US3694595A

US3694595A - Door-operated electric switch

Info

Publication number: US3694595A
Application number: US104680A
Authority: US
Inventors: Stanley V Horecky
Original assignee: Molex LLC
Current assignee: Molex LLC
Priority date: 1971-01-07
Filing date: 1971-01-07
Publication date: 1972-09-26
Anticipated expiration: 1989-09-26
Also published as: IT948129B; JPS54506B1; AU456353B2; GB1335590A; AU3765272A; DE2200337A1; CA945595A

Abstract

A door-operated electric switch for refrigerators and the like comprises a housing for recessed mounting in a door jamb, the housing containing switch contacts that are actuated by a switch button that projects through the housing and is depressed upon closing of the door. The contacts are actuated as a result of a relatively small initial increment of closing movement of the door. Further closing of the door maintains the contacts in their door-closed condition. The housing has a barrier that inhibits passage of water to the switch contacts and also holes that drain water from the housing to prevent accumulation of water and possible short-circuiting of the switch contacts.

Description

United States Patent Horecky i [54] DOOR-OPERATED ELECTRIC SWITCH [72] inventor: Stanley V. llorecky,.0ak- Park, Ill.

[731-Assignee: Molex Incorporated, Downers Grove, Ill.

22 Filed: Jan. 7, 1971 [21] Appl. No.2 104,680

[52] US. Cl ..200/6L76, 200/168 G [51] Int. Cl. .L ..H0lh 3/16 [58] Field of Search ..200/6l.62- 6l.84,

200/159 A, 61.76, 61.62, 164 R, I64 A, I68 G, 119R, 119B, ll9EL, ll9 L,'ll9TS, 119 WG, 168 R; l74/37;'337/l 12 [56] References Cited UNITED STATES PATENTS 3,586,810 6/1971 Brown .Q ..200/159R 2,289,816 7/1942 Werner ..........200/61.76 2,238,630 4/1941 Reamer ..200/61.82

2,761,936 Verkuil ..200/15'9A [151 3,694,595 1 1 Sept. 26, 1972 3,030,479 4/1962 Ehrlich et al ..200/168 R 3,260,814 7/l966 Turnbull ..200/l68R 522,972 7/1894 Cuttriss ..337/328 Primary Examiner-Robert K. Schaefer Assistant Examiner-M. Ginsburg Attorney-Olson, Trexler, Wolters & Bushnell [5 7] ABSTRACT A door-operated electric switch for refrigerators and the like comprises a housing for recessed mounting in a door jamb, the housing containing switch contacts that are actuated by a switch button that projects through the housing and is depressed upon closing of the door. The contacts are actuated as a result of a relatively small initial increment of closing movement of the door. Further closing of the door maintains the contacts in their door-closed condition. The housing has a barrier that inhibits passage of water to the switch contacts and also holes that drain water from the housing to prevent accumulation of water and possible short-circuiting of the switch contacts.

' 10 Claims, 9 Drawing Figures PATENTEDSEHB 1912 3.694 595 SHEET 2 OF 2 DOOR-OPERATED ELECTRIC SWITCH BACKGROUND OF THE INVENTION This invention relates generally to electric switches, and more particularly, to door-operated switches of the type primarily intended for refrigerators, although the switch is capable of use in other environments as well.

In refrigerator door switches as in other door switches, the switch button or actuator isoperated by the door and therefore has a closed position that is determined by the closed position of the door relative to the frame upon which the door is mounted. In the case of refrigerator doors, the fit between the door and the door frame tends to vary widely among different units due the presence of a sealing gasket on the door that serves to take up clearance between the door and frame when the former is closed. moreover, the clearance inany particular refrigerator unit may vary somewhat in use as the gasket tends to flatten out. Because of this, the travel of the door switch actuator and its position when the door is closed tends to be different in various units and also tends to change as the refrigerator is used. As a result it sometimes happens that the door switch becomes unreliable in its operation.

A further problem in refrigerator door switches renders in the possible collection of moisture and resultant shortcircuiting of switch contacts. This can come about by reason of condensation or from cleaning the refrigerator. In the latter case it should be noted that while the switch housing is recessed in the door frame the opening in the housing through which the actuator or button projects is usually substantially flush with the door frame and not water tight. As a result a wet rag or sponge passed over the door frame may tend to exude water into the switch housing causing a short circuit and/or corroding the switch contacts.

OBJECTS AND SUMMARY OF THE INVENTION It is an object of this invention to provide a switch of the door-operated type that is reliable in operation despite variations in tolerances in the fit between the door and the door frame. The switch is particularly suitable for a refrigerator. In one form of the invention the switch may be used to turn on the interior light of the refrigerator when the door is opened. In another form of the invention the switch may be used to turn off an air circulating fan in the refrigerator when the door is opened so as to reduce the discharge of cold air from the refrigerator when the door is opened. A refrigerator may embody two switches, one according to each of the aforesaid forms of the invention.

It is a further object of this invention to provide a switch of the type stated which is constructed so as to prevent or substantially inhibit the collection of moisture therein which might tend to corrode the switch contacts or cause a short circuit thereof.

In accordance with the foregoing objects the switch comprises a housing for recessed mounting in a door frame and switch contacts having a closed condition and an open condition. In the fan switch form of invention. the switch contacts are closed when the door is closed and are open when the door is open; in the interior light switch form of the invention, the contacts are open when the door is closed and are closed when the door is open. A door-operated switch actuator is pivoted in the switch housing and projects outwardly therefrom. The actuator has a cam for engagement with one of the contacts to move that contact into or out of wiping engagement, as the case may be, with the other or fixed contact during an initial increment of travel of the door from its open to its closed position. This increment may be a minor fractional part of the movement of the actuator from its door-open to its door-closed position. Once the contacts have been actuated during this initial increment of door movement (and consequent movement of the switch actuator) further movement of the door to its closed position serves merely to maintain the switch contacts in their door-closed condition.

The housing has a transverse dam or wall that constitutes a water barrier between the contact points of the switch contacts and the opening in the housing through which the actuator projects. The base of the housing between the barrier and said opening has one or more passageways by which water may be drained from the housing.

BRIEF DESCRIPTION OF THE FIGURES In the drawing:

FIG. 1 is a front elevational view of a refrigerator embodying door switches constructed in accordance with the present invention;

FIG. 2 is a fragmentary sectional view, on an enlarged scale, taken along line 2-3 of FIG. 1, and showing a switch in which the switch contacts are open when the refrigerator door is open;

FIG. 3 is a fragmentary sectional view, on an enlarged scale, taken approximately along line 3-3 of FIG. 2;

FIG. 4 is a fragmentary sectional view taken along line 4-4 of FIG. 3 but showing the full switch assembly as seen from the section line;

FIG. 5 is a fragmentary sectional view similar to FIG. 4 and showing the switch in the door-closed condition;

FIG. 6 is a fragmentary sectional view similar to FIG. 4 and showing a switch of the type wherein the switch contacts are closed when the refrigerator door is open;

FIG. 7 is a fragmentary sectional view of the arrangement of FIG. 6 but showing the switch in the doorclosed position;

FIG. 8 is a perspective view of the switch housing of the present invention, the housing cover being omitted so as to illustrate the interior of the switch housing; and

FIG. 9 is a perspective view of the switch button or actuator that forms part of the present invention.

DETAILED DESCRIPTION Referring now in more detail to the drawing there is shown a refrigerator 2 having a generally rectangular door frame 4 having a door opening 6. A door 8 is secured to the door frame 4 at the opening 6 by

hinges

10, 10 whereby the door 8 is swingable about a vertical axis to and from its open and closed positions shown respectively in full lines and broken lines in FIG. 2. The edge of the door 8 may be provided with a gasket 12 for sealing against the door jamb 14.

The door jamb 14 has an opening 16 for receiving a plastic switch housing 18. A pair of

opposed cantilever arms

20, 20 are integral with the

sides

28, 30 of the housing and are provided for retaining the housing in place in the opening 16. The arms 20, terminate at their free ends in

fingers

22, 22 such that when the housing 18 is inserted through the opening 16, the

arms

20, 20 are pressed toward the housing 18. The spring pressure of the

fingers

22, 22 press the fingers against the edge of the opening 16. The switch housing 18 is provided at its forward end with a marginal flange 24 that is adapted to lie flush against the exterior surface of the door jamb l4 and thus limit the extent of insertion of the housing 18 into the opening 16. By use of a small screwdriver or like tool for prying under the flange 24, the housing may be removed from the opening 16.

The housing 18 constitutes a portion of either a normally open switch S shown in FIGS. 2-5 or a normally closed switch shown in FIGS. 6 and 7. The'normally closed switch S may be used to control a fan within the refrigerator while the switch S may be used to control one or more interior lights within the refrigerator such that when the refrigerator door 8 is opened the switch S shuts off the fan while the switch S turns of the interior light or lights in the refrigerator. Conversely, when the refrigerator door 8 is closed the switch S turns off the interior light or lights while the switch S restarts the fan.

The housing 18 also comprises a bottom wall 26 and f a back 32 which are marginally secured to the sides 28, I 30. The housing 18 also comprises a top cover 34 which is secured to the

housing walls

28, 30, 32 in any suitable manner, which may include a depending flange 35 that engages the inside surfaces of the

sides

28, 30. At the junction of the side and back wall 32 the housing is formed with a vertical slot 36 for receiving a movable contact 38. The contact 38 includes a terminal 40 that projects upwardly through the cover 34 for attachment to a conductor in the fan circuit of the refrigerator. The contact 38 is in the form of a-flat tempered spring blade of brass having angularly related legs 42, 44 that are joined by an arcuate apex portion 46. At its free end the leg 44 has a silver contact point 48. Approximately at the junction of the back wall 32 and theside 28 the housing 18 if formed with an additional vertical slot 50 for receiving a fixed contact 52 which has a terminal 53 that projects upwardly through the housing cover 34 for connection with the other wire of the fan circuit. The fixed or stationary contact 52 is also a flat blade and outwardly of the slot 50 the contact 52 angles toward the leg 42, terminating in a contact point 54 that faces the contact point 48.

Intermediate the back 32 and the front marginal flange 24 and also forwardly of the contact point 54 is a wall or dam 56 that projects upwardly from the bottom wall 26 and extends between the

sides

28, 30. The wall 56 has a clearance slot 57 for receiving the legs 42, 44 of the movable contact 38. Adjacent to the wall 56 but forwardly thereof the bottom wall 26 is formed with

drain passageways

58, 58 and through which water may be drained from the part of the housing forwardly of 60 shown in FIG. 9, the actuator 62 is generally sector shaped and includes spaced apart

plates

64, 66 and integral opposed hinge pins 68, 69 that extend laterally of the

plates

64, 66 at the narrow end of the actuator 62. The actuator 62 is pivotally mounted within the housing 18 adjacent to the opening 60. In this regard the hinge pin 68 is pivotally mounted at one end in a hole 70 (FIG. 8) in the bottom wall 26 while the other hinge pin 69 is joumalled in a trunion 72 on the inside face of the marginal flange 24. When the cover 34 is assembled with the housing the cover 34 overlies the upper axial end of the hinge pin 69. A torsion spring 74 is disposed between the

plates

64, 66 at the narrow end of the actuator. One end 76 of the torsion spring 74 abuts the actuator 62 radially outwardly of the hinge pins while the other end 78 of the torsion spring is positioned between the side wall 28 and a shoulder 80 that projects upwardly from the bottom 26 offset from the side 28. The torsion spring 74 biases the actuator 62 of the switch S to its door-open position, namely as shown in FIGS. 2 and 4. However, when the door 8 is swung from its open position shown in full lines in FIG. 2 to its closed position shown in broken lines in FIG. 2 and also in FIG. 5, the door 8 presses against the actuator 62 in opposition to the force of the torsion spring 74 to move the actuator 62 to its fully recessed or door-closed position within the housing 18.

Between the

plates

64, 66 the actuator 62 is integrally formed with a cam 82 for moving the movable contact 38 and thereby actuate the switch. In the dooropen position of the actuator 62, the cam 82 is spaced from the movable contact 38. The cam surface 84 provides a small radius tip 85 (FIGS. 6 and 9) and an adjacent surface 87 of large radius such that during an initial part of an initial increment of movement of the actuator, the latter first moves into engagement with the movable contact 38. In the remainder os said initial increment of movement of the actuator 62 form its dooropen position to its door-closed position the movable contact 38 is moved such that the contact points 48, 54 are quickly brought into engagement with a wiping contact by the engagement of the cam surface tip portion 85 with the apex portion 46 of the contact 38. Further movement of the actuator 62 to its door-closed position serves simply to maintain the contact points 48, 54 in contact due to engagement of the surface portion 87 with the contact 38. This insures that the contact points 48, 54 will close before the gasket 12 engages the door jamb 14 despite wide variations among different refrigerator units in the final position of the door in its closed position relative to the door jamb. The amount of overtravel of the actuator 62 after the contact points 48, 54 have engaged may vary but such overtravel is preferably a substantial part of the total travel of the actuator. Viewed another way, the initial increment of travel of the actuator 62 of switch S from the door-open position (FIG. 4) to a position in which the contact points 48, 54 engage is only a minor fractional part of the total arcuate travel of the actuator.

In cleaning the refrigerator it is not uncommon for a wet rag or sponge to be passed over the door jamb 14 in the region of the switch S,. In some instances, water may be forced into the housing 18 through the opening 60. Such water can drain out of the

passageways

58, 58.

In the switch S of FIGS. 6 and 7, the housing 18 and actuator 62 are the same as in the switch 8,. However, the switch S differs from the switch S in that the switch S is normally closed (e. g. when the refrigerator door is open) to close the interior light circuit. Thus, themovable contact 38a is self biased by its spring temper such that its contact point 48a is normally (door open) in engagement with the contact point 54a on the fixed contact 52a. It should be noted that the

contact points

48a, 52a are respectively on oppositesides of their associated

contacts

38a, 52 as compared to the disposition of the contact points 48, 54. Thus, when the actuator 62 of the switch S moves from the door-open position (FIG. 6) toward the door-closed position (FIG. 7) an initial increment of movement causes the cam surface portion 85 to move the contact switch contacts in said housing and having a closed condition and an open condition, said switch contacts including a movable contact, and a rockable dooroperated actuator onsaid housing and having a dooropen position and a door-closed position, spring means biasing said actuator to its door-open position, said actuator having cam means in engagement with said movable contact when the actuator is in its door-closed position and biasing said movable contact to a position in which said contacts are in one of said conditions, the contacts being in the other condition when said actuator is in its door-open position, said cam means and said movable contact having coacting surface means shaped such that in an initial increment of movement 'of said actuator from its-door-open position toward its doorclosed position the cam means moves said movable contact to a position in which said contacts are in said one condition, and in the remaining movement of said actuator toward its door-closed position the cam means continues to bias said'movable contact to cause said switch contacts to remain in said one condition, said initial increment being a minor fractional part of the movement of said actuator from its door-open position to its door-closed position, said cam means and said movable contact being spaced apart when the actuator is in its door-open position so that in an initial part of said initial increment of movement, the actuator moves into engagement with the movable contact.

2. A switch according to claim 1 in which said movable contact has angularly related legs joined by an arcuate apex portion and said apex portion is engaged by said cam means.

3. A door-operated switch comprising a housing having means for mounting the same in a door frame, switch contacts in said housing and having a closed condition and an open condition, said switch contacts including a movable contact, and a rockable dooroperated actuator on said housing and having a dooropen position and a door-closed position, spring means biasing said actuator to its door-open position, said actuator having cam means in engagement with said movable contact when the actuator is in its door-closed position and biasing said movable contact to a position in which said contacts are in one of said conditions, the contacts being in the other condition when said actuator is in its door-open position, said cam means and said movable contact having coacting surface means shaped such that in an initial increment of movement of said actuator from its door-open position toward its doorclosed position the cam means moves said movable contact to a position in which said contacts are in said one condition, and in the remaining movement of said actuator toward its door-closed position the cam means continues to bias said movable contact to cause said switch contacts to remain in said one condition, said initial increment being a minor fractional part of the movement of said actuator from its door-open position to its door-closed position, said housing having an opening through which said actuator projects, a wall in said housing between said opening and the region of engagement of said contacts, and said housing having passage means between said wall and said opening for draining fluid from the housing.

4. A switch according to claim 3 in which said wall has a slot through which said movable contact projects.

5. A door-operated switch comprising a housing having means for mounting the same in a door frame, switch contacts in said housing and having a closed condition and an open condition, said switch contacts including a movable contact, and a rockable actuator door-operated on said housing and having a door-open position and a door-closed position, spring means biasing said actuator to its door-open position, said actuator having cam means with a cam surface for engagement with said movable contact when the actuator is in its door-closed position andbiasing said movable contact to a position in which said contacts are in one of said conditions, the contacts being in the other condition when said actuator is in its door-open position, said cam surface including a first surface portion that is spaced from said movable contact when the actuator is in its door-open position and which initially engages said movable contact, and an adjacent second surface portionfor subsequently engaging said movable contact, said first surface portion having a smaller radius of curvature than that of said second surface portion.

6. A door-operated switch comprising a housing, switch contacts in said housing, means carried by said housing for actuating said switch contacts, an opening in said housing and through which said means projects, and a wall in said housing and forming a fluid barrier between said opening and the region of engagement of said contacts, said housing having passage means between said wall and said opening for draining fluid from said housing.

7. A switch according to claim 6 in which said housing includes means for mounting the same in a door frame, said opening being approximately flushwith said frame.

8. A switch according to claim 6 in which said switch contacts include a movable contact that projects through said wall.

9. A door-operated switch according to claim 6 in which said housing has a bottom wall and a cover opposite to said bottom wall, the wall forming the fluid barrier projecting from said bottom wall toward said cover.

10. A-door-operated switch according to claim 9 in which said switch contacts includes a movable switch contact projecting through said wall forming the fluid barrier, and said actuating means includes a cam portion engaging said movable switch contact.

Claims

1. A door-operated switch comprising a housing having means for mounting the same in a door frame, switch contacts in said housing and having a closed condition and an open condition, said switch contacts including a movable contact, and a rockable dooroperated actuator on said housing and having a door-open position and a door-closed position, spring means biasing said actuator to its door-open position, said actuator having cam means in engagement with said movable contact when the actuator is in its door-closed position and biasing said movable contact to a position in which said contacts are in one of said conditions, the contacts being in the other condition when said actuator is in its door-open position, said cam means and said movable contact having coacting surface means shaped such that in an initial increment of movement of said actuator from its door-open position toward its door-closed position the cam means moves said movable contact to a position in which said contacts are in said one condition, and in the remaining movement of said actuator toward its door-closed position the cam means continues to bias said movable contact to cause said switch contacts to remain in said one condition, said initial increment being a minor fractional part of the movement of said actuator from its dooropen position to its door-closed position, said cam means and said movable contact being spaced apart when the actuator is in its door-open position so that in an initial part of said initial increment of movement, the actuator moves into engagement with the movable contact.

3. A door-operated switch comprising a housing having means for mounting the same in a door frame, switch contacts in said housing and having a closed condition and an open condition, said switch contacts including a movable contact, and a rockable door-operated actuator on said housing and having a door-open position and a door-closed position, spring means biasing said actuator to its door-open position, said actuator having cam means in engagement with said movable contact when the actuator is in its door-closed position and biasing said movable contact to a position in which said contacts are in one of said conditions, the contacts being in the other condition when said actuator is in its door-open position, said cam means and said movable contact having coacting surface means shaped such that in an initial increment of movement of said actuator from its door-open position toward its door-closed position the cam means moves said movable contact to a position in which said contacts are in said one condition, and in the remaining movement of said actuator toward its door-closed position the cam means continues to bias said movable contact to cause said switch contacts to remain in said one condition, said initial increment being a minor fractional part of the movement of said actuator from its door-open position to its door-closed position, said housing having an opening through which said actuator projects, a wall in said housing between said opening and the region of engagement of said contacts, and said housing having passage means between said wall and said opening for draining fluid from the housing.

5. A door-operated switch comprising a housing having means for mounting the same in a door frame, switch contacts in said housing and having a closed condition and an open condition, said switch contacts including a movable contact, and a rockable actuator door-operated on said housing and having a door-open position and a door-closed position, spring means biasing said actuator to its door-Open position, said actuator having cam means with a cam surface for engagement with said movable contact when the actuator is in its door-closed position and biasing said movable contact to a position in which said contacts are in one of said conditions, the contacts being in the other condition when said actuator is in its door-open position, said cam surface including a first surface portion that is spaced from said movable contact when the actuator is in its door-open position and which initially engages said movable contact, and an adjacent second surface portion for subsequently engaging said movable contact, said first surface portion having a smaller radius of curvature than that of said second surface portion.

7. A switch according to claim 6 in which said housing includes means for mounting the same in a door frame, said opening being approximately flush with said frame.

10. A door-operated switch according to claim 9 in which said switch contacts includes a movable switch contact projecting through said wall forming the fluid barrier, and said actuating means includes a cam portion engaging said movable switch contact.