US2749169A

US2749169A - Latch mechanism

Info

Publication number: US2749169A
Application number: US271239A
Authority: US
Inventors: Robert E Johnson
Original assignee: Jervis Corp
Current assignee: Jervis Corp
Priority date: 1952-02-12
Filing date: 1952-02-12
Publication date: 1956-06-05
Anticipated expiration: 1973-06-05

Description

June 5, 1956 R. E. JOHNSON 2,749,169

I LATCH MECHANISM Filed Feb. 12, 1952 4 Shets-Sheet 1 I, INVENTOR. 4 1/41? fljmjw June 5, 1956 R. E. JOHNSON 2,749,169

LATCH MECHANISM Filed Feb. 12, 1952 4 Sheets-Sheet 2 1N VEN TOR.

W 2 My, 4% y w R. E. JOHNSON LATCH MECHANISM June 5, 1956 4 Sheets-Sheet 23 Filed Feb. 12, 1952 INVENTOR.

Jaw, $4W9/M44 June 5, 1956 R. E. JOHNSON 2,749,159

LATCH MECHANISM Filed Feb. 12, 1952 4 Sheets-Sheet 4 @J in 205 .m 00 if United States Patent LATCH MECHANISM Robert E. Johnson, Marne, Mich., assigno'r to Jervis Corporation, a corporation of Michigan Application February 12, 1952, Serial No. 271,239

13 Claims. (Cl. 292*332) This invention relates to door control apparatus for refrigerators or the like and it is an object of the invention to provide improved apparatus of that character.

In the illustrated embodiment of the invention hereinafter described there is shown a solenoid for selectively controlling either of two refrigerator doors, "and alternatively usable hand and foot operated control elements for causing energization of the solenoid selectively to control one of the two refrigerator doors. Also, in the event that the solenoid fails to operate for any reason (such, for example, as current failure) the hand and foot operated controls may be further moved manually, preferably furth'er in the same direction beyond their solenoid energizing positions, to selectively control the refrigerator doors directly.

It is to be understood, however, that the invention is not limited to the overall combination, and that invention may lie in the various elements of the combination such, for example, as the solenoid operated latch, the means for selectively operating either of two refrigerator doors,

and the alternatively usable hand and foot operated control means, Accordingly, it is another object of the invention to provide a solenoid operated pair of latch mechanisms for two separate doors, the two latch mechanisms having separate manual controls and a common solenoid.

It is another object of the invention to provide an improved latch mechanism including a solenoid operated pair of latches for two separate doors, the two latches having separate manual controls and a common solenoid, the separate manual controls each comprising an alternatively usable foot pedal and a hand operated means.

It is another object of the invention to provide an improved cocking latch mechanism adapted for operation by a solenoid. I

It is another object of the invention to provide a solenoid operated latch mechanism having solenoid controls which permit use of a greatly overrated solenoid.

The invention together with further objects and advan tages thereof will best be understood 'by reference to the following description taken in connection'withthe accompanying drawings and its scope will bepointed out in the appended claims.

In the drawings in which like parts are designated by like reference numerals,

Fig. l is an elevational View, partially broken away, showing latch apparatus constructed 'in accordance with one embodiment of the invention and applied to a twodoor refrigerator cabinet;

Fig. 2 is an enlarged elevational view of aportion of the latch apparatus disclosed in Fig. 1;

Fig. 2a is a partial, front elevation.showingthearrangement of foot pedals included in the apparatus of Figs. :1 and '2;

Fig. 3 is afurther enlarged view of a portion of the latch mechanism disclosed in Figs. 1 and 2;

Fig. 4 is a partial cross-sectional view taken along the 2,749,l69 Patented June 5, 1956 line of Fig. l and enlarged to the same scale as Fig.

Fig. 4a is a'parti'al cross-sectional view taken along the line la -4a o'f'Fig. l and enlarged to the scale as Fig. 3;

Fig. 5 is a greatly enlarged elevational view of certain control apparatus seen in Figs. 1 and2;

Figs. 6, 7 and 8 are views similar to Fig. 5 but showing the control apparatus in diiferent operating positions;

Fig. 9 is a cross-sectional View taken along the line 9-9 of Fig. 2 showing a control element in one operating position; I

Fig. 10 is a cross-sectional view similar to Fig. 9 but showing the control element in a difierent operating position; and

Figs. ll, 12, 13 and 14 are partial views of control apparatus shown in variousoperating positions.

The embodiment of the invention disclosed in the drawings is well adapted to use on two-door refrigerator cabi nets and it is disclosed herein in such an application.

The refrigerator cabinet appearing in the drawings includes a box or casing 14, a lower door 15 and an upper door 15a. The lower door 15 carries a keeper 16 engageable with a box-mounted latch mechanism 18, and the upper door similarly carries a keeper 16a engage'able with a box-mounted latch mechanism 18a. The latch mechanism 18 for the lower door is operable alternatively by two

manual controls

21 and 22, the control 21 being hand operated and the control '22 being a foot pedal. Similarly, the latch mechanism 18a for the upper door is operable by a hand control 21a and a foot pedal 24,.seen'in Fig. 2a, the foot pedals '22 and 24 extending through slots 25 in a machinery compartment closure 26.

The

latch mechanism

18 and 18a are preferably iden tical and accordingly only one is described in detail herein. In .Fig. 2 the keeper 16 .may be seen engaged by a bolt member 38 and more specifically bya roller 31 mounted thereon. The bolt member is pivotally mounted on a pin 32 secured to a latch housing 33 and is controlled by an actuator member 34. The actuator member is also pivotally mounted on the housing 33 by a pin 35 and is controlled by a spring bar 36 pivotally connected to the actuator member by a pin 37. A spring 38 surrounds the bar 36 and engages a shoulder 36' near the upper end thereof. The lower end "of the spring 38 engages a protrusion 39 struck from the body member 33, whereby the spring 38, acting in compression, urges the bar 36 upwardly and hence urges the actuator member 34 in a counterclockwise direction about its pivot 35.

.A pin 40 having a flattened lower surface is rigidly secured to the bolt member .31). When the latch mechanism 18is in the position illustrated in Fig. 2 the pin 4% is engaged, as shown in Fig. 2, by a roller 41 mounted on the actuator 34, and the latch bolt 30 is thereby maintained in such a position that the latch bolt roller 31 engages the keeper 13 and retains the door 16 in closed position.

If the bar 36 is pulled downwardly against the action of the spring 38, the roller 41 is removed from the path of the pin 40 and the latch bolt 30 may pivot in a clockwise direction to the position illustrated in Fig. 3, in which position the latch bolt roller 31 is no longer engageable with the keeper 16. Accordingly, the door 13 is free to open. A relatively'lig'ht spring 42 is preferably provided for urging the latch bolt'3il in a clockwise direction in order to assure'the clockwise movement of the latch bolt when the bar 36 and the roller 41 are so withdrawn.

If the bar 36 is now released, the spring 38 tends to raise the spring bar but the pin 4% on the latch bolt 3%) now lies .in the path .of the roller 41 asillustrated in .Fig. 3 and prevents the upward movement or" the bar36.

The .roller 41 and hence the upper end of the bar 36 are limited to a specific curved linear path by virtue of the fact that they are connected to the actuator 34 which is pivotally mounted on the pin 35. This curved linear path of the roller 41 is substantially tangent to a line drawn between the cam pin 40 and the pivot pin 32 of the bolt member 30. The flattened lower surface of the cam pin 40 is so oriented that the force of the roller 41 exerted thereagainst actually urges the bolt member 30 in a clockwise direction and hence maintains the bolt member in the position illustrated in Fig. 3. Further clockwise movement of the bolt member 30 beyond the position illustrated in Fig. 3 is prevented by engagement of the edge of the bolt member against the pin 37 on which the roller 41 is mounted. When the bolt member 30 is in this position, it is toggled or cocked and will remain in this position indefinitely barring the application of external forces. However, since the toggling or camming elements comprising the cam pin 40 and the roller 41 are only slightly over center, a relatively light force, if properly applied, will cause the bolt member 30 to slip out of its toggled or cocked position whereupon the roller 41 will bear against the right-hand edge of the cam pin 40 and will drive the bolt member 30 forcefully to the left and into the position shown in Figs. 1 and 2.

As the roller 41 and the cam pin 40 approach the positions illustrated in Figs. 1 and 2 the force applied to the cam pin by the spring 38 through the roller 41 increases to a value many times that of the compressive force of the spring 38 because of the angle between the respective lines of movement of the roller 41 and the cam pin 40, whereby the latch bolt 30 and, more specifically, the latch bolt roller 31 may bear heavily against the keeper 16 and draw the door 15 forcefully toward its closed position. This is particularly desirable in a refrigerator cabinet application because it is desired that the latch mechanism furnish the necessary force to compress a gasket tightly between the refrigerator door and box.

When the door 15 is swung toward its closed position, it is desired that the latch mechanism be tripped whereby it may grasp the keeper and draw the door shut and maintain it in closed position. In a manually operated latch it is a relatively simple matter to provide a surface, usually on the keeper element, which will strike some part of the latch bolt when the door approaches closed position and trip the latch mechanism. In a solenoid operated latch mechanism, however, it has been found that such an arrangement is completely unsatisfactory, for reasons which will be explained subsequently.

The tripper 43 employed in the illustrated embodiment of the invention is pivotally mounted on the bolt member 30 by a pin 43'. When the latch mechanism is in the cocked position illustrated in Fig. 3, and when the door 15 is open, the tripper 43 assumes the position illustrated by the dotted lines in Fig. 3. The right end of the tripper is substantially heavier than the left-hand end or tail and accordingly the tripper tends to rotate about the pin 43' in a clockwise direction from any of its positions illustrated in Figs. 2 and 3. When the tripper assumes the position illustrated by the dotted lines in Fig. 3, however, the tail of the tripper strikes against the pivot pin 35 of the actuator 34 and restrains the tripper from further clockwise movement. The head end of the tripper is then in position to be struck by the keeper 16 when the door is pushed shut. A light spring may also be employed urging the tripper in a clockwise direction whereby the tripper may be moved more positively into its keeper striking position. Since the keeper strikes the head of the tripper at a point slightly below the pivotal axis of the tripper, the force applied to the tripper by the keeper drives the pin 43 and hence the bolt member 30 counterclockwise and out of its cocked position whereby the latch bolt roller 31 is brought into engagement with the keeper as previously described. The tripper 43 then assumes the position illustrated in Fig. 2 by virtue of 4 the fact that the tail of the tripper is restrained from movement to the left by the pivot pin 35.

As will subsequently be explained in detail, downward movement of the bar 36 to move the latch mechanism into cocked position is obtained primarily by a solenoid. In the preferred embodiment of the invention the solenoid operates with sutficient force, once it is energized, that it will move the latch mechanism into cocked position without further force being applied to the manual control. More specifically the force applied to the manual control 23 need be only of such magnitude as to actuate certain electrical contacts which cause cncr gization of the solenoid, whercafter the solenoid will move the latch mechanism into cocked position.

The operation of the latch mechanism under the in fluence of the solenoid is very rapid with the result that the latch mechanism will move completely into its cocked position before the door has made any substantial opening movement. Accordingly, if a tripper were mounted rigidly on the latch bolt 30, it will be apparent that it would strike the keeper 16 when the solenoid tends to move the latch bolt rapidly into cocked position while the door is still closed. Such an operation would tend to cause chattering of the solenoid and of the latch mechanism. This is particularly true in the illustrated embodiment of the invention wherein the solenoid is promptly de-energized when it has drawn the bar 36 downwardly a sufiicient distance to permit the latch bolt to move into its cocked position, all as will subsequently be explained in detail. In such an arrangement the latch mechanism would be alternately driven toward cocked position and then tripped by engagement of the tripper with the keeper, this chattering operation of the solenoid and latch mechanism continuing until the door has swung partially open to such extent that the tripper can no longer engage the keeper.

However, in the illustrated embodiment of the invention the tripper 43 is pivotally mounted as described above and is so arranged that it will not effectively strike the keeper when the latch mechanism is moved to cocked position even though the door momentarily remains closed. Examination of Fig. 2 will readily reveal that rapid movement of the bolt member 39 toward cocked position will result in the head of the tripper 43 striking the keeper obliquely and riding up over the upper su face thereof to the position illustrated by the solid lines in Fig. 3. Accordingly, the latch mechanism does not lend to trip itself by engagement of the tripper with the keeper even though it is moved rapidly into cocked position with the door remaining in its closed position. when the door 15 is subsequently opened the tripper 43 falls to the position illustrated by the dotted lines in Fig. 3 since the head of the tripper is no longer supported by the keeper. The tripper 43 is therefore in position to cause tripping of the latch mechanism when the door is again swung shut.

The problem solved by this apparatus is one which is found where the door is not opened as the latch mover; to cocked position (to remove the keeper from the path of the tripper), and is inherent in a latch mechanism which operates rapidly as in a solenoid operated latch. In the conventional manually operated latch, whether it be hand operated or foot operated, the pressure exerted to operate the latch normally urges the door toward its open position. The result is that the door is opened simultaneously with the movement of the latch mechanism into cocked position. Accordingly, when the latch mechanism reaches cocked position the door will have opened a sufiicient distance that the tripping element will not contact the keeper or other device which cooperates with the tripper to trip the latch. However, in a rapidly oper ating latch mechanism, for example, a solenoid operated latch, and particularly one in which the latch operation does not of itself force the door toward open position, the tripping operation tends to occur as rapidly and as often asthe latch mechanism maybe moved into ortoward its cocked position.

The tripping apparatus disclosed in the drawings and described above solves this problem eifectively while being very simple in construction and requiring only one additional moving part as compared to previously known latch mechanisms. The primary feature of thetripper is that when the latch mechanism is moved from keeper engaging position to cocked position with the door closed, that is starting from the position in which the keeper is engaged by the latch mechanism, the tripping element is not in a position to operatively engage the keeper or other device with which it normally cooperates to trip the latch mechanism. However, after the keeper has been withdrawn from the latch mechanism the trip element moves into a position in which it will be eifectively engaged by the keeper when'th'e door is again moved toward its closed position.

It will be noted that the bolt member has a slot 30' for receiving the pin 32. This slot permits movement of the bolt member from a keeper engaging position to a keeper by-passing position whereby the door may be slammed shut even though the corresponding latch mechanism may have become uncooked while the door is open. Such structure is disclosed and claimed in Patent No. 2,444,180 entitled latch, issued June 29, 1948, to Lloyd L. Anderson and assigned to the same assignee as the present invention. Since this feature of the disclosed latch mechanism does not constitute a feature of the invention in the present case, its operation is not described in detail herein. It will readily be seen that the spring 42, in addition to urging the bolt member 30 to rotate in a clockwise direction, also tends to maintain the pin 32 at the lower or left-hand end of the slot 30'.

The'latch mechanism so far described is the one controlling the lower door 15. The latch mechanism for the upper door 15a may be, and preferably is, identical to that associated with the lower door, and in the drawings the corresponding parts of the two latch mechanisms are designated by like reference numerals with the exception that the parts associated with the upper door include the reference letter a.

Linking apparatus is provided connecting the hand operated control 21 to certain control switches for the solenoid and directly to the latch mechanism 18for the lower refrigerator door 15. As previously pointed out, it is intended that the hand operated control 21 serve primarily to energize a solenoid to operate the latch mechanism 18, but that further movement of the hand control 21 may cause direct operation of the latch mechanism, this arrangement permitting manual operation of the latch mechanism in the event that the solenoid fails to operate.

The manual control 21 is in the form of a bell crank pivotally mounted on the door 15 by a pin 44. The free end of the bell crank .is pivotally connected to one end of a link 45 by a pin 46, and the other end of the link 45 is in turn pivotally connected to one end of a bell crank 47 by another pin 48. The bell crank 47 is pivotally mounted on the door 15 by a pin 49 and at its other end engages a push rod 50. The push rod 50 is biased to the right in Figs. 1, 2 and 3 by a spring 51 which is compressed between the inner wall of the door and a collar 50 secured to the push rod 59.

The inner end of the push "rod 50 extends through the inner wall of the door 15 and through the outer wall of the refrigerator 'box or casing 14 and is so aligned that it may strike a member 52 which is pivotally mounted on the refrigerator box by a pin 53. I

A vertical link 54 is connected to the lower end of the bar 36 and extends downwardly therefrom, passing close by the pivoted member '52. The connection between the vertical link 54 and the bar 36 is one which permits limited vertical movement of the link with respect tothe spring bar 36. More specifically, apin 55 is rigidly secured to the bar 36 and extends'through a's'lot 55' 'in'the vertical link .54. Normally, the vertical link is biased upwardly by springmeans, subsequently to be described, such that the pin 55 occupies a position with respect to the slot 55' as illustrated in Figs. 2 and 11. A flange 56-is secured to the vertical link 54, this .fiange being engageable by the pivoted member 52 as shown in Fig. 3.

It may now be seen by reference to Fig. 3 that manual manipulation of the hand operated control 21 will cause counterclockwise movement of the pivotable member 52 and a downward movement of the vertical link 54. It will also be seen that the initial downward movement of the vertical link will not effect a corresponding movement of the spring bar 36 since the latter will not be disturbed until the vertical link has moved downwardly a suificient distance that the upper end of the slot 55' may come into contact with the pin 55 as shown in Fig. 3. It is intended that this initial downward movement of the vertical link 54, and more specifically that portion of the downward movement which is not transmitted to the spring bar 36, cause actuation of electrical contacts which in turn energize a solenoid to operate the latch mechanism 13 through the vertical link 54, all as is described in detail below. More specifically, it is intended that the solenoid be energized when the vertical link has been lowered to the position illustrated in Fig. 12. Accordingly, when the sole noid is operative, no force need be transmitted from the hand operated control 21 to the latch mechanism. However, in the event that the solenoid should fail to operate, continued inward movement of the hand operated control 21 will cause further downward movement of the vertical link 54, whereupon the spring bar 36 will be drawn downwardly and the latch mechanism moved to its cocked or open position as described above.

It will be noted that the latch mechanisms are released to permit opening of the doors by inward movement of the coresponding hand controls 21 and 21a. The actual opening movement of the doors (after release of the latches) may be accomplished or initiated by any suitable device. For example, a concealed pin and spring may be employed, preferably on the hinged sides of the doors. Such devices are well-known in the art and do not form a part of the invention, and hence none is shown in the drawings.

The two

vertical links

54 and 54a which control the respective latch mechanisms extend from the respective latches to a point adjacent the bottom of the refrigerator box 14 where they may be actuated by

foot pedals

22 and 24, respectively, and by a solenoid. Located between the

vertical links

54 and 54a as may best be seen in Fig. 4a there is a common control element 63. Near the bottom of this element there is a vertical slot 64 through which a fixed pin 65 passes, this pin being secured to the refrigerator box 14. At the top of this control element are a pair of ears 66 and d7 which extend through corresponding slots as and so in the

vertical links

54a and 54, respectively. The cars do and 67 extending through the

slots

63 and 69 guide the control element 63 so that a pair of shoulders 7d and 71 on the control element are always in a position that they may move into the

slots

68 and 69, respectively.

A compression spring 72 encircles the lower end of the control element 63 and engages the lower surfaces of a pair of

arms

73 and 74 forming integral parts of the control element. The

arms

73 and 74 extend through corresponding slots 75 and 76 in the vertical links '54 and 54a, respectively, whereby the lower end of the control member 63 is also maintained in alignment with the vertical links 54 and 5411.

Under normal conditions, that is with no external forces applied, the spring 72 maintains the control element in its uppermost position with the

arms

73 and 74 engaging the upper ends of the slots 75 and 76, respectively. Through the contact of these arms with the upper ends of the slots 75 and 76 the control member 63 is normally maintained also in a vertical position symmetrical with the two

vertical links

54 and 54a. Tilting of the control member 63 in either the clockwise or counterclockwise direction as viewed in Fig. 4a brings one of the shoulders 70 or 71 within the corresponding

slots

68 or 69 whereby a downward movement of the control member 63 will be transmitted to the corresponding

vertical link

54 or 54a.

The

foot pedals

22 and 24 are secured to

levers

80 and 81 which are pivotally mounted at their inner ends on a pin 82. Suitable spring means 83 are provided for maintaining the corresponding levers and pedals in their uppermost position. The two

levers

80 and 81 are U-shaped in cross section and one leg of each lever is in a position to engage the upper edge of the corresponding

arms

73 and 74 of the control element 63.

Downward movement of the foot pedal 22. for example, brings the lever 80 into contact with the arm 73 and forces the latter downwardly. Initially the downward force on the arm 73 causes the control element 63 to pivot in the counterclockwise direction to the posh tion illustrated in Fig. 9. In this position the shoulder 70 lies within the slot 63 in the vertical link 54 whereupon further downward movement of the lever 80 and the control element causes engagement of the shoulder 70 with the bottom of the slot 68 and transfers the downward motion to the vertical link 54.

Similarly downward movement of the lever 81 tilts the control element 63 in the clockwise direction to the position illustrated in Fig. 10. Further downward movement of the lever 31 and of the control element causes engagement of the shoulder 71 with the bottom of the slot 69 whereupon the vertical link a is moved downwardly.

As in the case of operation through the hand controls 21 or 210, initial downward movement of either of the

vertical links

54 and 54a by the corresponding foot pedal is intended to cause energization of a solenoid, about to be described, which in turn moves the selected vertical link further downwardly to operate the selected latch. However, in the event of solenoid failure, the selected latch may be manually operated by further movement of the

corresponding foot pedal

22 or 24.

When one of the hand operated controls, for example the control 21a, is pressed in to operate the latch mechanism 18a, the vertical link 54a is moved downwardly as previously explained. Since the arm 74 is in contact with the upper end of the slot 76, downward movement of the link 54:: first tilts the control element 63 as in Fig. 10, and subsequently carries it downwardly therewith.

The purpose of the control element 63, common to the otherwise independent control apparatus for the two latch mechanisms 18 and 1&1, is to provide means through which a single electrical solenoid may transmit latch opening and actuating force to either of the latch operating apparatuses.

The solenoid is indicated generally by the reference numeral 85 in Figs. 1, 2 and 4a and is rigidly mounted on the refrigerator box 14 through suitable brackets 86. A solenoid plunger 87 is caused to move generally toward the right in Figs. 1 and 2 when the solenoid is energized and may return to the left when the solenoid is deenergized. A bell crank 83 is pivotally connected to the plunger 87 through a pin 8-9 and is pivotally connected to the refrigerator box 14 by another pin 90. A spring 91 is wound around a pin 9% and engages the bell crank 88 and a fixed pin 92 in such a manner as to urge the bell crank 83 in a counterclockwise direction.

The bell crank 83 is preferably channel shaped in cross section over at least part of its length and the two arms 93 forming the free end of the bell crank extend forwardly between the vertical links 54 and 5411 into a position immediately above the control element 63.

It will now be apparent that when the solenoid 85 is energized the free end 93 of the bell crank 88 will bear down against the control element 63. In the illustrated embodiment of the invention, the solenoid is not energized until the control element 63 has been tilted to one of the operating positions illustrated in Figs. 9 and 10 through operation of one of the hand operated

controls

21 and 21a or one of the

foot pedals

22 and 24. Accordingly, when the solenoid 85 is ultimately energized the downward force exerted on the control element 63 by the solenoid through the bell crank 83 is transmitted only to that particular one of the

vertical links

54 or 54a with which the shoulder 70 or 71 of the control element 63 is engaged. Through this means a single solenoid may be employed to operate a selected one of two latch mechanisms.

Electrical control apparatus for controlling energiz tion of the solenoid 85 is actuated by either of two arms 101 and 102 secured to the

vertical links

54 and 54a, respectively. Both of the arms 101 and 102 are so located that they may engage and normally be supported by the enlarged head 103 of a plunger 104. The latter extends into a switch housing 105, and a com pression spring 106 is arranged between the plunger head 103 and the upper wall of the switch housing 105. This spring normally maintains the plunger 104 and the two arms 101 and 102 in their uppermost positions. It is this spring, therefore, that holds the

links

54 and 54a upwardly so that the pins 55 engage the bottom of the slots 55 at the upper end of these links, this permitting a limited initial downward movement of either vertical link without drawing the corresponding latch toward cocked position.

Arranged within the switch housing 105 are two pairs of electrical contacts arranged in series with the control wiring of the solenoid 85. When both pairs of contacts are closed as in Fig. 5 the solenoid is energized, while it either pair of contacts is open as in Figs. 6, 7 and 8 the solenoid is de-energized.

The first pair of contacts comprises a contact mounted on a leaf spring 111, and a cooperating contact 112 mounted on a fixed block 113 of insulating material. The second pair of contacts includes another movable contact 114 mounted on a leaf spring 115 and another fixed contact 116 which is electrically connected to the other fixed contact 112. Also arranged within the switch housing 105 is an arm 117 pivotally mounted on a fixed pin 118 and urged in a downward or clockwise position by a spring 119. A bell crank 120 is also provided which is pivotable about a fixed pin 121 and which is urged to pivot in a clockwise direction by a spring 122. The bell crank 120 is prevented from pivoting in a clockwise direction beyond the position illustrated in Fig. 8 by any suitable means such as the stop pin 123.

When no external force is applied to the hand controls 23 or 23a or to the

foot pedals

22 or 24, both of the

vertical links

54 and 54a remain in their upward positions under the influence of the spring 106, the plunger 104 assuming the position illustrated in Fig. 8. In this position the upper pair of

contacts

110 and 112 are open as a result of the leaf spring 111 being raised by engagement with a collar 124 of irregular shape, integral with the plunger 104.

When either of the vertical links 54 or 540 is lowered a short distance to the position illustrated in Fig. 12. the corresponding arm 101 or 102 and tthe electrical control apparatus assume the position illustrated in Fig. 5 wherein the electrical contact 110 has been lowered into engagement with the contact 112. Since both pairs of contacts are now closed the solenoid is energized and drives the control element 63 and the selected link 54 or 540 downwardly, moving the selected latch mechanism into cocked position and unlatching the door selected to be opened. The slot 55' of the actuated vertical link and the pin 55 with which it cooperates will then be in the position illustrated in Fig. 13.

At the same time, the solenoid drives the corresponding am 101 or 102 .further downwardly and moves-the electrical control apparatus into the position illustrated in vFig. 6. In this figure it will be seen that the collar 124 has engaged the horizontal arm of the bell crank 120 and 'has pivoted the latter in a counterclockwise direction. The left or horizontal arm of the bell crank 124) has engaged the leafspring 115 and moved the contact 1114 away from the cooperatingcontact 116. This deenergizes the solenoid 85.

After the latch mechanism has been cocked and the solenoid (lo-energized the actuated

vertical link

54 or 54a may return toits raised position under the influence of the spring ass. This upward movement of the .vertical link is permitted by the extended .slot 55' at the upper end thereof. It will be noted in Fig. 14 that even though the pin 55 islowered (the associated latch mechanism being in cocked position), the slot 55 is long enough thatithe vertical .link may rise to its normal position. Accordingly, if it is desired to open the other door, the solenoid control apparatus is in position to permit solenoid operation of the corresponding llatch.

If the electrical control apparatus were permitted to pass again through the position illustrated in Fig. 5, it will be apparent that both pairs of contacts would be closed simultaneously with the result that the solenoid would again be-energized. Electrical control apparatus constructed 'in accordance with the illustrated embodiment of the invention prevents such an occurrence. More specifically it retains the

lower contacts

114 and 116 in the open position illustrated in Fig. 6 until the upper contacts 11th and .112 may .have been reopened, as will now be explained.

.In Fig. 6 .it will be seen that the arm 117 has pivoted downwardly and has hooked over the vertical arm of the bell crank 120. Accordingly, when the plunger 104 again rises the bell crank will not be permitted to return immediately to its clockwise position. Instead the bell crank is maintained in its counterclockwise position in which it holds thelower contacts 114 and .116 apart as illustrated in Fig. 7 in spite of the fact that the collar 124 on the plunger no longer engages the horizontal arm of the bell crank. The collar 124 on the plunger 104 in the position illustrated in Fig. 7 is about to engage the leaf spring 111 to disengage the

contacts

110 and 112. Shortly after these contacts are separated, thus assuring that the solenoid will not be .re-energized until one of the hand operated or .foot operated controls is again actuated, the collar or shoulder 124 engages the arm 117 and raises .it to the position illustrated in Fig. 8. The bell crank 120 is, therefore, released and moves to the positionillustrated in Fig. 8 under the influence of the spring 122.

It will .now be understood that the temporary holding of'lthe bell crank 120 hits counterclockwise position by the arm 117 permits the electrical control apparatus to return to its normal position illustrated in Fig. 8 without re-energizing the solenoid, and at the same time permits all parts ultimately to reassume their normal positions illustrated in Fig. 8 whereupon a subsequent operation of one of the :manual controls may again cause energization of the solenoid.

The prompt de-energization of the solenoid immediately upon movement of the selected latch mechanism into cocked position permits very substantial overrating of the solenoid, thatz'i's, a solenoid of relatively small capacity, on the basis of continuous operation, may be employed to operate latch mechanisms such as those disclosed in the drawings since the "control apparatus assures that the solenoid will be energized for only an extremely short period of time during each latch operation. This is of great importance in a highly competitive field such as in the sale of refrigerators wherein a few pennies saving in one small part of the entire appliance may represent a very substantial percentage of the net profit on each appliance. Also the illustrated embodi- 1 0 ment of the invention provides, as explained above, that the latch actuating :app'aratus :may reassume its normal position without re-energizing the solenoid.

'It will be understood that the novel tripping element 43 incorporated .inthe latch mechanisms .is eiiective in any solenoid operated latch and the invention embodied therein is not in any 'way limited .in application to a double latch mechanism such as that disclosed in the drawings and described above. The common control element 63 of the illustrated embodiment of the invention provides a very simple and inexpensive means through which a single solenoid may be made to operate a selected one of two latch mechanisms.

It will be apparent that the invention may be varied in its physical embodiment Without departing from the spirit of the invention, and it is desired, therefore, that the invention be limited only by the scope of the appended claims.

The invention having thus been described, what is claimed and desired to be secured by Letters Patent is:

l. In a latch mechanism, a bolt member movable between a keeper engaging position and a cocked position, bolt-actuating means movable between a normal position corresponding to said keeper engaging position of said bolt member and an energized position corresponding to said cocked position of said bolt member, a solenoid for moving said bolt-actuator means from substantially said normal position to said energized position, and electrical switch means operable by'said bolt-actuating means to energize said solenoid'when said actuating means moves away from said normal position.

2. In a latch mechanism, a bolt member movable between a keeper engaging position and a cocked position, spring biased bolt-actuating means movable between a normal position corresponding to said keeper engaging position of said bolt member and an energized position corresponding to said cocked position of said bolt member, a solenoid for moving said bolt-actuator means from substantially said normal position to said energized position, and electrical switch means operable by said boltactuating means to energize said solenoid when said actuating means moves away from said normal position, said switch means automatically de-energizing said solenoid when said actuator means reaches said energized position.

3. In a latch mechanism, a bolt member movable between a keeper engaging position and a cooked position, spring biased bolt-actuating means movable between a normal position corresponding to said keeper engaging position of said bolt member and an energized position corresponding to said cocked position of said bolt member, a solenoid for moving said bolt-actuator means from substantially said normal position to said energized position, and electrical switch means operable by said boltactuating' means to energize said solenoid when said actuating means moves away from said normal position and to de-energize said solenoid when said'actuator means reaches said energized position, said switch means comprising a normally open switch and a normally closed switch in series with said normally open switch, said normally open switch being closable by movement of said actuator means away from said normal position, and said normally closed switch being openable by movement of said actuator means to said energized position.

4. 'In a latch mechanism having a bolt member movable between a keeper engaging position and a cocked position, and spring biased bolt-actuating means movable between a normal position corresponding to said keeper engaging position of said bolt member and an energized position corresponding to said-cocked position of said bolt member; a solenoid for moving said bolt-actuator means from substantially said normal position to said energized position, and electrical switch means operable by said bolt-actuating means 'to energize said solenoid when said actuating meansmoves away from said normal position, to de-energize said solenoid when said actuator means reaches said energized position and to maintain said solenoid de-energized when said actuator means returns to its normal position, said switch means comprising a first normally open switch, a second normally closed switch in series with said first switch, said first switch being closable by movement of said actuator means away from said normal position and said second switch being openable by movement of said actuator means into said energized position, and means for maintaining said second switch open until said first switch is reopened when said actuator means returns to said normal position.

5. In a latch mechanism a bolt member movable between a keeper engaging position and a cocked position, spring biased bolt-actuating means movable between a normal position corresponding to said keeper engaging position of said bolt member and an energized position corresponding to said cocked position of said bolt member, manually operable means for moving said actuating means from said normal position to said energized position, a solenoid for moving said bolt-actuator means from substantially said normal position to said energized position, and electrical switch means operable by said boltactuating means to energize said solenoid when said actuating means is moved away from said normal position.

6. Apparatus for selectively operating a pair of latches on separate doors, said apparatus comprising, a first actuator for one of said latches, a second actuator for the other of said latches, an element common to said actuators movable between a first actuator engaging position and a second actuator engaging position and having an intermediate neutral position, said element also being movable from each of said actuator engaging positions in direction to cause the engaged actuator to actuate the corresponding latch, means for selectively moving said element into either of said actuator engaging positions, and solenoid means engageable with said element when said element is in either of said actuator engaging positions for driving said element in a direction to cause the actuator engaged by said element to actuate the corresponding latch.

7. Apparatus for selectively operating a pair of latches on separate doors, said apparatus comprising, a first actuator for one of said latches, a second actuator for the other of said latches, an element common to said actuators movable between a first actuator engaging position and a second actuator engaging position and having an intermediate neutral position, said element also being movable from each of said actuator engaging positions in a direction to cause the engaged actuator to actuate the corresponding latch, means for selectively moving said element into either of said actuator engaging positions, solenoid means for driving said element in a di rection to cause the actuator engaged by said element to actuate the corresponding latch, and control means for automatically energizing said solenoid means after said element has been moved to an actuator engaging position.

8. Apparatus for selectively operating a pair of latches on separate doors, said apparatus comprising, a first actuator for one of said latches, a second actuator for the other of said latches, an element common to said actuators movable between a first actuator engaging position and a second actuator engaging position and having an intermediate neutral position, said element also being movable from each or said actuator engaging positions in a direction to cause the engaged actuator to actuate the corresponding latch, means including an alternatively usable foot pedal and hand operated control for driving said element into said first actuator engaging position and for operating said first actuator, means including an alternatively usable foot pedal and hand operated means for driving said element into said second actuator engaging position and for operating said second actuator, and solenoid means engageable with said element when said element is in either of said actuator engaging positions for driving said element in a direction to cause the actuator engaged by said element to actuate the corresponding latch.

9. Apparatus for selectively operating a pair of latches on separate doors, said apparatus comprising, a first actuator for one of said latches, a second actuator for the other or said latches, each of said actuators including an elongated member, said members extending substantially parallel to each other and being longitudinally movable to actuate said latches, an element common to said actuators and lying intermediate said elongated members, said element being pivotable between a first actuator engaging position and a second actuator engaging position and having an intermediate neutral position, said element also being movable longitudinally of said elongated members from each of said actuator engaging positions in a direction to cause the engaged actuator to actuate the corresponding latch, means including an alternatively usable foot pedal and hand operated control for driving said element into said first actuator engaging position and for operating said first actuator, means including an alternatively usable foot pedal and hand operated control for driving said element into said second actuator engaging position and for operating said second actuator, and solenoid means engageable with said element when said element is in either of said actuator engaging positions for driving said element in a direction to cause the actuator engaged by said element to actuate the corresponding latch.

10. Latch apparatus, comprising a pair of keeper engaging latches for holding separate doors in closed position and control mechanism for selectively operating said latches; each of said latches including a bolt member movable between a keeper engaging position and a cocked position; said control mechanism comprising a solenoid for selectively operating said latches, a control member actuatable by said solenoid, a pair of links, one for each of said latches, said links being selectively engageable by said control member, and a pair of control elements operatively connecting respective ones of said latches to respective ones of said links, said links and said control elements being selectively movable from respective normal positions to respective actuated positions by said solenoid and said control member to move the corresponding bolt member to said cocked position, said links being connected to corresponding ones of said control elements by slot and pin connections, said slot and pin connections permittin g an actuated link to return to normal position while the corresponding bolt member remains in said cocked position and the corresponding control element remains in said actuated position.

11. Latch apparatus, comprising a pair of keeper engaging latches for holding separate doors in closed position and control mechanism for selectively operating said latches; each of said latches including a bolt member movable between a keeper engaging position and a cocked position; said control mechanism comprising a solenoid for selectively operating said latches, a control member actnatable by said solenoid, a pair of links, one for each of said latches, said links being selectively engageable by said control member, a pair of control elements operatively connecting respective ones of said latches to respective ones of said links, said links and said control elements being selectively movable from respective normal positions to respective actuated positions by said solenoid and said control member to move the corresponding bolt member to said cocked position, said links being connected to corresponding ones of said control elements by slot and pin connections, said slot and pin connections permitting an actuated link to return to normal position while the cor responding bolt member remains in said cocked position and the corresponding control element remains in said actuated position, a pair of manual control means connected to respective ones of said links for moving said links to Ward said actuated positions and for bringing said control member into engagement with the link so moved, and solenoid control means responsive to movement of either of said links a predetermined distance toward said actuated position to energize said solenoid, said slot and pin connections between said links and said control elements permitting movement of said links a sufficient distance toward said actuated positions by said manual control means, without movement by said control elements, .to permit energization of said solenoid by said solenoid control means. 1

12. In a latch mechanism for releasably holding a door member in closed position with respect to a cabinet member, said latch mechanism being mounted on one of said members, and the other of said members including a keeper for cooperating with said latch mechanism; said latch mechanism including a frame rigidly secured to said one member, a latch bolt mounted on said frame and movable with respect thereto between a keeper-engaging posi* tion and a released position, a spring-biased bolt actuator movable between a normal position and an energized position, cam means interconnecting said latch bolt and said bolt actuator, said spring-biased bolt actuator when in said energized position acting through said cam means to retain said latch bolt in said released position, said bolt actuator when in said normal position and when lying intermediate said normal position and said energized position acting through said cam means to urge said latch bolt toward said keeper-engaging position, a solenoid for moving said bolt actuator from substantially said normal position to said energized position, and a tripper element mounted on said latch bolt and movable with respect thereto between a neutral position and an active position, said tripper element when in said active position being strikable by said keeper when said door member approaches closed position to move said latch bolt away from said released position and thereby to trip said latch mechanism and permit said bolt actuator to force said latch bolt to said keeper-engaging position, said tripper element also being engageable with a fixed portion of said latch mechanism whereby as said latch bolt moves from said released position to said keeperengaging position under the influence of said bolt actuator said tripper element is moved laterally to one side of the path of relative movement of said keeper to said neutral position, said tripper element being maintained in said neutral position by said keeper when said bolt actuator is moved to said energized position and said bolt member moves to said released position, and being returnable to said active position only after said door member has been opened to move said keeper out of contact with said tripper element.

13. In a latch mechanism for releasably holding a door member in closed position with respect to a cabinet member, said latch mechanism being mounted on one of said members, and the other of said members including a keeper for cooperating with said latch mechanism; said latch mechanism including a frame rigidly secured to said one member, a latch bolt mounted on said frame and movable with respect thereto between a keeper-engaging position and a released position, a spring-biased bolt actuator movable between a normal position and an energized position, cam means interconnecting said latch bolt and said bolt actuator, said spring-biased bolt actuator when in said energized position acting through said cam means to retain said latch bolt in said released position, said bolt actuator when in said normal position and when lying intermediate said normal position and said energized position acting through said cam means to urge said latch bolt toward said keeper-engaging position, a solenoid for moving said bolt actuator from substantially said normal position to said energized position, and a tripper element mounted on said latch bolt and movable with respect thereto between .a neutral position and an active position, said tripper element when in said active position being strikable by ,said other member when said door member approaches closed position to move said latch bolt away from said released position and thereby to trip said latch mechanism and permit said bolt actuator to force said latch bolt to said keeper-engaging position, said tripper element also being engageable with a fixed portion of said latch mechanism whereby as said latch bolt moves from said released position to said keeper-engaging position under the influence of said bolt actuator said tripper element is moved laterally of the direction of relative closing movement of said door member to said neutral position, said tripper element being maintained in said neutral position by said other member when said bolt actuator is moved to said energized position and said bolt member moves to said released position, and being returnable to said active position only after said door member has been opened to move said other member out of contact with said tripper element.

References Cited in the file of this patent UNITED STATES PATENTS 1,940,537 Faber Dec. 19, 1933 2,218,038 Gaflfney Oct. 15, 1940 2,325,225 Burke July 27, 1943 2,348,955 Buchanan May 16, 1944 2,359,150 Peglow Sept. 26, 1944 2,444,180 Anderson June 29, 1948 2,459,190 Shuart Jan. 18, 1949 2,606,052 Soreng et a1. Aug. 5, 1952