US2786525A

US2786525A - Interval timing device

Info

Publication number: US2786525A
Application number: US386259A
Authority: US
Inventors: Lawrence E Vigneaux
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1953-10-15
Filing date: 1953-10-15
Publication date: 1957-03-26
Anticipated expiration: 1974-03-26

Description

March 26, 1957 L. E. VlGNEAUX 2,786,525

INTERVAL TIMING DEVICE Filed Oct. 1s, 195s 2 Sheets-Sheet 1 fr? Mentor La wrence E V/ firveaux March 1957 E. VIGNEAUX 2,786,525

INTERVAL TIMING DEVICE Filed Oct. 15, 1953 '2 Sheets-Sheet 2 4 Y///////// Ill ll/l/l/l/l llll/ [WI/Q7760)"; Jam/Pence 5 V/ neaux,

INTERVAL TIMING DEVICE.

Lawrence E. Vigncaux, Saugus, Mass, assignor to General Electric Company, a corporation of New York Application October 15, 1953, Serial No. 386,259

1 Claim. (Cl. 161-15) This invention relates to interval timing devices and more particularly to an improved arrangement for expandmg a portion of the scale of the setting dial of such a device.

Devices for timing a relatively short interval of time are used in many applications, such as range timers, photographic timers, etc. These devices ordinarily are driven by a small synchronous timing motor and are provided with a setting dial for manually preselecting the interval to be timed. The setting dial is conventionally connected to the motor driven gear train by a. clutch mechanism so that rotation of the setting dial during the setting operation slips the clutch and therefore does not transmit the setting motion back to the timing motor. Once the setting operation has been completed, the timing motor drives the setting dial through the gear train and when the desired interval has lapsed, a cam associated with the dial actuates an audible signal or contacts.

Many interval timers are provided with a dial having uniform spacing between the timing units indicated thereon, i. e. for example each ten minute interval would occopy the same angular space on the dial. It has been found, however, that it is desirable to expand the scale of the dial in the region of the lower time intervals i. e. so that for example the angular space on the dial occupied by the interval from to minutes is substantially greater than the angular space occupied by the interval from 10 to 20 minutes etc. This expansion of a portion of the scale has in the past been accomplished by various means-such as the use of scroll gears. Such systems however have been characterized by their relative complexity and cost.

nited States Patent 0 It is therefore desirable to provide an interval timing device having means for expanding a portion of the setting scale which is simpler and less expensive than the arrangements formerly used.

it is therefore an object of this invention to provide an approved interval timing device incorporating the desirable features set forth above.

Further objects and advantages of this invention will become apparent and the invention will be better understood by reference to the following description and the accompanying drawings, and the features of novelty which characterize this invention will be pointed out with particularity in the claim annexed to and forming a part of the specification.

This invention in its broadest aspects provides a 1'0- tatable driving member, such as an interval timing device setting dial, and a rotatable driven member such as a gear normally driven by the timing motor of the device. The axis of the driven member or gear is offset from the axis of the driving member or setting dial. In order to provide for imparting a smaller angular move ment to the driven member or gear than the angular movement of the driving member or setting dial when rotated between two given points, the driving member or setting dial is connected to the driven member or gear by a driving link. One end of the link is connected Patented Mar. 26, 1957 to the driving member or setting dial and spaced from the axis thereof while the other end is similarly connected to a driven member or gear and spaced from the axis thereof. This arrangement therefore provides for expanding a portion of the scale of the setting dial. Clutch means are preferably provided interconnecting the timing motor and the gear so that movement of the gear responsive to the movement of the setting dial is not transmitted to the timing motor. The gear is preferably provided with a cutout portion so that the timing motor will only drive the gear from the point set by the setting dial to the cutout portion where motion stops. An audible signal or contact is actuated by a cam as sociated with the setting dial just before motion stops.

In the drawing, Fig. 1 is a side elevational view, partly broken away, illustrating an interval timer provided with the improved scale expanding means of this invention;

Fig. 2 is a similar view showing the scale expanding mechanism in another position;

Fig. 3 is a schematic view showing the mode of operation of the scale expanding mechanism;

Fig. 4 is a fragmentary view in perspective showing the operating parts of the scale expanding mechanism; and

Fig. 5 is a cross sectional view taken along the 55 of Fig. 2.

Referring now to Figs. 1 and 2 of the drawing, there is shown a portion of an interval timing device it, such as a range timer, the particular portion shown being a relatively short interval timer which provides an audible signal after the elapse of a preselected time. The timing device 1 comprises a circular rotatable setting dial 2 having a suitable scale indicated thereon, shown here as being sixty minutes. Setting dial 2 is mounted on shaft 3 which extends through a suitable bearing 4 in frame element 5. Mounted on shaft 3 on the other side of frame 5 from setting dial 2 is a cam 6 which will be hereafter more fully described. It is thus seen that rotation of the setting dial 2 by means of manual knob 7 will produce corresponding rotation of cam 6.

Interval timing device 1 is driven by a timing motor shown schematically at 8, which may be any suitable type, such as a conventional synchronous clock-type motor. Driving motor 8 drives a suitable gear train 9 which terminates in a final gear 10. It will also be readily understood that timing motor 8 may drive another interval timing device, such as an oven timer (not shown).

In order to provide for driving the short interval timer and for expanding the scale of setting dial 2, the arrangement now to be described is provided. Referring now to Figs. 4 and 5 in addition to Figs. 1 and 2, mutilated gear 11 is journall-ed on shaft 12. Normally engaging gear 11 and gear 10 is a clutch gear 14. Clutch gear 14 is mounted on shaft 15 which is arranged for limited vertical sliding motion in slots 16 of

frame elements

13 and 5. Clutch gear 14 and shaft 15 are biased downwardly by spring element 17 having its end 18 pcsitioned in suitable notches 19 in

frame elements

5 and 13. Gear 11 is connected to cam 6 by a link 20 having its end 21 connected to gear 11 at a point olfset from the axis or shaft 12 having its other end 22 connected to cam 6 at a point also spaced from the axis of shaft 3. Gear 11 has one or more teeth removed thereby de fining a cutout portion 23.

Referring now specifically to Fig. 3, cam t; with its axis 3, gear 11 with its axis 12, and link 20 is shown in six different positions. Position A shows link 2%} in the position shown in Fig. 1. It will be seen that rotating earn 6 by means of dial 2 in the direction shown by the arrow 24 from the position A to position 3 will rotate gear 11 in the same direction between points G and H. Rotation of earn 6 from points B to C however only rotates gear 11 the same distance from H to I. It is thus seen that by means of the link connection between cam 6 and gear 11, gear 11 can be given a much smaller angular movement than the angular movement of cam 6 around a portion of its periphery. It is further readily seen that the portion of the scale of setting dial 2 which is desired to be expanded can be arranged to correspond to that portion of cam 6 which has a much greater angular movement for the same angular movement of gear 11, for example between points B and C of Fig. 3.

Referring specifically to Fig. 2, it will be seen that dial 2 is in an initial position adjacent the o indication and that gear 14 is adjacent cutout portion 23 of gear 11. Movement of the dial 2 in direction of arrow 25 to set a desired time interval will therefore move gear 11 in the same direction thus moving cutout portion 23 a predetermined number of teeth away from gear 14. As explained above with reference to Fig. 3, movement of dial 2 from the position shown in Fig. 2 to the position shown in Fig. 1 moves gear 11 a smaller angular amount than setting dial 2 has been moved thereby providing the expanded scale. It will be seen that as setting dial 2 and gear 11 are moved in the direction of arrow 25, gear 14 will tend to climb upon gear 10. In an ordinary gear train, this tendency is restrained by the fixed mounting of the shaft of the gear, however, by means of the mounting of shaft 15 of gear 14 in slot 16, gear 14 will move upwardly out of engagement with gear 11. As soon as movement of setting dial 2 and gear 11 in the direction of arrow 25 ceases, spring 17 will bias gear 14 back into engagement with teeth of gear 11. Timing motor 8 will then drive gear train 9, and

gears

10, 14, and 11 in the direction of the arrows 25. This drives gear 11 and setting dial 2 toward the off position and with the cutout portion of 23 of gear 11 approaching gear 14. It will be seen that when cutout portion 23 of gear 11 reaches gear 14, further movement of gear 11 and setting dial 2 responsive to timing motor 8 will cease.

Referring again to Figs. 1 and 2, earn 6 is provided with a suitable cutout portion 26 and is engaged by a follower 27. Follower 27, in turn is arranged to latch a buzzer 23 which is actuated by the alternating current flux in the core 29 of motor 8. It will be seen that as motor 3 drives gear 11 and setting dial 2 toward the cutout portion 23 and off position respectively, follower 27 will ride into cutout portion 26 of cam 6 thereby unlatching buzzer 28 to provide an audible signal. The cam 6 subsequently shuts off the buzzer just prior to gear 11 reaching cutout portion 23.

While the improved scale expanding arrangement of this invention has been shown in connection with an electric timing motor drive, it will readily be understood that it may be driven by a suitable clockwork mechanism.

It will also be readily understood that while an audible signal arrangement is shown, cam 6 may be arranged to open or close suitable contacts as desired. It will further be readily understood that while a circular setting dial 2 is shown, shaft 3 may be connected to drive a linear scale by means of conventional drums and cords.

It will now be readily seen that this invention provides an improved, simple and inexpensive arrangement for expanding a portion of a scale and this expanded scale portion may be utilized on any desired portion of a circular or linear dial.

The clutch mechanism 14-19 inclusive is not my invention and is more fully described and claimed in copending application Serial No. 386,837 filed October 19, 1953 of Paul V. Terry, assigned to the assignee of the present application.

While I have shown and described a particular embodiment of this invention, further modifications and improvcments will occur to those skilled in the art. I desire it to be understood therefore that this invention is not limited to the form shown and I intend in the appended claim to cover all modifications which do not depart from the spirit and scope of this invention.

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

An interval timing device comprising a rotatable setting dial having a scale indicated thereon, a rotatable cam driven by said setting dial and adapted to actuate a signal on expiration of a desired time interval, a gear having its axis offset from the axis of said cam, a timing motor arranged to drive said gear, said gear having at least one tooth removed therefrom forming a cutout portion whereby said timing motor Will only drive said gear to said cutout portion, means driving said gear by said cam thereby to set said desired time interval comprising a driving link having one end pivotally connected to said cam and spaced from the axis thereof and having other end pivotally connected to said gear and spaced from said axis thereof whereby a smaller angular movement is imparted to said gear than the angular movement of said cam when rotated between two given points thereby expanding a portion of said scale, and clutch means interconnecting said timing motor and said gear whereby movement of said gear responsive to movement of said setting dial is not transmitted to said timing motor.

References Cited in the file of this patent UNITED STATES PATENTS 1,295,756 Johnson Feb. 25, 1919 2,003,317 Strandgren June 4, 1935 2,261,723 Hoffman Nov. 4, 1941 2,620,872 Wyman Dec. 9, 1952