US2595313A - Timer - Google Patents

Description

C. R. TURNER May 6, 1952 TIMER 2 SHEETSSHEET 1 Filed March 6, 1944 /z'forize 5.

fizz/elder if Ckarfi g fi o ewfarizer MMMQZMM May 6, 1952 c. R. TURNER TIMER Filed March 6, 1944 2 SHEETS-SHEET 2 jiweizfor Patented May 6, 1952 UNITED STATES PATENT OFFICE TIMER Charles Roger Turner, Philadelphia, Pa.

Application March 6, 1944, Serial No. 525,167

12 Claims. 1

This invention relates to improvements in timers and more especially to interval timers which are particularly useful in determining the proper length of time for a processing step or treatment.

An important object of the invention is to provide a small, compact and inexpensive but withal an extremely accurate timing unit which is particularly susceptible to being utilized in the form of a small portable device that can readily be transported manually to the site of activity and will there taken such a minimum amountof space that it can be used where space is quite limited and furthermore will require but a small amount of storage space when put away. 1

Another object of the invention is to provide a novel interval timer which is adapted for automatically adjustin itself to compensate for temperature variations in connection with the treatment to be timed, such, for example, as in the development of photographic films, plates or prints where the temperature of the developer bath is an important factor in the length of time development should be permitted to continue in order to secure optimum results.

Another object of the inventionis to provide a hydraulically controlled timer which is rendered exceedingly accurate by direct heat exchange relationship between the hydraulic system and'the substance of variable temperature responsible for the treatment to be timed.

' A further object is to provide an improved interval timer involving the use of a hydraulic control system, in which the hydraulic system is automatically cocked at the termination of each timing operation for the next succeeding timing operation.

Other objects, features and advantages of the invention will be readily apparent from the following description and in the accompanying two sheets of drawings, in which:

- Fig. l is a side elevational view, partially in section,- of a timer embodying the features of the invention;

-Fig. 2 is a front elevational view of the timer;

Fig. 3 is a top plan view of the timer;

Fig. 4 is a fragmentary sectional side elevational view of the operating mechanism "of the timer showing the various cooperating parts in one operative relationship.

Fig. 5 is a fragmentary side elevational view similar to Fig. 4, but partially in section and broken away and showing certain operating parts in a different operative relationship;

Fig. 6 is a fragmentary enlarged horizontal sec- 'adapted to be relatively quickly displaced from 66 of Fig. 4;

Fig. 7 is a side elevational view, partially in section of a modifiedform of the invention; and

Fig. 8 is a top plan view of the modified form of Fig. 7.

An important need has existed in the photographic developin art, in particular, for a reliable, inexpensive but above all accurate interval timer capable of adjusting itself to variations in the developer bath or the fixer bath, as the case may be. Merely by way of example therefore, the invention has been illustrated as embodied in a photographic interval timer.

Having reference first to Figs. 1 to 6, inclusive, showing a self-suflicient, portable timer device, a hydraulic control system is shown including a flexible bellows unit I0 mounted upon a base II and enclosed within a housing I2. The base I I is preferably of such character as to enable the unit to be supported in convenient operating position upon a table or work bench. However, in order to enable the unit to be mounted upon the side of a treating tank such as a developer tank I3, a screw clamp I4 may be provided on the rear wall of the housing I2 for the purpose of fasten ing the unit onto the upper side wall margin of the tank.

The hydraulic unit In comprises a pair of metallic bellows I5 and I6 (Fig. 5) secured in fluidtight relation to respective opposite sides of a dividing plate I! of" substantial thickness. The respective outer ends of the bellows I5 and I6 are hermetically sealed and permanently secured to the adjacent parallel reaches of a rectangular supporting frame I 8 which is fixedly supported in a horizontal plane above the base II by means of'a U-shaped bracket I9.

All of the space Within the chamber defined by the bellows members I5 and I6 is filled with a liquid of viscosity characteristics best suited to the. purpose at hand, such as one of a number of oils readily available on the market. Provision is made for rapidly ejecting a part of the liquid from one of the chambers into the other of the chambers and then directing the displaced liquid back again slowly during a time interval for which the device will have been set. To'this end, the dividing plate I! is formed with a port 20 of liberal dimensions through which liquid is the bellows I5 into the chamber of the bellows I6 but through which the liquid cannot return by reason of a one-way check valve 2I. Return of the liquid from the bellows I6 to the bellows I5 is through a bleeder duct 22 communicating through the respective ends of the bellows members and extending as a loop out through an opening 23 in the rear wall of the housing l2 (Fig. l) and adapted to dip down into the treating bath such as developer or fixer, as the case may be, in the tank 13. In that portion where it is immersed within the treating bath, the duct l2 may be formed as indicated at 23 to provide a passage of particularly restricted cross-sectional flow area so that at a given hydraulic pressure and temperature it will take a predetermined quantity of the liquid an accurately determinable length of time to pass through the bleeder duct. In a round duct, this restricted portion 23 may be attained by flattening the tube.

In the present instance the pressure for forcing the liquid through the bleeder duct 22 is generated by fiexure of the bellows I5 and it as in incident to driving the liquid from the bellows l5 to the bellows H5 in the course of which the bellows I5 is compressed to a certain extent and the bellows l6 expanded by movement of the separating member l'l' uniformly in a horizontal direction while the ends of the bellows are, of course, held in a fixed position by the supporting frame I8. The resulting flexure of the bellows members throws them out of flexible balance to which they promptly seek to return and thus set up a pumping action. This creates hydraulic pressure which force liquid from the bellows l6 through the duct into the bellows 15.

As the liquid bleeds through the ultra-restricted section 23 of the bleeder duct, it is subjected to direct heat transfer with the bath, thus assuming or tending to assume the prevailing temperature of the bath. Since the temperature has a direct eifect upon the viscosity of the timer liquid, there will be an accurate correlation with the prevailing: temperature of the time required for the given displaced quantity of liquid in the bellows unit to return through the bleeder duct 22. Thus, the liquid will increase in viscosity, become more sluggish and flow slower when the temperature is lower than a predetermined optimum temper-.

ature, and it will decrease in viscosity in accordance with increases in temperature over the optimum temperature and flow more rapidly, thus respectively lengthening or shortening the interval of the time to complete transit through the circuit. This phenomenon is utilized in effecting secondary adjustment in the time interval, such interval being tolled from the manual setting of the device through the medium of a handle 24 to cock a signalling device, in this instance, of audible type, including a clapper 25 adapted to ring a bell 27.

As shown, the setting member 24 is in the form of a bale having a handle 28 projecting from the front of the housing l2 and supported in associ ationwith a shaft 29 by a pair of bearing posts engagement of its tensioning loop with a loading post 32.

To set the device for a timing interval after the bellows unit 10 has been cooked, the handle 28 is swung down until the setting bale 24 engages with a catch 33- forming part of a load and fire mechanism which is loaded by such interengagement (Fig. 4). The catch 33 is pivotally mounted as at 34 upon an upward extension 35 of one leg of the U-bracket l9 (Figs. 2 and 4) so as to be oscillable in a vertical plane. In its inactive condition, the catch 33 is maintained by a trigger spring 31 in a counterclockwise position as shown in Fig. 1, wherein a bale engaging mouth 38 yaws to receive the horizontal bar of the setting bale 24. The limit of rotary movement in this position is defined by a stop dog 39 (Fig. 3) engaging the edge of the support 35. When the bale is brought into the mouth 38 and cammed down against a lower jaw surface 40, the catch 33 is swung down until a leg 4| thereon is engaged by a trigger latch 42 held in operative position by the constantly loaded trigger spring 31. After the catch 33 is latched, a retaining finger 43 thereon locks the bale against return.

As the timing bellows unit l0 returns toward resilient and hydraulic balance during the timing interval, a trip arm 44 carried thereby sweeps toward and ultimately engages a trigger finger 45 rigid with and upstanding from the latch member 42. After the trigger finger 45 is swung sufliciently to trip the trigger and release the catch 33, the latch tilts up so that the bale member 24 instantaneously escapes and snaps up under the force of the spring 3| to drive the clapper 25 against the bell 21, ringing of which announces termination of the timing interval.

The energy of the returning bale member 24 is preferably utilized to cook the bellows unit 10 for the next succeeding timing interval. According- 1y, a cooking arm 41 presents an arcuate bearing surface to an anti-friction roller 48 carried by the outer connecting bar of the setting bale 24 and is adapted to be-swung counterclockwise as indicated in Fig. 5 by the returning bale member and thus correspondingly swing a rigidly united bellows cocking yoke 49. The latter is preferably of inverted U-shape and-has its legs extending down in straddling relation to the bellows separating plate l1 inside of the upstanding legs of the supporting bracket IS. The yoke legs are pivoted to the bracket H! as by means of screws 50 (Fig. 2) on an axis below the horizontal diameter of the bellows. An operating connection between the separating plate I! and the cooking yoke 43 is effected by means of laterally projecting studs 51 extending on the horizontal diameter of the bellows unit into vertical bearing slots 5 la in the cocking yoke legs (Figs. 2 and 6). Thus, swinging of the cooking yoke 49 counterclockwise as shown in Fig. 5 causes the bellows separator ll to be shifted in bellows-cocking direction to prepare the hydraulic timing circuit for the next timing operation. At the same time the trip arm 44 isswung back into cocked position (Fig. 1). In this instance the arm 44 is rigid with the top of the cooking yoke 49 and may be formed in one integral piece with the arm 41.

At the end of its upward or released swing, the setting bale 24 is brought to a halt by engagement of the anti-friction roller 43 with a limiting hook 52 formed on the upper end of the cocking arm 41.

' Primary adjustments in the timing interval are preferably accomplished herein by adjusting the operational spacing of the trip arm 44 and the trigger finger 45. To this end, the trigger membr42 is preferably mounted upon an adjustment eccentric 53 (Fig. 6) which is adapted to be oscillated, through the medium of a handle 54, upon a stud shaft 55 mounted upon the adjacent leg of the supporting bracket IS. The

eccentric is'so organized that by swinging the handle 54 up, the latch member 42 will be caused to shift and rock the trigger finger 45 toward the trip arm 44 to shorten the distance, and thus the time required for interengagement. Swinging the handle 54 down will eifect reverse swinging of the trigger finger 45 and thus increase the space from the trip arm 44 and consequently the length of time it will take the trip arm to engage the trigger finger. To enable visual determination of the incremental trigger adjustment, an adjustment scale 51 calibrated by degrees from fast to slow may be provided upon a bracket 58 providing upper and lower limit stops 59 and 60, respectively, for the handle 54.

In any adjusted condition of the trigger 42, the horizontal level of the trigger catch is maintained by a stop or dog 6| (Figs. 1, 3 and 6) fixed upon the adjacent leg of the supporting bracket I9 and engaging slidably within the latching notch or recess of the trigger member.

To meet the demand for a very low cost unit in which ruggednessis of minor consequence is an aim of the modified form of the invention shown in Figs. '7 and 8. This form operates .on the same principle as the form just described, but the mechanism is substantially less elaborate. Accordingly, a bellows unit 65 is'mounted within a housing 6.6 which is supported. upon a base 61. The timing unit comprises a pair of expansible metallic bellows 68 and 69 hermetically secured to a supporting separator plate 10, the outer ends of the bellows being also hermetically sealed. The unit 65 is secured on a vertical-axis against the rear wall of the housing 66.

In the present instance, the bellows 68 is adapted to be compressed upon cooking of the bellows unit to displace timing liquid therefrom through an orifice H past a one-way check valve 12 into the bellows 69 which is correspondingly expanded due to the influx of liquid. The spring loading of the resilient bellows thus occasioned by. the hydraulic unbalancing and distortion of the bellows causes the timing liquid to be pumped through a bleeder duct 13 which is in the form of a, loop communicating through ports 14 and 75 in the supporting separator with respectively the bellows 68 and 69. By preference, the bleeder duct loop 13 is formed from a readily pliable material such as copper so that it can be bent into any preferred adjusted relationship with respect to a fluid container such as a photographic tray 11 containing a bath of a photographic solution such as developer or fixer, in which the treatment of articles is to be timed.

After the bellows unit has been cocked, a setting lever 18 is swung down from the terminate broken-line position of Fig. 7 to the full line position to initiate a. timing interval. This causes a triggerlatch head19 to engage a stud 80 on the setting lever. The trigger head 19 is preferably in bell crank relationship with a trigger arm 8! interposed in the path of a depending trigger tripping boss 82 at the lower end -of the bellows 68. The trigger is preferably mounted through the medium of an eccentric adjuster 83 pivotally upon a supporting bracket 84, and. adjustment handle 85 projecting parallel to the lever 18 is adaptedto be manipulated for oscillating the eccentric 83 to swing the trip ,arm 8| toward or away from the tripping boss 82. A leaf spring- 81 mounted on the base 61 bears against the trip 8| to normally resiliently maintain the trigger in the operative position. A limiting dog 88! carried by the trigger structure engages the bracket 84 to maintain the trigger structure against clockwise rotation beyond a certain limit under the influence of the spring 81, as seen in Fig. 7.

The lever 18 is pivotally secured as at 89 to the rear wall of .the housing below the bellows unit in such manner that when the lever is released from the trigger l9 and is drawn upwardly by a tension spring 90, the lever will engage the tripping boss 82 of the bellows and thus cock the bellows unit for the next succeeding timing operation coincident with release of the lever at termination of a timing interval.

Release of the setting lever 18 is also utilized to operate a signal such as a bell 9| located to be struck by a clapper 92 carried by the lever 18. As shown, the clapper 92 is pivotally connected as at 93 to the lever 18 in such manner that when the lever 18 is snapped back to the initial brokenlineposition by the spring 90, the clapper 92 is pitched by inertia against the bell 9|, and then falls back by gravity as a result of an overcentered disposition of weight in the clapper head.

Although the timer has been particularlydescribed in connection with use in timing certain photographic treatments, many other uses for the timer will readily suggest themselves, such, for example, as in electrical appliances, where instead of merely operating a signalling device, the setting and cocking lever structure may beutilized for a certain operative function of the associated mechanism.

While I have shown in the drawings and have herein described in detail preferred embodiments, it is to be understood'that I do not thereby intend to limit the invention to the specific forms disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the following claims.

I claim:

1. In combination in a timing device of the character described, a pair of metallic bellows members joined in a unit and adapted to be loaded with liquid, means providing one-way communication between said bellows to enable the displacement of liquid quickly from one bellows to the second bellows, a bleeder duct communicating with both bellows and providing a liquid passage of such restricted cross-sectional flow area that liquid will return but slowly at given hydraulic pressure and thus require a predetermined time for a given quantity of the liquid to return from the second bellows to the first bellows, means for actuating said one bellows to drive the liquid through said one-way com municating means into said second bellows and holding the bellows in the displaced condition,

means for removing the actuating means from bellows engagement, a load and fire mechanism for holding said actuating means inactive and adapted to be released after a predetermined time" interval as determined by return of the bellows to undistorted condition, by return of the liquid from the second bellows to said one bellows through said restrictedpassage, said actuating means being operable upon release from said load and fire mechanism to recondition the bellows means, and means for adjusting said load and fire mechanism to vary the operative interval thereof.

H 2. In combination in a timing device of the character described, a pair of liquid chambers having a' relatively unrestricted one-way passage therebetween and another passage of quite restricted cross-sectional fiow area so that liq-- uid of given viscosity characteristics will require a predetermined time interval for aquantity of the liquid under any given temperature conditions to flow through the restricted passage, means including a lever structure operative. to drive the liquid from one chamber into the other chamber through said one-way passage, means associated with said other chamber to drive the liquid therefrom through said restricted passage into the one chamber, means for holding said lever out of the operative association with the chambers during a timing interval, means for normally biasing the lever into the operative association with the said chambers whereby to drive liquid from said one chamber to the other chamber and constructed and arranged to be released as an incident to passage of said given quantity of liquid from said other chamber to said one chamber through said restricted passage, and signal means including a sounding member mounted in a fixed position and a clapper member carried by and movable with said lever structure and adapted to be activated upon movement of the lever structure tothe liquid forcing relation to said chambers to strike said sounding member.

3. In combination in a timing device of the character described, resilient bellows means adapted to contain a liquid of predetermined viscosity characteristics, a passage communicating with said bellows means for flow of liquid therethrough, means for compressing the bellows to drive the liquid therefrom and for normally holding the bellows in the compressed condition, means for releasing the bellows compressing means from the bellows to permit the bellows to expand for return of the liquid thereto, trigger means for holding said compressing means inactive until the bellows has expanded and being operable by the expanded bellows to release said compressing means toreturn to the bellows compressing condition thereof, and means for adjusting thetrigger means to vary at will the time interval it holds the compressing. means in active.

4. In combination-in a timing device of the character described, a pair of bellows members separated and having a one-way rapid displacement passage therebetween and a second passage of restricted cross-sectional fiow area, the construction and relationship of the bellows being such that when a fiuid is displaced from oneof the bellows through said one-way passage into the other bellows the normal reaction of the bellows. is to force the fluid to return through the restricted passage to said one bellows to efiect a balanced condition, a lever structure having a handle thereon and mounted to be moved in an operative are, a spring normally biasing the lever in one direction, means associated with said bellows arranged for engagement bysaid lever under the bias of said spring for compressing said one bellows, said handle being engageable to move the lever away from saidv means so as to release the latter and allow the one bellowsto' return to the balanced condition, a trigger mechanism normally operative to retain the leverinactive in opposition to said biasing spring, and means for automatically releasing said trigger mechanism when said one bellows returns to substantially balanced condition for releasing the lever to recompress' the bellows.

5. A device as defined in claim 4 wherein the trigger mechanism includes an eccentric adjust- 8, ing means having a handle manipulable to effect. adjustment of said releasing means to lengthen or shorten the interval until the trigger is released.

5 6. A device as defined in claim 4 wherein the lever structure: has mounted thereon a clapper,

and a sounding member disposed to be struck by the clapper as an incident to bellows compressing movement of the lever.

'7. In combination in a timer bellows structure wherein a fluid is adapted to be displaced from one portion of the structure to another portionof the structure, a pair of Sylphon type bellows, a common base separating said bellows, means confiningly opposing the opposite ends of thebellows assembly, means providing a pair of stationary arms at opposite sides of the bellows assembly at said base, said base being movable in an axial direction between said arms, and an actu- "-:ating lever structure including a pair of arms pivotally connected to said stationary arms and having off-set pivotal connection with said base whereby upon swinging of the lever about its pivots with said stationary arms said base is moved axially to efiect equal expansion and contraction of the respective bellows to efiect fluid displacement therebetween.

8. In combination in a timing unit of the char-' acter described, a bellows structure adapted to zo have liquid displaced therefrom, and means for effecting displacement compression of the bellows comprising a cocking arm pivotally mounted and operatively associated with the bellows and a swingably mounted setting member having a roller engageable with the cocking arm and operative in the swinging movement of the setting member to roll on said cocking arm and move the same into bellows compressing position.

9. A timing unit as defined in claim 8 wherein t-the setting member includes a clapper, and a sounding member disposed to be struck by' the clapper when the latter is moved with said setting member as an incident to acting upon said cocking arm to compress the bellows.

., 10. In combination .in a timing unit of the character described, a compressible bellows structure, means including a lever for compressing said bellows, means for moving said lever out of bellows compressing relation, said bellows being automatically movable back to an initial position when released from compressing action of said lever, a restraining trigger assembly for holding said lever inactive, a trigger release arm, actuating means operative as an incident. to return of the bellows to the initial position to act on said release arm and trip the trigger to release the lever, said lever including means for normally biasing the same upon release to enter into the bellows compressing activity thereof automatically, and means operable to vary the. op-

erative relation of said release arm and said actuating means for predetermining the interval between release of the bellows from compression and release of the trigger.

11. In combination in a timing unit, a pair of compressible bellows, a separating plate, said bellows being sealingly secured to opposite sides of said separating plate, a stationary frame; the ends of'the bellows remote from said separating plate being sealingly fixedly secured to said frame, said separating plate being movablerelative to said frame for flexing and compressing saidv bellows, an actuating lever operatively connected to said plate for moving the same to com-- To press one of the bellows and extend the other of the bellows simultaneously, and means providing fluid displacement communication between said bellows so that fluid displaced from the compressed bellows will displace into the extended bellows.

12. In combination in a self-contained timer unit, an enclosing housing adapted to be positioned adjacent a body of fluid of variable temperature, a bellows structure in said housing including separated fluid chambers having quick displacement communication and check valve means for one way displacement only, a duct of substantial length defining a restricted fluid path and comprising a loop extending from said bellows structure to the exterior of the housing and being of such length as to be immersed in said fluid oi. variable temperature; one end of the duct being in communication with one of said chambers and the other end of the duct being in communication with the other of said chambers, a lever pivotally mounted within said housing and projecting from the housing for manipulation externally of the housing, means normally biasing the lever into one position, means providing an operative connection between said lever and said bellows structure to actuate the bellows structure for quick displacement of viscous timing fluid from one of said chambers into the other of said chambers as an incident to movement of said lever responsive to said biasing means into said one position, said lever being movable by actuation of the portion thereof externally oi the housing into a position to release the bellows structure for return of the viscous timing fluid from said other chamber to said one chamber through said duct so that the timing fluid must pass through the loop of the duct immersed in said fluid of variable temperature and thus condition the viscosity of the timing fluid in relation to the temperature of the fluid of variable temperature, a'load and fire mechanism operative to restrain said lever against return to said one position thereof and including means responsive to predetermined movement of the bellows structure upon return of the timing fluid from said other chamber to said one chamber for firing said mechanism to release the lever, and means for varying the responsive interval of said load and me mechanism and including a member operable externally of said housing.

CHARLES ROGER TURNER.

REFERENCES CITED The following references are of record in the file of thispatent: V I

UNITED STATES PATENTS

Images