direction necessary to cause closure of the switch. Moreover, on the reverse movement of the handle, there is no possibility of unlocking the door until said handle has been so far moved as to insure the opening of the switch. Moreover the plate 33, which constitutes a member intermediate the operating handle and the door, will be found to efiectually prevent a force exerted on the door 5 to move it from its closed position, being trans mitted to the operating handleor in any way affecting the operation of the switch mechanism.

While I have referred to fuses and have shown fuse holding clips as mounted within the compartment 2 whose door or cover is made to be dependent upon the switch and its controlling member, it is to be understood that the specific device or apparatus in said compartment is immaterial since the invention broadly contemplates the use of the mechanism shown for insuring that current is certainly cut off from the conductor or conductors leading into the compartment before its door or cover can be opened to permit access thereto.

I claim: 7

1. In combination, a casing having a door; an electric switch in the casing; an operating member for the switch; an arm on the door;

connection with said operating member, so

that movement of the arm and door from their closed positions may be prevented until after the switch has been opened by the operating member.

2. The combination of an enclosing casing having a door; an electric switch in the casing; an operating member for the switch; an arm on the door; and an intermediate member held by said arm to prevent closure of the switch by the operating member until the door is fully closed, said intermediate member being so mounted as to prevent force on the door from afiecting said operating member.

3. The combination of an enclosing casing having a door; an electric switch in the casing; an operating member for the switch; an arm on the door; an intermediate member cooperating with said door arm to prevent closure of the switch by the operating memher until the door is fully closed; with a lostmotion connection between the operating member and the switch for insuring locking of the door by the intermediate member before the movable element of the switch is actuated.

4. A casing having a door provided with a cam; mechanism in the casing; a member for actuating said mechanism; turally independent intermediate member having a cam, said intermediate cam being held by said door cam to prevent the operation of said mechanism by said actuating member until said door occupies a predetermined position, said intermediate member being adapted .to prevent a force exerted on said door from affecting said mechanism.

5. The combination of an enclosing casing having a door;mechanism in said casing; an operating member outside the casing for actuating said mechanism; an independently supported intermediate member actuated by said operating member and including a cam; with a second cam on the door, the cam of the intermediate member preventing movement of the second 'cam and door when the operating member is in one position and the door is closed, and the cam on the door preventing movement of the intermediate member and the operating member when said door is open.

6. The combination of an enclosing casing having a door; mechanism in thelcasing; an operating member outside the casing for said mechanism; an intermediate member geared to said operating member; a cam on said in termediate member having a portion concentrlc with its axis of rotation and a second portion concentric with the axis of rotation of the door with a cam on said door having a portion concentric with its axis and a second portion concentric with the axis of the intermediate member, the intermediate member being connected to block movement of the cam on the door when the operating member is in any but a predetermined position and to prevent movement of the operating member when the door is open.

7 The combination of an enclosing casing having a switch and a fuse chamber; fuse terminals in the latter chamber; a switch in the former chamber; a door for the fuse chamber; an operating member for actuating the switch; quick make-and-break mechanism in the casing having lost-motion connections with the switch and with the operating member; and an intermediate member actuated by the operating member for locking the door except when the operating member is in its fully off position.

8. The combination of an enclosing casing having a switch and a fuse chamber; fuse terminals in the latter chamber; a switch in the former chamber; a door for the fuse chamber; an operating member for actuating the switch; quick make-and-break mechanism in the casing having lost motion connections with the switch and with the operating member; an intermediate member actuated by the operating member for locking the door except when the operating member is in its fully off position; with means on the door for preventing movement of the operating member except when said door is closed.

9. The combination of an enclosing casing having a door; an electric switch in the casing; an operating member for the switch; with an intermediate member actuated by the operating member to lock the door shut when the switch is closed and so mounted that the operation of the switch is not affected by a force exerted on the door tending to open the same.

10. A casing having a door element; a switch in said casing; an operating element for said switch; and an intermediate member having a geared connection to one of said elements, whereby the other element may be locked when said switch is in a predetermined position.

11. A casing having a door element; a switch in said casing; an operating element for said switch; and an intermediate member having a geared connection to one of said elements so as to prevent a movement of said door element from its closed position until after said switch has been opened by said operating element.

12. A casing having a door element; a switch for said casing; an operating member for said switch; and an intermediate independently mounted member actuated by said operating member to lock said door when said switch is closed said intermediate member also being held by said door to prevent the closure of the switch until said door is closed.

13. A casing having a door element; a

switch for said casing; an operating member for said switch; an intermediate member actuated by said operating member to lock said door when said switch is closed, said intermediate member also being held by said door to prevent the closure of the switch until said door is closed; and means for mounting said intermediate member, so that the operation of the switch is not affected by a force on said door tending to open the same.

14. A casing having a door provided with a cam; mechanism in the casing; an operating member for said mechanism; an intermediate member provided with a cam and adapted to be actuated by the operating member whereby said door may be locked when said mechanism is in a predetermined position; and means for so mounting said intermediate member as to prevent a force on the door from affecting the operation of said mechanism.

15. A casing having a door provided with a cam; mechanism for said casing; operat ing means for said mechanism; and a second cam member having a geared connection to said operating means, whereby said door may be locked when said mechanism is in a predetermined position, said second-mentioned cam being adapted to prevent a force exerted thereon by said first-mentioned cam from affecting the operation of said mechanism.

16. A casing having a door provided with a cam; mechanism for the casing; operating means for said mechanism; and adapted to be actuated by said operating means and provided with a portion concentric with its axis of rotation and a second portion concentric with the axis of rotation of said door, said door cam having a portion concentric with the axis of said second mentioned cam and a second portion concentric with the axis of said door, said second mentioned cam being so mounted as to prevent a force on said door from affecting the operation of said mechanism.

17. A casing having a fuse chamber; a switch; a door for said fuse chamber; an operating member for said switch; quick make-and-break mechanism having lostmotion connections with said switch and with said operating member; and an intermediate structurally independent member held by said door to prevent the closing of said switch by said operating member until said door occupies a desired position.

18. A casing having switch and fuse members; a switch in said switch chamber; a door for said fuse chamber; an operating member for said switch; quick make-andbreak mechanism having lostmotion connections with said switch and with said operating member; and an intermediate member having a geared connection to said opl io crating member to prevent a movement of said door from its closed position until said switch occupies a predetermined position.

19. A casing having a door provided with a cam; a switch in said casing; an operating member for said switch; quick'makeand-break mechanism having lost-motion connections with said switch and with said operating member; and an intermediate cani having a'geared connection to said operating member, whereby said door may be locked for certain positions of said switch.

20. The combination of an enclosing casinghaving a door; an electric switch in said casing; an operating member for the switch; means for connecting said member and switch including a lost-motion connection; door-locking means operated by the mem ber asfit is moved to close the switch and before motion is transmitted from said member to said switch, said locking means including a member intermediate said operating member and the door for preventing force applied to said door being transmitted to said operating member, said door being in abutting relation to said intermediate member when said door is in itsopen position; with quick make-and-break mecha nism in the casing connected to cause closure of the switch independently of the operating member after the latter has been moved to a predetermined position. i

JAMES F. BURNS.

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