US2609704A - Electromagnetically controlled latch device - Google Patents

Description

w 4 m 0 m M 3N w am M, Mm E 5 M m M a U w w W. S. ANDERSON, JR

ELECTROMAGNETICALLY CONTROLLED LATCH DEVICE Filed Aug. 23, 1948 Fig.

Sept. 9, 1952 known in the art.

Patented Sept. 9, 1952 ELECTROMAGNETICALLY CONTROLLED LATCH DEVICE William S. Anderson, Jr., Williamsport, Pa., as-

signor of one-half to James Williamsport, Pa.

E. Axeman,

Application August 23, 1948, Serial No. 45,777

Claims.

This invention relates to electromagnetically controlled latch devices which are interposed between electromagnetic devices and independently moved members in order to control the latter, and it has for its main object to provide a latch device of great simplicity, having intermediate members which ar not positively connected or linked with the said electromagnetic devices or independently moved members, but which nevertheless permit perfect control of the last named members at the right moment without entailing any reaction on the electromagnetic device.

Latching devices for the armatures or other movable elements of electromagnetic devices such as solenoids, relay switches, and the like are well But such devices are complicated, requiring usually trip coils or manually operable tripping means and are therefore unreliable in operation. Moreover they do not always eliminate completely reaction of the movable elements onthe electromagnetic device and they free the movable member to be controlled immediately upon operation of the electromagnetic device. These facts cause certain drawbacks or disadvantages.

It is, for instance, repeatedly necessary to use electromagnetic devices in installations in a home, where noisy operation is highly objectionable. Such noisy operation is however a necescesary consequence of the operation of parts, such as above described, as the reaction of moved parts on 'a solenoid core for instance, holding the latter in a position in which the magnetic forces are not capable of moving said parts'into the position to which-they are attracted, causes a noisy buzzing and other sounds due to magnetically produced vibrations and also excessive heating. Likewise a positive connection of an electromagnetic device with an independently movable member which operates under the influence of gravity in certain moments, causes noisy striking of said member'against some stop or cooperating member. Further disadvantages result from complexity and from the possibility of a locking or unlocking action at the wrong moment.

It is therefore an object of this invention to provide a latch mechanism for the control of independently moving members, which may or may not move under the influence of gravity, which eliminates the above defects and which always allows the electromagnetically operated members to go to the home position in which no further movement will be set up, without any interference by those members which are controlled by said electromagnetic device.

It is a further object of the invention to provide a latch mechanism which consists solely of members moving under the influence of forces associated with them, but cooperating with the electro-magnetically operated members, which mechanism therefore does not require auxiliary coils or apparatus.

It is a further object of the invention to provide a latch mechanism which frees the movement of a gravity influenced independently movable member only when the latter is in a certain phase of its movement and which guarantees that no gravity influenced striking of other parts will take place.

It is a further object of the invention to provide a latch mechanism with members provided with or influenced by biasing means, imparting to them the tendency to adopt a predetermined position, said members cooperating with movable electromagnetically controlled members of an electromagnetic device, likewise provided with biasing means, imparting to them the tendency to move towards and to press upon the first named members of the latch mechanism.

It is a further object of the invention to provide a latch mechanism with members provided with or influenced by biasing means, imparting to them a tendency towards moving into a predetermined position, cooperating with electromagnetically controlled members, provided with biasing means which are counteracted by electromagnetic action and which overbalance or overcome the biasing means of the first named members when th said electromagnetically controlled members are not under electromagnetic influence.

It is a further object of the invention to provide a latch mechanism, interposed between an electromagnetic control device and an independently movable member, which comprises members provided or connected with biasing means imparting to them the tendency to move into an unlocking position in which they unlock the independently movable member, and permit motion of the same, said electromagnetic control device including members, likewise provided with or influenced by biasing means urging them towards the members of the latch mechanism, the biasing means of said last named member, if not countered by electromagnetic action, overcomin the biasing means of the members of the latch mechanism and holding the latter in their looking position in which they look the independently movable member.

It is a further object of the invention to provide a pivoted spring or latch, cooperating with a spring or by gravity influenced member of an electromagnetic device, the latch being operated either by the influence of its own spring or gravity and by the spring or gravity influenced member of the electromagnetic device, pressing on it and overcoming the force acting on it.

It is a further object of the invention to provide a pivoted gravity operated weighted latch which is operated by a gravity influenced core or armature member of an electromagnetic device, counterbalancing the weighted latch when the electromagnetic device is deenergized, but freeing it when the device is energized, the gravity influenced movement of said latch being also controlled by the pressure of the controlled independently influenced member.

It is a further object of the invention to pro vide a pivoted gravity operated weighted latch for the control of a gravity operated independently movable member, which. is capable of adopting two positions, said latch cooperating with an electromagnetic device having a gravity influenced core or armature'one of the positions adopted by the latch being a locking position for the independently movable member and being produced by the counterbalancing of the weighted portion of the latch by the action exercised by the gravity operated .armature of the electromagnetic"device on one hand and by pressure exercised by the independently movable member on the other hand, the release of the latch from both forces, such as electromagnetic attraction of the armature and the removal of pressure exercisedby the independently movable member, occurring merely in a certain phase of operation, being necessary for moving the latch member into its inoperative or unlocking position.

Further more specific objects will be apparent from. the following detailed specification.

The invention is illustrated in the accompanying drawing, showing one embodiment thereof by way of example. It is however tobe understood that the example shown is merely illustrative, and has been selected for the purpose of explaining, the principle of the invention and the best modeof applying saidprinciple. Other modes of applying the principle of the invention will be either foreshadowed in the following specification or will be obvious to experts skilled in this'art on the base of the explanations given. Modifications of the example shown are therefore not necessarily departures from the essence of the invention.

In the accompanying drawing:

Figure l is an elevational side view of the latch arrangement, the lever controlledby the latch, and the solenoid controlling the latter.

Figure 2 is a sectional elevationalview of the solenoid and latch arrangement showing the solenoid in a positionof de-energizatibn;

Figures 3 and 4 are sectional elevational views similar to that in Figure 2' showing the solenoid in its position of energization and the latch in two different positions.

Figure 5 is a diagram illustrating a mechanism which is operated by the latch.

Figure 6 is a' fragmentary view of the upper portion of the latch, showing a modification.

The invention as above explained comprises latching means, which are operated by, but not in positive engagement or'connection with a'solenoid or electromagnet, said latching means being capable of controlling the movement of an independently movable member, for instance-limiting its movement in one position and releasing the 4 said member for free movement in the other position. In this way two members each capable of performing independent movements and not directly connected with the solenoid or electromagnet are controlled by the latter, in a way which is sufficiently indirect to permit a substantially noiseless and smooth 'operation'of each part to the desired extent, while the-control is sufiiciently intensive to prevent any failure or accidental escape of the independently movable members from the electromagnetic control.

In the figures it is assumed that a lever H] has to be controlled by a latch mechanism in such a way that its movement which is derived from an independent source, not shown in Figure 1, would carry it from an upper position Illa, indicated in dotted lines, to a position lBb, indicated in dots and dashes. The function of the latch is to confine or limit the movement of the lever 59 in such a way that it should not be capable to move downwardly beyond the position it (shown infull lines), or may only perform a limited stroke or oscillation in one position of the latch while being free to perform a full stroke of oscillation under its own power in the second position of the latch.

The latch I2 is of gooseneck shape and consists of a hp [4 and arm [5 projecting at the two ends of a connecting portion I 6. At one end of the lip M a weight I? is attached, acting as a biasing means which has the tendency to cause a rotational movement of the latch in the. sense of the clock in Figures 2-4. The latch may rock around a pivot pin i8 which is preferably secured to the projecting arm !5, at a point which is located near the middle or connecting portion [6.

The pivot pin 18 is preferably held in the two cheek pieces l9, mounted on a support bracket 21 by means of screws 22. a

A supporting plate 9 carries the foot structure 23 of the solenoid 24. This foot structure may be screwed into the supporting plate as shown so asto be firmly secured thereon and a gasket 3i may or may not be used to secure a firm seat. The foot member has a central bore 34 providing access to the central portion of the solenoid structure, generally indicated ;by reference numeral 24. k r V The solenoid structure is of a conventional type, It comprises the coil 2%,a sleeve 28 holding the coil and also encircling the solenoid. core member 2 1 in its interior, a base plug 39 at the top of the sleeve in which the screw bolt-47 is held; cylindricaljacket or mantle 32 enclosing the coil structure and a closure plate 33;, closing saidjacket and held between-said foot member newc e s.

Y Slidably arranged withinthe sleev e;;28g is the movable armature or core- 35 made'of soft iron which carries a bolt or stem 3'6 projecting outwardly through the-foot member whichcarries a collared head disk; Ml secured t0 it. Between the collar of the disk eii and astepped portion of the ccntralbore 34, a coil spring 42 is-inserted which presses the disk 40 outwardly. Under normal conditions in. which the solenoidis deener giaed the core 35 and therefore-rest against the arm 15 of thelat ch l2 V v 1,

in the supporting bracketffi; or cheek piece 9 a stop plate 45 is held againstwhich the-arm IE or latch l2 mayrest when. held by Some; external means, such as the head diskdlli-onicore 35 or by lever).- .1,

The operation of the latch mechanismgwill b'e more clearly understood when". some example 31S advancing material to be processed.

given illustrating a specific case of a moving lever [0. In Figure 5 a cam 50 is shown, seated on a rotating shaft 52, the eccentric portion 5| of which lifts the lever III at each revolution for a short time. The positions of the lever I are illustrated which correspond tothe positions [0,

10a and lllb in Figure 1. It may be assumed that the end of the lever l0 operated by the cam moves some further member such as a ratchet pawl 54 engaging a ratchet wheel 55 of an intermittently operating mechanism, whose operation is made dependent on the solenoid. For instance, the ratchet wheel may be the driving means of an automatic stoker or of some industrial machine If the process is dependent on heat for instance, a suitable thermostatic switch may operate the solenoid. These examples are merely given in order to attach some meaning to the movements of lever H! but it will be clearly understood that the nature of the mechanism moved by lever ID or the method of moving lever ID or the conditions of the energization of the solenoid have no direct connection with the operation.

Let it now be assumed that the lever i0 is lifted to its uppermost position Illa while the solenoid is deenergized. The latch I2 is then held by the weight of the core and the spring 42 forming in this case the biasing means of the core member 35 in the position shown in Figure 2 and when the lever 10 moves downwardly from its position Illa to the position [0 the lip of the latch will prevent further movement and will immobilize the lever [0, which can solely be moved upwardly at the next passage of the eccentric portion of the cam.

Let it now be assumed that the lever l8 rests on the latch [2 as indicated in Figure 3, and that the solenoid coil 26 is energized. The core of the solenoid then slides immediately into its home position withdrawing the head disk 40 from the .arm [5. The coil spring is' thereby compressed but is preferably not completely compressed so that a certain amount of elasticity or resiliency is still present. The latch 12 in this case does not fall back as long as lever l0 rests on lip I4, as the pressure of the lever prevents the tilting of the latch. However when the lever is again moved upwardly, for instance, by the passage of the eccentric portion of the cam, the latch is freed and tilts and assumes the position shown in Figure 4, its arm I being now moved against the head disk 40 under the influence of its biasing means, such as the weight H. The lever [0 when moving downwardly is no longer arrested by the lip 14 of latch 12 and can move under the influence of gravity for instance, while keeping its end or head pressed against the cam disk 5|. The latch remains in the position shown until the solenoid i deenergized, at which time the biasing means of the core consisting of the weight of the core and of the head 40 and the tension of the spring overbalance the biasing means of the latch and return the latter to its looking or stroke limiting position.

It will be clear that instead of using gravity as a biasing means for the latch or for the core other means may be used, such as springs, air or fluid pressure or the like. The latch especially is only provided with a special overbalancing weight such as shown, where the pivot has to be so arranged that a tendency to tilt in the desired direction cannot be imparted by proper selection of the fulcrum point. Instead of a weight a spring 48, as shown in Figure 6, may be used.

Likewise, in order to secure a holding of the 6 latch by the pressure or the position of the movable lever l0, several means may be used. The-plane in which the lever moves may for instance, pass close to the pivot so that the contactof the lever with the lip prevents movement. Likewise the shape and position of the lever and of the lip may be utilized for obtaining the holding of the lip. This is shown in Figures 2, 3 and 4 where it is manifest that the latch [2 cannot be tilted when the lever 10 rests on or is close to the lip [4.

A further mean is shown in Figure 6 in which the lip HI is provided with a short finger or projection 55 preventing tilting of the latch as long as contact between said projection and the lever is made.

The described arrangement has many advantages of a mechanical nature as it operates without any mechanical connections between the controlled parts. One of the main advantages, which is diiiicult to obtain with solenoid arrangements, consists in its practically noiseless operation, Solenoids in which the core is mechanically connected with the load and in which therefore the load offers a resistance are emitting a most disagreeable buzzing sound as long as the resistance is not completely overcome and the core is not in the home position. Moreover the solenoid is excessively heated as lon as the core is in any position other than home position,

Another cause of such noise is the lever I0. If for instance the lever ID has to be arrested in a position'no't coinciding with its end position (which is frequently necessary) the subsequent energization of the solenoid causes the latch to withdraw and the lever then strikes the cam again with much force making a most objectionable noise. However with the present arrangement thelever It] holds the latch l2 itself and only frees the latch when raised by the cam, and in this case the lever slides on the cam and goes down with the cam in permanent contact with the same. The noise thus disappears.

The two main sources of noise connected with the energizing of the solenoid thus are elimi nated.

The sole source of possible noise is therefore the dropping of the relatively light latch, which may easily be cushioned by a rubber piece applied on arm I5 and which in any case strikes against a still resilient member which may yield.

Deenergizing of the solenoid does not cause any objectionable clattering.

It is thus seen that all sources of objectionable noise are eliminated, so that the latch mechanism is applicable to all apparatus operating in a home or oifice.

It is to be understood that unessential details may be changed without in any way affecting the invention.

Having described the invention, what is claimed as new is:

1. An electromagnetically controlled latching mechanism for controlling the movement of an operating member comprising in combination, a magnet having a fixed part and a movable part and including means for causing the movable magnet part to be moved in a first direction when the magnet is energized and to be moved in a second or reverse direction when the magnet is deenergized, a movable latch for said operating member mounted adjacent to but not connected with said movable magnet part, the latch having a part thereof mounted in the path of movement of the movable magnet part and having movement in the line of movement of the movable magnet part so that the movable magnet part moves away from the said latch part when the magnet is energized and moves against the latch part to move the latch to latching position when the magnet'is deenergized and means associated with the latch for moving the said latch part toward the movable magnet part but with a, force less than the force urging the movable magnet part in the reverse direction to operate the latch.

2. An electromagnetically controlled latch mechanism for controlling the movementof an operating member comprising incombination, a magnet having a fixed part and a movable part and including means for moving the movable part in a first direction When' the magnet is energized and in a second or'reverse direction but with a smaller and constantly acting force when the magnet is deenergized, a latch for said operating member movably mounted adjacent to but not connected with the movable magnet part and having a portion which is mounted to be movable in the same directional line as the movable-magnet part, said latch portion being 'disposedin the path of movement of the movable magnet part in such position as to be moved thereby when the magnet moveslin the reverse directionto carry the latch to latching position, and means constantly urging the latch out of latching position and toward the movable magnet part but with a force less than that exerted bythe'movabl'e magnet part when moving in the reverse direction to operate the latch.

3'; An electromagnetically controlled mechanism as set forth" in claim 2, wherein said latch is made as a pivoted lever having one arm portion arranged transversely'of the directional line of movement of said movable part of the magnet and movable along said directional line to be acted upon and moved by said movable part of the magnet, and the latch lever having'a connected arm portion arranged to coact with said operating member.

4. An electromagnetically controlled latching mechanism, comprising in combination, anoperating member, means'associated with said operating'memb'erfor periodically moving it ina first or outwardly direction and constantly urging it in 8 the return direction, a" latch for'holding said oper'ating member near the end of its outward movement to prevent itsactuation except for a short movement beyond latching position, the latch-and operating member having interengaging parts holding them together when engaged, the latch also having asecond part which is movable in a given directional line-for latching and unlatching' the operating member, amagnet having alateh operating part which moves in said given directional line to move said second latch part to move the latch into latching position when the magnet is deenergized and which movesaway from the said second latch part when the magnet is energized and the latch is held in engagement with said opera-ting member, and means constantly urging saidlatch out of latching position and toward said latch operating part to cause the latch to be moved out of latching position when released from said operating member at the outer end of its movement in the first direction if the latch is not held in latching position by the latch operating part of the magnet at this time.

5. Latching mechanism as set forthin claim 4, further characterized by the fact that said latch is formed as a pivoted lever having one arm portion cooperating with said magnet controlled latch operating part and one arm portion cooperating with said operating member;

S. ANDERSON, JR.

REFERENCES- CITEI) The following. references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 830,209 Conk-linget-al. Sept. 4, 1906 869,014 Obester Oct. 22, 1907 883,029 King Mar. 24, 1908 978,857 Day Dec. 20, 1910 1,144,033 Jacobs June 22, 1918 2,120,555 Good June'li, 1938 2,262,061 Somers- Nov. 11, I941 FOREIGN PATENTS Number Country Date 289,022 Germany Dec. 2, 1915

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