GB2120853A - Liquid contaminant resistant electric switches - Google Patents

Abstract

The liquid contaminant resistant electric switch 10 may have a plastics pushbutton 70 closely fitting in a plastics housing 16 to resist entry of liquid. A drain hole 40 is provided in the floor 32 of the housing for prompt draining of any liquid that might enter. Integral plastics protuberances 62,64 may be provided to space conductive surfaces of the contacts 46,50 away from any liquid that might not yet have drained of the floor's top surface 66. <IMAGE>

Description

SPECIFICATION Liquid contaminant resistant electric switches Video and other electronic games are very popular at the present time. Typically such games are operated commercially and are installed in for example a games arcade, a restaurant or a public house. The establishment operating the games normally provides or permits the customers or players to partake of food and beverages. Beverages are inevitably spilled from time to time.

In view of the electronic nature of the games, electrical switches and contacts are a necessity.

Typically, such a game may be provided with one or more momentary contact switches which must be operated by the player or customer to control the progress of the game. Switches as heretofore used in such games have been susceptible to penetration by liquid, and to shorting out of the switches, whereupon the game becomes inoperable.

As is known, there are switches which are entirely waterproof. However, such switches tend to be either extraordinarily expensive, or adapted only to light duty or light-fingered use. Very expensive waterproof switches are contraindicated by economics, while light duty switches will not stand up for the desirable long life of a game. Switches which must be operated by light-fingered individuals likewise will not survive since game players in the excitement of the game tend to become rather heavy-handed.

It is an object of the present invention to provide an electric switch, suitable for use in an electronics game, which resists liquid contamination such as from spilled beverages.

It is a further object of the present invention to provide a simple and economical electric switch which resists liquid contamination by resisting penetration by liquid contaminants, and by providing means for promptly disposing of any liquid contaminant that does penetrate the electric switch.

In accordance with the present invention, a liquid contaminant resistant electric switch comprises a housing, a switch actuator movable relatively to the housing, switch contact means in the housing and having electrical connections extending from the housing, the switch contact means being operable by the switch actuator between conducting and non-conducting conditions, and means providing a liquid drain from the housing.

Preferably, the housing is a generally cylindrical housing open at the top and closed at the bottom, the switch actuator is a pushbutton switch actuator manually movable axially of the housing, the switch contact means comprises a pair of switch contacts extending up from the bottom of the housing into the proximity of the pushbutton actuator and having portions extending exteriorly of the housing for the making of electrical connection thereto, the pushbutton actuator and the switch contacts being operatively interconnected for movement of the switch contacts from open to closed position and return, and the drain providing means is located near the bottom of the housing.

The switch is intended to be operable in a generally vertical position so that the drain providing means may comprise a hole in the bottom of the housing. Protuberance means may extend up from the bottom of the housing and encircle the contacts to space uninsulated portions of the contacts above the bottom of the housing. The switch actuator or pushbutton is intended to fit closely within the housing so that penetration by beverages and other liquids is resisted.

Switches in accordance with the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which Figure 1 is a perspective view of a switch in accordance with the present invention; Figure2 is a vertical axial section through the switch in open or non-conductive condition; Figure2A is afragmentaryviewsimilarto a portion of Figure 2 and illustrating a modification of the invention; Figure 3 is a vertical axial section generally similar to that of Figure 2 showing the switch in closed or conductive condition; and Figure 4 is a fragmentary view similar to Figure 2 showing a modification of the invention incorporating a light source internally of the switch.

A momentary contact electric switch 10 comprises a two-piece, cylindrical housing including a tubular body 12 and a base 14. Both the tubular body 12 and the base 14 are moulded of a suitable plastics material and interfit to form a single body 16.

The tubular body 12 is provided at its upper extremity with a circumferential, radially extending flange 18 having a convex upper and outer surface 20 providing a shoulder 22 for seating against the surface of an apertured panel. The major length of the tubular body 12 is provided with external threads 24 for receipt of a nut member to retain the body in an aperture in a panel. It is contemplated that the body could be screwed into a threaded aperture, but more typically the body would be held in an aperture by a nut. The lower extremity of the body has a smooth, cylindrical periphery 26 provided with diametral apertures 28.

The housing further includes the base 14, as heretofore noted, which comprises generally a tubular plug 30 which slides up into the tubular body 12, and which is sealed by an integral floor 32. A peripheral radial flange 34 about the lowermost portion of the base limits the degree of insertion. The base is provided with a pair of diametrically opposed tapered teeth 36 which cam past the lower cylindrical portion of the body and snap into the apertures 28.

The base 14 is provided with a central depression or well 38. Adjacent the periphery of the well there is provided an axially extending drain hole or bore 40.

At the upper edge of the well 38 there is an annular shoulder 42 providing a seat for a helical spring 44 about which more will be said later.

A fixed electrical contact 46 extends up through the floor 32 of the base to a position somewhat above the axial halfway point of the housing. This contact 46 preferably is apertured at 48 adjacent the lower end for securing of a wire thereto, as by soldering or other type of connection. The contact 46 is made of a metal of good electrical conductivity, and a certain degree of resiliency. The metal either should be corrosion-resistant or provided with a corrosion-resistant coating for effecting good electrical contact, and for resisting arcing, pitting, and burning.

A movable contact 50 extends up through the floor 32 in spaced parallel reiation to the fixed contact 46 and the extending lower end thereof is provided with an aperture 52 corresponding to the aperture 48. The contact 50 is longer than the contact 46, and intermediate its length is provided with a portion 54 inclined toward the fixed contact 46, joined at an elbow or apex 56 to a subsequent portion 58 angling upwardly in the opposite direction from the portion 54. The movable contact 50 further includes an upper end portion 60 joined to the portion 58 at an elbow or apex 61, and angling upwardly in generally the same direction as the portion 54, the end portion 60 being disposed substantially above the upper end of the fixed contact 46. The electrical and physical characteristics and requirements of the movable contact 50 are essentially the same as those for the fixed contact 46.

Protuberances 62 and 64 integral with the floor 32 extend upwardly therefrom about the contacts 46 and 50 so that the bare or uninsulated portions of the contacts are spaced above the surface 66 at the bottom of the well 38. Thus, any liquid, such as a beverage, penetrating the interior of the switch and perhaps leaving residue behind upon draining out through the bore 40 would be ineffective to short out the contacts.

In the modification of Figure 2A there is a single protuberance 68 extending upwardly from the upper surface 66 of the floor 32 about both of the contacts 46 and 50. The embodiment of Figure 2 is to be preferred from a functional standpoint in that if any liquid should splash between or otherwise penetrate the space between the contacts 46 and 50 the two protuberances of Figure 2 would provide a longer leakage path between the contacts. Furthermore, drainage of liquid away from the upper surface of the surfaces of the two protuberances would be more effective than from the single surface of the single protuberance.

The switch 10 is completed by a pushbutton or switch actuator 70. The switch actuator is generally in the nature of a thimble, having a cylindrical sidewall 72 and a top cover or plate 74 which is generally concave upwardly and convex downwardly, this presenting an upper dished surface 76 which is readily engaged by a finger without a tendency for the finger to slip off the push-button or actuator.

At the bottom of the cylindrical wall 72 there is provided an internal seat 78 forthe upper end of the helical spring 44, which is a compression spring and continuously urges the actuator in an upward direction. The wall 72 of the actuator is also provided adjacent the lower end with an outer, upwardly directed shoulder 80 coacting with a complementary seat 82 on the inner surface of the tubular body 12 to limit upward movement of the pushbutton under the force of the spring 44. In the uppermost position of the actuator 70 (Figure 2) the lower end 84 of the wall 72 is vertically spaced above the upper surface 86 of the base 14.

As will be seen in Figures 2 and 3 the outer diameter of the actuator wall 72 is slightly less than the inner diameter of the tubular body 12. Arcuately spaced, axially directed ribs 88 are provided on the outer surface of the wall 72 below the top end of the flange 18 to provide limited areas of engagement between the actuator and the housing, and thereby to reduce friction.

A switch operator 90 depends from the top wall 74 of the pushbutton, being generally an axially extending tubular member having a hollow bore 92. The switch operator 90 is provided adjacent its lower end with a tapered wall 94 and a rounded nose 96. In the open-switch position of Figure 2 the rounded nose 96 and taper sidewall rest against the inclined upper end 60 of the movable switch contact.

When a customer or game player wishes to close the switch he simply presses down on the pushbutton or actuator 70 to move it from the position of Figure 2 to the position of Figure 3. The surface 84 at the bottom of the actuator bottoms-out against the surface 86, providing a positive stop and avoiding a spongy feel to the finger of the operator. In such movement the apex 61 of the movable switch contact 50 is deflected progressively further to the left by the tapered surface 94 of the switch operator 90. This brings the apex 56 into engagement with the upper portion of the fixed contact 46, the switch contact 46 being deflected slightly toward the outer portion of the switch. Each switch contact deflects somewhat throughout its length, but all of the deflection is above the top of the corresponding protuberance 62,64.Thus, the mutually engaging portions of the switch contacts are moving generally arcuately about different centers of rotation. This causes the apex 56 of the movable switch contact 50 to engage the fixed contact 46 with a wiping motion which is advantageous in maintaining the mutually contacting surfaces clean, thereby ensuring the best possible electrical conductivity between the two switch contacts.

It will be observed that there are provided one or more radially disposed ribs 98 on the convex undersurface of the top wall 74 of the pushbutton or actuator, extending between the sidewall 72 and the depending switch operator 90. This prevents undesired flexing of the top wall of the actuator as engaged by the operator or game player's finger, and it also ensures against lateral deflection of the switch operator 90 as it engages the movable switch contact.

Assembly of the switch 10 is remarkably simple. It is only necessary to install the pushbutton or actuator 70 from the bottom of the tubular body 12, then to install the spring 44, and finally to move the base 14 axially into place so that the teeth 36 will snap into the apertures 28. Since the entire structure is symmetrical about the longitudinal axis of the switch, with the exception of the switch contacts 46 and 50 and the possible exception of the ribs 98, it is not necessary for the person or machine assembling the switch parts to pay any attention as to rotational positioning, except that the teeth 36 must be rota tionally aligned with the apertures 28. Even this modest bit of alignment can be simplified by the provision of additional apertures 28 if desired.

Installation of the switch is equally simple. It need only be placed through an aperture in a more or less horizontal panel, with a nut being threaded on from the underside to retain the switch in position. Any beverage or other liquid that might be spilled on and seep into the interior of the switch will quickly flow out through the opening or drain 40, leaving the interior of the switch substantially free of liquid that might tend to short out the switch contacts. The protuberances 62 and 64 further act against shorting out of the switch contacts, and it will be apparent that the wiping action of the engaging portions of the switch contacts will clean off any liquid that might fall thereon, and it further will be apparent that the lack of any pivot connections ensures against inhibition of pivoting action by accumulation of any residue carried into the switch by a liquid.The hole 40 also provides for air entrance and exit.

As will be appreciated, video and other electronic games are often used in places having low ambient lighting levels. In one form of our invention we therefore provide for internal lighting of the switch to aid the player in locating it. This is shown in the embodiment of Figure 4 wherein most parts remain as previously shown and described and are indentified by similar numbers with the addition of the suffix a.

There are two significant distinctions in the embo diment of Figure 4. A suitable light source 100 illustrated as a light emitting diode is connected across the contacts 46a, 50a by wires 102, 104 which may be soldered, brazed, or welded direct to the contacts. Other light sources including an incandes cent light source could be used. The second distinction is that the push-button 70a is formed of a light transmitting plastics material. The plastics material can be either transparent or transluscent, both coming under the generic term pellucid. Alternative ly, or additionally, the switch body could be formed of a pellucid plastics material or the like.

The light source 100 is energized and emits light whenever the contacts 46a, 50a are open-circuited.

When they close the light goes out which may be advantageous to the player in providing to him an indication that the contact is made. This is also an asset to a serviceman in troubleshooting in that if a pushbutton is not illuminated it will provide him with a valuable clue as to where to look for a fault.

Should it be desired for any reason to have the light source illuminated at all times, or to be illuminated only when the pushbutton is depressed, additional wiring connections can be provided with in the skill of any technician.

In most instances a single drain hole, as illus trated, is sufficient. It is contemplated that additional drain holes could be provided if necessary or desired.

Claims (19)

1. A liquid contaminant resistant electric switch comprising a housing, a switch actuator movable relatively to the housing, switch contact means in the housing and having electrical connections extending from the housing, the switch contact means being operable by the switch actuator between conducting and non-conducting conditions, and means providing a liquid drain from the housing.

2. A switch according to claim 1 wherein the drain providing means comprises a hole in the housing.

3. A switch according to claim 1 or claim 2 wherein the actuator comprises a pushbutton extending from the housing.

4. A switch according to any preceding claim wherein the housing includes means for mounting the switch on a support.

5. A switch according to any preceding claim wherein the housing is a generally cylindrical housing open at the top and closed at the bottom, the switch actuator is a pushbutton switch actuator manually movable axially of the housing, the switch contact means comprises a pair of switch contacts extending up from the bottom of the housing into the proximity of the pushbutton actuator and having portions extending exteriorly of the housing for the making of electrical connection thereto, the pushbutton actuator and the switch contacts being operatively interconnected for movement of the switch contacts from open to closed position and return, and the drain providing means is located near the bottom of the housing.

6. A switch according to claim 5 wherein the drain providing means comprises a hole in the bottom of the housing.

7. A switch according to claim 5 or claim 6 wherein at least one of the contacts is off-center and the other of the contacts is deflected into engage menttherewith upon manual depression of the pushbutton.

8. A switch according to claim 7 wherein both of the contacts are off-center, and the pushbutton has an axially tapered operator thereon engageable with the other of the contacts to deflect it against the first-mentioned contact.

9. A switch according to claim 8 wherein the other of the contacts has both an offset portion engageable with the first-mentioned contact, and a portion extending above the offset portion and engageable by the tapered operator on the pushbutton.

10. A switch according to any one of claims 5 to 9 wherein protuberance means extend up from the bottom of the housing and encircle the contacts to space uninsulated portions of the contacts above the bottom of the housing.

11. A switch according to claim 10 wherein the protuberance means comprises two protuberances respectively encircling the contacts.

12. A switch according to claim 10 wherein the protuberance means comprises a single protuberance encircling both of the contacts.

13. A switch according to any preceding claim wherein the housing comprises a two-piece housing, the two pieces thereof having snap-together means for holding the two pieces of the housing in assembled relation.

14. A switch according to any preceding claim wherein an electric light source is located in the housing and there is means for transmitting light from the source exteriorly of the switch.

15. A switch according to claim 14 wherein at least one of the housing and the actuator is pellucid.

16. A switch according to claim 14 or claim 15 wherein the light source is connected to the switch contact means.

17. A switch according to claim 16 wherein the light source is energised when the switch contact means is in the non-conducting condition.

18. A switch according to any preceding claim wherein the actuator is continuously urged by spring means to a position relatively to the housing in which the switch contact means is in the nonconducting condition.

19. A switch substantially as hereinbefore described with reference to Figures 1,2 and 3, Figure 2A or Figure 4, of the accompanying drawings.