Switch Activating Hinge

Abstract

A switch activating hinge comprises a pair of adjacent, pivotally connected hinge leaves, a magnet mounted on one hinge leaf and a switch responsive to the magnet mounted on the other hinge leaf. Tubular casings that are closed at one end receive the magnet and the switch and each casing is inserted into an opening formed in one of the hinge leaves. The casings extend from the rear surfaces of the hinge leaves and the closed ends of the casings define continuous planes with the front surfaces of the hinge leaves, to give the appearance of a conventional hinge. The switch is normally in a predetermined position and it assumes a second position in response to the magnet when the front surfaces of the hinge leaves are in a selected relative orientation, for example, face-to-face relation, as when a door on which the hinge is mounted is closed.

Parent Case Text

BACKGROUND OF THE INVENTION

The present application is a continuation-in-part of my copending application Ser. No. 294,253, filed Oct. 2, 1972.

Description

Rising crime statistics have led to concern with building security and to the development of security devices and systems to protect life and property. A typical security system includes devices for monitoring the use of entrances to and within a building. Although monitoring devices may be prominently displayed to discourage casual intruders, it is preferable to conceal the devices to avoid alerting determined intruders who might then circumvent the devices.

One monitoring device known in the art utilizes a magnetically operated switch. The switch is mounted on a jamb above a door and a magnet is mounted on the upper edge of the door. The switch is either normally open or normally closed and assumes the opposite position in response to the magnet when it and the magnet are in closely spaced relation, as when the door is closed. The position of the switch is monitored, for example, by a light on a display panel connected in an electrical circuit with the switch.

With use of the arrangement described above, both the switch and the magnet are in a relatively conspicuous location and accessible to intruders; hence they may be readily disabled. Moreover, since both are additional attachments to the door and the jamb, extra installation time and mounting fixtures are required, increasing the cost of using the system.

SUMMARY OF THE INVENTION

The present invention relates to a new and unique hinge which, when its leaves are in a selected relative orientation, activates a switch and thereby functions as a monitoring device for a door on which it is mounted. The hinge comprises a pair of adjacent, pivotally connected hinge leaves, a magnet mounted on one hinge leaf and a switch responsive to the magnet mounted on the second hinge leaf. In the absence of a magnetic field of a predetermined strength, the switch normally assumes a predetermined position. In a single-pole, single throw reed switch, for example, the switch is either normally open or normally closed.

The magnet and the switch are received in tubular casings that are closed at one end and are inserted into openings formed in different hinge leaves. Each casing extends from the rear surface of its associated hinge leaf and the closed end of the casing defines a continuous plane with the front surface of the hinge leaf, to give the appearance of a conventional hinge. When the front surfaces of the hinge leaves are oriented in generally face-to-face relation, the closed ends of the casings are in registration with each other.

In operation, the hinge leaf with the magnet is mounted on a door and the hinge leaf with the switch is mounted on a jamb. When the front surfaces of the hinge leaves are oriented, for example, in face-to-face relation, as when the door on which the hinge is mounted is closed, the switch responds to the magnet and assumes its non-normal position. When the door is opened and the hinge leaves pivot away from each other, the switch returns to its normal position. The switch is connected in an electrical circuit, for example, in a circuit with a light on a display panel which indicates the position of the switch and hence the position of the door.

The longitudinal position of the magnet within its associated tubular casing may be adjustable to permit selective adjustment of the relative orientation of the hinge leaves necessary to activate the switch. The farther the magnet is moved away from the closed end of its casing, the closer the hinge leaves have to be to each other to activate the switch, and vice versa.

As can be understood from the above description, the present invention functions as a monitoring device, but its function is effectively concealed. Not only are the switch and the activating magnet essentially hidden from view, but the casings for the switch and the magnet are integral parts of a common and necessary piece of door hardware, thereby preventing intruders from determining that there is a security system associated with the door. Furthermore, the only additional installation expense involved is that necessary to drill simple, circular holes in the door and the jamb to accept the switch and magnet casings. The casings are held in place by the hinge leaves to which they are securely attached.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention, reference may be made to the following description of three exemplary embodiments, taken in conjunction with the figures of the accompanying drawings, in which:

FIG. 1 is a front view of a hinge arranged according to the invention;

FIG. 2 is a sectional view of the hinge of FIG. 1 taken along view line 2--2;

FIG. 3 is a top sectional view of a second hinge arranged according to the invention;

FIG. 4 is an end view of a magnet and associated casing shown in FIG. 3, taken along view line 4--4;

FIG. 5 is a top sectional view of a magnet and associated casing of FIG. 3, showing the magnet rotated from its position in FIG. 3;

FIG. 6 is an end view, partly in section, of the magnet and associated casing shown in FIG. 5, taken along view line 6--6; and

FIG. 7 is a top sectional view of a third hinge arranged according to the invention.

DESCRIPTION OF EMBODIMENTS

In the embodiment of the invention shown in FIGS. 1 and 2, a switch activating hinge comprises a pair of adjacent, pivotally connected hinge leaves 10 and 12, each having a plurality of holes 14 for receiving mounting screws. Three spaced-apart hinge knuckles 16 are arranged on hinge leaf 12 and two spaced-apart knuckles 16 are arranged on hinge leaf 10, fitting between the knuckles 16 on leaf 12. The knuckles 16 are axially alignable and longitudinally closely spaced, such that a hinge pin assembly, generally designated 18, may be received within the knuckles to secure them in axial alignment, while permitting relative pivotal movement about a common axis. The hinge pin assembly 18 may be of any convenient construction. As shown in FIG. 1, it includes an elongated, generally cylindrical pin 20 with a laterally extending flange 21 at one end and an associated tip member 22, which fits into the lower knuckle 16 adjacent to the other end of the pin 20. Two annular bearings 24 are provided, one adjacent each hinge knuckle 16 of hinge leaf 10 to reduce the friction between the hinge knuckles 16 and permit the hinge leaves 10 and 12 to pivot more easily.

Circular openings 26 and 28 are formed in identical positions in hinge leaves 10 and 12, respectively. As shown in FIG. 2, the openings 26 and 28 are counter-bored from the front surfaces 30 and 32 of the hinge leaves 10 and 12 to provide shoulders 34 and 36 part-way through the openings. Near the rear surfaces 38 and 40 of the hinge leaves 10 and 12, the openings 26 and 28 are flared radially outwardly.

The openings 26 and 28 respectively receive non-magnetic tubular casings 42 and 44, both of which are closed at one end by end walls 46 and 48. The thickness of the casings provides some magnetic isolation for their contents. The casings 42 and 44 have laterally extending end flanges 50 and 52 located adjacent the end walls 46 and 48. Immediately adjacent to and axially behind end flanges 50 and 52 are flanges 54 and 56, the peripheral edges of which are disposed radially inwardly from the peripheral edges of end flanges 50 and 52.

As the casings 42 and 44 are inserted into the openings 26 and 28 from the front surfaces 30 and 32 of hinge leaves 10 and 12, end flanges 50 and 52 contact the shoulders 34 and 36 and prevent further axial movement of the casings 42 and 44 outwardly from the rear surfaces 38 and 40 of the hinge leaves 10 and 12. To prevent the casings 42 and 44 from slipping back through the openings 26 and 28, the flanges 54 and 56 are ring-staked, as shown in FIG. 2.

In the ring-staking operation, the flanges 54 and 56 are partially separated from the tubular main portions of the casings 42 and 44 by a sharp instrument and are wedged tightly against the flared side walls of the openings 26 and 28 adjacent the rear surfaces 38 and 40 of the hinge leaves 10 and 12. The frictional forces between the flanges 54 and 56 and the side walls and the flaring of the side walls prevents the casings 42 and 44 from slipping back through the openings 26 and 28. The end surfaces of end walls 46 and 48 and flanges 50 and 52 should be flush with front surfaces 30 and 32 of the hinge leaves 10 and 12 to help conceal the casings 42 and 44 and to avoid interfering with the operation of the hinge. Further, it is preferable to provide a thin layer 80, by plating, painting or the like, over at least the front faces of the hinge leaves and the exposed portions of the hinge knuckles to conceal the existence of the magnetically activated switch and the magnet and to provide an attractive appearance.

The casing 42 in hinge leaf 10 receives in its open end a magnetically responsive electrical switch of any convenient type that is small enough to fit into the casing 42. In the illustrated embodiment, the switch 58 is a reed-type magnetically actuated switch that is well known in the art and consists of two fine metal reeds 60 partially enclosed in a sealed glass tube 62. The reeds 60 extend in opposite directions along the major axis of the tube 62. Within the tube 62, the reeds 60 overlap slightly but may be normally spaced apart laterally to afford a small gap (not shown), between the reed ends. The reeds 60 are joined to insulated wires 64 extending out of the tube 62 to connect the switch 58 in an electrical circuit forming a portion of a security or other electrical system (not shown).

Since the gap between the reed ends prohibits the flow of current between the reeds 60, the switch 58 is normally open. A small biasing magnet 66 may be placed adjacent the reed ends, however, to bias the reeds 60 and cause engagement of the reed ends, as shown, thereby converting the switch 58 into a normally closed switch in this combination. Either a normally open or a normally closed switch may be used in the invention with or without biasing magnets.

Both the switch 58 and the biasing magnet 66 are enclosed in a cylindrical housing 68, which may be of any convenient and preferably non-magnetic material, such as brass or aluminum. The switch 58 is held in place by a ring-like mounting 70 which engages the tube 62 and the interior wall of the housing 68. The biasing magnet 66 is held against the wall of the housing 68 by an adhesive. Other protective packaging methods, however, are within the scope of the invention.

To prevent the housing 68 from slipping out of the casing 42 and to protect the wires 64, the open end of the casing 42 beyond the housing 68 is filled with an appropriate protective material 72, such as an epoxy resin.

The casing 44 in hinge leaf 12 receives in its open end a permanent activating magnet 74 enclosed in a housing 76. The housing 76 is held in place in the casing 44 by an appropriate protective material 78, such as an epoxy resin, that fills the open end of the casing 44 beyond the housing 76. The activating magnet 74 should be oriented such that when the hinge leaves 10 and 12 are in face-to-face relation, the poles of the activating magnet 74 and the biasing magnet 66 are suitably positioned in accordance with known reed switch practices to achieve the results described below.

In operation, the hinge leaf 10 and its associated switch 58 are mounted on a jamb (not shown) and the hinge leaf 12 and its associated activating magnet 74 are mounted on a door (not shown). When the door is closed, the openings 26 and 28 and the end walls 46 and 48 are brought into registration with each other and the magnets 66 and 74 are closely spaced. The magnetic field of the activating magnet 74 is oriented in such a manner relative to that of the biasing magnet 66 to nullify the biasing effect of the biasing magnet 66 and allow the ends of the reeds 60 to move apart, opening the switch. When the door is opened, the activating magnet 74 is no longer spaced closely enough to the biasing magnet 66 to nullify its magnetic effects and the switch returns to its normal closed position. The circuit in which the switch is connected is then completed and an appropriate function is achieved, for example an indication may appear on a monitoring display panel (not shown).

In the past, plunger activated switches could be disabled by holding the plunger inwardly by a blade or other thin instrument thrust between the hinge leaves. If tried with the inventive hinge switch, there will be no effect if the blade is non-magnetic. If the blade is magnetic, the magnetic field to the switch will be interrupted and the switch will operate to produce an appropriate indication.

The sensitivity of the switch 58, the spacings of the switch 58 and the magnet 74 from the closed ends of their casings, the strength of the magnets 66 and 74, and the thickness of the end walls 46 and 48, are all variables that may be adjusted to determine the relative position which the hinge leaves 10 and 12 must assume before the switch 58 responds to the presence of the activating magnet 74. To insure that the switch 58 will respond to the magnet 74 regardless of whether the material of the hinge is magnetic or non-magnetic, at least the end walls 46 and 48 and the flanges 50 and 52 should be of a non-magnetic material, such as brass. Ordinarily the entire casings are formed of non-magnetic material.

FIGS. 3-6 of the application illustrate a second embodiment of the invention which includes a single throw, double-pole reed switch and a magnet that is movable axially within its associated casing. The hinge of FIGS. 3-6 is generally similar to the hinge of FIGS. 1 and 2 with the exception of the two features noted above.

In considering the differences between the hinge of FIGS. 3-6 and the hinge of FIGS. 1 and 2, attention is first directed to the switch 82. The switch 82 is generally similar to the switch 58 of FIGS. 1 and 2, except that it includes three fine metal reeds 84a, b, and c enclosed in a sealed glass tube 86. Within the tube 86, the three reeds 84a-c overlap slightly and at least two of the reeds are normally spaced apart laterally to afford a small gap between their respective reed ends. The reeds 84a-c are joined to three insulated wires 88a-c extending out of the tube 86 to connect the switch 82 in an electrical circuit forming a portion of a security or other electrical system (not shown).

As shown in FIG. 3, a small biasing magnet 66' may be placed adjacent the reed ends on one side of the glass tube 86. The biasing magnet thus causes the center reed 84b to contact the outer reed 84a adjacent the biasing magnet 66', as shown, thereby completing the circuit that includes the two insulated wires 88a and 88b connected to the two reeds. When a permanent magnet 90 for activating the switch 82 is moved into appropriate proximity with the switch, by pivotal movement of the hinge leaves 10 and 12, the magnetic field of the activating magnet 90 causes the center reed 84b of the switch 82 to move to the left, as viewed in FIG. 3, to contact the left hand reed 84c and complete a second circuit.

The activating permanent magnet 90, like the activating magnet 74 of FIGS. 1 and 2, is enclosed in a generally cylindrical housing 92. Unlike the housing 76 for magnet 74, however, the exterior surface of the housing 92 is threaded and the closed end of the housing is provided with a slot 93 extending across its diameter. Both the magnet 90 and the housing 92 are received in a casing 94, generally similar to the casing 44 of the hinge of FIGS. 1 and 2. As shown in FIG. 4, however, the housing 92 has four axially extending grooves 96 cut by a tool pressed into the casing 94 to provide axially extending ridges 98 on each side of the grooves. The ridges 98 project radially inwardly from the interior circumferential surface of the casing 94.

To allow the housing 92 to be slipped or dropped into the casing 94, the casing 94 and the magnet housing 92 are dimensioned so that the outer diameter of the threads of the housing 92 is no greater than the inner diameter of the casing 94 defined by the eight ridges 98 spaced around the internal circumference of the casing 94. Since it may be commercially more practical to produce only one type of casing for both the magnet 90 and the switch 82, the switch 82 and its housing 68 may be placed in a casing 100 similar to the casing 94. The use of identical casings also permits the magnet 90 and the switch 82 to be located on either hinge leaf.

In order to be able to adjust the axial position of the magnet 90 relative to the closed end of the casing 94, and thereby select the relative orientation that the hinge leaves 10 and 12 must assume before the switch 82 responds to the activating magnet 90, a threaded member is provided that will cooperate with the threaded housing 92 to hold the magnet in a selected position in the casing 94. As more fully described hereinafter, such a member is a thin filament of material, for example, an 0.025 inch diameter nylon monofilament, designated in the drawings by the reference numeral 102.

When installing the housing 92 in the casing 94 the filament 102 is placed lengthwise in the casing 94 along its interior surface, preferably spaced from the grooves 96. The housing 92 is slipped into the casing 94 simultaneously with the filament 102. With the dimensions of the threads and casing suitably selected, indentations will be formed in the monofilament 102 by the threaded housing 92, and, following insertion, the housing 92 and filament 102 are as shown in FIG. 4. The end of a screw driver, or similar tool, is then inserted into the slot 93 in the closed end of the housing 92 to rotate the housing 92. The housing 92, casing 94, and filament 102 are dimensioned as that rotational movement of the housing 92 carries the filament 102 with the housing 92 until the filament 102 is urged against one of the ridges 98. After the filament has been urged against one of the ridges 98, as shown in FIG. 6, it is restrained against further rotational movement with the housing 92 and the threads on the housing 92 cooperate with the indentations formed in the filament 102. The housing 92 and the monofilament 102 are now jammed tightly into the casing 94 and neither will slip out to the open end of the casing 94. At the same time, the axial position within the casing 94 of the housing 92 and its enclosed magnet 90 can be adjusted by rotating the housing 92 and thereby screwing it into or out of the casing 94.

As can be seen from the above description, the hinge of FIGS. 3-6 represents a convenient yet inexpensive arrangement for selectively adjusting the relative orientation of the hinge leaves 10 and 12 which must be assumed by the hinge leaves before the switch 82 is activated by the magnet 90. Of course, the housing 92 may be permanently fixed in one place in the casing 94, by an appropriate adhesive or potting compound. This may be done by filling the open end of the casing as shown in connection with the housing 76 of the hinge of FIGS. 1 and 2.

A third embodiment of the invention is illustrated in FIG. 7 of the application. The hinge of FIG. 7 is similar to the hinge of FIGS. 3-6 except for the means by which the magnet is axially movable within its casing.

The switch (not shown) in its housing 68 and the permanent magnet 90 in its housing 92 are received in identical casings 104 and 106, respectively. Both casings 104 and 106 are outwardly similar to the casings 42, 44 and 100, 94 of FIGS. 1-2 and 3-6, respectively. The interior surfaces of the casings 104 and 106, however, are threaded so that the magnet housing 92 can be screwed into either casing. As shown in FIG. 7, the axial position of the housing 92 within the casing 106 can be adjusted by rotating the housing and thereby screwing it into or out of the casing 106.

If it is desired to fix the magnet housing 92 in a particular position, an adhesive, such as the compound sold under the tradename "Loctite," may be used. The switch housing 68 is held in the casing 104 by a potting compound 108, for example.

It will be understood that the above-described embodiments are merely exemplary and that those skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention. All such modifications and variations are intended to be within the scope of the invention as defined in the appended claims.

Claims

I claim:

1. A switch activating hinge comprising a pair of adjacent, pivotally connected hinge leaves, a magnet producing a magnetic field mounted on a first hinge leaf, and a magnetically activated switch responsive to the magnet mounted on a second hinge leaf, the switch responding to the magnet when the first hinge leaf is oriented in a predetermined position relative to the second hinge leaf.

2. A hinge according to claim 1, wherein front surfaces of the hinge leaves are oriented in generally face-to-face relation when in the predetermined position.

3. A hinge according to claim 1, further comprising casings adapted to receive the magnet and the switch, each casing being closed at one end and being inserted into an opening formed in a hinge leaf, whereby the casing extends from a rear surface of the hinge leaf and the one end of the casing generally defines a continuous plane with a front surface of the hinge leaf.

4. A hinge according to claim 3, wherein one end of a casing in the first hinge leaf is in registration with one end of a casing in the second hinge leaf when the front surfaces of the hinge leaves are oriented in generally face-to-face relation.

5. A hinge according to claim 3, where the one end of each casing is fabricated of a non-magnetic materal.

6. A hinge according to claim 1, wherein the first hinge leaf is mounted on a door and the second hinge leaf is mounted on a jamb.

7. A hinge according to claim 1, wherein the switch assumes a constant first position relative to permitting a flow of current therethrough when the magnetic field produced by the magnet at the switch is less than a predetermined strength, the switch assuming a second position when the magnetic field produced by the magnet at the switch reaches the predetermined strength, and the switch reassumes the first position whenever the magnetic field produced by the magnet at the switch is less than the predetermined strength.

8. A hinge according to claim 1, wherein the magnet is selectively movable relative to the first hinge leaf, to permit selective adjustment of the predetermined position of the leaves.

9. A hinge according to claim 8, further comprising a cylindrical casing extending from a rear surface of the first hinge leaf and adapted threadedly to receive the magnet, whereby the magnet can assume a selectively adjustable position axially within the casing.

10. A hinge according to claim 9, further comprising a housing encircling the magnet and having a threaded exterior surface, a filament of deformable material positioned by a ridge formed axially on an interior surface of the casing and engaged by threads of the housing, the filament being dimensioned to prevent axial sliding movement of the housing within the casing and being deformed by the threads of the housing to permit screw-like combined rotation and axial translational movement of the housing within the casing.

11. A hinge according to claim 9, further comprising a housing encircling the magnet and having a threaded exterior surface and wherein the casing has a threaded interior surface, the threaded exterior surface of the housing and the threaded interior surface of the casing cooperating to permit screw-like combined rotation and axial translational movement of the housing within the casing.