US1665677A - Alarm device - Google Patents

Description

April l0, 1928. 1,665,677

w. c. ROE

ALARM DEVICE Filed Jan. 10.- 1923 ffy;

Patented Apr. 10, 1928.

UNITED STATES y PATENT OFFICE.

WILLIAM C. ROE, OE NEW YORK,` N. Y., ASSIGNOR To HOLMES ELECTRIC PROTECTIVE COMPANY, OE NEW YORK, N, Y.,

A CORPORATION OF NEW YORK.

ALARM DEVICE.

Application led January 10, 1923. Serial No. 611,770.

This invention relates to circuitcontrolling devices employed in connection with burglar alarm systems.

It is an object of the invention to provide a new and improved alarm device which may readily be attached to any portion of a door or window, and in which the Chance of defeating the alarm is reducedA to a minimum.

More specifically, the invention provides an alarmy trap having a pivoted lever arm which controls a bank of Contact springs. The device is fastened to the wall or Hoor near the door or Window which it is desired to protect, and is connected to such door or window by a cord which holds the pivoted lever in a central position against the tension of a spring member. When the cord is cut or burned, the levery will be forced to one side by the spring, thus operating'the alarm contacts; and when the cord isdisplaced by opening the door or window, or by walking into the cord, the lever arm will be drawn forward to operate the alarm contacts. As an additional feature, means is provided whereby the operation of the lever arm in either direction will open one alarm contact and close another, thus providing means for controlling two separate alarm circuits, which practically eliminates any chance of the alarm failing to operate.

Other features and advantages of the invention, and the particular arrangement of parts which is thought to be most advantageous, will appear from a consideration of the following description taken in conne'tion with the accompanvingrv drawing, in which;

Fig. 1 is a plan view showingthe device mounted in position for protecting a window;

Fig. 2 is a front view of the device with a portion of the cover removed;

Figs. 3, 4 and 5 are fragmentary views showing the device in various operated positions.

As shown in the drawings, 10 designates a base or housing supporting a plurality of binding posts 11 to which the protection circuits are connected. The binding posts 11 are connected with a bank of contact springs consisting of end contacts 12 and 13 and a main contact spring 14. The 1main spring 14 is so flexed that it is normally in engagement with the contact 12 and out of engagement with the contact 13. This alarm device may be used in connection with a circuit of the typein which a normally closed circuit is fortified by a normally open circuit, and -when so used an alarm will be sounded upon the opening of contacts 12 and14 and also upon the closing of contacts 13 and 14. A latch 15 is fulcrumed at 16 to a pivoted lever 17, and is provided with a pin 18 which rests at the sloping end of the main spring contact 14. A lever arm 19 vis pivoted on a bearing 20 and is normally held in engagement with the upturned edge 21 of the lever 17 by the action of a coil spring 22. The lever arm 19 is provided with a cam 23 which is adapted to rest in a notch 24 in the latch 15 when the lever 19 is moved against the tension of the spring 22. It will be seen that when the lever 19 is movedto an extreme position against the tension of the spring 22 and then released, the cam 23 Will ride into the notch 24 and force the latch 15 and lever 17 downward until the lever 17 engages the wall of the housing 10. Normally, however,v the latch 15 and lever 17 arev held 1n the position shown in Fig. 2 by the 4main spring contact 14 which engages the pin 18, as pointed out above, and forces the latch 15 and lever 17 upward, their movement in this direction being limited by the engagement of the lever 17 with a pin 26 in the housing 10.

The operating mechanisms described above are enclosed within a cover 27 which may be supported on the housing 10 in any suitable manner as by means of studs 28. The cover 27 is provided with a small window 29 which is centrally mounted therein so that it will be possible to see whether the lever arm is correctly positioned when the cover is mounted in. place. The lever arm 19 may be rovided on its upper portion ywith a ban 3() of distinct-ive color attached thereto by means of studs 31,`or which may, if desired, be painted directly on the arm. This distinctive color may be readily seen through the window 29 when the arm is properly set. A cord 32 isl attached to the lever arm 19 and passes through a slot 33 which is provided in the housing 10 and cover 27. This cord is connected with a cord 34 on the door or window to be protected, by means of an adjustment clip 35. It will be obvious that the cord 32 may be adjusted in the vclip 35 until the lever arm 19 is moved to a posi'- tion where the distinctive color band 30 is sol visible through the window 29. When this condition prevails the trap is set in an operable position, as shown in Fig. 1. For the purpose of resetting the lever-19 after the cam 23 has been moved into the notch 24, the tip of the latch 15 is extended through a slot 37 in the housing 1() and cover 27 `When the cam 23 is caught in the notch 24,'

it may be released by simply pressing the tip of the latch 15 to the opposite side of its slot 37.

The action of the latch and lever arm to control the spring contacts is shown more clearly in Figs. 3, 4 and 5. In Fig. 3, the cord 32 has heen displaced, suchas by being walked into, vcausing the cordto be drawn up and then let go. In this case, the cord draws the lever arm 19r upward until the cam 23 rests in the notch 24. Under the ,action of the spring 22,` Vthe cam 23 in engaging the notch 24 causes the pm 13 to force the main spring contact 14away from the contact 12 and into engagement with the contact 13. This breaks the normally closed alarm circuit and closes the normally open alarm circuit, thus insuring the operation of the alarm signal. YTo resetrthe device, the tip of the latch 15 is moved to the other side of the slot 37, releasing the cam 23 from the notch 24. Vhen this has been done, the arm 19 may be set in its normal central position behind the window 29 by moving the adjustment clip 35 along the cord 32.

In Fig. 4, the cord has been drawn up, as by raising the window or opening the door to which it is connected, but has not been released. In such a case, where the string is kept taut, the cam 23 will be carried over the notch 24 causing it to ride on a raised portion 25 on the latch 15, thus forcing the pin 18 to ride down the sloping portion of the main spring contact 14 to force this contact away from the contact 12 and into engagement with the contact 13, thus opening one alarm circuit and closing` another as before. The trap may be reset from this position in the same manner as described above. Y

In Fig. 5, the cord has either `been cut, burned or otherwise severed. In this case, the lever arm 19 will fly back under the action of the spring 22 and strike the edge 21 of the lever 17, forcing the lever 17 and the latch 15 downward. When this condition prevails, the pin 18 will draw the main spring contact 14 ont of engagement with the contact12 and into engagement with the contact `13.

This alarm device may be readily mounted in any position on a door or window orvmay be concealed in such a position that the controlling cord will reach across a room where it will easily be broken or ldisplaced by an unauthorized person who is not aware' of its presence.

kif the cord is cut or otherwise severed the lever arm 19 will fly back with such rapidity as to throw the cord 32 attached to the lever arm out of reach. Thus, even if a burglar is able to discover the whereabouts `of the alarm device, which is unlikely, the contacts will have been operated long enough to turn in a positive alarm before he can manipulate the tip of the lever 15 in its slot 37. Furthermore, it is impossible for an unauthorized person to cripple the alarm device preparatory to a night raid by stuiiing bits of material between the contact lever and,` walls of the 'housing without being noticed,

as has heretofore been possible. If this is done, when the cord is cut the lever 19 `will iiy down, under the action of the coil spring, carrying with it the lever V17 as well as all the bits of stuii'ing material resting between them, and causing the pin 18'to operate the alarm contacts. The same result will be ob-V tained if the cord is drawn upward since the cam 23 will rest in the notch 24, or else the lever 19 will press the bits of stuflingv material against the spring contacts and cause them to operate." Furthermore, if such bits of stuiiing material make it difficult to raise the-lever 19, the cord will break when the window4 or door is opened, thus causing the operation of the alarm contacts.

Various changes in the details of construction may obviously be made without departing from the scope and spirit of the invention and it is not, therefore, intended to limit the invention to the specific construction shown and described.

What is claimed is:

1. In an alarm device a member to be protected, a pivoted lever, a spring urging said lever in one direction, a set of contact springs for controlling an alarm circuit, an'arm for operating said springs, and a cord secured to said protected member and to said lever in such manner as to hold the lever in a normal position against the tension of said spring, said lever rotating in one direction due to a pull on said cord when the pro. tected member is disturbedy and in the other direction if said cord is severed, said lever arranged to operate said arm when rotating in either direction to cause the actuationY of Y said springs.

in either direction to cause the actuation of 10 said springs, and means associated with said lever and arm for maintaining said springs in their closed position.

In Witness whereof, I hereunto subscribe my name this 4th day of January A. D., 15

VILLIAM C. ROE.

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