US3557332A - Momentary pushbutton switch with bridging block, ramp and cam means - Google Patents

Abstract

Switch with reciprocal plunger on which is mounted a leaf spring which, during one direction of movement of plunger, brushes a bridging conductor out of position whereat two terminals are connected. A ramp is used to disengage the leaf spring from the bridging conductor after the latter has been displaced. Switch is used to actuate an alarm by disconnecting the two terminals which being disconnected only briefly can be jumped by a second switch to avoid actuation of the alarm when so desired.

Description

United States Patent Erwin Fernandes 117 Arleigh Drive, Alberston, N.Y. 10467 673,118

Oct. 5, 1967 Jan. 19, 1971 Inventor Appl. No. Filed Patented MOMENTARY PUSHBU'I'ION SWITCH WITH BRIDGING BLOCK, RAMP AND CAM MEANS 1 Claim, 5 Drawing Figs.

US. Cl 200/160 Int. Cl 1-10lh 3/12, HOlh 13/56 Field 01' Search 200/ 160, 159(Cursory), 153.13(Cursory), 16.1, 16683, 77

References Cited UNITED STATES PATENTS 2,722,579 11/1955 Rohacs 200/160X 2,919,333 12/1959 Scholin et al. 200/160 3,039,833 6/1962 Farkas ...2.00/153(.22)UX 3,238,341 3/1966 Haydu...... 200/166(B3) 3,371,178 2/1968 Lallemand 200/160X 3,392,252 7/1968 Crawford et a1. 200/160 Primary ExaminerRobert K. Schaefer Assistant ExaminerR0bert A. Vanderhye AttorneyRoberts and Cohen ABSTRACT: Switch with reciprocal plunger on which is mounted a leaf spring which, during one direction of mo vement of plunger, brushes a bridging conductor out of position whereat two terminals are connected. A ramp is used to disengage the leaf spring from the bridging conductor after the latter has been displaced. Switch is used to actuate an alarm by disconnecting the two terminals which being disconnected only briefly can be jumped by a second switch to avoid actuation of the alarm when so desired.

PATENTED-JAMQISYI j f 3557,3132

sum 10F 2 INVI'IN'IOR. ERWIN FERNANDES Q BY 45 MF$AAI MOMENTARY PUSHBUTTON SWlTClI WITH-BRIDGING BLocK. RAMP AND CAM MEANS DRAWING FIG. 1 is a cross-sectional-view from above of a door in which a portion of an alarm system has been installed in accordance with the-invention; FIG. 2 is a cross-sectional view on enlarged scale taken along line 2-2 of FIG. I illustrating a rear view of a'switching device provided in accordance with the invention;

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 1 on enlarged scale illustrating a longitudinal cross section of said switching device;

FIG. 4 is a cross-sectional viewtaken along line 44 of FIG:

3; and v FIG. 5 is a schematic diagram diagrammatically illustrating thecircuit in which the switching device of FIGS. 2-4 is incorporated, as well asthe circuit associated with the access of FIG. I.

; DETAILED DESCRIPTION In the security field and more particularly in the art of providing alarms for preventing unauthorized access to -protected areas, there exists the problem that the alarm system dominates itsenvironment and therefore sometimes becomes an inconvenience which lessens its overall value. For example, an alarm system which has been placed inoperative condition to detect unauthorized access will also sound an alarm if actuated by an authorized penetration of the protected perimeter. It is therefore necessary to provide means for the convenient and temporary deactivation of such alarm systems so. that authorized access is permitted without sounding an alarm.

The above problem will be best understood by reference to a specific example and, for this purpose, the situationwill be considered in which a housewife is athome with a protective system which has been energized to perform an alarm sounding function. It will be obvious, under these conditions, that an alarm will be sounded if the housewife voluntarily opens the door for various reasons unless some provision is made for deactivating the system temporarily. Moreover, unless the provision is convenient, it is likely that the housewife will tend to keep the systemmore or less permanently deactivated while ,she is at homethereby decreasing the overall value of the system.

One known technique for the temporary deactivating of alarm systems has involved the use on doors of a magnetic elethe alarm until the door is opened at which time said parts are separated and the alarm sounded. In this arrangement, a pushbutton can be provided on one of the parts for temporarily deactivating the associated system so that the door can be opened without sounding the alarm.

One disadvantage of this known technique is that both of the aforesaid parts are readily visible which is unacceptable in some decorative schemes. It is accordingly an object of the invention to avoid this'disadvantage and to provide an improved switch in which the component parts can be readily concealed from view.

Another disadvantage of the known technique is that the control must be mounted on one of the aforesaid parts so that the possibilities of remote control are nil. It is an object of the invention to avoid this latter disadvantage and to provide an improved switch in association with which the control can be located remotely .of the access for purposes of remote control and for esthetic reasons.

Still another disadvantage of the known technique is that the control is provided in two parts, one of which is installed on the access means such as a door, while the other part is installed on the surrounding structure in such a manner that when the access is closed the two parts are juxtaposed. It is a further object of the invention to avoid this disadvantage and to provide an improved switching means in which the entire operation of actuating the alarm is performed within a single unit which is readily and conveniently installed and relative to which a temporary deactivating device can be remotely mounted.

In achieving the above and other objects of the invention, there is proposed a switch apparatus comprising two electrical terminals, a movable actuator and a means for electrically connecting the aforesaid terminals, said means being responsive to movement of said actuator for electrically isolating the terminals for a limited period during such movement. More particularly, the actuator is preferably adapted for reciprocal movement in opposite directions and the aforesaid means is responsive to movement of this actuator in only one of said directions to effect the isolating of the terminals, this isolating action being effected for a relatively small fraction of said movement in the one direction between the end limits of this movement.

In connection with the aforesaid construction an alarm device is coupled to the above noted terminals and is actuated, for example, upon the terminals being electrically isolated. A further switch can be connected across the terminals and will be operable to connect the same independently of the first described structure to prevent operation of the alarm means.

As will become apparent from the detailed description which follows, the second switch can be installed in a position which is remote from the position of the first switch. Moreover, it will become apparent that all of the elements necessary for sounding the alarm in the absence of actuation of the second switch is included in the first switch. Still further, it will become apparent that it is readily possible to install both of the aforesaid switches in such a manner that they are readily concealed as is useful bothcstheticallyand from the security viewpoint.

Referring next to FIG. 1 of the drawing, an access is illustrated with consists of a door 10 having knobs l2 and mounted by a hinge 14in turn mounted on the frame 16 of a dwelling or other such enclosure with respect to which unauthorized access is to be prevented. Concealed within the door frame is a first switch 18, the details of which will hereinafter be described with greater particularity, this switch including a 'plunger 20 responsive to the opening of the door 10 for operating the switch. Also illustrated is a second switch 22 having a pushbutton 24, the switch 22 being mounted in the frame 16 adjacent the door 10 for purposes of illustration, it being understood that the location of this switch can be varied at will and can be completely independent of the location of switch 18.

In the rear view of the switch 18 appearing in FIG. 2, it is seen that the switch includes a terminal 26 and a terminal 28, electrical conductors 30 and 32 being respectively connected thereto. Terminals 26 and 28 also appear in FIG. 3 wherein is also shown the plunger 20.

As appears in FIG. 3, the switch 18 comprises a casing or housing 34 within which is slidably accommodated the enlarged base 36 of plunger 20. A spiral compression spring 38 is sandwiched between part 36 and the rear portion 40 of the housing so that the plunger 20 is urged under the influence of said spring to the illustrated position. Normally, however, in the preferred embodiment the location of the plunger 20 is such that it is maintained in displaced position as shown by the phantom lines under the influence of the closed condition of door 10.

Terminal 26 is connected to an L-shaped conductor 42. Terminal 28 is mounted on the tongue 44 of a conductor 46. Conductors 42 and 46 are in spaced parallel alignment which alignment is parallel to the axis and direction of movement of the plunger 20.

A block 48 is provided which is of conductive material and which is usually supported by the conductor 46. A spring 50 installed between the block 48 and insulating member 52 normally urges block 48 against conductor 42 which engages the block in endwise manner. With the block 48 in the illustrated position, a circuit is complete between terminals 26 and 28 via conductor 42, block 48 and conductor 46. The switch is therefore normally closed.

With the switch is installed as indicated in FIG. 1 and with the door closed, the plunger 20 is depressed. The base part 36 is therefore also displaced from the illustrated position to the position indicated by phantom lines. lt carries with it a leaf spring 54 mounted on part 36 in a recess 56 provided for this purpose. As shown in phantom lines, the leaf spring 54 is of such a construction as normally to curl away from the base part 36. To perform its function adequately, the leaf spring 54 ill normally be of metal. However, the leaf spring operates to perform a mechanical function as will hereinafter be indicated with greater particularity and therefore it is not essential that the leaf spring 54 be a conductor. Since it normally will be fabricated of a conductive metal, however, and to prevent the electrical coupling of the plunger 20 thereto, the base part 36 may preferably be fabricated of an insulating material or, alternatively, an insulated mounting will normally be provided between leaf spring 54 and part 36.

In the displaced condition of leaf spring 54, its end 58 will normally have a position of interference with respect to block 48 when the plunger 20 is released and moves away from terminal 26 in FIG. 3 under the influence of spring 38. The spring 54 will thus dislodge the block 48 from its engagement against the end of conductor 42. The circuit between terminals 26 and 28 will be opened on this occasion.

There is, however, provided a ramp 60 in two parts straddling and guiding the block 48 and it will be understood that the ramp 60 performs the function of raising the end 58 of spring 54 as the spring moves to the right with the plunger 20 as illustrated in FIG. 3.

When the end 58 moves to the intersection 62 between the plane of the top of block 48 and the plane of ramp 60, the end 58 of spring 54 will be disengaged from block 48. Block 48 will thus be freed of forces opposing that of the spring 50 and will be urged by the latter said spring back to the position in which it engages conductor 42. The circuit will once again be completed as between terminals 26 and 28.

Further movement of plunger 20 away from terminal 26 in FIG. 3 as the door 10 is further opened will enable end 58 to pass to the top of ramp 60 and to occupy the position illustrated in solid lines.

Thereafter when the plunger 20 is depressed as will occur when the door 10 is closed, the spring 54 will be carried along and will trail down the ramp 60. It will, of course, brush against and over the corner 64 of block 48 but will not in this instance have the effect of dislodging the block 48 so that the circuit between terminals 26 and 28 is not interrupted. The spring 54 will then return to the position illustrated in phantom lines.

From what has been stated above, it will be understood that the plunger 20 and the spring 54 have a reciprocating movement in two opposite directions and that during a relatively small fraction of the movement in one of these directions the circuit between terminals 26 and 28 will be opened. Such opening does not occur during the return movement of the plunger 20 and spring 54. The extent of the opening of the circuit is controlled by the contacting of the end 58 of the spring 54 with the exposed corner of block 48 and the disengaging of end 58 at point 62 of ramp 60. This contact of the spring 54 with block 48 may thus, for example, occur during one-tenth of the total extent of the movement of plunger 20.

Reference is next made to FIG. 5 illustrate how the aforegoing switching elements are incorporated into an alarm system to obtain the desired results.

In FIG. 5 are illustrated the switch 18 and switch 22, these switches being connected in parallel by lines 66 and 68. Line 68 leads to a power supply 70 which is connected via line 72 to an alarm control 74. Line 66 is also connected to control 74 and completes a circuit therewith. An alarm 76 is connected via a line 78 on the one hand and a switch 80 on the other hand to control 74. The alarm 76 can be a conventional bell alarm of known construction. Switch will be a key operated switch of known type by means'of which the alarm can be deactivated. The control 74 will be a known type of control including, for example, a relay which once operated has to be manually reset to its original condition. Therefore, assuming switch 80 to be closed if the control 74 is actuated, the alarm 76 will inturn be actuated and the alarm will be sounded until the switch 80 is opened or the control 74 is reset.

Preferably, control 74 will be of the type which when supplied with current by source 70 will prevent alarm 76 from sounding and will only cause alarm 76 to be operated when the supply of current via lines 72 and 76 is terminated. This arrangement is preferred so that should a person seeking unauthorized access attempt to deactivate the alarm by cutting line 66 or 72 he will cause the alarm to be sounded and will therefore defeat his own purpose.

To maintain a supply of current to control 74, it will be apparent that one of the two switches 18 or 22 or both must be closed. Switch 18 will normally be closed since the plunger 20 (FIG. 3) will be depressed by the door l0. Should, however, the door 10 be opened, the switch 18 will be opened for the relatively short period of ti time referred to hereinabove. The lock-in nature of the relay of control 74 will respond to this brief opening of switch 18 to initiate the sounding of alarm 76 which will continue to operate as aforesaid despite the fact that switch 18 is immediately closed after it has once been opened.

For such circumstances in which it is desired that the door 10 be opened without sounding the alarm it is of course possible to operate the key switch 80. This, however, necessitates that a key be readily available for such operation. Moreover, the key turns off the entire system and not just a part. To avoid the need for being constantly in possession of such a key and to avoid turning off the entire system, the above noted switch 22 is provided. This switch can be any conventional switch such as, for example, a spring-loaded pushbutton switch, the temporary depression of which will maintain a closed circuit despite the opening of switch 18 whereupon the sounding of the alarm can be avoided. it will be further apparent that since the switch 18 is only open for a brief instant, the switch 22 need only be operated for this brief instant whereafter the door can be further opened and subsequently closed without requiring the continued operation of switch 22.

Due to the fact that the operation of switch 18 does not require the juxtapositioning of switch 22, the latter said switch can be located in any position consistent with esthetic requirements. Switch 22 can in fact be located completely independently of the location of switch 18 and door 10 as to permit a remote control of access via door 10 without operating alarm 76. In addition, since switch 18 is completely self-contained and need not be formed as two separate elements, it is possible to install the switch 18 in such a manner that it is completely concealed from view when the door 10 is closed.

From what has been stated above, it will appear that a switch is provided wherein an actuator or plunger is adapted for reciprocal movement in opposite directions and alarm means are provided 5 responsive to the movement of the actuator in only one of these directions to effect an isolating of the terminals of the switch, the isolating being effected for a relatively small fraction of the movement of the plunger in the one direction. Such means as are provided in this switch include a block or bridging conductor 48 engaged by a leaf spring which brushes the block out of engagement in which it bridges parallel conductors respectively connected to the aforesaid terminals.

It will also appear from the above that a cam arrangement is provided in the form of a ramp in order to displace the leaf spring from its attitude of interference with the bridging conductor after the latter has been displaced.

There will now be obvious to those skilled in the art many modifications and variations of the construction and elements set forth hereinabove. These modifications and variations will not however depart from the scope of the invention if defined by the following claims.

lclaim:

l. Switch apparatus comprising two electrical terminals, a movable actuator, and means for electrically connecting said terminals, said means being responsive to movement of said actuator for electrically isolating the terminals for a limited period of said movement, said actuator being adapted for reciprocal movement in opposite directions and said means being responsive to movement of said actuator in only one of said directions to effect said isolating of the terminals, the isolating being effected for a relatively small fraction of said movement is in said direction between theend limits thereof, said actuator being a plunger comprising a spring urging said plunger to one of said end limits, said terminals including spaced conductors and said means including a bridging conductor in a position contacting both said conductors, a spring holding the bridging conductor in said position, and means on said plunger to brush the bridging conductor out of engagement with at least one of the first said conductors during movement of said plunger in said one direction, the first said means including cam means to remove the second said means from engagement with said bridging conductor after the latter had lost contact with said one conductor whereupon the conductor from said position during the movement of said plunger in the other of said directions, the second said means being a leaf spring including a portion having a position of interference with said bridging conductor during said one direction of movement of said plunger and said cam means being a ramp adjacent said position to displace the leaf spring from said position of interference after the bridging conductor has been displaced, said bridging conductor being a block and said ramp being in two parts straddling said block, the first said conductors being in parallel alignment, one supporting said block and the other having endwise engagement therewith, said plunger moving in parallel with said alignment.

Claims (1)

1. Switch apparatus comprising two electrical terminals, a movable actuator, and means for electrically connecting said terminals, said means being responsive to movement of said actuator for electrically isolating the terminals for a limited period of said movement, said actuator being adapted for reciprocal movement in opposite directions and said means being responsive to movement of said actuator in only one of said directions to effect said isolating of the terminals, the isolating being effected for a relatively small fraction of said movement is in said direction between the end limits thereof, said actuator being a plunger comprising a spring urging said plunger to one of said end limits, said terminals including spaced conductors and said means including a bridging conductor in a position contacting both said conductors, a spring holding the bridging conductor in said position, and means on said plunger to brush the bridging conductor out of engagement with at least one of the first said conductors during movement of said plunger in said one direction, the first said means including cam means to remove the second said means from engagement with said bridging conductor after the latter had lost contact with said one conductor whereupon the second said spring returns the bridging conductor to the position in which it engages both the first said conductors, the second said means being ineffective to remove the bridging conductor from said position during the movement of said plunger in the other of said directions, the second said means being a leaf spring including a portion having a position of interference with said bridging conductor during said one direction of movement of said plunger and said cam means being a ramp adjacent said position to displace the leaf spring from said position of interference after the bridging conductor has been displaced, said bridging conductor being a block and said ramp being in two parts straddling said block, the first said conductors being in parallel alignment, one supporting said block and the other having endwise engagement therewith, said plunger moving in parallel with said alignment.

Images