US3841086A

US3841086A - Time display mechanism

Info

Publication number: US3841086A
Application number: US00413243A
Authority: US
Inventors: M Robin
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-11-17
Filing date: 1973-11-06
Publication date: 1974-10-15
Anticipated expiration: 1991-10-15
Also published as: GB1430668A; SU564831A3; JPS50871A; DE2357313A1; FR2207301A1; FR2207301B1

Abstract

A time display mechanism for use with the movement of a timepiece, which movement has separate hour and minute shafts. The mechanism comprises separate hour and minute display rotors to be mounted on and rotatable with their respective shafts. The hour display rotor is marked completely around its periphery with indicia indicating hours, conveniently 0 to 12 and the minute display rotor is marked with the indicia 0 to 60 about a portion of the minute display rotor surface leaving a space between the 0 and 60 marks, which space is equivalent to the spacing between two successive hour markings on the first display rotor. An indicator is disposed over both display rotors to indicate the time. Two alternative means are provided for moving the indicator at substantially the same speed as the hour display rotor during each hour but at the end of the hour to shift the indicator rapidly across the space between the 60 and 0 marks to assume a position over the next following hour indicia. The indicator may comprise a pointer or, alternatively, a movable shutter having a window therein for indicating hours and a pointer for indicating minutes.

Description

United States Patent 1191 Robin 1 11 3,841,086 1 51 Oct 15, 1974 TIME DISPLAY MECHANISM [76] Inventor: Maurice Robin, 15 ter, Allee de la Pepiniere, 92 Suresnes, France [22] Filed: Nov. 6, 1973 [2]] Appl. No.: 413,243

[30] Foreign Application Priority Data Nov. 17, 1972 France 1. 72.40990 [52] U.S. Cl. 58/125 C, 235/] C [51] Int. Cl. G04b 19/02 [58] Field of Search 58/125 C; 235/] C [56] References Cited I UNITED STATES PATENTS 3,712,050 1/1973 Kawada 58/125 c Primary Examiner Edith Simmons Jackmon Attorney, Agent, or Firm-Clelle W. Upchurch [57] ABSTRACT A time display mechanism for use with the movement of a timepiece, which movement has separate hour and minute shafts. The mechanism comprises separate hour and minute display rotors to be mounted on and rotatable with their respective shafts. The hour display rotor is marked completely around its periphery with indicia indicating hours, conveniently 0 to 12 and the minute display rotor is marked with the indicia 0 to 60 about a portion of the minute display rotor surface leaving a space between the O and 60 marks, which space is equivalent to the spacing between two successive hour markings on the first display rotor. An indicator is disposed over both display rotors to indicate the time. Two alternative means are provided for moving the indicator at substantially the same speed as the hour display rotor during each hour but at the end of the hour to shift the indicator rapidly across the space between the 60 and 0 marks to assume a position over the next following hour indicia. The indicator may comprise a pointer or, alternatively, a movable shutter having a window therein for indicating hours and a pointer for indicating minutes.

10 Claims, 8 Drawing Figures 1 TIME DISPLAY MECHANISM The present invention relates to a time display mechanism for displaying hours and minutes.

It is known to replace the hour and minute hands in a timepiece such'as a clock or watch by two drums driven so as to rotate by the corresponding axles of a clockwork movement.

These drums indicate the hours and the minutes respectively.

According to the present invention there is provided a time indicating mechanism comprising a first display rotor having indicia thereon representing hours and having means for connection to an hour shaft of a timepiece movement, a second display having indicia thereon representing zero to 60 minutes with a spacing between the 60 and minute marks equivalent to the spacing between two successive hour markings on the first display rotor and having means for connection to a minute shaft of a timepiece movement, an indicator mounted over said first and second display rotors to indicate the time in hours and minutes, and indicator moving means for moving the indicator, during each hour, in the same direction as the first display rotor, at a speed which is a function of the speed of the first display rotor to maintain said indicator substantially on the same hour marking and for shifting the indicator rapidly in the opposite direction through 'a distance equivalent to the spacing between the 60 and 0 minute marks at the end of each hour, in order to indicate the next following hour.

The present invention further relates to a timepiece having hour and minute drive shafts and a time display mechanism in accordance with the present invention of which the first display rotor is in driven engagement with the hour shaft and the second display rotor is in driven engagement with the minute shaft;

If desired, the pointer moving means may shift the pointer in accordance with the continuous forward movement of the hour display rotor and the reading of both the hours and the minutes is taken opposite the pointer.

Preferably the minute display rotor is furthermore scaled from 00 to 60through an arc of 330, a dead angle of results from this and at the 60th minute the pointer moves backwards by 30 to appear opposite the next hour and the scale 0 minute.

The display rotors may comprise drums, discs or concentrically disposed annular members.

This display mechanism serves to prevent any ambiguity in reading the time when one hour passes to the next.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a view in elevation of one embodiment of FIG. 2 is a view in cross-section along the line II--II.

the time display mechanism along the line 1-1 of FIG.

FIG. 6 is a view in crosssection of the embodiment represented in FIG. 5;'

FIG.. 7 is a perspective view of a further, simplified embodiment of the invention, and

FIG. 8 is a view in cross-section of the embodiment of FIG. 7.

FIGS, 1 and 2 represent a time display mechanism for displaying hours and minutes which comprises a support frame 1 in which are rotatably mounted a minute shaft 2 and an hourshaft which are connected in a known manner to for example a clockwork or electric movement not shown in the drawing.

A display rotor in the form of a drum 4 is fixed at one of its sides to the'minute shaft 2 and rests at its other side against a stud 5 which is firmly fixed to the support frame 1. The drum 4 has a scale of minutes from 0 to 60, distributed over 330 of the peripheral surface thereof with a dead angle a of 30 between the 00 and 60 marks (FIGS. 3 and 4).

Another display rotor in the form of a drum 6 which carries a scale of hours from 1 to 12 is fixed on the hour shaft 3.

An indicator in the form of a pointer 7 firmly fixed to an arm 8 mounted so as to rotate freely around the shaft 2 is located opposite the hour drum 6 and the minute drum 4, the pointer 7 simultaneously indicating the hours and the minutes.

The arm 8 possesses an elongate aperture or slot 9 in which is mounted a stud l0 fixed to one end of a lever 11, which is mounted at its other end about a pivot pin 12 attached to a lug 13 firmly fixed to the support frame 1. i

In its middle part,the lever 11 possesses a boss 14 by means of which it rests against a snail cam 15 which is firmly fixed to, and rotates with, the minute shaft 2 and which makes one revolution per hour.

The cam 15 possesses a spiral-shaped edge 16 of which the parts having the minimum and maximum radii are joined by a radial face 17.

The device operates in the following manner:

Both the minute drum 4 and the hour drum 6 are driven by their respective shafts, so as to rotate continuously in the direction of the arrow F; the arm 8 which is subject to the action of the cam 15 through the interengagement of the spiral-shaped edge 16 and the lever 11, moves in the direction of the arrow F as does the pointer 7, that is to say in the same direction as the hour drum 4, in order to balance the forward movement of the hour drum 4 and to hold the pointer opposite the particular hour indicated on the hour drum 6.

At the sixtieth minute, when the pointer indicates for example 9 hours 60 minutes, the boss 14 of the lever 11 is situated opposite the radial face 17 of the cam 15 (FIG. 1) and passes from a large radius to a small radius of the spiral shape edge 16. As the lever 11 falls, for example under the influence of gravity or a spring bias, it causes the arm 8 and the pointer 7 to shift or move backwards in the direction of the arrow F in the opposite direction to that F in which the drums rotate. The shift corresponds to the dead angle a separating the scale numbers 60 to 0 of the minute drum 4.

In this way the pointer 7 passes from the indication 9 hours 60 minutes to indicate the next hour which is 10 hours 00 minute on

drums

4 and 6.

As shownin FIGS. Sand 6, the pointer 7 can be replaced by an indicator in the form of a movable shutter l8 possessing a window 19 in which only the indication of the desired hour appears; the shutter also possesses a pointer 20 which moves opposite the minute indicator. An aperture 22 is provided in a case 21 of the mechanism so that the window remains completely visible in its end positions.

In the embodiment represented in FIGS. 1 and 2, the pointer 7 moves concentrically with the drums, but this requires the use of the intermediate lever 11.

Now according to a simplified further embodiment represented in FIGS. 7 and 8, the intermediate lever 11 is dispensed with. In this case the movable shutter 18 is connected by means of arms 24, 24a to a pivotally movable, eccentrically mounted shaft 23, one of the arms 24 is provided with a boss 25 which co-operates directly with the cam 15 firmly fixed to the shaft 2.

The operation is identical to that described above, the cam 15 co-operating with the boss 25 in the same way as with the boss 14 in order to shift the movable shutter 18 at substantially the same speed as the hour drum 6 during each hour.

It will be appreciated that various modifications of the time display mechanism are possible, for example if the mechanism is to be used to indicate time on a 24 hour basis instead of a 12 hour one as described, the angle a would be 15 instead of 30 as with the illustrated embodiments.

The

drums

4 and 6 may be replaced by display rotors in the form of discs or concentrically disposed annular members.

I claim:

1. A time display mechanism for use with a timepiece movement having separate hour and minute drive shafts, said mechanism comprising:

a. a first display rotor having indicia thereon representing hours and means for mounting said first display rotor on said hour shaft for rotation therewith;

b. a second display rotor having indicia thereon representing to 60 minutes with a spacing between a sixty minute mark and a zero minute mark equivalent to the spacing between two successive hour markings on the first display rotor and means for mounting said second display rotor on said minute shaft for rotation therewith;

an indicator mounted over said first and second display rotors to indicate the time in hours and minutes, said indicator being mounted for movement between first and second positions spaced apart by a distance equivalent to said spacing between two successive hour markings; and d. indicator moving means for moving said indicator in the same direction as said first display rotor from said first position to said second position during each hour and for rapidly shifting said indicator from said second position back to said first position at the end of each hour, whereby the indicator is moved from said first position to said second position at a speed which is a function of the speed of the first display rotor to maintain said indicator substantially on the same hour marking and is rapidly shifted back to its first position at the end of each hour in order to indicate the next following hour.

2. A mechanism as claimed in claim 1, wherein the indicator is movable through a distance to subtend, about the axis of the minute display rotor, an angle of 30.-

3. A mechanism as claimed in claim 1, wherein said indicator is freely movable about said minute shaft and said indicator moving means comprises:

a. a support frame;

b. a lever pivotally mounted at one end on said support frame;

0. means for operably coupling the other end of said lever to said indicator;

d. a cam to be securely fixed to said minute shaft for rotation therewith; and

e. a cam follower on said lever adapted to engage said cam.

4. A mechanism as claimed in claim 3, wherein said means operably coupling said lever to said indicator comprises an aperture in said indicator and a stud on said lever, which stud is engageable in said aperture.

5. A mechanism as claimed in claim 3, wherein said cam is a disc in the form of a snail cam having a spiral shaped peripheral edge with the minimum and maximum radii points thereof being connected by a radial face and wherein said radial face of said disc is so orientated that said cam follower is at the immediate vicinity of the maximum radius point when said indicator is over the sixtieth minute mark.

6. A mechanism as claimed in claim 3, wherein said lever has an offset portion intermediate its ends and wherein said cam follower comprises a boss secured to said offset portion of said lever.

7. A mechanism as claimed in claim 1, wherein said indicator comprises a pointer.

8. A mechanism as claimed in claim 1, wherein said indicator comprises a movable shutter having a window disposed over said first display rotor and a pointer located opposite said second display rotor.

9. A mechanism as claimed in claim 8, wherein said indicator moving means comprises:

a. a cam to be secured to said minute shaft for movement therewith;

b. means mounting said movable shutter for pivotal movement about an axis offset from that of said first drum, and

c. a cam follower on said last-mentioned means for co-operation with said cam.

10. A mechanism as claimed in claim 1, wherein the first and second display rotors comprise first and second drums, respectively.

Claims

1. A time display mechanism for use with a timepiece movement having separate hour and minute drive shafts, said mechanism comprising: a. a first display rotor having indicia thereon representing hours and means for mounting said first display rotor on said hour shaft for rotation therewith; b. a second display rotor having indicia thereon representing 0 to 60 minutes with a spacing between a sixty minute mark and a zero minute mark equivalent to the spacing between two successive hour markings on the first display rotor and means for mounting said second display rotor on said minute shaft for rotation therewith; c. an indicator mounted over said first and second display rotors to indicate the time in hours and minutes, said indicator being mounted for movement between first and second positions spaced apart by a distance equivalent to said spacing between two successive hour markings; and d. indicator moving means for moving said indicator in the same direction as said first display rotor from said first position to said second position during each hour and for rapidly shifting said indicator from said second position back to said first position at the end of each hour, whereby the indicator is moved from said first position to said second position at a speed which is a function of the speed of the first display rotor to maintain said indicator substantially on the same hour marking and is rapidly shifted back to its first position at the end of each hour in order to indicate the next following hour.

2. A mechanism as claimed in claim 1, wherein the indicator is movable through a distance to subtend, about the axis of the minute display rotor, an angle of 30*.

3. A mechanism as claimed in claim 1, wherein said indicator is freely movable about said minute shaft and said indicator moving means comprises: a. a support frame; b. a lever pivotally mounted at one end on said support frame; c. means for operably coupling the other end of said lever to said indicator; d. a cam to be securely fixed to said minute shaft for rotation therewith; and e. a cam follower on said lever adapted to engage said cam.

9. A mechanism as claimed in claim 8, wherein said indicator moving means comprises: a. a cam to be secured to said minute shaft for movement therewith; b. means mounting said movable shutter for pivotal movement about an axis offset from that of said first drum, and c. a cam follower on said last-mentioned means for co-operation with said cam.