US1838843A

US1838843A - Clockwork driving mechanism in tachometers and the like

Info

Publication number: US1838843A
Application number: US521376A
Authority: US
Inventors: Kohler Ulrich
Original assignee: Hasler AG
Current assignee: Hasler AG
Priority date: 1930-03-15
Filing date: 1931-03-09
Publication date: 1931-12-29
Anticipated expiration: 1948-12-29
Also published as: GB373313A; FR713036A; DE558092C

Description

U. KOHLER Dec. 29, 1931.

CLOCKWORK DRIVING MECHANISM IN TAGHOMETERS AND THE LIKE Filed March 9, 1951 'Umr-ao STATES-v ULRiCH KOHLER, on sw'rrz'nianniv1), AssrGNon T 'HAsLnnhle-vonMALs g, VON c. HASLER, or BERN, SWITZERLAND, A 00330- RATIQNOF swrrzEnL Nn Patented Dec, 29, 1931 pmmorrm TELEGRAPHENWERKSTATTE "cnookwon'x DRIVING MECHANISM m TAGHOMETEBS AND THE LII-{E Application filed Mai-ch19, 1931, Seria1No. 521,376, and in Switzerland March 15, 19.30.

This invention relates to clockwork driving mechanism in tachometers, and the like, and has for its objecttogprovide an improved construction such that only a quite small predetermined tension-of the main spring is re, quired for driving the Clockwork.

According to the invention there 1s provided a clockwork driving mechanism comprising a rotary escapernent device whereof an escapement wheel isrigidly connected with a driving wheel arranged. on a mainspring loading-shaft, and whereof a pawl s controlled by a releasing member which 1s itself controlled by a part rotating with a main-spring barrel, so that when the driving or main springis loaded after a predetermined angular movement of the part rotating with said barrel in relatio'nto the ratchet wheel, the releasing device, becomes inoperative in relation tothe said pawl and the escapementdevice is thereby disengaged. 1

According to a feature of the invention, the pawl aforesaid is constructed in the form of an escapement anchor and the escapement wheelas' a star wheel, the said pawl and releasing member being mounted on. a locking wheel that is fast on saidloadingshaft and is held against rearward "rotation, Y

According to a further feature of the invention', the said pawl is formed with an extension or tail-piece that reaches tothe side of the loading-shaft diametrically opposite the pivot of the pawl, andrthe releasing memher is formed as atwo-armed lever-controlled by a retardation catch which is itself controlled in such a manner by a cam on the spring barrel aforesaid that the releasing member, after release 'of' the said'pawl by the retardation catch, is prevented} from re turning into its locking position until, after a predetermined rotation of the camin relation to the ratchet wheel the retardation catchis caused to release'the releasing member. i

' Other features'of the invention will be de: scribedhereinafter. and pointed out in the v claims.

One embodiment of the invention is dia ple in the accompanying drawings, where Figure 1 shows one form ofdrivingmechanism according to the invention in side felevation as viewed from the right-hand side ofFigure2,. M v t w 1 Figure 2 is a cross-section taken on the line IIII in Figure-1, j

1 Figure 3 is a side elevation as viewed from the left-hand side of. Figure .2, r ,Figures 4 and 5 are sections similar Figure 2, but showing various parts in difs ferent positions, and

Figures 6 and positions. 3 H y i 3 Like reference characters designate like parts throughoutthe several views. A

Referring; to the drawings, a spring-barrel 2 is free to rotate ona shaftl for winding orv loadingadrivingor main spring,knot shown, in the barrel; The inner endxof this main spring is attached to the shaft 1 and its outer end is firmly connected to the-pe riphery of the barrel; A ring 3 of teeth on the barrel drives a time shaft, not shown, of a clockwork; l c h A spur gear ,4 carrying a four-point star wheel 5 is freely rotatable on the loading shaftv land is driven by the shaft of the tachometer which is tobe measured. This star wheel 5 together with an escapement anchor 8 forms a rotary escapement device, the anchor 8' being mounted at, 6 on a locking wheel 7 that is faston the shaft 1 andprevented from rotating backwards. The one arm of the anchor 8 has a lugor tail piece 811. that extends to the side of the shaft 1 diametrally opposite the pivot pin 6, whichlug hasat its free end a tooth 8b. The anchor 8 with,its lug 8a 8b constitutes the pawl aforesaid of the rotary escapementdevice, Whereof'the star whee1i5 constitutes the escapement wheel.

The

locking pawl

8, 8a, 8b is controlled by a two-armed releasing lever 10 fulcrumed on the locking wheel 7 at 9. This releasing member 10 has at one end an inwardly directedtooth 11. Oneuend .of a spring 10 mounted on the locking wheel 7 tendsto hold grammatically illustratedby way-offexam the tooth 311 ofthe releasing member 10 in 7 show details in various the path of movement of the tooth 8b of the pawl 8. The inner end position of the releasing member 10 is determined by a stop pin 13 which passes with play through a hole 14 in the locking wheel 7 and engages with a lever 15 fulcrumed-also at 9 but at the other side of the locking wheel 7. The lever 15 is controlled by a locking lever 16 constituting the retardation catch aforesaid which is fulcrumed at 16 on the locking wheel 7 The other end of the spring 10' presses inwards a pin 17 of the catch 16 that extends through a hole 18 in the locking wheel 7 and the catch. 16 is'thus held with its free shouldered end in the path of a rise or projection 21 of a cam 20 fast on the barrel 2. A

The lever 15 has a lug 15 extending within range of the rise 21. If the main spring is loaded sufficiently and the rise 21 of the cam 20 coacts with the lug 15 (position I in Figure 7) the releasing member 10 will be disengaged, that is moved from its position shown in Figure 2 into that shown in Figures 4 and 7. Under the influence of the spring 10 the catch 16 swings inwards at once and takes under the lever 15 so that the releasing member 10 coupled with the lever 15 is prevented from moving into the path of the

pawl

8, 8a, 8b (and thus engaging with the escapement device) when the rise 21 of the cam moves away from under the lug 15 in consequence of the main spring starting to unwind. After the disengagement of the releasing member the

pawl

8, 8a, 8b meets with no resistance during the continued rotation of the wheel 4 and star wheel 5, but swings idly to and fro between its two end positions. The coupling between the driving wheel 4 and barrel 2 is thus disconnected until the main spring has unwound so far' that the

cam

20, 21 forces the lever 16 outwards (Figure 6). Under the influence of the spring 10' the releasingmember returns into the path of movement of the

locking pawl

8, 8a, 8b which is then prevented from swinging to and fro and drives the locking wheel 7 and with it the shaft 1 under the influence ofthe main spring. When the locking wheel 7 has rotated approximately one revolution in relation to the spring barrel 2, and the main spring is thus fully wound up and loadedto a maximum, the rotary escapement device is disengaged afresh by the cam 20. 21.

When the above described clockwork drive is employed it is possible to use a definitely predetermined and small mean tension of the main or driving spring'so that in spite of the non-uniform rotation of the driving wheel 4 corresponding to the speed at any time of the vehicle a quite uniform driving force can be exerted on the clockwork.

The invention is not restricted to the precise constructional details enumerated.

I claim 1. A clockwork driving mechanism com-' prising in combination a shaft, a barrel freely rotatable about the same, a spring having one end connected to said shaft and its other end connected to the barrel, a driving wheel on the shaft, and a rotary pawl-and-ratchet device comprising a ratchet-wheel firmly connected with said driving wheel, and a p awl coacting with the ratchet-wheel, a releasing member arranged to engage and be disengaged from said pawl, and amember rotatable with said barrel and arranged to control said releasing member so that when said spring is loaded after a predetermined angular movement of said member about the shaft in relation to said ratchet-wheel, the releasing member is moved out of engagement with said pawl and the .pawl-and-ratchet device thereby becomes operative.

2. A clockwork driving mechanism comprising in combination a shaft, a barrel freely rotatable about the same, a spring having one end connected to said shaft and its other end connected to the barrel, a driving wheel on the shaft, a locking wheel free to rotate on the shaft in only one direction, a rotary escapement device comprising a star wheel firmly connected to said driving wheel, and a pawl pivoted on said locking wheel and coacting with said star wheel, a releasing member pivoted on said locking wheel and arranged to control said pawl, and a member rotatable with'said barrel and arranged to control said releasing member so that when said spring is loaded after a predetrmined angular movement of said member about the shaft in relation to said escapement wheel, the releasing member is moved out of engagement with said pawl and the escapement device thereby becomes operative.

3. A clockwork driving mechanism comprising in combination a shaft, a barrel freely rotatable thereon, a spring connected at one end to the shaft and at its other end to the barrel,'a driving wheel on the shaft, a locking wheel free to rotate on the shaft in only one direction, a rotary escapement device comprising a star wheel rigidly connected to said driving wheel, and a pawl pivoted on said locking wheel and coacting with said star wheel, a cam rotatable with said barrel, a releasing member in the form of a twoarmed lever pivoted on said locking wheel and having one arm arranged to control said pawl, and a retardation catch mounted on said locking wheel and arrangedto control the other arm of said lever, which catch is so controlled by said cam that the releasing member, after being moved into its releasing position in which it is disengaged from said pawl, is prevented from returning into its locking position until, after a predetermined rotation of the cam in relation to the star wheel, the catch is caused to release the releasing member.

4. A clockwork driving mechanism comprising in combination, a shaft, a barrel free- 1y rotatable thereon, a spring connected at one end to the shaft and at its other end to the barrel, a driving wheel on the shaft, a locking wheel free to rotate about the shaft in only one direction, a rotary escapement device comprising a star wheel rigidly connected to said driving wheel, and a pawl pivoted on said locking wheel at one side of the shaft and coacting with said star wheel, which pawl has a tailpiece extending around said shaft to a situation opposite the pivot of the pawl, a cam rotatable with said barrel, a releasing member in the form of a twoarmed lever pivoted on said'locking-wheel,

one arm of which lever is spring pressed and arranged to lock and release said tail-piece,

a control member carried'by the barrel and arranged to coact with the second arm of said lever extending through the locking wheel, and a spring-controlled retardation catch mounted on said locking wheel and arranged to engage the said second arm of the lever and hold the latter against its spring out of engagement with said tail-piece, and a pin on said catch extending through the locking wheel and controlled ,b said cam.

ULRICH OHLER.