US2547283A - Screen alarm - Google Patents

Description

April 1951 E. B. PURDIN 2,547,283

SCREEN ALARM Filed Nov. 21, 1949 Fig. 2.

Im'eutor Earl B. Purdin Patented Apr. 3, 1 951 SCREEN ALARM Earl B. Purdin, Killeen, Tex.

Application November 21, 1949, Serial No. 128,525

1 Claim.

This invention relates to new and useful improvements and structural refinements in burglar alarms, and the like, and the principal object of the invention is to provide a device of the character herein described, such as may be depended upon for issuing an audible or a visible warning when a screen door or a window screen is opened or removed by unauthorized persons.

An important feature of the invention resides in the provision of means for automatically actuating the alarm in response to unauthorized opening or removal of the screen, while some of the advantages of the invention lie in its simplicity of construction, its eflicient and dependable operation, and in its adaptability for use with door or window screens of different sizes and types.

With the above more important objects and features in view and such other objects and features as become apparent as this specification proceeds, the invention consists essentially of the arrangement and construction of parts as illustrated in the accompanying drawing, in which:

Figure 1 is a fragmentary elevational view of a wall, door frame and screen door, these being partially broken away so as to reveal the invention, and

Figure 2 is a fragmentary sectional view, taken substantially in the plane of the line 22 in Figure 1. I

Like characters of reference are employed to designate like parts in the specification and throughout the several views. 4

Referring now to the accompanying drawings in detail, the general reference character I6 designates a door or window frame in a wall l2, while N indicates a closure in the form of a screen door or window, as will be clearly apparent.

The invention resides in the provision of a burglar alarm consisting of an electric switch l6 of any suitable type, which is preferably mounted between the jamb [8 of the frame I and a wall stud 26, the switch 16 including the usual, rockable actuating member 22.

The switch I6 is connected in series with a suitable warning device such as a bell 24 and with a source of electric current 26, while a second, manually actuated switch 28 is interposed in series in the circuit and is preferably mounted on the inner surface of the wall l2, as is the bell 24.

A keeper in the form of a strap 36 is pivotally connected at one end thereof to the actuating member 22 of the switch l and slidably projects through an opening or slot 32 provided in the jamb IS. The outwardly projecting portion of the keeper 30 is formed with an aperture 34 to receive a fastener in the form of a hook 36 provided on the closure l4. Moreover, an end portion of the keeper 36 immediately adjacent the aperture 34 affords a finger piece 38, the purpose of which will be hereinafter more fully described.

When the hook 36 is in the aperture 34 of the keeper 30, the actuating member 22 of the switch I6 is in such a position that the switch 16 is open, whereby the warning device 24 is silent even though the switch 28 is closed.

However, a tension spring 40, anchored to the stud 20, is connected to the actuating member 22, preferably at the point of connection of the keeper 30 to the member 22, so that when the hook 36 is removed from the opening 34, the spring 40 slides the keeper 30 inwardly as shown at 42, thus closing the switch l6 through the medium of the actuating member 22 and energizing the electric circuit as well as the warning device 24.

In this manner, an authorized opening of the closure I4 will attract the attention of the occupants of the premises wherein the invention is installed, but if the closure I 4 is to be opened by authorized persons, such as for example, during daytime, the switch 28 may be manually opened so that energization of the warning device 24 will not take place when the switch [6 is automatically closed.

When the hook 36 is removed from the aperture 34 and the keeper 36 is drawn into the slot 32 by the spring 40, the keeper may be withdrawn by simply pulling the finger piece 38 outwardly, so that the hook 36 may again be inserted in the aperture 34 when the closure I4 is returned to its closed position.

Finally, it is to be noted that in addition to the warning device 24, a lamp (not shown) may be included in the electric circuit and located, preferably, outside of the closure [4, whereby the apparatus will not only issue an audible warning to attract attention, but will also cause illumination of the area outside the closure for the purpose of detecting and identifying persons who have made the attempt of unauthorized entry.

It is believed that the advantages and use of the invention will be clearly apparent from the foregoing disclosure and accordingly, further description thereof at this point is deemed runnecessary.

While in the foregoing there has been shown and described the preferred embodiment of this invention it is to be understood that minor changes in the details of construction, combination and arrangement of parts may be resorted to .fastenerfsaiii latching "fastener being pivotally connected to said eyelet and adapted to have an end engaging said keeper when in latched posi-- tion, a switch in juxtaposition to said aperture and on the side opposite to said latching fastener, a switch arm extending from said switch and pivotally connected to said keeper, and resilient means for urging said switch arm to actuated position when said latching fastener is unlatched for actuating an alarm.

EARL B. PURDIN.

REFERENCES CITED The following references are of record in the file of this patent:

EUNITED STATES P ENTS Number Name Date 118,199 Cook et a1 Aug. 22, 1871 492,330 Kamsler Feb.21, 1893 1,525,215 Wolif Feb. 3, 1925 Jones Nov. 15, 1927

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