US1810189A - Protective device - Google Patents

Description

W. J. STANTON PROTECTIVE DEVICE Filed March 27. 1929 June16, 1931.

Inuen or Millard 115131112111 Patented June 16, 1931 uurran STATES WILLARD J. STANTON, OF CHICAGO, ILLINOIS, ASSIGNOR, BY HESNE ASSIGNMENTS, TO

AMERICAN ELECTRIC COMPANY, INC., OF

DELAWARE CHICAGO, ILmNors, A CORPORATION 01* PROTECTIVE DEVICE Application filed March'27, 1929. Serial No. 350,245.

My invention relates to protective devices in general, but,more particularly it pertains to protective devicesof'the character used to protect the user of a telephone instrument from high potential currents which might be induced into the telephone line from nearby power lines.

I have assumed as the principal object of m my invention the provision of a telephone protective device which cannot fail to function properly and which is readily adapted for use with almost any make of a telephone instrument. a

, The "principal features and other objects 15 will be apparent from the description of the construction and adaption of the deviceof my invention when taken inconj unction with the single sheet of drawings in which 20 Fig. 1 is a perspective view of the protective device with the cover of the encasing box removed and enough of the side broken away to give a clear viewof its contents;

Fig. 2 is a diagrammatic representation of a telephone line and the protective device combined; and 3 c i Fig. 3 is a ,plan view of a modification of my invention.

A detailed description will first be given of m the construction'of the protective device, reference being had particularly to Fig. '1.

Reference numeral 1 designates a telephone instrument of the type which mounts on the wall. The telephone has been shown inpartial outline only, since instruments of that type are well known. The telephone 1 has the usual receiver 2' and receiver hook 3. Attached in any suitable manner to the side of the telephone 1 is the protective device 40 which is assembled in the metal box 4. This box is lined with thin sheets of insulating material 5. In the top of the box there are shown six holes which are bushed by the bushings 6 of insulating material. Through these holes the various conductors of theline, the arresters and the telephone instrument enter the box where they are terminated in the connecting lugs The lugs 8 are on a block of insulatingmaterial 7. which is located near the top of the box. i v

Centrally located in the box and fastened to the back thereof,'but inside, is'the bracket9 which is substantially U-shaped. The ends 10 and :11 of this bracket have holes therein, in which the shaft 12 slides- Fastened by means of screws to the end 10 of bracket 9 is a block 13 of insulating material. The block 13 is provided with slots into which are force-fitted the contact springs 14, 15, 16, 17 18 and 19, the u'pper'ends of which are formed into tagsto which the jumper wires connectingthem with lugs 8 may be soldered. Those springs are made easily accessible for replacement by the removable strips of insulating material 20 and 21 which'are fastened to block 13 by means of screws.

Rigidly fastened to shaft 12 by means of a screw 23 is another block of insulating ma.- terial 22. A helical spring 24 about the shaft 12 and abutting the blocks 13 and 22, forces block 22 and shaft 12 downwards until block 22 stops up against arm 11-of bracket 9. Gontact members 25 and 26 are fastened to the ends of block22 by screws such as 27;. One of the screws 27 which fastens member 25 projects into block 22 until it threads into contacting member 28 which fits into a slot" in block 22. Members 25 -and28 are thereby conductively connected together. In a similar'manner, contacting member 29, which also fits intoa'slot in block 22, is conductively connected to member 26. It will be noted that members 28 and 29 "do not project as far above the uppersur-faceof block 22 as do members 25 and 26. The reason for that arrangement will be explained subsequently. I

' Mounted on the inside back of the box 4 and perpendicular to bracket 9 is another bracket 30. Theen'ds 31 and 32 of bracket are provided with holes in which the rod 33 may slide. The right hand end of rod 33 is slotted and the extremity is provided with the screw cap 34 of insulating material which projects through the front side of the box. A pin 35 projects through the slot in rod 33 and a pin 36 projects through a slot in the lower end of shaft 12. A post 37 fastened to the base, or back, of the box 4, carries the V-shaped rocker arm 39 which is pivotally mounted on the post 37 by means of screw 38. The arms 40 and 41 of the member 39 are slotted to receive the pins 36 and 35, respectively, when the arms are inserted in the slots in shaft 12 and rod 33, respectively. Thus the slots in the arms 40 and 41 and the pins 36 and form sliding pivots. The member 39 prevents the shaft 12 and the rod 33 from rotating in the brackets 9 and 30.

It can now readily be seen that if the cap 34 is pressed into the box, the rod 33 will move to the left, imparting a clockwise rotation to member 39 which through the action of arms 41 and 40 lifts the shaft 12 and the block 22 carried thereby. against the tension of spring 24. When this takes place, the contacting members 25 and 26 engage contact springs 18 and 19, and 14 and 15, respectively. Further lifting of the shaft 1.2 causes contacting members 28 and 29 to engage contact springs 17 and 16, respectively, after the other members have engaged the other springs.

In this manner, the outside line conductors, fastened to springs 15 and 18, are first grounded through carbon arresters connected to springs 14 and 19, before the line connected to the line conductors of the tele phone instrument which are connected to springs 16 and 17.

The spring 24 restores the mechanism to normal when pressure is removed from the cap 34.

Attached to the rod 33 by means of screws is a flat piece of steel 42 which projects through a slot in the box 4 as shown. 11t tached to the outside of box 4 is a right angle bracket 43 to which. is pivotally fastened the forked member 44. The bracket 43 and member 44 are so positioned that the receiver hook fits between the prongs of the fork. Movement of the receiver hook up and down rotates the member 44 ack and forth about its pivot hen the receiver hook is down, and th equipment in the box is in nor mal, the piece 42 is in position above the upper prong of the member 44 so that the receiver hook cannot be moved upward without first pressing the cap 34 to move the piece 42 to the left. The upper prong of the member is provided with a step 46. hen the member 42 is moved to the left of the vertical edge of this step, the book 3 may move upward. If the pressure is released from cap 4 after the upward movement of the hook, the member 42 presses against the vertical edge of the step 46 and is held there, thereby holding the members carried by block 22 in engagement with the contact springs.

The amount of movement of member 42 to the left necessary before step 46 is reached is enough to prevent upward movement of the hook 3 until members 25 and 26 have engaged their respective contact springs. In this manner, it is assured that the outside line is first connected to the arresters before the 1 receiver hook is allowed to move to operate the usual receiver hook springs within the telephone instrument which control the local circuits of the instrument.

When the receiver is placed upon the hook, the weight thereof pulls down the receiver hook and thereby releases the eql'iii unent, allowing the member 42 to slide over the membe 44 to lock the hook in position.

In Fig. 2 the parts of the equipment of Fig. 1 shown therein, are ninnbered to correspond with parts in Fig. 1.

The lines to which the telephone has access are terminated in the fuse be): and then iumpered to the act: box. The person desiring to use the telephone selects the desired line by inserting the dunnny plug P into the proper jack. Assuming that the line comrsis conductors 4'? and 48 is the desired D the insertion of plug P into the uppc gack connects conductors 4T and 48 with line conductors 49 and 50. respectively. The user of the telephone now removes the receiver from the hook and presses the cap 34. If desi 1 l, the receiver may be left on the hook until the cap 34 has been pressed. .Vhen member 44 has been freed by the movement of piece 42 to the left, the receiver hook and the free ends of the member 44 move upward under the inthiencc of the usual hook springs within the telephone instrun'ient. Shaft 12 moved upward as has been explained causing contacting inen'ibers and to engage the springs 13 and 19, and 14 and 1", respectively. Gonductors 49 and 50 are thereby connected to ground by wa of the arrester and conductors 52 and 53. Further move ment of shaft 12 causes contacting members and 29 to engage springs 17 and 16, respectively, thereby connecting the line conductors 49 and 50 to the conductors 54 and 55, respectively, which lead to the telephone instrument. The user of the telephone may now proceed to establish the desired connection in accordance with the type of telephone system.

rom the foregoing it can be seen that I have provided a protective device which cannot fail in its operation so that the user of a telephone instrument in cases where the telephone line is in close proximity to high potential power lines is fully protected from high. potential currents induced in the telephone line by making the telephone instrument unavailable for use until after the line has first been grounded through arresters be fore it is connected to the telephone instrument. It will be noted that the arrester is only in use as long as the telephone instrument is in use.

An extra precaution may be taken by tying the receiver cord to the switchhook so that if the receiver is dropped or left off the book, he weight of the receiver will pull down the hook and release the protective cut-off equipment as has been explained.

No means has been shown for signalling this telephone station for it is assumed that this station is only for outgoing calls and might be a. station such as located along the right-of-way of a railroad.

A modification of the invention which is also readily adaptable will now be briefly explained, it being shown in Fig. 3 of the drawings.

In the modification, the box 4: holding the equipment is not attached to the telephone but is installed in a separate steel box upon the floor of the telephone booth. The equipment in the box is operated by a foot pedal. In that case, the piece 42, the bracket 43 and member ii are left oif of the equipment. Pressure on the foot pedal operates the rod 33 as if the telephone user had pressed with his thumb on the cap 34L. However, it is necessary to maintain pressure on the foot pedal as long as the telephone is in use. Removal of pressure from the foot pedal allows the equipment to restore to normal.

Having thus described my invention, what I consider new and desire to have protected by Letters Patent is pointed out in the appended claims: 7

1. In a telephone system having a line and arresters, the combination of a telephone, and means for preventing the mechanical operation of said telephone until after said line has been connected to said arresters.

2. In a telephone system, the combination of a telephone, a telephone line,-and means for connecting said line to arresters and for connecting said line to said telephone, said means preventing the mechanical operation of said telephone until said line has been connected to the arresters.

3. In a telephone system, the combination of a telephone having a receiver hook, a telephone line, an arrester, and means for connecting said line to said arrester and then connecting said line to said telephone, said means preventing the operation of said hook until said line has been connected to said arrester.

4. In a telephone system, a line, an arrester,

, a telephone having a receiver'hook, a protective device for said telephone,

and then connecting said line to said telephone,

said receiver hook in inoperative position until said line has been connected to said arrester.

5. In a telephone system, a line, an arrester, a subscribers telephone having a receiver hook, a protective device for said telephone,

means in said device for connecting said line to said arrester and for then connecting said means in said device for connecting sa1d line to sa1d arrester and means in said device for locking maintaining said connections until said hook is returned to normal.

6. In a telephone system, a line, a subscribers telephone having a receiver hook, a pushbutton switch for connecting the telephone to the line, and means controlled by said hook for locking said switch in its operated position to maintain said connection while the receiver is off the hook and for releasing said switch and said connection when the receiver is replaced on the hook.

7 In a telephone system, a line,an arrester, a subscribers telephone having a receiver hook, a push-button switch for connecting said line to said arrester and then connecting said line to said telephone, and means controlled by said hook :tor locking said switch in operated position to maintain said connections while the receiver is off the hook, said means effective upon the replacement of the receiver upon the hook for releasing said switch and said connections.

8. In a telephone system, a line, arresters, a subscribers telephone, connecting means, and means operated by the subscriber for operating said connecting means to first connect said line to said arresters and to then connect said line to said telephone.

9. In a telephone system, a line, arresters, a subscribers telephone having a receiver hook, connecting means, means operated by the subscriber for operating said connecting means to first connect said line to said arresters and then connect said line to said telephone, and means operated by said hook responsive to the removal of the receiver therefrom for maintaining said subscriber-operated means and said connecting means operated to maintain said connections.

In witness whereof, I hereunto subscribe my name this 25th day of March, A. D. 1929.

" WILLARD J. STANTON.

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