US1347345A - lofgren - Google Patents

Description

J. LOFGREN. COMBINATIUN SAFETY SWITCH AND RECEPTACLE. APPLICATION FILED DEc.2s.191a.

Ill/111AA @www 1. I OFGREN.

CUMBINATION SAFETY SWITCH AND RECEPTACLE.

APPLICATION FILED DEC.26. I9I8.

Patented July 20, 1920.l

2 SHEETS-SHEET 2.

'for vestablishm UNITED STATES PATEVr ,oFFlcI-:Ql

JOHN LOFGREN, 0F CHICAGO, ILLINOIS, ASSIGNOR T0 RALCO MANUFACTURING C0.,

0F CHICAGO, ILLINOIS, A C

OBPORATION OF ILLINOI COMBINATION SAFETY SWITCH AND RECEPTACLE.

'Application mea December 2s, 191s.

To all whom timely concern: y

Bewitlmown that I, JOHN LoFGnEN, a citizen of the United States, residin at Chicago,in'the county of Cookand tate of Illinois, have invented 'a certain new and useful CombinationSafet Switch and Reg ceptacle,fof which the fol owing is laspeciiication. p

My invention is embodied in a combined switchand receptacle, the general object of which is tojprevent misoperationof the 'parts and toprevent their operation in ,im

proper sequence.,` In installing electric translating devices, especially ,portable or removable ones, it is common practice to employ a plug and' 'receptacle 4as a. connector electrical connection .between,A the trans ating device andthe supply conductors; Good practice demands thata service switch, be interposed f between the connector and the leading-in wires;also thattheswitch should be open 4whenever the plug is being inserted or Withdrawn from the receptacle. i But users of translating devices are often careless or ignorant of the demands ofy oodpractice and it is very common for t e operator to withdraw or insert the plug While the service switch is closed. This frequently causes arcing, which endangers the apparatus and may even injure theoperator. One of the objects of my invention' is to make it impossible for the operator to insert or withdraw the 'plug unless the switch is open. Ordinarily the service switch is an independent piece of apparatus from the receptacle and is some times installed at a distance from it. One of the contributory objects ofmy invention is to combine them so that they may constitute a sin le piece ofapparatus. Safety is the undeying purpose of the invention and in .order-to provide safety it .is one of the objects of the invention to inclose the switch within ya box and operate it from a point outside of the box. so that if there is any arcing it Will occur within the box and hence be relatively harmless. With this in mind Iprovide a door for the box and provide mechanism which. will hold the door closed until after the plug has been withdrawn, and the switch opened. Another ob Iiect is to provide means by which the switch will be locked open so long as the door remains open. In the form selected to illustrate the invention the plug is inserted by Specification of Letters Patent.

my purpose to Patented July 20, 1920. Serial No. 268.311. i

this connection it is provide means for preventingthe reversal of the plug the purpose being to insure that the conr uctors in the cord or cable will always beconnected to thefproper respective supply conductors. Anotherobject is to provide means whereby the plug will, if only partially insertedpr withdrawn from the receptacle, prevent the switch from being closed.- Other contributorynbjects lwill become apparent ,as the descriptlon proceeds. q

In the accompan ingdrawingsf-A `i Figure`1 is `a ontLelevationofnapparatus embodyingthe invention, the box-being shown vertical section 'and thel -plug and receptacle also being'shown chiefly ,in vertical section.

Fig. 2 is a perspective view illustrating the cooperation of constituentparts ofthe device. i

Fig. 3 Vis a p1 an;secti0n showin theA receptacle and bracket and parts o the receptacle. i

Fig. 4 is a side elevation of the complete apparatus, the box and its door being in section. v l

Fig. 5 is similar to Fig. 4 except that the parts are shown in changed position.

Like reference numerals denote like parts throughout the several views.

In the illustrated form of the invention there is a boiY 1 which is intended `to be mounted in fixed osition. It is with a doorA 2 in ront which is hinged at the upper end upon a pintle 3. A Vpanel 4 of slate or other insulating material is fastened at the back of the box for supporting the service switch. This is illustrated as a single throw, three pole switch having three switch blades 6, 7 and .8 adapted to engage three stationary contacts 9, 10 and 11 respectively, to which are fastened three leading-in wires 12, 13, 14 respectively. It will be understood, however, that while I have illustrated a three wire system the same principle would apply to a system having more or less than three wires. The switch is operated by a handle 16 and the switch blades or arms are pivoted to the terminals 17, 18, 19, thesefbeing electrically connected to the conductors 20, 21 and 22, respectively which lead to sockets 23, 24, 25, respectively, mounted in the receptacle block 26. Block 26 consists of porcelain or a straight-in push. In

provided 1iii) l receptacle,

other insulating material und is supported upon a bracket 27 within the box. The precise form o the punts thus ar described is immaterial, the mint boing thwt the switch is mounted within the box and connected to the terminals .nifthe receptacle7 which is also carried by the box and preferably with- :4 The plug consists'in the present case, of a block 3H of porcelain cr other insulating material mounted within a shelll having a clamp 32liy whiclfit may y=be coi'inected to 'flexible `conduit 3B; The conductors 34, 35,"36 whichare ihcased Within the sheath -of the coinduit 33 are electrically connected 'to the pins 37, 38, 39 respectively, which are adpted to lit-intothejsockets 2 3, 9A', 25, respectively1 ,to make electrical connections therewith. A 4^ v At the sidfof the shell 31 there'is ormed a `lug 40 A'which is adapted to pass .through the slot'4l orrned in thejbottornof the box. As this slot .affords the lonly entrance for the lug,Y itprevents the =plug rom being ini i butithie ii itonc to connect theproper conductors t Ae conduit to the propei'pois oftht/ switch.' -:Hence it may'besaladier the plug with itsiqgj 4u is non-reversible. Y

Iriiiledu near he *bottoin ofl the 4box. is s. roclrsht 345'3 operated'bya ha'ri'dlevcr I44 located outside of the boxes best shownin Fig.' 'IMstirieitothisA4 haft inside vof the boztls an iti-'in -l5 which `is bifu'rcfit'ed 'at the upper end to engage the switch handie 1G. Thusthels'vvitch inay point oiits'ideof the box by oper-"ating:r handle 44. rI `he rock shaft also has an arm lffastened toit which carries ido'g 47 so placed as to move into and out of thepath ofthe lug?y 40 in harmony-` with'the movements of the rock shaft and switch. `The construc- 1tionY is such that when the switch is closed -the dog will block the path of the lug, preventing the plug,r bein'ginserted 'if out of the and preventing the plug being withdrawn if within the receptacle. If the 'plug is not pushed completel h'ome in -zhe recemment@ dog win-stri, ze u1@ Side of the lu" )and preventthe switch from 'being close' Thus it 'will seen, 'thatj'the plug e'annotbe Withdrawn unless the switch -is open 'not' can it be inserted uhiess'th'e switch is open', 'and the switch cannot'be 'closed unlessthep'lu'g is inserted `to the full 'and :proper distance.'

Now, referring to the lockout, whereby the switch is prevented from closing when the plug i's not inV position in the receptacle; an arm 50 is vpii'roted'to abracket'l' extending back of the box. his erm'v hs a shoulder 52 adapted, when lowerechto dro behind the rr'nglG and prevent the rock shaft from being rotated in a' Iii- 4motion to close the switch.Y A lug 54 is "the door locked.v XYVhen be operated from a- "formed on the side of arm 50 in such inanner that when the plug is in position in the receptacle the lug 40 will engageiiug-LM and holdthe lockout firm 50 up in non-acting position, but when the plug is withdrawn it will permit seid arm to drop. lf the switch operating arm is in a position corresponding to the closed position of the switch the shoulder 52 will drop onto the upper endof a'rm '46 and be supported by it. lf, however, the arm 45 moves therswitch to open position the arm 4G wil-lfp'ass to the front of shoulder 52, thus permittinfrhsaid shoulder' to drop behind arm 446 and lock the switch -open. Hence, the switch cannot be again closed until the ,plug has been re inserted andthe lug 40 has engaged the lufT 54and raised the lockout arm high enougi to permit the arm 46 to clear the shoulder 52. y

The mechanism for holding the door locked includes ahook 5G adapted to be en- .gaged by aheok 57 formed at the outer end 'of arm 50. When the plug is inposition "inthe receptacle it holds the :ir/m sufhhooli 56y and hold the vplugjs4 Withfar" @H011 h'lo Clear thehook 56 beforefthe shoulder 2bn "said armiwili contact theuppcr end o f'the arm ciently elevateA to engage drawm' arm 50 will drop 4G. Thus the"withdrawai of thelplug will unlock the door. l n

I haveprovided means' or requiring door .tobe closed before 4the switchfcan lbe movedfrom open to yclosed position. n is mechanism includes a latch 60', pivotedA-to the bracket 61, fastened `to the back of the box near the top. vSaid latchhas'y a shoulder GQ'adapted to drop behindthehorizontal portion 63 of the arm 45 when the latter is moved forward far enough to open the switch. A bracket 64 is mounted on the 4inside of the door near the hinge and' is ,so positioned that when the door is closed the bracket will hold the latch hi h enough to clear the horizontal portion 6 of arm 45, and permit the switch to moveto closed position. If thedoor vis opcn, 'hitch 62, will rest upon the horizontal portion 63 so 'that the moment it passes beyond shoulder 62. said shoulder will drop back ofit ,and lock it in open position.

Operation: Let it be assumed that the parts are'hssemblcd as shown in Eig's.-4 1 and 4,4 the switch being closed` the door closed and the plugr in position. The luge() holds lug 54 elevated so thatA ho'k 5'( will' engawe the hook 56 and hold the door locked. e dog 47 will also block the path lof lug 54H and prevent the withdrawal o -the plug.

`Hence if itisdesired towithdrew the p'lug ble to withdraw the plug, whereupon the arm 5() will drop sullciently to cause the hook 57 to disengage the hook 56. Consequently, the door is now unlocked and may be opened. The lowering of arm 5() causes the shoulder 52 to drop back of the arm 46 and lock the switch open. Furthermore, the opening, of the door permits the shoulder 62 to drop behind the horizontal portion 63 fof the arin45, sol that the switch will nowbe locked open by two separate and independent mechanisms. The advantage of the latch 6() is that it prevents the plug from heilig inserted and the switch subsequently closed while the door is open.- It compels the.attendant to operate the parts in the proper sequence,-that is, to first close the door, then insert the plug, and then close the switch.

It will be noted that the latch 60 is up near the top of the box where it is not readily accessible. The advantage of this arrangement is that it makes it diiicult for the attendant to get at the latch to deliberately raise it while the door is open and thus'defeat the purpose of the latch.

It will be understood that the actual form of the parts may be considerably varied without departing from the spirit of the invention. It will al'so be understoodthat it is not essential that all of the elements of the device be present in order to produce an operative and useful structure. For example, the door .locking mechanism may be omitted without destroying the cooperative effect of the lug 40 with the dog 47. Similarly, the latch 60 may be omitted without destroying the ability of the coperating hooks 56, 57, to hold the door locked so long as the plug remains within the receptacle.

In the accompanying claims I do not wish to be understood as employing the terms plug and receptacle in the unduly restricted sense that the receptacle is the chambered part and that the plug has a portion entering into it. I employ the terms in the broader sense that the receptacle is the stationary part and the plug the removable one.

Having thus described my invention what I claim as new and desire to secure by Letters Patent, is

l. Electric apparatus comprising a throw switch, a box inclosing said switch, a receptacle carried by said box, a plug for said receptacle, the receptacle having a longitudinal slot and the plug having a lug sliding in said slot whereby the plug is nonreversible, a dog adapted to move into and out of the path of the lug for blocking its movement, a handle for operating said dog, and means operated by said handle and adapted to coordinate the switch with the dog for moving the dog into acting position when the switch is closed.

2. In a device of the class described, thc.` combination of a switch box, a door for closing it, a receptacle carried by the box, a plug for the receptacle, and locking means for holding the door closed. said locking means being held by the plug in acting position when the plug is in position within the receptacle. whereby the door cannot be opened without first withdrawing the plug.

3. In combination, a switch box, a door for it, a locking arm, adapted when in raised position to engage the door for locking it, a receptacle, and a plug for the receptacle` said plug being adapted to hold the locking arm raised in locking position, when the plug is in the receptacle.

4. In a device of the class described, the combination of a switch, a box inclosing it, a door for the box, a receptacle carried by the box, a plug for the receptacle, and locking means for holding the door closed, said locking means being held in actin position when the plug is in position in t e recep tacle, said locking means being adapted to unlock the door when the plug is withdrawn and said locking means being also adapted when thus released by the plug to automatically engage the switch and lock it 1n open position when said switch has been moved to open position.

A combined switch and receptacle comprising a box, a switch mounted therein, a door hinged to the box, a latch within the box adapted to hold the switch open, means operated by the door for lifting the latch when the door is closed and thus releasing the switch so that it may be closed, a receptacle carried by the box, a plug for entering said receptacle, and a lockout adaptedto hold the switch in open position, said lockout being adapted to release the switch when the plug is inserted into the receptacle, whereby the door must be 'closed and the plug inserted before the switch can be closed.

6. A combined switch and receptacle comprising a box, a switch mounted therein, a door hinged to the box, a latch Within the box adapted to hold the switch open, means op erated by the door for lifting the latch when the door is closed and thus releasing the switch so that it may be closed, a receptacle carried by the box, a plugr for entering said receptacle, a lockout adapted to hold the switch in open position, said lockout being adapted to release the switch when the plug is inserted into the receptacle, whereby the door must be closed and the plug inserted before the switch can be closed, and a handle located outside the box, and having connections passing through the wall of the box and adapted to engage the switch to thereby enable the operator to close the switch after the door has been closed and the plug inserted.

7. A combined switch and receptacle comwhereby the switeh must prising :i box, u switch mounted therein`r :L door for the box, :1, reccptuclo carried by the box, :L plug for enteringr Said receptacle, u door look controlled by the plug and adopted to hold the door locked when the plug is inserted, a dog for preventingr the withdrawal of the plug, and Ineens moving in harmony with the switch Jfor moving:4 the dogr to. nonaeting position us the switch moves open, be open before the plug can `be withdrawn and the door cannot -befopened until the plug is withdrawn.

8. A combined switch und receptacle eemprising u box, it switch mounted therein, u a door for the box, a receptacle carried by the box, a plug for entering said receptaele u door lock controlled by the plu r and adapted to hold Athe door locked when t 1e plug is inserted, a dog for preventing the withdrawal o'lI the plugyun :mn connected `to the :switch und moving in unison therewith for moving the dog to non-notin position when the switch moves open, nn n handle located outside of the box und connected to the switch for opening it.

9. In a device switch, u reeeptuele, mele, u box inclosing the of the class described, at

:t plug for the recepswiteh, a handle Aoutside of the box'oonnected to the switch for lclosing 1t, a, lug on the side of the plug, und

:in 'arm adapted to engage seid lug when the plug is in an intermediate position in the receptacle to thereby prevent the bundle from closing the switch.

In witness whereof' l have hereunto subscribed my name.

JoHN LoFGREN.

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