US2279015A - Electric clock - Google Patents

Description

PP 1942- M. scHLENKER I 2,279,015

ELECTRIC CLOCK Filed July 23, 1958 mm vron.

M ax Schlenkzr.

ATTORNEY.

Patented Apr. 7, 1942 hairp n STAT-ES PATENT oF -cef Y r 2,279,015 Y r Time Instruments Corporation; New N. Y., a corporation of Delaware Application July 23, 1938, Serial No. 220,872

York,

2 Claims. (01. 200-67) This invention relates to improvements in electric clocks, and in particular to clocks wherein a springis the principal source of power for driving the clock train and electro-magnetic means are provided for intermittently tensioning the spring. 7

; This type of clock is widely used in automobiles which use, due to the vibration and the dust and dirt accompanying such use, imposes severe conditions of operation upon the clock and in particular upon the'contacts for said electromagnetic means. One difiiculty in the construction of the contacts is that if they come together with sufiicient impact to make, a good contact there will be a rebound which immediately destroys the contact and causes arcing, whereas if they are brought together slowly to avoid therebound there is not likely to be sufficient force to efiect a low resistance contact. This difficulty may be overcome by mounting one of the contacts upon a resilient member which will absorb the impact and prevent rebound. r

I have found that the above mentioned resilient mounting in combination with certain means herein described to effect a rapid and forcible make and break will produce a very satisfactory contact mechanism, that will not arc, and one.

that is especially well suited for use in electric clocks. -I have further found that an electric clock embodying said contact mechanismv and certain other novel features herein described will operate accurately throughout a long life in the presence of such adverse conditions as may be encountered in automobile use, and is of sturdy, compact and inexpensive construction.

An object of my invention is to provide an improved electric clock wherein the powerfor the operation is supplied intermittentlyby electromagnetic means.

A further object is to provide a clock in which the contacts are closed forciblyand in which'a wiping action ensues if an electrical contact is not eifected simultaneously with mechanical contact.

A further object is to provide, for an electric clock, mechanism whereby electric contact can be made without arcing and wherein rebound of the contacts is eliminated.

A further object is'to provide a clock in which the contacts are mounted on movable members providing relative motionbetween the two contacts, such that the break is efiected at a difierent point than the make so that any corrosion due to arcingwill not impede the facility with which the circuit is made.

A further object is to provide a clock in which means are provided'for driving the clockwork while the main driving spring. is being tensioned.

A further object is to provide an. improved electrical clock of simple and inexpensive con,- struction and of positive and accurate operation.

Otherobjects, features and advantages will become apparent as this description proceeds.

Referenceis hereby made to the accompanying figures which illustrate a preferred embodiment of my invention and in which like reference numeralsgrefer to like parts. v

Figure 1 is an elevation of an electrical-clock a portion of the contact mechanism being omitted for the sake of clarity; c i

, Figure 2 is a section taken along 3line-2'-2 of F ure Figure 3 is a section taken along lines 3-3. of Figure l; j

Figure 4 is a detailed viewof the contacts;

Figure 5 isa side elevation of the contacts shown in Figure 4; and v o Figure 6 is a detail sectional view of the'center shafts and thegears, ratchets and contact lever mounted thereon; P Reference numerals If) to I3 refer to suitable frame plates, the plates I0 and I I supporting-the usual clockwork which is not shown herein and the plates I2 and I3 supporting the electromagnetic'driving means for'the clockwork, the plates being-afiixed to and spaced from each otherby suitable spacing members only one of .which, spacing member I4, is herein shown. A'gear I5 andan associated'collar I6 are loosely mounted on shaft H, the shaft'being journaled in plate I0 and in bearing 63 aflixed to plate I2. The gear I 5 and collar I6 normally. rotate with; shaft I'I',the friction spider 6I forcing collar I6 against the shoulder of the enlarged portionBZ, of shaft II. This friction isprovided to'permit setting of the clock hands. Gear I 5 is adapted to meshwith and drive the clockwork. A ratchet I8 isloosely mounted on'cshaft I'I torotate independently thereof, and a spring I 9 is connected at'either end to ratchet I8 andto gear I5 so thatfthe gear and shaftmayj be driven by the rotation of l3 and an armature 23 is provided to co-operate with the magnets, the armature being afiixed to shaft 26. A pin 24 projects from armature 23 to which pin is adapted to be aflixed one end of spring 26, the other end of the spring being aflixed to a suitable pin 25 which projects from the plate l2. Arms 21 and 28 carrying pawls 29 and 30 are mounted on armature 23 and project through slots 3| and 32 in plate [2 so that the pawls may engage ratchet l8 and rotate the same when the armature is rotated in the clockwise direction as shown in Figure 2.

gize the magnets and attract armature 23 from the position shown in Figure 2 to a position overlying the poles of the magnets, thereby tensioning the spring 26. Upon energization of the magnets, arm 36, resilient member 31 and contact 38 are rotated from the position shown in Figure 3, causing rotation of pivoted member 44 in a clockwise direction through an intermediate position wherein overcenter spring 50 passes over the center of pivot 43 so that further rotation of the thereby breaking the contact and bringing the pawl 33 is provided to prevent counterclockwise It will be noted that as the armature 23 is rotated by spring 26, the resulting rotation of the ratchet wheel will drive the clockwork pivoted member into engagement with a suitable stop, or bringing the insulating arm 45 into engagement with contact 38. It will be noted in Figure 3 that the contact is first eflected at a I point near the outer end of contact 41, and as through gear l5 and driving spring I9. Just before the armature has reached the limit of its rotation, which is defined by theengagement of the armature with spacing member [4, certain contacts are closed-energizing the electromagnet and attracting the armature in a counterclockwise direction to tension the spring. During this period there is no .force tending to rotate the ratchet in the clockwise direction but the spring l9 will continue to drive the clockwork for a short period of time, thus providing a continuous driving force for the clockwork.

An arm 36 isaffixed to shaft 26 to which arm is attached resilient member 31 carrying at one end contact 38. r

It will be noted that arm 36 extends out from the shaft in a direction generally opposite to the direction in which the resilient member extends from the arm, the intermediate portion of the arm being positioned close to shaft 26. This permits the use of a longer resilient'member which is found to give superior results in preventing rebound of the contact than if one end of the resilient member were afiixed directly to shaft 20. I

Frame plates 39 and 40 are suitably amxed to the frame plate l3 and insulated therefrom by I an insulating member 4|, the plates being suitably spaced from one another by members 42.

A shaft 43 is journaled in plates 39 and 40 to which shaft is aflixed a pivoted member 44 having an insulating arm 45 projecting therefrom and a second arm which carries a co-operating contact 41 and a projection 48. One end of overcenter spring 50 is afiixed to projection 48, the other end being attached to a pin 49 suitably mounted on plate 39. The positioning of the spring is such that as the pivoted member is rotated the spring will pass over the center of shaft 43 and tend to continue the rotation of the pivoted member to an extreme position In other words the overcenter'spring acts as a positioning member which may be tripped-through an intermediate position to cause the pivoted member to assume one of two-extreme positions. A pigtail connector 5|, in the form of a hair spring is provided which is affixed to shaft "43, the other end'of the pigtail being anchored to the plate 40 at 52, to provide a low resistance electrical connection between contact 41 and plate 40.

Terminal posts 55 and 56 are provided on plate [3, terminal 55, magnet 2i, conductor 51, magnet 22, conductor 58, plate 40 and contact 41 being in series with each other, and terminal 56 being grounded. Contact 38 is also grounded so that the making of contacts 38 and 41 will enerthe two contacts are rotated about their respective centers, the point of contact moves inwardly along contact 41 and around the convex surface of contact 38, so that the break is effected between different points of the contacts than the make which results in a wiping action which keeps the contacts clean. Consequently, any corrosion of the contactsdue toarcing will be confined to portions of the contact surfaces that are not in contact with each other until after the circuit has been well establishedthrough other portions of the contact surfaces.

Immediately after the break, the rotation of arm 36 reverses due to the action of the spring 26 on armature 23, magnets 2| and 22 having been de-energized, and the pivoted member 44 is rotated in a counterclockwise direction, in opposition to overcenter spring 56, by contact 38 which is in engagement with insulating arm 45. The rate of rotation is controlled by the escapement of the clockwork which is driven through ratchet l8 and gear l5 by rotating armature 23 as above described. As the pivoted member is rotated from the position shown in Figure 4 through an intermediate position wherein spring 56 passes over the center of pivot 43, the contact 41 is snapped into engagement with contact 38 as shown in Figure 3, thereby establishing the circuit through the magnets 2! and 22 for ten- .sioning spring 26. If, however, the circuit is not established immediately due to the presence of dust or dirt on the contacts, further rotation of the contacts beyond the position shown in Figure 3 produces a wiping action which will tend to clean the contacts and permit establishment of the circuit before the contact 38 comes into contact with stop 65, projecting from plate 39. Contact with the stop will provide an additional opportunity for establishment of the circuit, should the usual contacting means fail.

If the battery or other source of power be disconnected for a sufficient period, contact 38 will be forced against stop 60 by the tension of spring 26 and by the tension of spring 50 acting through contact 41, thereby ensuring a good contact immediately upon the connection of the battery into the circuit. I It will be noted that with the construction herein disclosed the relative motions between the two contacts results in a wiping action which keeps the surfaces clean and that the break occurs at a different-point than the make. Furthermore, the resilient mounting of the actuating contact 38 tends to absorb any shock tending to 'causea rebound between the contacts. The overcenter spring and the pigtail connector also serve as a resilient mounting for the other contact and may co-operate with resilient member 3'! to prevent rebound and consequent arcing.

The stop 66 provides an additional point of contact enabling the clock to be started immediately after a period of non-use during which the contacts often become dirty. The stop also prevents excess wear of the resiliently mounted contacts due to vibration of the automobile during a period of non-use, that is, when the battery is disconnected from the circuit.

Although I have herein shown and described a preferred embodiment of my invention, it is understood that certain modifications thereof and changes in the shape and size of the parts thereof may be effected without departing from the spirit of my invention as defined in the following claims;

I claim:

1. Contact mechanism comprising a frame, a pivoted member carrying a first contact and an insulating projection, a second contact mounted for oscillating motion and adapted to engage said insulating projection to rotate said pivoted member in one direction, and adapted to engage said first contact to rotate said pivoted member in the other direction, resilient positioning means mounted between said pivoted member and said frame to snap said pivoted member from an intermediate position to either of two extreme positions, and a projection from said frame against which said second contact is urged by said first contact through influence ofsaid resilient positioning means to define one of said extreme positions 2. Contact mechanism comprising a frame, a rotatable shaft, an arm rigidly affixed to said shaft, a resilient member afiixed to and extending from said arm back toward said shaft and beyond said shaft, an actuating contact carried by said resilient member at its free end, an actuated contact for co-operation therewith pivotally mounted with respect to said frame, and overcenter resilient means for rotating said actuated contact into and out of engagement with said actuating contact.

' MAX SCHLENKER.

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