US3405518A

US3405518A - Test arrangement for batterypowered alarm clocks

Info

Publication number: US3405518A
Application number: US495216A
Authority: US
Inventors: Alan E Patrick; Ralph C Robinson
Original assignee: General Time Corp
Current assignee: General Time Corp
Priority date: 1965-10-12
Filing date: 1965-10-12
Publication date: 1968-10-15
Anticipated expiration: 1985-10-15
Also published as: GB1102009A; DE1548093A1; ES332195A1; DE1548093B2

Description

Oct. 15, 1968 A. E. PATRICK ET AL 3,405,518

TEST ARRANGEMENT FOR BATTERY-POWERED ALARM CLOCKS Filed Oct. 12, 1965 v 2 Sheets-Sheet l II I "ii 51 ALARM fivl TEST ALA! l i "r /V30 v 57 BUZZER J I Q. 3 1 F .20. P .21:

7 8| 8| 2 '83 8! 82 W 82 ALARM ON- 7 ALARMON- TE.ST TEST" 7o ALARM OFF INVENTORS ALAN E. PATRICK RALPH C. Roenvsou Arru Oct. 15, 1968 A. E. PATRICK ET AL 3,405,518

TEST ARRANGEMENT FOR BATTBRY-POWERED ALARM CLOCKS Filed Oct. 12, 1965 2 Sheets-Sheet 2 we 5, :35 Ba I35 I35 :37

37 I37 I 52a.

, 8M. 3 no I3! 3 :50 I

' 90 f i\ \\\Y& 2\

mmgg :02 I

INVENTOIZS 93 15 ALAN E. PATRICK l RALPH C. Roauvsorv b my Arrv.

United States Patent 3,405,518 TEST ARRANGEMENT FOR BATTERY- POWERED ALARM CLOCKS Alan E. Patrick and Ralph C. Robinson, Athens, Ga., assignors to General Time Corporation, New York,

N.Y., a corporation of Delaware Filed Oct. 12, 1965, Ser. No. 495,216 12 Claims. (Cl. 58-20) ABSTRACT OF THE DISCLOSURE A battery operated alarm clock having an electric alarm device including an alarm circuit, a manually settable control member for enabling and disabling the alarm device, and means for closing the alarm circuit at a preset time. For the purpose of determining whether the battery has sufficient power to sound the alarm at the preset time, when the manual control member is set, an auxiliary test circuit is included with a test switch coupled to the manual control member so as to momentarily connect the alarm circuit to the battery as the manual control member is moved between its limit positions. The auxiliary circuit is preferably designed to subject the battery to a load requirement greater than that imposed by the alarm device alone to insure that the battery will have sufficient power to sound the alarm at the preset time.

Transistorized clocks, because of their easy portability, have found a substantial market even in the face of the competition of conventional A-C clocks notwithstanding the reputation which the latter enjoy for absolute accuracy and freedom from maintenance. One reason that it is possible for the transistorized clock movement to make such inroads is that the low battery drain enables operation for a full year or more with a single battery while achieving an acceptable order of accuracy. However in the case of transistorized alarm clocks an additional obstacle is presented in that the buzzer or other alarm device draws relatively heavy current making the life of the battery short and largely unpredictable.

It is an object of the present invention to provide an improvement for a battery-powered alarm clock which raises its level of reliability to that of a conventional A-C alarm clock. It is more specifically an object of the present invention to provide an improvement in a batterypowered alarm clock which automatically tests the condition of the battery each time the alarm clock is set and under conditions which are sufficiently conservative so as to insure sounding of the buzzer when the alarm clock goes off. Nevertheless, it is an object to provide an improvement in a battery-powered alarm clock which, although permitting a conservative test, makes it possible to use the battery to its full extent before discarding.

Other objects and advantages of the invention will become apparent upon reading the attached detailed description and upon reference to the drawings in which:

FIGURE 1 is a schematic diagram showing one form of the present invention.

FIGS. 1a and 1b show the succeeding settings of the switch operator.

FIG. 2 is a schematic diagram showing an alternate form of the invention.

FIGS. 2a and 2b are fragmentary diagrams showing successive positions of the switch operator.

FIG. 3 is a fragmentary perspective showing a portion of the driving train of a clock employing the present invention.

FIG. 4 is an elevation showing the alarm control plunger in its alarm off position.

FIG. 4a is a view similar to FIG. 4 but showing the plunger traversing its midor test position.

3,405,518 Patented Oct. 15, 1968 FIG. 4b is a view similar to FIG. 4 but showing the plunger in its alarm on position.

FIG. 5 is a fragment showing the plunger detenting spring.

FIG. 6 is a fragmentary elevation of the structure shown in FIG. 3 with the trip lever in its tripped and rotated position and with the alarm switch contacts closed.

While the invention has been described in connection with certain preferred embodiments, it will be understood that there is no intention to limit the invention to the particular embodiments set forth but we intend, on the contrary, to cover the various modifications, alternatives, and equivalent constructions falling within the spirit and scope of the appended claims.

Turning now to FIG. 1 there is shown a test circuit 10 for an alarm clock embodying the presentinvention. The circuit 10 includes a clock movement 11 having

input terminals

12, 13, which are connected to a small battery 15. In a practical case the movement 11 may be one of the well known transistor movements having an integral alarm switch 16 which is connected to the clock movement by a suitable mechanical connection 17 so arranged that the switch 16 is normally open but automatically closed when the indicated time corresponds to the moment of time for which the clock has been pre-set. The closure of the switch 16 serves to energize a buzzer 20 or other alarm device having

input terminals

21, 22, the buzzer being supplied from the same battery 15 that drives the clock movement.

The invention will be described in connection with use of the usual carbon-zinc dry battery since these are inexpensive and readily available to the average clock owner in either C or D size, although it will be understood that the invention is not limited to use with any particular kind of battery and, if desired, other types such as the longerlived alkaline batteries may be used.

For the purpose of enabling and disabling the alarm a control switch 25 is used having a fixed contact 26 and a movable contact 27 interposed between the alarm switch 16 and the buzzer 20. For throwing the control switch, a manual operator 30 is used which is connected to the movable contact 27 by means of a mechanical connection such as a plunger 31. When the alarm feature is not wanted the manual operator is simply retracted to its alarm off position, opening the switch 25 so that the alarm is disabled even though the alarm switch 16 may, upon passage of time, be closed. When the alarm feature is desired, the manual operator is moved to its alarm on position closing the switch 25 thus enabling the alarm switch 16 to sound the alarm at the pre-set time.

In accordance with the present invention an auxiliary circuit including a test switch is provided for momentarily connecting the battery to the alarm device for test purposes so that the brief sound thereof assures the user that the battery still has sufficient power to operate the buzzer. More specifically in accordance with the invention means are included in the test circuit for subjecting the battery to a load requirement which is greater than that imposed by the alarm device alone which tends to give further assurance that the battery will, when called upon a number of hours later, still have sufficient power to sound the alarm and thus making the test a conservative one. Still further in accordance with the invention the test switch is coupled to the same manual operator as the control switch in such a way that the test switch is closed momentarily incident to movement of the manual operator from its alarm off to its alarm on position. This results in a test which is not only conservative but which is automatic, requiring no particular thought on the part of the user.

Thus directing attention to FIG. 1, the test switch indicated at 40 has a first section 41 and a second section 42 which are both closed when the operator travers'es'its midposition. The first section serves to connect the grounded end of the battery to the buzzer 20'. The second section 42 serves to connect a shunt resistor indicated at 43 to the grounded end of the battery effectively in shunt with the buzzer 20 so that the battery is subjected to a current drain which is higher than that of the buzzer alone. If the battery has sufficient power to operate the buzzer and simultaneously carry the shunt loading, it may be presumed that the battery will have suflicient power to operate the buzzer alone whenthe alarm switch 16 is subsequently closed by the clock movement 11. Thus, as the condition shown in FIG. 1a is traversed, there will be a brief burst from the buzzer sufiicient to notify the user that the battery is still satisfactory. Movement of the manual operator is continued until it is in the full on condition illustrated in FIG. 1b which establishes, via control switch 25, a direct connection between the alarm switch 16 and the buzzer, with the shunt resistor out of the circuit.

If desired the manual operator may be caused to traverse the central test condition in motion by use of a two-position detent mechanism consisting, for example, of a detent 45 coupled to the plunger 31 and a two-position detent spring 46.

In the embodiment discussed above the current load requirement is increased by the shunt resistor 43. However, it will be understood that the term load requirement as used in the claims relates not only to current but to the voltage requirement as well. Thus there is shown in FIG. 2 an alternate embodiment 50 employing a transistorized clock movement 51 having

terminals

52, 53 energized by a battery 55. An alarm switch 56 having a mechanical connection 57 to the clock movement, as in the preceding embodiment, closes when the pre-set time is achieved for the sounding of a buzzer 60 having terminals 61, 62. To enable the switch 56 to turn on the buzzer at the pre-set time a control switch 65 is used which is of the sliding contact type having terminals 66-, 67. To operate the switch member 65 a manual operator 70 is used having a mechanical connection such as a plunger 71. As shown in FIG. 2 the manual operator is in its alarm off position with the switch member 65 retracted so that the alarm switch 56 is disabled. In accordance with the invention an auxiliary circuit is provided including a test switch having terminals which are momentarily closed incident to movement of the manual operator 70 from its alarm off to its alarm on position and with the auxiliary circuit including a series resistor so that the load requirement, i.e., the voltage required to operate the buzzer via the resistor, is increased. Thus referring to FIG. 2, the auxiliary circuit is in the form of a bridging circuit extending from the battery through the

contacts

81, 82 of the test switch and through auxiliary resistor 83 to the lower terminal 62 of the buzzer. Consequently when the manual operator is in its midposition as illustrated in FIG. 2a, the circuit is closed with an additional small voltage drop introduced in the series resistor. If the buzzer sounds, notwithstanding the presence of the series resistor, it can be presumed that the battery has suflicient power to operate the buzzer in the alarm on circuit condition shown in FIG. 2b upon closure of the alarm switch 56 several hours later.

While the invention has been described in connection with an increase in the current taken from the battery under test conditions and a decrease in the effective voltage, experience shows that only a few percentage points of change in the current or voltage will suflice to give a conservative test. The reason for this is that the amount of energy drawn by the clock movement alone, from the time that the alarm is set to the time that the alarm actually sounds, normally only a few hours, is not sufliciently great so that there will be a substantial change in the condition of the battery. In short, while the test is conservative it will not indicate a ba tery fa r until the battery is about to expire so that thelife of tHe ba'ttery is fully untilized.

The present invention hasbeen found especially useful when employing relatively cheap flashlight cells of the carbon-zinc variety. While such cells normally have a useful life of over a year when operating a transistorized clock movement alone, the large amountof current' drawn by a conventional buzzerconstruction will generally reducethis useful life' fromover a year to a matter of, three to four months, depending upon how much the alarm feature is used. This means that abattery inja transistorized alarm clock may normally be expected to fail, by inability to sound the buzzer, several times per year. However, for most users of alarm clocks even this failure rate is intolerable and would normally discourage use of a battery-powered alarm clock. However, with-the present improvement, the inability of the battery to sound the alarm is clearly indicated by lack of a test signal when traversing the midposition of the control plunger so that the user can, at that time, either substitute a new battery or use an alternate clock until a battery can be obtained. V

Where a buzzer is used as the alarm device, the initial current inrush tends to be relatively high since the buzzer contact is initially closed. Thus in order to make the battery more capable of operating the buzzer toward the end of its useful life and to make the battery more capable of passing the performance test described above, the battery may be shunted by a capacitor 15a of the lowleakage type and having a capacitance of several microfarads. Where such a capacitor is used the useful battery life may be extended for a period of several weeks or months. i

It is one of the by-product advantages of the present invention that the test circuitry not only performs a conservative test of the batterys capability to operate the buzzer but the test also serves as an indication of the batterys ability to supply the transistor movement for accurate timekeeping. Thus, as the battery approaches the end of its useful life a reduction in voltage tends to occur which, in the case of the usual transistor movement, results in a corresponding loss of accuracy. It is found that the test circuitry described above is quite sensitive to this drop off in voltage, or increase in internal battery resistance. In short, because of the warning provided by the test circuitry, an alarm clock embodying the present invention may be expected to keep time more accurately than a clock of the ordinary or non-alarm type.

In the above discussion, for the sake of simplicity, the means for closing the alarm switch at a pre-set time has been indicated diagrammatically at 17, 57. A preferred form of mechanism for controlling an alarm switch is set forth in FIG. 3 which shows a portion of an alarm clock mechanism. Thus there is shown a frame mounting an hour wheel 91 which is coupled by a shaft 92 to the hour hand 93 of the clock. It will be understood that the hour wheel 91 is advanced by a timing train (not shown) at the rate of one revolution every twelve hours. A suitable 12:1 step up connection (also not shown) is normally provided for operating the minute hand 94. Arranged adjacent the hour wheel 91 is a settable index wheel 95 connected by means of a shaft 96 to an alarm setting hand 97. The index wheel 95- may be adjusted to any desired phase position with respect to the hour wheel by a setting pinion 98 under the control of a rotatable setting knob 99. Means are provided for causing the hour wheel 91 to move endwise relative to the index wheel upon reaching the time for which the alarm has been set. In the present instance this is accomplished by opposed cam surfaces 101, 102 on the respective wheels, engagement of the cam surfaces caus ing the hour wheel to move inwardly of the frame plate 90.

For the purpose of responding to the endwise movement of the hour wheel, an alarm trip'lever is provided, pivoted at 111 and having a tip or rider 112 which rides on the surface of the hour wheel 91. The lever 110 is biased in the clockwise direction (as indicated in FIG. 3) by spring 113. However, for maintaining the alarm trip lever latched against the force of the spring, a stationary stop 115 is provided in the path of movement of the lever.

In the present instance the alarm switch, indicated at 56a, is in the form of a pair of

contact wires

121, 122 mounted upon a suitable insulating support 123, with the wire 122 being in the path of movement of a lug 124 which is formed on the edge of the lever. As a result, when the pre-set time is reached, the cam 101 on the hour wheel 91 rides up on cam 102 pushing the tip 112 of the alarm trip lever axially so that it clears the stop 115 and rotates clockwise under the urging of the spring 113. This causes the lug 124 to press the contact wire 122 against the wire 121 thereby closing an electrical circuit through the alarm switch 56a as shown, in elevation, in FIG. 6.

For the purpose of normally disabling the alarm trip lever 110, an alarm control plunger 31a is provided having a cam 130 which engages a cam follower surface 131 formed along one side of an opening in the trip lever. The successive positions of the alarm control plunger 31a are shown in FIGS. 4, 4a and 4b. FIG. 4 shows the plunger 31a inserted into engagement with the alarm trip lever not only latching the trip lever but blocking it against movement and thereby disabling the alarm. The plunger is temporarily held in its disabling or alarm off position by reason of a detent spring 135 engaging a groove 136 on the plunger. As shown in FIG. 5, the spring 135 is anchored at its ends so that it is capable of flexing or bowing into the phantom line position when the plunger is moved endwise. Thus, when the plunger is withdrawn to energize the alarm, it first traverses the mid-position shown in FIG. 4a and then moves into the alarm on position shown in FIG. 4b in which the cam 130 is retracted from the alarm trip lever so that the latter is free to release and close the alarm switch 56a when the set time is reached. The plunger is temporarily maintained in the alarm on position by a second groove 137 formed in the plunger and which is engaged by the detent spring 135.

In carrying out the present invention, the plunger is caused to close an auxiliary switch when it traverses its mid-position. Such auxiliary switch has a first or movable contact 81a which corresponds to the contact 81 in FIG. 2, and a second or relatively fixed contact 82:: in the form of a short leaf spring which corresponds to the contact 82 in FIG. 2. Conveniently, the movable contact may be formed as an integral flange on the plunger which is automatically grounded to the frame. In series with the fixed contact 82 is a resistor 83a leading to the buzzer 60a. The buzzer is connected to the battery 55a, the opposite battery terminal being returned to ground. Of the contacts which comprise the alarm switch 56a, the contact 121 is connected directly to the buzzer 6011, as shown, while the remaining contact 122 is grounded.

In reviewing the operation of the mechanism shown in FIG. 3, it will be assumed that the plunger 31a is initially pressed inwardly so that the cam 130 thereon retracts the alarm trip lever 110 latching it behind the stop 115. The setting knob 99 is rotated thereby rotating the index wheel 95 to a position in which the alarm set hand 97 indicates the time at which the alarm is to go off. The plunger 31a is retracted from the alarm off position shown in FIG. 4b. As the mid-position, shown in FIG. 4a, is traversed, the stationary contact 82a is momentarily wiped thus energizing the buzzer 60a through the resistor 83a, with the sound providing a check on the battery condition.

Subsequently, at the pre-set time, and following rotation of the hour wheel 91, engagement between the

cams

101, 102 presses the hour wheel 91 endwise lifting the tip of the alarm trip lever and clearing the stop so that the alarm trip lever is free to rotate under the action of its biasing spring thereby bringing the contact 122 against the contact 121 to sound the buzzer.

To turn off the buzzer the plunger 31a is pressed inwardly so that the cam engages the cam follower surface 131 causing the trip lever 110 to rotate counterclockwise to its latched position thereby freeing the contact 122 and opening the buzzer circuit.

It will be noted that one of the diiferences between the embodiment described in FIGS. 3-6 and the earlierdescri-bed embodiments is that the enabling and disabling of the alarm is brought about by mechanical means. Thus, with the plunger pressed in, the cam 130 bears against the alarm trip lever 110 to prevent the latter from responding when the hour wheel reaches the pre-set time. By contrast, in the embodiments of FIGS. 1 and 2 the disabling is brought about by a control switch which is in series with the alarm switch and which is maintained as long as the plunger is in its alarm ofi? position. Consequently, in the following claims the reference to the means for enabling and disabling the alarm device shall be understood to include both the mechanical and electrical versions.

We claim as our invention:

1. In a battery operated alarm clock the combination comprising means including an alarm switch for closing an alarm circuit at a pr-set time, a battery and an electric alarm device connected in the alarm circuit, means including a manual operator for enabling and disabling the alarm device, said manual operator movable between an alarm off position and an alarm on position in which the alarm device is enabled for sounding at the pre-set time, an auxiliary circuit including a test switch for connecting the battery to the alarm device for test purposes, said test switch being coupled to the manual operator for closing of the auxiliary circuit as the manual operator traverses the central portion of its movement from its alarm off to its alarm on condition, said auxiliary circuit including means for simultaneously subjecting the battery to a load requirement greater than that imposed by the alarm device alone thereby to insure that the battery has sufiicient power for sounding of the alarm at the pre-set time.

2. In a battery operated alarm clock, the combination comprising a battery and an electric alarm device forming an alarm circuit, a manually settable alarm control member movable between respective limit position, means for closing the alarm circuit at a pre-set time, and an auxiliary circuit including a test switch operatively connected to said control member for momentarily connecting the battery to the alarm device for test purposes as the control member traverses an intermediate position between its respective limit positions during the setting thereof, said auxiliary circuit including means for simultaneously subjecting the battery to a load requirement greater than that imposed by the alarm device alone thereby to insure sounding of the alarm at the pre-set time.

3. In a battery operated alarm clock the combination comprising a battery and an electric alarm device forming an alarm circuit, means for closing an alarm circuit at a pre-set time, control means for the alarm device including a manual operator moveable between respective limit positions, an auxiliary circuit including a test switch for connecting the battery to the alarm device for test purposes, said auxiliary circuit including means for simultaneously subjecting the battery to a load requirement greater than that imposed by the alarm device alone thereby to insure that the battery has sutficient power for sounding of the alarm at the pre-set time, said test switch being coupled to the manual operator for momentary operation as the manual operator traverses a central position between its respective limit positions.

4. In a battery operated alarm clock the combination comprising a battery and an electric alarm device forming an alarm circuit, means for closing the alarm circuit at a pre-set time, a control switch inthe alarm circuit, a manual operator coupled to the control switch and movable between alarm on and alarm oii positions, an auxiliary circuit including a test switch for connecting the battery to the alarm device for test purposes, said auxiliary circuit including means for simultaneously subjecting the battery to a load requirement greater than that imposed by the alarm device alone thereby to insure that the battery has sufiicient power for sounding of the alarm at the pre-set time, said test switchbeing coupled tothe manual operator for momentary operation incident to moving the operator from its alarm off to its alarm on position.

'5. In a battery operated alarm clock, the combination comprising abatte-ry and an electric alarm device forming an alarm circuit, means including an alarm switch for closing the alarm circuit at a pre-set time, a control switch in series with the alarm switch, said control switch having a manual plunger movable between an alarm H position in which the control switch is open and the alarm thereby disabled and an alarm on position in which the cont-r01 switch is closed and in which the alarm device is enabled for sounding at the pre-set time, an auxilary circuit including a test switch for connecting the battery to the alarm device for test purposes, said test switch 'being coupled to the plunger for closing of the auxiliary circuit as the plunge-r traverses the central portion of its movement from its alarm off to its alarm on condition, said auxiliary circuit including means for simultaneously subjecting the battery to a load requirement greater than that imposed by the alarm device alone thereby to insure that the battery has sufiicient power for sounding of the alarm at the pre-set time.

6. In a battery operated alarm clock, the combination comprising a battery and an electric alarm device forming an alarm circuit, means for closing the alarm circuit at a pre-set time, means for controlling the alarm device including a manual operator coupled to the movable between alarm on and alarm off positions, an auxiliary circuit including a test switch for connecting the battery to the alarm device for test purposes, said auxiliary circuit including means for simultaneously subjecting the battery to a load requirement greater than that imposed "by the alarm device alone thereby to insure that the battery has sufficient power for sounding of the alarm at the pre-set time, means for detenting the manual operator in its alarm off and alarm on positions, said test switch being coupled to the manual operator for momen' tary operation incident to moving the operator from its alarm off to its alarm on positions.

7. In a battery operated alarm clock, the combination comprising a battery and an electric alarm device forming an alarm circuit, means for closing the alarm circuit at a pre-set time, alarm control means including a manual operator movable between respective limit positions, an auxiliary circuit including a test switch for momentarily connecting the battery to the alarm device for test purposes, said test switch being coupled to the operator for momentary closure during movement of the operator, said auxiliary circuit including a shunt resistor for subjecting the battery to a greater current drain under test conditions than under normal alarm conditions.

8. In a battery operated alarm clock, the combination comprising a battery and an electric buzzer forming an alarm circuit, means for closing the alarm circuit at a predetermined time, alarm control means including a manual operator movable between an alarm ofl position in which the buzzer is disabled and an alarm on position in which the buzzer is enabled to sound at the pre-set time, an auxiliary circuit including a test switch for connecting the battery to the buzzer for test purposes, said test switch being coupled to the manual operator so that it closes momentarily incident to moving the operatorfrom its alarm off to its alarm on condition, said auxiliary circuit including a shunt resistor for simultaneously subjecting the battery 'to a current drain greater than that imposed by the buzzer alone, said battery being a'capacitor connected in parallel therewith for assisting the battery in carrying the initial portion of the said current drain.

9. In a battery operated alarm clock the combination comprising a battery and an electric alarm device forming' an alarm circuit, having means for closing the alarm circuit ata predetermined time, alarm control means including a manual operator movable for enabling and disabling the alarm, an auxiliary circuit including a test switch for momentarily connecting the battery to the alarm device for test purposes, said test switch being coupled to the operator for momentary closure during movement of the operator, said auxiliary circuit including a series resistor to produce a slight voltage drop to the alarm device under test conditions thereby to insure that the battery has sufiicient voltage to sound the alarm at the pre-set time.

10. In a battery operated alarm clock the combination comprising an hour wheel having means for timingly driving the same, an alarm index wheel having means for manually setting its phase position, an alarm trip lever having a biasing spring and a stop for maintaining the lever in a latched position, means responsive to said wheels reaching a condition of register for tripping the lever free of the stop so that the lever moves from its latched position to a released position, a pair of electrical alarm contacts associated with the trip lever for making electrical contact when the alarm trip lever is tripped, an alarm control member having means defining a first position in which the member is retracted and a second position in which the member moves into engagement with the trip lever for moving the same to its latched position, a test switch including a stationary contact, and means on the control member for operating the switch as the plunger is moved from its second position to its first position incident to setting the alarm, a buzzer and battery in series with said pair of alarm contacts, and an auxiliary circuit controlled by said test switch for momentarily connecting the buzzer to the battery when the fixed contact is engaged thereby to signal to the user that the battery has sufficient power to operate the alarm.

11. The combination as claimed in claim 10 in which the auxiliary circuit includes a series resistor to produce a slight voltage drop to the buzzer.

12. In a battery operated alarm clock, the combination comprising a battery and an electric alarm device forming an alarm circuit, means including an alarm switch for closing the alarm circuit at a pre-set time, control means for the alarm device including a manual operator movable between an alarm o position in which the alarm device is disabled and an alarm on position in which the alarm device is enabled for sounding at the pre-set time, an auxiliary circuit including a test switch for connecting the battery to the alarm for test purposes, said test switch being coupled to the manual operator for momentary operation as the manual operator traverses an intermediate position between its alarm off and alarm on positions.

References Cited UNITED STATES PATENTS 370,932 10/1887 Colby 58-20 2,845,614 7/1958 Bell 340--214 3,081,594 3/1963 Atkins et al. 58-2l.15 3,196,357 7/1965 Hoag 324-2 9.5 3,230,420 I/ 1966 Kapteyn 340 -249 3,243,795 3/ 1966 Obrien 340--249 ROBERT S. WARD, JR., Primary Examiner. EDITH c. SIMMONS, Assistant Examiner.