US1184550A - Burglar-alarm. - Google Patents

Description

.l. L. McMAHON.

BURGLAR ALARM.

APPLICATION FILED JUNE :7. 1915.

1 ,1 84,5 50. Patented May 23, 1916.

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JOHN LUKE MoMLAI-ION, OF NEW YORK, N. Y.

BURGLAR-ALARM.

Specification of Letters Patent.

Patented May 23, 1916.

Application filed June 17, 1915. Serial No. 34,623.

To all whom it may concern:

Be it known that I, JOHN LUKE MGMA- HON, a citizen of the United States, and a resident of the city of New York, borough. of Manhattan, in the county and State of New York, have invented a new and Improved Burglar-Alarm, of which the following is a full, clear, and exact description.

The object of the invention is to provide a new and improved burglar alarm more especially designedfor sounding a whistle on the opening of a door, window or like device by a burglar or other unauthorized person, and arranged to enable the occupant of the room to render the burglar alarm inactive on the owner entering the room.

In order to accomplish the desired result, use is made of a whistle, a valve fixed adjacent a door, window or similar movable part and connected with the mouth of the said whistle, the valve being provided at its valve stem with a cam and the said valve being connected with a source of fluid pressure, and an operating member attached to the movable part and engaging the said cam at the time the door and the valve are in closed positions, the said operating member imparting a swinging motion to the said cam to open the valve at the time the door is opened to allow the fluid pressure to pass from the said source of fluid pressure into the whistle and to sound the same.

A practical embodiment of the invention is represented in the accompanying drawings forming a part of this speclficatlon, rnl which similar characters of reference indi-f cate corresponding parts in all the views.

Figure 1 is a perspective view of the burglar alarm as applied to a door; Flg. 2 is a face view of the key-controlled bolt forthe valve; Fig. 3 is a cross section of the same as ap lied; and Fig. 4 is a perspective view of the olt carrying the operating member for the valve. v

As shown in Figs. 1 and 3, a bracket A is attached to the inner face of the top of a door casing B adjacent a door G. On the bracket A is secured an elbow D connected at one end by a nipple E with the mouth or entrance end of a whistle F, preferably one. of the policeman type. The other end of the elbow D is connected with a Valve G connected by a pipe H with a tank or reservoir I containing compressed air or other suitable fluid under pressure, the outflow of the fluid pressure from the reservoir I to the pipe H being controlled by a valve J. The valve J is normally open and the valve G 1s normally closed.

The bottom of the valve stem G of the valve G is provided with a horizontally disposed cam K engaged by a pin L extending upwardly on the free end of an arm N disposed horizontally and attached to the upper end of a bolt 0 mounted to slide vertically in a bracket P attached to the door C. The bolt 0 is normally in uppermost posltion so that the pin L engages the cam K and when the door C is opened by a traveler or other unauthorized person then the pin L imparts a swinging motion to the cam K whereby the valve G is opened and the fluid pressure from the reservoir I passes by way of the pipe H, valve G, elbow D and nipple E into the whistle F to sound the same, thus giving an alarm.

The bolt 0 is key-controlled on the outside of the door to permit the owner or user of the room to retract the bolt 0 prior to opening the'door so that the pin L is moved out 'of engagement with the cam K and hence the valve G is not opened and the whistle F is not sounded. After the owner has entered the room he can move the bolt 0 upward to reengage the pin L with the cam K. In order to control the bolt 0 use is made of a key-controlled roll-back Q, having a hub Q, j ournaled in the casing P and adapted to be engaged by a key inserted through a keyhole C formed in the door C. The roll-back Q controls a tumbler. R pivoted at It on the casing P and pressed on by a spring R to normally engage the tumbler R with a lug 0 formed on the bolt 0 to hold the latter normally in shot-out position. The bolt 0 is provided with a lug 0 adapted to be engaged in one direction by the rol1-back Q and adapted to be en gaged in an opposite direction by an arm Q formed on the roll-back Q. When the key is inserted in the roll-back Q and turned a swinging motion is given to the roll-back to cause the latter to swing the tumbler R out of engagement with the lug O and then the roll-back engages the lug O to retract the bolt 0 for the purpose previously mentioned. When the key is turned in the opposite direction or an upward pressure is exerted on the arm N then the bolt 0 is shot out to normal position and locked in place by the tumbler R engaging the lug O.

The burglar alarm shown and described is very simple in construction and can be readily attached to a door, window or other movable part, so that when the latter is opened the valve G is opened to allow fluid pressure to pass into the whistle F to sound the same.

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

1. A burglar alarm, comprising a whistle, a valve fixed adjacent the door, and connected with the mouth of the said whistle, the valve being provided at its valve stem with a cam, a source of fluid pressure connected with the said valve, and an operating member attached to the door and movable into and out of engagement with the said valve stem cam, the said operating member engaging the cam when the door is closed and imparting a swinging motion to the said cam to open the valve when the door is opened to allow fluid pressure to pass from the said source of fluid pressure into the whistle and sound the same.

2. A burglar alarm, comprising a whistle, a valve fixed adjacent the door, and connected with the mouth of the said whistle, the valve being provided at its valve stem with a cam, a source of fluid pressure connected with the said valve, and a lock on the movable part' having a key-controlled 8. A burglar'alarm, comprising a whistle,

a valve connected with the whistle, the valve and whistle being secured to a door frame, a source of fluid pressure connected with the valve, a sliding member secured to the door a cam and lug engaging means between the sliding'member and the valve stem, the said cam and lug being in engagement with each other when the door is closed, whereby when thedoor isopened the valve will be opened and the whistle sounded, and means for operating the sliding member. V

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

Witnesses:

THEO. G. HosTER, PHILIP D. RoLLHAUs.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. 0.?

JOHN LUKE MQMAHON.

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