US2768332A

US2768332A - Timing device

Info

Publication number: US2768332A
Application number: US393779A
Authority: US
Inventors: Donald E Protzmann; Edgar A Phaneuf; Malcolm G Doyle
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1953-11-23
Filing date: 1953-11-23
Publication date: 1956-10-23
Anticipated expiration: 1973-10-23

Description

Oct. 23, 1956 D. E. PROTZMANN ET AL 2,768,332

TIMING DEVICE Filed NOV. 23, 1953 i Inventors Donald E. Protzmann 24 2 Edgar A. Phaneuf.

Malcolm G. Doyle Their Attorney.

2,768,332 TIMING DEVICE Application November 23, 1953, Serial No. 393,779 4 Claims. (Cl. 317-99) This invention relates to timing devices having means associated therewith for actuating at a preset position various forms of controlled devices such as alarm mechanisms, electric switches, radios, electric appliances and similar devices.

In devices of this type, it has been a common practice to provide a pair of coaxially mounted gear driven cam members having cam surfaces thereon interacting with each other with one of these members being axially movable to actuate an alarm means or other form of con trolled mechanism. One of the cam members is driven by a timing mechanism and the other is adjustable so that the position at which the axial actuating movement occurs can be preset. In a mechanism of this type, it is obvious that some means, such as a spring, must be provided for urging the axially movable cam member into engagement with the mating cam member in order to ensure that the axial actuating movement takes place. In the past, this has been accomplished by permanently spring loading the axially movable cam member into engagement with the mating cam member. This method has a number of disadvantages, some of which will be enumerated below.

it is usually desirable that the actuating movement occur very rapidly, that is by means of some form of snap action. In cases where it is undesirable or impracticabie to provide a separate snap acting mechanism, abrupt surfaces are provided directly on the interacting cam members so that the axially movable cam member may move with a snap action under the influence of the spring load when the cam members reach the preset position. This rapid snap acting movement of the actuating cam member usually causes a sharp audible clicking sound when the actuating cam reaches the limit of its travel. Normally some form of shut-ofi? device, such as a lever, is provided which in the o position renders the alarm or signal means inoperable. This shut-elf device may be used either for the purpose of turning off the alarm or signal once it has been actuated or for preventing actuation of the signal when the cams pass through the preset actuating position. Consequently, when the shut-oil device is in the off position, actuation of the alarm or signal means is not desired and the audible clicking noise which occurs when the cams pass through the actuating position constitutes an undesirable disturbance to the user.

Another disadvantage arising from permanently spring loading the axially movable cam member is that the timing mechanism must supply the driving force to recharge the spring by pushing the axially movable cam back to its original position once the axial actuating movement has occurred. In order to minimize the driving force required to recharge the spring, it has been necessary to carefully control the shape of the mating cam surfaces so that the rate of charging the spring is decreased as the force required to move the spring increases, thereby maintaining a near constant load on the driving mechanism. This requirement for carefully controlling the shape of the cam surfaces results in a corresponding cost penalty by reason of the various special manufacturing and inspection processes required.

States Patent Otlice 2,768,332 Patented Oct. 23, 1956 Accordingly, it is an object of this invention to provide an improved timing device in which means are provided for removing the spring force from the axially movable cam member when actuation of the signal means is not desired, thereby preventing the occurrence of the above-mentioned clicking noise when the cams pass through the position in which the actuating movement would normally occur.

It is a further object of this invention to provide an improved timing device in which means associated with a shut-off device for rendering the controlled apparatus inoperative are provided for rechanging the spring from the movement of the shut-off device to the off position, thereby removing the spring charging load from the timing mechanism and making close control of the cam surface shapes unnecessary.

In accordance with one aspect of this invention as applied to electric alarm clocks, the resilient leaf spring type of vibrator arm associated with the alarm mechanism is utilized to spring load the axially movable cam member through an associated lever mechanism. A shut-off lever is provided having a portion thereon which engages the vibrator arm when the lever is moved to the off position. The vibrator arm engaging portion of the shut-off lever forces the vibrator arm out of engagement with the associated lever mechanism thereby removing the spring force from the axially movable cam member when the shut-off lever is moved to the off position. Thus the movement of the shut-oif lever to the off position not only removes the spring force from the axially movable cam member and restrains vibratory movement of the alarm vibrator arm but also forces the vibrator arm to the recharged position thereby removing the spring charging load from the timing mechanism. It can be seen, therefore, that this invention not only avoids the occurrence of the undesirable clicking noise when the shut-off lever is in the off position but also reduces the load on the timing mechanism thereby making it unnecessary to closely control the shape of the cam surfaces and also increasing the life of the timing mechanism parts and drive motor.

It should be obvious that this invention is not only applicable to alarm clocks but also to timing mechanisms having associated therewith various types of signal means either visible or audible, such as radios or other appliances, or other forms of devices adapted to be controlled by timing mechanisms.

Other objects and advantages of this invention will be apparent from the following description taken in connection with the accompanying drawing and its scope will be pointed out in the appended claims.

Referring to the drawing, Fig. l is a perspective view of a portion of an electric alarm clock embodying this invention showing the shut-otl lever in the on position; Fig. 2 is a side view of the embodiment illustrated in Fig. 1 showing the shut-otf lever in the on position and the cam members in a position actuating the alarm, while Fig. 3 is a side view of the same embodiment showing the shut-cit lever in the off position engaging the vibrator arm.

Referring in particular to Fig. having a projecting cam portion 2- located thereon, is rotatably mounted on the supporting structure 1 of the clock framework in a manner shown in Figs. 2 and 3. The cam portion 2 comprises an abrupt axially extending surface 2a located on one side thereof and a sloping surface 21) located on the other. A second cam member 3 having abrupt cam surfaces formed by the slot 4 is also rotatably mounted on the clock supporting structom 14 as shown in Figs. 2 and 3 and is axially movable to actuate the alarm mechanism in a manner hereinl, a cam member 1,

after described. The angular position of the cam member 1 is manually adjustable by means of the gear members 5 and 6 and the knob '7. The time at which the cam members 1 and 3 will pass through the alarm actuating position is indicated on the face of the clock by the indicating hand 8.-

The alarm mechanism shown generally at 9 is of the conventional type having a resilient electromagnetically driven vibrator arm 10 which causes an audible sound upon vibration thereof. In the embodiment shown, the cam member 3 is driven by the timing mechanism of the clock, not shown, through .a suitable gearing arrangement.

The alarm mechanism is provided with a suitable shutoff device, such as lever 11, having a projection 12 thereon which is positioned so as to engage the vibrator arm 10 and restrain vibratory movement thereof when the lever is moved to the off position. The shut-off lever 11 is shown in the on position in Fig. 1, that is, with the projection 12 out of engagement with the vibrator arm 10.

The resilient vibrator arm 10 is utilized to spring load the axially movable cam member 3 into engagement with the cam member 1 through a suitable lever mechanism such as bell crank 13 which is pivoted to the supporting structure 14 by means of the ears l5 and the pivot pin 16, all shown in Figs. 2 and 3. As shown in Figs. 2 and 3, the bell crank 13 transmits the spring force of vibrator arm 10 to the end of shaft 17 which is attached to the cam member 3.

Thus, when the timing mechanism of the clock drives the cam member 3 to a position where the abrupt cam surface 2b becomes aligned with the abrupt surface formed by the slot 4, the vibrator arm 10 acting through the bell crank 13 rapidly forces the cam member 3 toward the cam member 1 until the projecting portion 18 on the cam member 3 engages the stop portion 19 on the cam member 1 as shown in Fig. 2. In the position of the elements as shown in Fig. 2, therefore, the vibrator arm is unrestrained and is free to vibrate under the influence of the continuously applied electromagnetic forces to give an audible alarm signal.

Referring to Fig. 2, it can be seen that if the shutoff lever 11 were to be moved to theleft to the off position shown in Fig. 3, the projecting portion 12 will be brought into engagement with the vibrator arm 10, forcing it out of engagement with the bell crank 13 thereby not only restraining further vibratory movement of the vibrator arm but also removing the spring force from the projecting shaft 17 of the cam member 3. Thus, when the user shuts off the alarm mechanism by moving the shut-off lever to the left to the posit-ion shown in Fig. 3, the continued rotation of the cam member 3 by the timing mechanism can force the cam members apart to the position shown in Fig. 3 through the interaction of the slanting or curved surface 2a on the projection 2 and the edge of slot 4 without having to work against the spring force of the vibrator arm 16. That is, the vibrator arm 10, act-ing as a spring, is automatically recharged by the movement of the shut-off lever 1-1 to the off position illustrated in Fig. 3, thereby removing the spring charging load which has in the past been placed on the timing mechanism in devices of this type. As a result of this invention, therefore, it becomes unnecessary to accurately control the shape of the surface Zn on the projection 2 which forces the cam members 1 and 3 apart, a requirement which has heretofore been necessary in order to maintain a near constant load on the timing mechanism in view of the increasing force encountered as the spring is charged. it can be appreciated that the elimination of this requirement effects a corresponding cost saving in the various manufacturing and inspection processes.

As has been stated above, when the shut-off lever 11 is in the on position as shown in Figs. 1 and 2 and the cam member 3 is driven by the timing mechanism of the clock to a position wherein the abrupt surface on the projection 2 is aligned with the edge of the slot 4, the

cam member 3 is abruptly moved under the influence of the spring force exerted by vibrator arm 10 to the position shown in Fig. 2. This rapid movement of the cam member 3 is accompanied by an audible click when the cam member 3 reaches the extent of its travel. In arrangements heretofore used in this type of device, it has been the custom to provide a separate spring member permanently engaging the movable cam member and applying a continuous spring force thereto independently of the position of the shut-off lever. In an arrangement of this type, the rapid actuating movement of the actuating cam will always occur when the cams pass through the preset position regardless of the position of the shut-off lever. Therefore, when the shut-off lever is placed in the off position and the alarm signal is not desired, the sharp clicking noise caused by the actuation of the cams causes an undesirable disturbance to the user. In this invention, however, this disadvantage is overcome, since the positioning of the shut-off lever 11 in the off position as shown in Fig. 3 removes the spring force of Vibrator arm 10 from the bell crank 13 and the shaft 17 of cam member 3. It can be seen, therefore, that when the shut-off lever is in the off position, the cam members 1 and 3 can pass through the actuating position without the occurrence of the forced actuating movement and accompanying clicking noise heretofore encountered.

It should be apparent from the foregoing that the principles of this invention are equally applicable to other types of devices in which a timing mechanism is associated with some other form of controlled device adapted to be actuated thereby. For instance, referring to Fig. 3, an arrangement is shown for actuating an electric switch 29 in conjunction with the alarm mechanism by the axial movement of cam member 3. A flanged portion 21 extending from the shaft of the cam member 3 is arranged so as to engage the rings 22 on the actuating shaft 23 of the switch and close a set of contacts within the switch upon movement of cam member 3 to the position shown in Fig. 2. An actuating lever 24 pivotally mounted on the switch structure controls a second set of contacts within the switch in series with the first mentioned set of contacts. A series circuit therefore extends through the two sets of contacts within the switch 20 from the leads 25 which may be connected to a device to be energized by the closing of the series circuit. The lever 24 interacts with the pins 26 and 27 which extend from the shut-on" lever 11 and which can pass through a suitable slot provided in the supporting structure 14. The contacts controlled by the lever 24 are opened by movement of the shut-off lever to the off position as shown in Fig. 3 and are closed by movement of the shut-off lever to the on position illustrated in Fig. 2. Thus, when the shut-off lever is moved to the off position, the series circuit comprising the two sets of contacts within the switch is interrupted and at the same time the spring force exerted by the vibrator arm 14 is removed from the cam mechanism. As long as the shut-off lever remains in the off position, the circuit through the switch 24 can not be completed by movement of the shaft 23 since the second set of contacts remain in the open position. When the shut-off lever is moved to the on position, the contacts controlled by the'lever 24 are closed, thereby rendering the switch 21? once again operable by the actuating movement of the cam 3 as described above. It should be obvious that this arrangement could be utilized to operate the switch only and in such a case the electromagnetic structure of the alarm mechanism would be removed so that the arm 16 would serve as a leaf spring only.

Various other types of devices other than the switch and alarm mechanism may, of course, be actuated by the axial movement of the actuating cam member and other variations, modifications and substitutions within the scope of this invention will occur to those skilled in the art.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. Alarm means comprising a timing mechanism, a supporting structure, a first cam member rotatably mounted on said supporting structure, a second cam member rotatably mounted on said supporting structure in coaxial relationship with said first cam member and axially movable with respect thereto, one of said. cam members being caused to rotate by said timing mechanism, means for manually adjusting the relative angular position of said cam members, an alarm mechanism h ag a re silient vibrator arm causing an audible sound upon vibration thereof, said vibrator arm exerting a spring force urging said second cam member into engagement with said first cam member, and being restrained from vibrating by the reaction force exerted by said second cam member against said spring force, said second cam memher being disposed to move axially under the influence of said spring force to remove said reaction force and permit vibration of said vibrator arm upon the relative rotation of said cam members through a predetermined relative angular position, and a manually operable shut off lever, said shut-off lever having a portion thereon engaging said vibrator arm when said shut-oil lever is moved to one position and moving said vibrator arm against said spring force to restrain vibratory movement thereof and to simultaneously remove said spring force from said second cam member and disengaging said vibrator arm when said shut-ol'f lever is moved to another position to allow said alarm mechanism to be actuated by said axial movement of said second cam member, whereby when said shut-oft" lever is in said one position, said forced axial movement of said second cam member does not occur.

2. An electric clock comprising a timing mechanism, a supporting structure, a first cam member rotatably mounted on said supporting structure, a second cam member rotatably mounted on said supporting structure in coaxial relationship with said first cam member and axially movable with respect thereto, one of said cam members being caused to rotate by said timing mechanism, means for manually adjusting the relative angular position of said cam members, an alarm mechanism having a resilient vibrator arm causing an audible sound upon vibration thereof, a bell crank pivotally mounted on said supporting structure and having a first portion engaging said second cam member and a second portion engaging said vibrator arm and restraining vibratory movement thereof, said vibrator arm exerting a spring force on said bell crank tending to cause pivotal motion thereof, said second cam member restraining pivotal motion of said bell crank and being thereby urged into engagement with said first cam member, said first and second cam members having interacting cam surfaces thereon allowing a forced axial movement of said second cam member at a predetermined relative angular position thereof to permit pivotal motion of said bell crank and release said vibrator arm to allow vibratory movement thereof, and a manually operable shut-off lever, said shut-01f lever having a portion thereon engageable with said vibrator arm to restrain vibratory movement thereof and to force said vibrator arm out of engagement with said bell crank so as to remove said force tending to cause pivotal movement thereof, whereby when said shut-off lever is moved into a position engaging said vibrator arm, said spring force is removed from said bell crank and the reaction force exerted by said second cam member restraining pivotal movement of said bell crank and urging said second cam member into engagement with said first cam member is removed.

3. Control means comprising a timing mechanism, a fixed supporting structure, a first cam member rotatably mounted on said fixed supporting structure, a second cam member rotatably mounted on said fixed supporting structure in coaxial relationship with said first cam member and axially movable with respect thereto, one of said cam members being caused to rotate by said timing mechanism, means for manually adjusting the relative angular position of said cam members, spring means exerting an axial force on said second cam member tending to cause engagement thereof with said first cam member, spring disengaging means for removing spring force from said second cam member, said members interacting to cause axial movement of said second cam member upon relative rotation of said cam members as a function of time through predetermined relative angular position of said cam members, switch means having first and second actuators, a manually operable shut-off device for operating said first actuator when in its active position, means operated by said shut-oil device in an active position for actuating spring disengaging means and removing spring force said second cam member and for releasing said g disnrgaging means when in the inactive position, 5 operating said second actuator upon spring urged movement of said second cam member, whereby operation of said switch means as a function of time requires operation of said first actuator by said shut-off device and operation of said second actuator by the spring ur cd axial movement of said second cam member.

4. Alarm means comprising a timing mechanism, a supporting structure, a first cam member rotatably mounted on said supporting structure, a second cam member rotatably mounted on said supporting structure in coaxial relationship with said first cam member and axially movable with respect thereto, one of said cam members being caused to rotate by said timing mechanism, means for manually adjusting the relative angular position of said cam members, an alarm mechanism having a resilient vibrator arm causing an audible sound upon vibration thereof, said vibrator arm exerting a spring force urging said second cam member into engagement with said first cam memoer, and being restrained from vibrating by the reaction force exerted by said second cam member against said spring force, said second cam member being disposed to move axially under the influence of said spring force to remove said reaction force and permit vibration of said vibrator arm upon the relative rotation of said cam members through a predetermined relative angular position, and a manually operable shut-off lever, said shut-01f lever raving a portion thereon engaging said vibrator arm when said shut-off lever is moved to one position and moving said vibrator arm against said spring force to restrain vibratory movement thereof and to simultaneously remove said spring force from said second cam member and disengaging said vibrato-r arm when said shut-off lever is moved to another position to allow said alarm mechanism to be actuated by said axial movement of said second cam member, whereby when said shut-off lever is in said one position, said forced axial movement of said second cam member does not occur, switch means having first and second actuators, said shut-off lever having portions there on for operating said first actuator and means attached to said second cam member for operating said second actuator upon axial movement of said second cam member by said resilient vibrator arm, whereby operation of said switch means requires operation of said first actuator by said shut-off lever and operation of said second actuator by the resilient vibrator arm.

References Cited in the file of this patent UNITED STATES PATENTS 1,502,491 Treger July 22, 1924 1,795,251 Dolgin Mar. 3, 1931 1,818,958 Chapman Aug. 11, 1931 2,002,433 Cowles May 21, 1935 2,027,531 Hammond Jan. 14, 1936 2,607,186 Schulze Aug. 19, 1952 FOREIGN PATENTS 680,594 Germany Sept. 1, 1939