US2891377A

US2891377A - Horological mechanism

Info

Publication number: US2891377A
Application number: US412041A
Authority: US
Inventors: Waldemar A Ayres
Original assignee: AYRES CLOCK Co Inc
Current assignee: AYRES CLOCK Co Inc; AYRES CLOCK COMPANY Inc
Priority date: 1950-06-01
Filing date: 1954-02-03
Publication date: 1959-06-23
Anticipated expiration: 1976-06-23

Description

W. A. A YRES June 23, 1959 HOROLOGICAL MECHANISM 2 Sheets-Sheet 1 Original Filed June 1, 1950 INVENTOR. WALDEMAR A. AYRES June 23, N-

HOROLOGICAL MECHANISM 2 Sheets-Sheet 2 Original Filed June 1 1950 INVENTOR. V WALDEMAR A. AYRES 2,891,377 Patented June 23, 1959 HOROLOGICAL MECHANISM Waldemar A. Ayres, Flushing, N.Y., assignor to Ayres Clock Company, Inc., Long Island City, 'N;Y., a corporation of New York Original application June 1, .1950, Serial No. 165,427, now Patent No. 2,763,121, dated September 18, 1956. Divided and this application February 3, 1954, Serial No. 412,041

1 Claim. (CI. 58-28) The present invention relates to time keeping and indicating devices and particularly to electrically driven clocks.

The present application is a division of parent application Serial No. 165,427, now Patent No. 2,763,121, filed by the same inventor, having a filing date of June 1, 19,50.

It is an object of the present invention .to provide an electrically driven timepiece which employs a novel frequency generator.

It is a further object of the present invention :to provide a clock energized by direct current requiring a very low current drain for operation.

It is another object of the present invention to provide a novel timepiece which obviates sliding friction in the frequency generator and eliminates fragile and sensitive jewel and staff elements.

A further object of the present invention is accomplished by a novel timepiece which does not require oiling of bearing surfaces.

Yet another object of the present invention is the provision of a timepiece that obviates the need for delicate balance spring elements.

vIt is a further object of the present invention .to provide a clock having a unique and efficient magnetic drive for the indicator hands.

Another object of the present invention is the provision of a novel rate adjusting means .for a unique frequency generator in a timepiece.

An additional object of the present invention is the provision in a time piece of a frequency generator and separate magnetically energized power drive for the time indicator.

Further objects of the present invention are the provision of a timepiece wherein the frequency generator is not deprived of energy to drive the .time indicating gear train and the provision of novel spring suspension means for the oscillating mass of the'frequency generator.

Other objects and advantages of the present invention will become clear from a reading of the following specification in conjunction with the appended drawings, in which:

Fig. l is a schematicshowing of one form of the-novel timepiece of the present invention;

Fig. 2 is a detail showing, on enlarged scale, of an embodiment of the novel frequency generator of the present invention;

Figs. 3 and 4 are views, on an enlarged scale,vshowing an embodiment of the contactor and regulator assembly of the present invention; and

Figs. 5, 6 and 7 are detail showings .ofa second form of contactor and regulator assembly that is adapted for use in the present invention.

The present invention is shown schematically in Fig. 1. An oscillating mass 10 comprising an arm 11 of nonmagnetic material such as brass has a central, laterally extending bore 12 and at one end a permanent magnet .13 and at its other end a Weight 14 counterbalancing the magnet 13. The top center of arm 11 is tapped to receive a set screw 15. A helical spring 16 has its ends attached to frame members. One frame member 17 is shown and the other is omitted for clarity. Spring 16 passes through bore 12 and arm 11 is firmly secured to one of the spring convolutions by means of set screw 15.

Spring 16 also carries a collar 18 secured to the spring by means of a set screw 19 and welded or otherwise secured to collar 18 is a metal contact arm 20. The free end of contact arm '20 carries a small block 24 of insulating material such as fiber or the like which may be cemented to the .upper face of contact arm 20.

Oscillating mass 10 and spring 16 form a frequency generator having a period that may be on the order of one-fifth to onehalf second for ordinary timekeeping purposes. The period of this frequency generator may be regulated by means of the contact arm 20 as 'will be described.

A contact member 21 fixed 'to the clock frame (not shown) breaks and makes contact with contact arm 20 during each oscillation cycle of frequency generator 10. A cam member 22 mounted to an adjustable shaft 23 mounted in the clock frame (not shown) can be rotated to adjust its clearance above insulating block 24 between a minimumclearance determined by high point 25 of said cam and a maximum clearance determined by the low point thereof. When mass 10 is put into oscillation, torsion is imparted to spring 16 so that as the mass 10 rocks counterclockwise, contact arm 20 is lifted from engagement with contact member 21 andas it'rocks clockwise, contact arm 2i) is swung back into engagement withrcontact member 21. Cam 22 is so :placed that as contact arm 20 moves upwardly it engages cam 22 prior to the complete counterclockwise excursion of oscillating mass 10. While contact member .20 is moving upwardly and prior to block .24 striking cam 22, torsion is being distributed along the whole length of spring 16. When block 24 strikes cam 22 the portion of the spring between collar 18 and frame member 17, indicated as 16, is immobilized, that is spring 16 is effectively shortened leaving the stiffness of the remainder of the spring 16 as the factor determining the period of the oscillating mass. The-ratio of the time during which the whole length of spring 16 is effective as compared to the time during whichspring 16 minus section 16 is effective determines'the overall stiffness of the torsion spring 16 and the'relation of this overall stiffness to the oscillation mass 10 determines the period of the frequency generator. Since the gap between cam 22 and block 24 is adjustable then the above ratios are adjustable hence regulation is achieved by adjusting cam 22.

The clock of the present invention is electrically energized. A solenoid comprises a core 26 of iron or other magnetic material and a coil or winding 27 which is connected by lead 28 to one terminal of battery 29 and by lead 30 to frame member 17. The other terminal ofbattery 29 is connected to contact member 21 by way of leads 31, 32 and switch 33. When switch 33 is closed, current will flow through the above outlined circuit which ineludes frame 17, spring 16 and contact arm 20.

Contact arm 2t is secured to spring 16 in such-position that with the system at rest contact arm 20 is closed against contact member 21. The electro-magnetic field of the solenoid is so related to the pole of bar magnet 13 closest to the solenoid that the oscillating mass 10 will be driven counterclockwise. Mass 10 is so poised on spring 16 that, with the system at rest, bar magnet 13 is near the upper end of its normal oscillatory motion.

It will be understood from the above description that upon closing switch 33, a magnetic field is set up by the solenoid, and bar magnet 13 will be driven downwardly; that is, counterclockwise. The torsion thereby set up in spring 16 causes contact arm 20 to be lifted away magnetic indicator drive which will be now described.

A rock shaft, ,iournalled in the clock frame, not shown, has mounted on one end a cylindrical cam 35, which will be described later, and at its other end a plate 36 having a sector cut away at 37. Projecting into this sector is a pin 38, mounted on the clock frame, not shown, so that shaft 34 is free to rock through the angle represented by sector 37. A bar magnet 39 is mounted to shaft 34. Cam engages with a diamond toothed wheel or gear 40, which will be described later, so that upon rotation of shaft 34 through one cycle, first counterclockwise then clockwise, gear 40 is stepped or rotated by an amount equal to the angular distance between two diamond teeth 41. Gear 40 is mounted on a shaft 42 which carries a worm gear 43 in engagement with a worm wheel 44. Worm wheel 44 drives a shaft 45 which in turn drives a conventional gear train indicated generally at 46 and this gear train terminates in a conventional hour hand 47 and a conventional minute hand 48.

Mounted on the cover of winding 27 is a small permanent magnet 49. This magnet may be cemented in place and is so positioned adjacent the bar magnet 39 that the pole of magnet 39 will be attracted toward pole 51 of magnet 49.

Pole 50 of magnet 39 is so related to the magnetic field set up by

solenoid

26, 27 that magnet 39 is driven clockwise by interaction between the two fields. With the system at rest and switch 33 open, magnet 39 is in the position shown in Fig. 1; that is, pole 50, attracted toward pole 51 of magnet 49 causes shaft 34 to be retained in its maximum counterclockwise position.

When switch 33 is closed, the magnetic field of the solenoid overcomes the lesser attractive force between

poles

50 and 51, causing magnet 39 to be driven clockwise until stopped by the left hand shoulder of plate 36 striking pin 38. Upon decay of the solenoids magnetic field (caused by the lifting of contact arm 20 from contact member 21 as above described), the attractive force between

poles

50 and 51 causes bar magnet 39 to be rocked counterclockwise again to the position shown. It will be clear, therefore, that for each oscillation cycle of the mass 10, shaft 34 will be rocked clockwise and counterclockwise one cycle, causing cam 35 to advance the gear 40 by the angular distance between two of the teeth L In order to minimize arcing between contact arm 28 and contact member 21, a resistance R may be shunted across contact arm 20 and contact member 21.

Referring now to Fig. 2 of the drawings wherein is disclosed an embodiment of the novel frequency genera tor of the present invention. Helical spring 81 has its ends attached to frame plate 63 and mounting lug 87 by means of

screw studs

89 and 90. Screw

studs

89 and 98 have shank portions attached to the end convolutions of spring 81 and these convolutions are soldered or staked to said stud members. Stud 89 has an integral conical shoulder portion which mates with a conical shoulder formed in frame plate 63. The hole in frame plate 63 through which stud 89 projects is not tapped, and the threaded section can be freely drawn through the hole in assembly. Nut 91 will draw up conical shoulder 95 tightly into engagement with the mating shoulder of frame plate 63 to keep stud 89 and spring 81 from accidental rotation. A hole 96 is provided in the threaded section of stud 89 to receive an assembly tool.

Stud 90 has a threaded section in screw threaded engagement with lug 87, and nut 92 is screwed to stud 98 against a spring washer 94. The end of stud 90 is slotted at 93 to receive a screw driver for adjusting the tension of spring 81.

Oscillating arm 98 is mounted on spring 81 as shown in Fig. 2 by a set screw 99 engageable with a convolution of spring 81. Oscillating arm 98 includes the permanent magnet 100 which may be cemented in place and the counterweight 101 which may be likewise held in place or which may be integral with the bar member 98.

Contact arm 80 is a strip of metal having one end fixed to helical spring 81 by means of a collar 82 rigidly connected to contact arm 80 and a set screw 83 which passes through a tapped hole in the collar 82 into engagement with a convolution of spring 81. The other end of contact arm 80 has cemented or otherwise fixed to its upper surface an insulating block 84 of fiber or the like.

Figs. 3 and 4 of the drawings show the details of the relation between the contactor of Fig. 2 and the regulator therefor. Fig. 4 shows a U-shaped plate 74 which is fixed in position. Plate 74 carries on its upper leg a disc cam 77 which is mounted to screw stud 70 which is mounted in a tapped hole of upper leg of plate 74. The lower leg of plate 74 carries an electrical contact member 79. Fig. 3 shows cam 77 spaced from plate 74 by a spacer bushing 78 surrounding stud 70.

The end of contact arm 80 to which is attached block 84 forms a contact surface on its under side engageable with contact member 79 which is struck laterally of plate 74.

An alternate system for periodically making and breaking the driving circuit and also for regulating the period of the frequency generator is shown in Figs. 5, 6 and 7. An adjustable arm 126, mounted by machine screw 124 and spaced from frame plate 62 by a spacing washer 125, terminates in a bifurcated head member 127 having an insert 128 of insulating material such as fiber cemented to the top bifurcation. An arcuate contact arm 80 of spring metal such as spring steel passes through the slot 129 formed in the bifurcated head 127 and the slot has a width greater than the thickness of the contact arm 80'. The lower bifurcation forms a contact member or surface 130 which is in the clock energizing circuit; arm 126 is electrically insulated from frame plate 62, however, by suitable insulation between screw 124 and arm 126 and frame 62 (not shown). Arcuate contact arm 80' has a 1 radius equal to the distance of slot 129 from the axis of machine screw 124 so that arm 126 can be manually rotated in either direction about its position in Fig. 5 without affecting the ability of contact arm 80' and contact member 130 to make and break the electrical driving circuit satisfactorily. Contact arm is welded or otherwise secured to a collar 82 which attaches to spring 81 by means of set screw 83' in the manner earlier set forth.

It will be clear that the flexibility of contact arm 80' will vary with the angular position of arm 126, so that the net period of the frequency generator can be shortened by rotating arm 126 counterclockwise (Fig. 5) and lengthened by rotating arm 126 clockwise. The spacing washer affords sufficient frictional drag to arm 126 so that it will stay in the position to which it is manually adjusted.

The spring member 81 shown is made of spring strip having a rectangular cross-section. It will be noted that the adjacent convolutions of spring 81 are spaced apart so that there is no energy loss due to sliding friction between convolutions. In practice the actual spacing may be less.

It is within the scope of the present invention to use a spring of circular cross-section. The rectangular crosssection gives added stiffness which is desirable for certain applications.

Metal fatigue, which is a critical problem in conventional torsional devices, is minimized in the novel helical spring construction shown and described since the fatigue forces are distributed over a length of spring considerably greater than the distance between the spring supports.

By the present invention, sliding friction in the frequency generator is eliminated, and no lubrication of the generator is required. t is well recognized that in a conventional balance wheel and balance spring frequency generator, lubrication is essential and the period of a balance wheel and balance spring generator is critically affected by failure of lubrication and by the presence of too much oil at low temperatures.

It will be noted that the novel frequency generator shown and described serves no power function; that is, energy is not taken from the generator to drive the clock gears or to control an escapement. This results in increased stability of the frequency generated, which of course has a direct effect on the timekeeping accuracy of the clock, Watch, fuse or other timer which may be constructed in accordance with the present invention.

The novel magnetic drive of the present invention is free of frictional losses inherent in mechanical drive and escapement systems and is much quieter in operation.

It will be understood from the above description that a number of changes may be made to the novel system as shown and/r described without exceeding the scope of the present invention.

The invention, therefore, is not to be limited by the foregoing description and the attached drawings, but solely by the scope of the appended claim.

What is claimed is:

In a torsion pendulum comprising a coiled spring member, a mass attached to said spring member to oscillate therewith, and a member attached to said spring member between said mass and a mounting support for said spring member, and means associated with said attached member for controlling actuating means for maintaining said mass in oscillation, said attached member being so adjusted when said pendulum is at rest that the actuating means responds as soon as operating energy is applied to the system.

References Cited in the file of this patent UNITED STATES PATENTS 273,138 Oldroyd et al. Feb. 27, 1883 441,547 Gilbert Nov. 25, 1890 1,593,724 Schenk July 27, 1926 2,183,062 Conrad Dec, 12, 1939 2,584,786 Burghoff Feb. 5, 1952 2,640,175 Morrison May 26, 1953 FOREIGN PATENTS 436,778 France Apr. 4, 1912 451,035 Germany Oct. 22, 1927 616,969 Great Britain Jan. 31, 1949 843,361 France Mar. 27, 1939