US3161013A - Sound deadening case means for electric clock - Google Patents

Description

1964 R. SIEF'ERT 3,161,013

SOUND DEADENING CASE MEANS FOR ELECTRIC CLOCK Filed March 26, 1962 United States Patent Ofiice 3,161,013 Patented Dec. 15, 1964 3,161,013 @OUND DEADENTNG CASE MEANS FOR ELECTRIC CLOCK Roland Siefert, Schwenningen (Neckar), Germany, as-

signor to Kienzle Ulirenfabriken A.G., Schwenningen (l ieckar), Germany, a corporation of Germany Filed Mar. 26, 1%2, Ser. No. 182,521 3 Claims. (Cl. 58-=-41) The present invention relates to battery powered electrically wound clocks and more particularly to clockwork support mountings in works housings.

in this type of clock the inner end of the mainspring is usually fixed, as to a stub shaft on a frame, and the outer end connected to a barrel or disc rotatable or oscillatory about the stub shaft.

Through a pawl on the disc and engaging on a ratchet wheel on the main drive shaft of the work train, unwinding of the spring drives the ratchet wheel and works. The mainspring is wound by a blow, imparted by an armat-ure, to turn the disc in the reverse direction, with the pawl riding freely back along the periphery of the ratchet wheel. The armature strikes the disc somewhat tangentially, usually at an electrical contact lug thereon, when the disc and contact lug turn, during unwinding of the Spring, to a position to engage the armature for completing magnetizing circuit for the actuating electromagnet. A small storage spring is usually added to the works to keep the clock running while it is being wound. Such wind-up devices are well known, and as such are not novel features of the invention.

The armatures are usually biased from the associated magnet by gravity or a light spring and function somewhat in the same manner as for a single stroke bell clapper and are often called clapper armatures.

The inherent disadvantage of clocks having these clapper armatures is the disturbing noise produced by the blow of the armature on the contact or disc or against the magnet.

Many possibilities for the practical elimination or dampening of the noise have been explored but the beneficial results heretofore have been meager. There have been constructions involving electrical insulation mounts for the battery which resulted in the need for complicated conductive elements.

In general, the prior construction involved mounting the works directly, or by posts, on the clock dial plate. In the case of expensive clocks the works were mounted on a housing plate carrying the dial plate. Over the works was disposed a works capsule or cover which was fastened either to the housing plate or the back side of the dial plate, and more or less sealed at the dial plate or at the housing plate. The winding-up noise of the clapper armature was readily transmitted to the dial, or to the housing plate, whereupon either the latter or the dial plate became a noisy diaphragm.

Moreover, the combination of the capsule and the dial plate or housing plate produced a resonant sound chamher. The noise of the wind-up action was very easily heard.

Numerous cures have been sought, for example, the posts for mounting the works on a mounting member in the housing were supported in ubber or plastic. Any dampening of the conducted noise was not perceptible. Moreover, mounting of the works was no longer exact. Dampening elements on the clapper armature could be employed only in few instances since by their use there was an appreciable accompanying loss in efliciency of the electro-magnetic system and the battery had to be replaced more frequently.

No practical solution to the problem was found for eliminating the conducted noise from the outer parts of the clock, that is, from the dial plate or housing.

In the present invention there is no metallic connection between the works or the wind-up mechanism and the outer part of the clock or the works case. This is accomplished by use of a plate of soft or slightly yieldable electrical insulating material mounted fast in a clock case as a rear partition or false cover for the case and to which are mounted the works and the wind-up mechanism within the case.

In the accompanying drawing:

FIG. 1 is a nearly diametric vertical cross sectional view along the line 1-1 of FIG. 3 looking in the direction of the arrows of said line and showing one for-m of the invention.

FIG. 2 is a similar view of another form of the invention.

P16. 3 is a rear view of the partition plate and FIG. 4 shows a construction detail.

FIG. 1 shows a works case or housing 1 having a forward end-wall 1a and a rearwardly projecting flange 1b therefrom. A dial plate (not shown) may be mounted, for instance, on the end Wall. The works housing is provided at the rear with a plate 3 of slightly soft electrical insulation and noise isolating material such as a thermoplastic, methylmethacrylate or polystyrene for example. The plate 3 may be suitably mounted fast on the housing as by posts 5' and passing through holes 5 secured to the end wall 1a, or it may he, say, force-fitted at the edge portions 6 of the plate in and against the fiange 1b. The plate 3 carries the entire wind-up mechanism consisting of the usual electromagnet 14 with clapper armature 114, the oscillatory wind-up disc 13 with pawl, and the main spring 113. By means of posts 7, preferably three in number, the clockwork, generally designated 8, is mounted on the isolating or insulating plate 3. The battery is received in a recess a in the lower part of the back side of the plate 3.

In any suitable manner, as by a close fit, a back cover plate 4 is fastened to the insulating plate 3. The electric connectors 12 and 19 from the battery 10 to the electromagnetic wind-up device are on the same side of the plate 3 with the battery, the connector 12 being mentioned later as a mounting plate. The battery and the works 8 are carried on opposite sides of the plate 3 from each other so that no corrosion of the wind-up device or works can occur due to electrolyte exuding from the battery. This is important in clocks of this type since running of the clock turns the disc in the direction for closing the switch contacts C between the battery and the magnet. When the battery becomes too Weak to actuate the clapper armaure, the magnet continually draws current from the battery which is likely to cause perforation of the zinc container of the battery and permit escape of electrolyte. The electrolyte usually gives off ammonical and other fumes injurious to clock works as well as efliorescent salts.

In FIG. 2 there is shown a modified form of the invention. Here no works housing in the usual sense is employed but only an end wall or works plate 2. The isolation part 3' has a rear wall 3a similar to the plate 3 in FIG. 1 and has a forwardly projecting flange 11 around the wall which meets the works plate 2 as at 2a to form a Works case or capsule. The Works 8 are not shown but may be mounted on the isolation part 3' as in FIG. 1 by means of three posts and the part is mounted on the works plate 2 as by posts 5. Here again the part 3 has a recess 9 in the rear wall 33a for the battery.

The isolation part 3' and the isolation plate 3 are preferably of round iron, i.e., respectively cylindrical and circular and both carry a battery 19 in their lower part. On the side of the wall 3a on which the works to be wound are situated, there is fastened the electromagnetic wind-up device consisting of the magnet, oscillatory disc 13, and the drive or main spring. The works 8 and the disc are preferably connected to the positive pole of the battery. For the stabilization of their positions, the tines posts and the oscillatory disc may be mounted on the mentioned stiff metallic mounting plate 12 secured by eyelets 7' on the isolation plate 3 or the wall 3 with the posts passing through the eyelets.

In FIG. 3 there is shown the stiff metallic plate 12 on the back side of the plate 3, to which metallic plate are secured the posts 7 and the stub shaft pin 17 of the oscillatory disc 13. The metallic plate also is provided with a clip 9' and serves as a battery holder and ground conductor from the battery lit to the disc. The other pole of the battery is connected to an end of the magnet coil by a lead 19.

in FIG. 4 there are shown details of the rim 6 of the plate 3 for engaging the casing at the flange 1b. The rim 6 includes a forward annular flange 15 which may be provided with annular serrations 20, a shoulder 21 and a back flange 22 on which to fit the cover i.

The operation can be described more easily by reference to FIG. 3, showing the disc 13 in a position just before the main spring is to be wound. As the contacts C close a winding blow is given to the disc 13 by the clapper armature 23 to wind the mainspring a partial turn.

There is no metallic connection between the stiff mounting plate 12 and the case or cover and the noise of the blow is not transmitted to any appreciable extent to these outer parts.

To close off sound passage in the zone of setting spindle 24 the central portions of the plate 3 or wall 3a and cover 4 are provided with telescoping nipples 25 and 26 respectively and through which the spindle 24 passes. Packing 28 such as felt between the spindle and the inner nipple is employed to reduce sound transmission.

As the spring unwinds, the contacts C on the disc and the clapper armature 23 respectively approach each other and finally make contact, thereby completing the circuit of the battery and the electromagnet. Upon magnetization of the magnet, the armature is suddenly lifted to knock the disc 13 in a counterclockwise direction and thus wind the mainspring to a certain extent.

The invention claimed is:

1. In an electrically wound clock of the type having 8' a mainspring intermittently wound by a periodic blow on a carrier for the spring imparted by a clapper armature and cooperating electromagnet, the combination of a front wall member and a rear wall member, the latter being of somewhat soft yieldable material having noise deadening and electrical insulating properties, one of the members having a complete peripheral flange and extending to the other and joining same to provide a works casing; a works train and wind-up mechanism therefor carried on the rear wall member and between the two members; a rear cover secured to the rear Wall member and free from metallic connection with the front wall member.

2. In an electrically wound clock having a forwardly facing dial, a casing including a rear case wall of somewhat soft, yieldable sound deadening electrical insulating material, and a clock works and electrically operated wind-up means therefor in the casing and mounted only on said wall at the forward surface thereof to provide a low sound conduction of the noise of the wind-up means to the exterior of the casing, said wall being provided at the rear face thereof with a recess for receiving at least part of a battery to actuate the wind-up means, means for holding the battery in the recess, and posts for mounting the clock works, a stub shaft for mounting a part of the wind-up means on the rear Wall, and a stiff etallic mounting plate on the rear face of the rear Wall and remote from the margins of the Wall for maintaining the works and stub shaft in predetermined position.

3. A clock as claimed in claim 2, said plate being an electrical conductor from the battery to the wind-up means.

References Cited by the Examiner UNITED STATES PATENTS 1,345,766 7/20 Hammond 58-53 2,245,918 6/41 Hobbs 58--53 X 2,491,453 12/49 Knobel 58-52 2,922,276 1/60 Braitsch et al. 58-53 X 3,049,861 8/62 Jensen 58-53 FOREIGN PATENTS 727,118 3/32 France.

ROBERT L. EVANS, Primary Examiner.

JOSEPH P. STRIZAK, LEO SMILOW, Examiners.

Claims (1)

1. IN AN ELECTRICALLY WOUND CLOCK OF THE TYPE HAVING A MAINSPRING INTERMITTENTLY WOUND BY A PERIODIC BLOW ON A CARRIER FOR THE SPRING IMPARTED BY A CLAPPER ARMATURE AND COOPERATING ELECTROMAGNET, THE COMBINATION OF A FRONT WALL MEMBER AND A REAR WALL MEMBER, THE LATTER BEING OF SOMEWHAT SOFT YIELDABLE MATERIAL HAVING NOISE DEADENING AND ELECTRICAL INSULATING PROPERTIES, ONE OF THE MEMBERS HAVING A COMPLETE PERIPHERAL FLANGE AND EXTENDING TO THE OTHER AND JOINING SAME TO PROVIDE A WORKS CASING; A WORKS TRAIN AND WIND-UP MECHANISM THEREFOR CARRIED ON THE REAR WALL MEMBER AND BETWEEN THE TWO MEMBERS; A REAR COVER SECURED TO THE REAR WALL MEMBER AND FREE FROM METALLIC CONNECTION WITH THE FRONT WALL MEMBER.

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