GB2369897A

GB2369897A - Large date display mechanism for clocks & watches

Info

Publication number: GB2369897A
Application number: GB0029701A
Authority: GB
Inventors: Souza Paul Gerard D
Original assignee: SOUZA PAUL GERARD D
Current assignee: SOUZA PAUL GERARD D
Priority date: 2000-12-06
Filing date: 2000-12-06
Publication date: 2002-06-12
Anticipated expiration: 2020-12-06
Also published as: GB0029701D0; GB2369897B

Abstract

A Large Date Display Mechanism comprises two concentric drive disks (1, 2, Fig 1-4) of ten divisions each. These disks have teeth at different levels or pitch circles, and hence permit either or both disks to be driven, depending on which teeth of which disk are currently in operation. This facilitates a base 31 counter, unique in that it resets from 31 to 1 which is suitable for a watch or clock date display. Each drive disk is attached to a units and tens display disk 3, 4 which together form a composite double digit date counter. The double digit counter facilitates a date display that is more than thrice the size of conventional displays, given the same external dimensions or space requirements. The drive disks (1, 2) are moved by a pawl/lever 15. The tens disk (2) has a profile such that every five movements thereof, only the tens disk moves by one division and the tens display disk 4 is marked 0,1,2,3,3 twice and the units ring 0-9.

Description

LARGE DATE DISPLAY MECHANISM for clocks and watches. This Invention relates to a LARGE DATE DISPLAY mechanism particularly suited for indicating or displaying the date in large digits for mechanical clocks and watches.

Hitherto known date display mechanisms found in mechanical clocks and watches (quartz mechanical, electrical etc), are simple in design but have small display windows. This is because 31 days are to be indicated on a small ring or disk that is limited by the size or diameter of the watch dial.

The known LARGE DATE DISPLAY MECHANISMS are very complex and hence, are very expensive to produce. These necessarily involve using separate units and tens counters. Special problems arise when the counting mechanism needs to reset itself to 1 after the 31st day, instead of continuing to count 32,33 etc. According to the present invention there is provided A Large Date Display Mechanism comprising of two concentric disks 1 & 2 of ten divisions each or suitable multiple thereof, each disk having teeth and notches which serve as a means by which the said disks can be made to rotate with the help of an additional pawl or lever 15, either together or individually, actuated once every twenty four hours, the said teeth and notches being of specific size, shape and location such that a means of encoding is achieved for selective driving of either or both disks, to achieve a counting sequence suitable for a one to thirty one counter employing separate units and tens counting disks. A specific embodiment of the invention will now be described with the help of the following diagrams wherein: Figure 1. is a plan view of the'units drive wheel'showing the profile and levels of co-operation (dashed and dotted lines), encountered by the trigger drive pawl 15.

Figure 2. is a plan view of the'units drive wheel'showing only the profile of the teeth and notches. Notch at position 9 is deeper as is indicated by 6.

Figure 3. is a plan view of the'tens drive wheel'showing the profile and three levels of co-operation encountered by the trigger drive pawl 15.

Figure 4. is a plan view of the'tens drive wheel'showing only the profile of the three types of teeth.

Figure 5. Shows a typical display using separate'Units'3 and'Tens'4, disks overlapping (transparent disks with printed numerals) to provide a composite double digit counter.

Figure 6. Shows the action of the pawl 15 on the two overlapping ('Units' 1 and'Tens'2) disks.

Figure 7. Shows a practical suggested actuating cam driven mechanism that drives the actuating pawl 15. Only essential parts and schematically simplified portions of components are depicted.

Figure 8. Shows a means of obtaining positional locking by using the two star wheels 21 & 22 for the two disks 1 & 2 With reference to Figures 1 & 3, the'Large Date Display Mechanism' comprises a Units Disk 1 divided into ten equal divisions, each of which is identified by the presence of a tooth which serves also as a means to rotate the said ring. Rotation of the'Units Disk'1 is achieved by the action of 'Drive Pawl'15 that is fixed to a cam operated lever 17.

Each action of the said Pawl 15 causes the units disk to rotate by 36 degrees or one division.

The'Tens Disk'mounted co-axially with the'Units Disk'1 has its teeth profiles that have two levels of co-operation that are at the same levels as those of the'units disk'1. This enables both disks to be driven together or each one independently as is required depending upon which teeth are being acted on or co-operating with the pawl 15.

The common levels of co-operation where both disks are driven together are when:

a) Notch or root of tooth representing digit 9 on'units disk'1 is at the same level as notches representing 0, 1 & 2 on the'tens disk'. b) Notch on 3B of'tens disk'is at the same level as notches 0-8 on'units disk'. (Action however occurs only at 0 i. e. when the counter displays30) The landing or protuberance on 3a of'tens disk'is at a level not common to any levels on the'units disk'. This landing at 3a masks the action of the pawl 15 preventing it from acting on the units disk 1, and restricts its action to only the tens disk 2, advancing only the tens disk by one division.

The sequence of numbers represented on the ten's disk is repeated twice, thus normalizing the angles of operation with the units disk. The digit 3 is repeated twice in each sequence and will be explained later.

The components thus far described shows how the pawl 15 acts only on the units disk 1 for nine consecutive actions by said pawl. The lower root of the tenth tooth (marked tooth 9 on fig 1) enables the pawl to go down to a lower level of co-operation and to act on tens disk 2 enabling both disks to be activated for the nine to zero (9-0) transition of the units disk 1. This enables normal counter operation where the units disk operates alone for numerals 0-9, and both disks operate only for the 9-0 transition.

The operation changes when the tens disk moves to display the digit three marked as 3B on fig 3. Since there are two representations of the digit 3 (i. e. to display thirty (30) and thirty one (31), the level of co-operation on the tens disk for the digit three (3B) is made the same as that of the units disk digits 0-8. This permits both units and tens disks to rotate together for what will be the thirty to thirty one date transitions. When the date is thirty one (31) as displayed on the counter, the odd shaped tooth with a raised landing 3a comes into play. The landing serves as a higher root to the tooth for the date transition from thirty one to one. The landing prevents the pawl 15 from meshing with any teeth of the units disk.

This results in only the tens disk being advanced. In effect the tens digit 3 'rolls over'and the units remains fixed. The date effectively changes from thirty one to one.

A suggested implementation has the units and tens disks 1 & 2 fixed to overlapping transparent display disks 3 & 4 respectively as depicted in Fig. 5, that provide a composite date display when mounted co-axially. The tens disk is has the sequence of numerals space (O), 1, 2,3, 3 repeated twice. The units disk has the numerals 0,1, 2,3, 4,5, 6,7, 8, & 9.

A suggested implementation of a means to provide positional locking or indexing of the two disks 1 & 2 is depicted in Fig. 8 where two star wheels 22 and 21 are shown locked by double spring 23. The drive disks 1 & 2 are implemented as part of the display disks 3 & 4 (on their inner radii) and are fitted with suitably positioned star wheels 21 & 22 on their undersides.

The tens disk 4 needs (as depicted in this example), to be of a smaller diameter so that the star wheel 21 does not foul with it.

The use of this particular means of positional locking is chosen (in spite of being more complex), so that the units display disk 3 can extend to a larger diameter than would be possible had the star wheels been implemented as part of or on the periphery of the units and tens disks.

The most practical means of implementation would have the drive disks 1 & 2 fixed to or integral with the respective transparent display disks 3 & 4 on their inner periphery. The star wheels (identical in size) could be implemented on their outer periphery. A slight sacrifice needs to be made on the diameter of the display.

The Large Date Mechanism is operated as follows: The date is set using the time setting mechanism of the watch or clock.

It requires no further setting except at the end of short months, for as long as the clock/watch is kept working.

Claims

I Claim: Claim 1.

A Large Date Display Mechanism comprising of two concentric disks 1 & 2 of ten divisions each or suitable multiple thereof, each disk having teeth and notches which serve as a means by which the said disks can be made to rotate with the help of an additional pawl or lever 15, either together or individually, actuated once every twenty four hours, the said teeth and notches being of specific size, shape and location such that a means of encoding is achieved for selective driving of either or both disks, to achieve a counting sequence suitable for a one to thirty one counter employing separate units and tens counting disks.
Claim 2.

A Large Date Display Mechanism as claimed in Claim 1. wherein the 'units disk'1 has every tenth tooth at a level common to at least one tooth on the'tens disk'2, ensuring that both disks move together by one division, at least once for every ten divisions of rotation of the'units disk'.
Claim 3.

A Large Date Display Mechanism as claimed in Claim 1 and Claim 2 wherein the'tens disk'2 has every fifth tooth of a profile and level that is not common to any teeth on the'units disk'1, ensuring that only the'tens disk'2 moves by one division at least once for every five divisions of rotation of the'tens disk'2, the said tooth profile restricting the action of the drive pawl 15 to only that tooth of the said tens disk'.
Claim 4.

A Large Date Display Mechanism as claimed in Claim 1, Claim 2, and Claim 3 wherein the tens counting sequence is characterised by the presence of the tens digit 3 (Three) being repeated twice in the sequence from zero to three i. e. Zero (space), One, Two, Three, Three, specifically as depicted by counting sequence of disk 2 depicted in Fig 3. and Fig 4.
Claim 5.

A Large Date Display Mechanism as substantially described herein with reference to Figures 1,2, 3,4, 6 & 8 of the accompanying diagrams.

Claim 5.

A Large Date Display Mechanism as claimed in Claim 1, Claim 2, Claim 3 and Claim 4 consisting of a display device wherein the tens display has the sequence of digits from zero (space) to three, the tens digit 3 (Three) being repeated twice in succession as depicted on display disk 4 with specific reference to the inner circle of digits shown in Fig 5.

Claim
6.

A Large Date Display Mechanism as substantially described herein with reference to Figures 1,2, 3,4, 5,6, 7 & 8 of the accompanying diagrams.

Claims : Claim 1.

A Large Date Display Mechanism comprising of two concentric disks 1 & 2 of ten divisions each or suitable multiples thereof, the said disks provided with a set of teeth and notches of profile designed to provide different levels of cooperation to a common actuating pawl, a level of cooperation being defined as the dedendum circle of the notch or notches that are being acted upon by the pawl at that particular instant on either or both of the disks as the case may be, the said teeth and notches being of specific size, shape and location such that a means of encoding is achieved for selective driving of either or both disks by the same pawl, the units disk being provided with teeth and notches that operate at two levels of cooperation and the tens disk with teeth that operate at three levels of cooperation, specific teeth on the tens disk being arranged to prevent the pawl from acting on the units disk when contacting therewith.

Claim 2.

A Large Date Display Mechanism as claimed in Claim 1, wherein the 'units disk'1 is provided with teeth that operate at two levels of cooperation characterised by two different dedendum levels provided for the notches of the said disk.

Claim 3.

A Large Date Display Mechanism as claimed in Claim 1, wherein the 'tens disk'2 is provided with teeth that operate at three levels of cooperation characterised by three different dedendum levels, the innermost level derived from teeth that are provided with a landing.

Claim 4.

A Large Date Display Mechanism as claimed in Claim 1 or Claim 3 wherein the'tens disk'2 has every fifth tooth at a level of cooperation and profile that is not common to any teeth on the'units disk'1, ensuring that only the'tens disk'2 moves by one division at least once for every five divisions of rotation of the'tens disk'2, the said tooth profile restricting the action of the common drive pawl 15 to only that tooth of the said tens disk'.