US3440370A - Interval timer - Google Patents

Description

INTERVAL TIMER Sheet of 2 Filed Jan. 50, 1967 April 22, 1969 T, G. WILLIS ET AL INTERVAL TIMER of 2 I Sheet Filed Jan. 50, 1967 United States Patent 3,440,370 INTERVAL TIMER Thomas G. Willis and Eugene C. Knecht, Raleigh, N.C.,

assi'gnors to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Jan. 30, 1967, Ser. No. 612,705 Int. Cl. H01h 7/08, 43/04, 43/10 U.S. Cl. 20038 13 Claims ABSTRACT OF THE DISCLOSURE Two shafts move axially to start and stop a time interval measurement. The shafts are rotatable for adjusting the starting and stopping times. The shafts control a switch through a single-lever arrangement. On movement of a timing disc to an interval-completed position, a window in the disc releases an indicator device.

This invention relates to an interval timer and switch and it has particular relation to an interval timer suitable for setting the energizing time of an appliance such as a range.

In a prior-art interval timer and switch, two shafts are arranged to move axially for the purpose of starting and stopping the measurement of a time interval. One of the shafts termed a start shaft is rotatable for preselecting the time at which the measurement is to start. The second shaft termed a stop shaft is rotatable to preselect the time at which the measurement of the time interval is to stop. In the prior art, a multiple lever arrangement is employed for controlling an electric switch.

In accordance with the invention, an interval timer is provided which includes a start shaft 'and a stop shaft as described above. However, a single lever is arranged to respond to the axial movement of the shafts for the purpose of controlling a translating device such as an electric switch. A stop shaft may be latched in a predetermined position by a latch which is directly released by a part secured to the start shaft.

An indicator is provided for indicating completion of a predetermined time interval. The indicator is operated by a finger which rests on a timing disc. When a window in the disc becomes aligned with the finger, the indicator is released for operation.

It is, therefore, an object of the invention to provide an improved interval timer.

It is another object of the invention to provide an internal timer having a single lever controlled by the axial position of a start shaft and a stop shaft.

It is also an object of the invention to provide an interval timer having a simplified indicator mechanism.

Other objects of the invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a view in end elevation of an interval timer embodying the invention;

FIG. 2 is a view in perspective with parts shown exploded and with parts broken away of the interval timer of FIG. 1;

FIG. 3 is a detail view in plan showing a latching arrangement employed in the interval timer of FIG. 1;

FIG. 4 is a view in sectional elevation taken along the line IVIV of FIG. 2;

FIG. 5 is a view in perspective with parts shown exploded and with parts broken away of the portion of the interval timer shown in FIG. 4; and

FIG. 5a is a detail view taken along the line VaVa 'of FIG. 5.

Referring to the drawings, FIGURE 1 shows a start member comprising a start shaft 20 which is arranged for axial and rotational movement and which is biased upwardly. In operation when an interval is to be measured, the shaft 20 is manually moved downwardly as viewed in FIGURE 1 and rotated to a position corresponding to the time at which the measurement of an interval is to be started. The shaft is held in this position until a timing mechanism operated by a clock or synchronous motor 16 reaches the desired starting time. At this instant, the start shaft 20 is released and is moved upwardly to start the measurement of the desired interval.

A stop member comprising a stop shaft 22 also is arranged for axial and rotational movement and is biased upwardly. In operation, the shaft 22 is manually pressed downwardly as viewed in FIGURE 1 and rotated to a position corresponding to the time at which the interval is to stop. The shaft is held in this position until the timing mechanism operated by the clock or synchronous motor 16 reaches the desired time. At this instant, the shaft 22 is released and moved upwardly to complete the measurement of the desired interval.

Shafts controlled in this manner are well known. In

order to simplify the presentation of the invention, it will be assumed that these shafts 20 and 22 correspond to the shafts 20 and 22 of U.S. Patent 3,038,041 which issued June 5, 1962. Each part which is herein illustrated and which is similar to a part of the aforesaid patent is identified by the same reference character employed in the patent.

Various parts are mounted on or between two plates 44a and 46a which correspond respectively to the plates 44 and 46 of the aforesaid patent. However, these plates 44a and 46a are modified slightly to accommodate certain parts which now will be discussed.

As shown clearly in FIGURE 2, the plate 46a has two posts 46a1 and 46a2 which project from the rear surface of the plate to establish a fulcrum for a single lever 201. These posts have guide fingers respectively 46a3 and 46a4 which project freely through notches 201a and 201b formed in two edges of the lever 201. These notches permit pivotal motion of the lever relative to the associated fulcrum while permitting limited movement of the lever away from the fulcrum without loss of registry.

As viewed in FIGURE 2, the upper end of the lever 201 is located in the path of and slightly to the rear of the shaft 20. The lower end of the lever is located in the path of and at the rear of the stop shaft 22, A U-shaped spring 203 biases the lower end of the lever 201 towards the shaft 22. The U-shaped spring straddles the lever at a position intermediate the axis of the shaft 22 and the notches 201a, 201b, and the free ends of the spring are passed through a window 46a5 in the plate 46a and then backwardly through a second window 46:16 in the plate. Each leg of the spring has a coil which is located on a pin respectively 46a7 and 46a8 which is made from the base plate 46a.

In the aforesaid patent, a latch is provided for releasable reception in a groove 172 on the stop shaft 22 for the purpose of releasably holding the shaft 22 in a predetermined position. In the present case, a latch 205 of different construction cooperates with the groove 172 for the purpose of releasably holding the shaft 22 in the same position.

The latch 205 is pivotally secured to the plate 46a by a rivet 207. The latch 205 includes a lip 205a which is positioned for releasable reception in the groove 172. The latch is biased towards the groove by means of a spring 209 having one end engaging an ear 211 on the latch and having the other end engaging an ear 211a on projects through the window 46x16 into the path of the the plate 46a. The latch 205 also has a finger 20512 which periphery of the gear 21 when the gear is moved axially.

When the shaft 20 is in its released position, the gear 21 is clear of the finger 205b. When the shaft 20 is moved to the left as viewed in FIGURE 2, the perimeter of the gear 21 engages the finger 20511 to force the latch 205 in a clockwise direction as viewed in FIGURE 3 against the resilience of the spring 209 for the purpose of withdrawing the lip 205a from the groove 172. The shaft 22 thereupon moves to the right as viewed in FIGURE 2 to terminate the manual operation condition of the range timer as discussed in the aforesaid patent. It should be noted that this is a positive release operation initiated directly by a part or gear 21 carried by the shaft 20. Furthermore, while the finger 20512 engages the gear 21, it restrains rotation of the gear 21. Thus, when the gear is manually rotated to select a predetermined starting position, the finger 2051) inhibits any change in position of the gear due to vibration or friction.

The lever 201 controls the condition of an electric switch 213 through the intermediary of a switch operator 214. It will be noted that the switch 213 includes a fixed contact 215 which is secured to an insulating block 215a which in turn is secured in any suitable manner to the plate 460. In addition, the switch includes a resilient yieldable finger 213a which is biased towards the fixed contact 215 but which may be operated away from such fixed contact.

As viewed in FIGURE 2, the operator 214 is positioned adjacent the left-hand face of the lever 201 and is mounted for pivotal movement about an axis adjacent its lower end. The operator may be constructed of an insulating material and has a protuberance 214a positioned to engage the upper end of the lever 201. A second protuberance 214b is positioned to engage the rear face of the finger 213a. A third protuberance 2140 on the lefthand face of the operator 214 may be positioned to cooperate similarly with a switch (not shown) similar to the switch 213.

The operation of the device illustrated in FIGURE 2 now will be considered. It will be assumed that at the outset the start and stop shafts 20 and 22 occupy their extreme right positions. Under the circumstances, the spring 203 maintains the lever 201 in a position such that it acts through the operator 214 to maintain the switch 213 in open condition.

In order to set up the time interval during which the switch 213 is to be closed, the start member 20 is manually moved to the left and is rotated to a position corresponding to the time at which the switch 213 is to be closed. Next, the stop shaft 22 is moved to the left and also is rotated to a position corresponding to the time at which the switch 213 is to be returned to its open condition.

As a result of its movement to the left, the stop shaft 22 engages the lower end of the lever 201 and rotates the lever against its bias. The rotation of the lever frees the operator 214 and permits the resilience of the spring finger 213a to close the switch 213. The lever may move away from its fulcrum while being guided by the fingers 46a3, 46:14.

The synchronous motor 16 rotates the gears 68 and 70 in accordance with the time of day. When the time of day coincides with the time at which the switch 213 is to close, the nose 64 carried by the gear 68 is in alignment with the aperture 60 in the disc 21. The line of action of the force exerted by the spring 203 against the lever 201 is located between the axis of the shaft 22 and the fulcrum of the lever. Consequently, when the start shaft 20 moves to the right, the lever 201 pivots about the end of the stop shaft 22 and the fingers 46a3 and 46a4 slip through their associated notches until the lever engages its fulcrum. This pivotal movement of the lever permits the resilient finger 213a to close the switch 213.

When the time of the day coincides with the time at which the switch 213 is to be reopened, the nose 66 is aligned with the aperture 62 in the disc 23. The stop shaft 22 now is free to move to the right and the spring 203 consequently moves the lever 201 in a counterclockwise direcion about its fulcrum. Such movement of the lever acts through the operator 214 to open the switch 213.

If the switch 213 is to be maintained in closed condition, the stop shaft 22 is moved manually to the left until the spring-biased latch 205 moves its lip 205a into the groove 172. The latch now holds the stop shaft 22 in its operated position. The movement of the stop shaft 22 acts to pivot the lever 201 in a clockwise direction about its fulcrum. This releases the operator 214 and permits the resilient finger 213a to close the switch 213.

When the switch 213 is to be reopened, the start shaft 20 is moved to the left to bring the disc 21 into engagement with, and to move, the finger 205b. This moves the latch 205 in a clockwise direction as viewed in FIG. 3 to withdraw the lip 205a from the groove 172. Such removal permits movement of the stop shaft 22 to the right in FIGURE 2. The spring 203 consequently rotates the lever 201 in a counterclockwise direction to reopen the switch 213.

It is often desirable to operate an indicator at a predetermined time or at the end of a time interval. For example, a finger may be biased against one face of the gear 68. The gear is provided with the window into which the finger drops at a predetermined time for the purpose of operating an indicator. In order to simplify the presentation of this aspect of the invention, it will be described as applied to a mechanism of the general type shown in Patent 2,993,099 which issued July 18, 1961. FIGURES 4 and 5 correspond respectively to FIGURES 6 and 5 of such patent with modifications which will be discussed below. Each component of these figures which is similar to a component of the patent is identified by the same reference character followed by the subscript e. The previously mentioned plates 44a and 46a are employed in place of the front and rear supporting plates of the Patent 2,993,099. A mutilated gear 53f corresponds to the gear 53 of this patent but is mounted somewhat differently.

As shown in FIGURE 4, the gear 53f is secured to a hub 53 1 which is slidably splined to the shaft 5 which corresponds to the shaft 5 of Patent 2,993,099. In the present case, the shaft 5 has a square section 5]1 which is slidably received in a square opening in the hub 53f1. A clapper of soft-magnetic resilient sheet material has one end secured to the plate 46a by means of a rivet 227 and has a second end shaped as a finger 229 riding on the upper face of the gear 53f as viewed in FIGURE 4. The resilience of the clapper material biases the finger 229 lightly against the face of the gear. The clapper also has a portion 230 extending adjacent but spaced from the core of the synchronous motor 16. Thus, if the clapper is free, it will vibrate under the influence of the alternating field developed by the motor 16 to produce a buzzing sound. However, when the finger 229 is in engagement with the face of the gear 53f, the clapper is prevented from vibrating. In order to release the clapper at the proper time, the gear 53f is provided with an aperture or window 231 which is so located that at the end of the interval being measured by the rotation of the gear 53f the window 231 moves beneath the finger 229 for the purpose of releasing the clapper 225. The resulting buzzing sound produced by the clapper thus signifies the end of the interval being measured.

When the buzzer is to be turned off the stem Sae is rotated manually to move the gear 53] to an off position. During such movement the finger 229 rides over a rib 231a formed on the gear 53 to a position shown in broken lines in FIGURE 51:. In this position the gear prevents vibration of the finger. When a new interval is to be measured the stem Sue is rotated manually in the reverse direction to move the rib 231a beneath the finger 229, then to move the window 231 past the finger, and finally to move the gear to the desired time position.

When the setting stem Sae is pressed downwardly as viewed in FIGURE 4 for the purpose of setting the associated clock, the square section 5 1 slides downwardly in the hub 53 1 but the coup-ling is such that the shaft and the gear 53 continued to rotate as a unit.

This construction materially simplifies the association of the gear 53 with the remainder of the assembly and the structure required to control the clapper 225.

We claim as our invention:

1. A timing device having a start member mounted for rotation about a first axis in accordance with time, said start member having a first axial position when approaching a preselected interval starting time and operating to a second axial position in response to arrival at said preselected starting time, and a stop member mounted for rotation about a second axis in accordance with time, said stop member having a first axial position when approaching a preselected interval stopping time and operating to a second axial position in response to arrival at said stopping time, and an electric switch operable between closed and open conditions, wherein the improvement comprises a single lever, a fulcrum about which the lever pivots, means biasing the lever in a first direction about the fulcrum, said lever having a portion positioned for operation by said stop member in a second direction about the fulcrum in direct response to movement of the stop member from the second to the first position of such stop member, said lever having a portion positioned for direct operation by said start member in said first direction in response to movement of the start member from the second to the first position of such start member, said switch being responsive to the lever position for maintaining a first one of said conditions when said start and stop members are in their second axial positions and when said start and stop members are in their first axial positions, and said switch being responsive to the lever position for maintaining said switch in a second one of said conditions when said start member is in its second axial posiiton and said stop member is in its first position.

2. A device as claimed in claim 1 wherein said switch comprises a fixed contact and a resilient spring finger carrying a contact movable towards and from the fixed contact in response to pivotal operation of the lever.

3. A device as claimed in claim 2 wherein said fulcrum permits a substantial movement of translation of said lever in a direction parallel to said axis.

4. A device as claimed in claim 2 wherein said axes are parallel and spaced radially from each other, said fulcrum being located intermediate said axes, said lever intersecting both of said axes, and said members engaging said lever adjacent the respective axes of said members.

5. A device as claimed in claim 1 in combination with a latch for releasably holding said stop member in a predetermined axial position, said latch having a portion in the path of said start member for releasing the latch from the stop member in response to a predetermined axial movement of the start member.

6. A device as claimed in claim 5 wherein said stop member has a latch recess, said latch comprising a latch lever mounted for rotation about a pivot axis, said latch lever having a part positioned in the path of said start member for pivotal rotation about the pivot axis in response to axial movement of the start member in a predetermined direction, and said latch lever having a part movable from latching reception in said recess to a position clear of the stop member in response to said pivotal rotation.

7. A device as claimed in claim 6 wherein said latch lever is yieldably biased towards latching position, said first-named part when engaging said start member acting to restrain rotating motion of the start member.

8. A device as claimed in claim 1 in combination with a disc, means mounting the disc for rotation about its axis in accordance with time from a preselected angular starting position, a vibratory-sound-producing element having a portion biased against a face of said disc to inhibit vibration of the element, said disc having a window proportioned to receive said portion at a predetermined angular position of the disc to free the element for soundproducing vibration.

9. A device as claimed in claim 8 wherein said disc mounting means comprises a shaft splined to said disc for rotation therewith while permitting relative axial movement therebetween, a clock having time-indicating hands concentric with said shaft, and means responsive to axial movement of said shaft for coupling said hands for a setting operation.

10. A timing device having a start member mounted for rotation about a first axis in accordance with time, said start member having a first axial position when approaching a preselected interval starting time and operating to a second axial position in response to arrival at said preselected starting time, and a stop member mounted for rotation about a second axis in accordance with time, said stop member having a first axial position when approaching a preselected interval stopping time and operating to a second axial position in response to arrival at said stopping time wherein the improvement comprises a latch for releasably holding said stop member in a predetermined axial position, said latch having a portion in the path of said start member for releasing the latch from the stop member in response to a predetermined axial movement of the start member.

11. A device as claimed in claim 10 wherein said stop member has a latch recess, said latch comprising a latch lever mounted for rotation about a pivot axis, said latch lever having a part positioned in the path of said start member for pivotal rotation about the pivot axis in response to axial movement of the start member in a predetermined direction, and said latch lever having a part movable from latching reception in said recess to a position clear of the stop member in response to said pivotal rotation.

12. A timing device having a supporting structure and a disc mounted for rotation about its axis relative to the supporting structure from a preselected starting position in accordance with time, wherein the improvement comprises a vibratory-sound-producing element having a portion biased against a face of the disc to inhibit vibration of the element, said disc having a window proportioned to receive said portion at a predetermined angular position of said disc to free the element for sound-producing vibration.

13. A device as claimed in claim 12 wherein said stop member has a latch recess, said latch comprising a latch lever mounted for rotation about a pivot axis, said latch lever having a part positioned in the path of said start member for pivotal rotation about the pivot axis in response to axial movement of the start member in a predetermined direction, and said latch lever having a part movable from latching reception in said recess to a position clear of i the stop member in response to said pivotal rotation.

References Cited UNITED STATES PATENTS 2,689,005 9/1954 Schroeder. 2,993,099 7/1961 Doyle. 3,038,041 6/1962 Zagorski. 3,262,110 7/1966 Gardes.

ROBERT S. MACON, Primary Exan'ziner.

HERMAN O. I ONES, Assistant Examiner.

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