US3598948A

US3598948A - Miniature square oiltight pushbutton switch

Info

Publication number: US3598948A
Application number: US31502A
Authority: US
Inventors: Jack L Bowen; Richard L Chace
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1970-04-24
Filing date: 1970-04-24
Publication date: 1971-08-10
Anticipated expiration: 1988-08-10

Abstract

A miniature square oiltight pushbutton switch including a multipart elongated square housing one end of which receives and is closed by a contact and terminal supporting base plug and the other end of which is formed as an externally threaded cylindrical portion having a cylindrical bore, a hollow cylindrical bushing being received for reciprocal movement within the cylindrical bore, a two-piece knob assembly formed of a base and a lens cap being secured to the outer end of the bushing, a bore being provided in the aforesaid base for receiving an electrical lamp which illuminates the lens, the inner wall of the square segment of the housing being formed with a cylindrical bore surrounded by a plurality of alternately arranged splines and slots, alternate slots having barriers therein, the splines and slots cooperating with splines on the flanged portion of the aforesaid bushing and legs on a ratchet member such that the flanged portion and the ratchet member may reciprocate in the housing and the ratchet member may also rotate, a printed circuit card bearing against the ratchet member to move the bushing to its extended position, the end of the splines in the housing which face toward the base plug providing cam surfaces which cooperate with follower surfaces at the ends of the legs on the ratchet member to effect indexing rotation of the ratchet member in response to depression and release of the knob assembly.

Description

United States Patent [72] Inventors Jack L. Bowen Waseca, Minn; Richard L. C hace, Bloomington, Ill. [21] Appl. No. 31.502 [22] Filed Apr. 24,1970 [45] Patented Aug. 10, 1971 [73] Assignee General Electric Company [54] MINIATURE SQUARE OILTIGHT PUSHBU'I'ION SWITCH 6 Claims, 5 Drawing Figs.

[52] U.S.Cl 200/159 R, 200/153 .1. 200/166 P. 200/167 A [51] Int.Cl ..H01hl3/58, H0lh 13/06 [50] Field oisearch 200/159 R, 159A, 167 A, 166 P, 153 J, 16R

[56] References Cited UNITED STATES PATENTS 2,853,565 9/1958 Arthur et a1. 200/16 R 2,916,673 12/1959 Maslin et a1. 200/167 A X 2,978,555 4/1961 Jones 200/159 X 3,437,775 4/1969 Piber 200/167 A FOREIGN PATENTS 1,200,412 9/1965 Germany 200/166 P Primary Examiner- Robert K. Schaefer Assistant Examiner-Robert A. Vanderhye Attorneys-Arthur E. Fournier, Jr., David M Schiller. Frank L. Neuhauser, Oscar B. Waddcll and Joseph B. Forman ABSTRACT: A miniature square oiltight pushbutton switch including a multipart elongated square housing one end of which receives and is closed by a contact and terminal supporting base plug and the other end of which is formed as an externally threaded cylindrical portion having a cylindrical bore, a hollow cylindrical bushing being received for reciprocal movement within the cylindrical bore, a two-piece knob assembly formed of a base and a lens cap being secured to the outer end of the bushing, a bore being provided in the aforesaid base for receiving an electrical lamp which illuminates the lens, the inner wall of the square segment of the housing being formed with a cylindrical bore surrounded by a plurality of alternately arranged splines and slots, alternate slots having barriers therein, the splines and slots cooperating with splines on the flanged portion of the aforesaid bushing and legs on a ratchet member such that the flanged portion and the ratchet member may reciprocate in the housing and the ratchet member may also rotate, a printed circuit card bearing against the ratchet member to move the bushing to its extended position, the end of the splines in the housing which face toward the base plug providing cam surfaces which cooperate with follower surfaces at the ends of the legs on the ratchet member to effect indexing rotation of the ratchet member in response to depression and release of the knob assembly.

-33 P a 34 I as 32 40 44 s9 1 s50, 36 37 b s3 50 5o 23 50a. 4s 11 seeQ I2 56 5* 55b b E 17 g 1.7 16

PATENTED Ausl 0 I97: 3 598 948 INVENTOR JACK L. BOWEN RlCHARD L. CHACE ATTORNEY MINIATURE SQUARE OILTIGHT PUSHBUTTON SWITCH BACKGROUND OF THE INVENTION 1 Field of the invention Our imention relates to manually operated electrical switches. and more particularly to a pushbutton switch structure adapted for small size and compact assembly.

2 Description of the Prior Art Typically the manually operated electrical switches used in the prior art constitute mechanisms for making or breaking electrical contacts. The operation of these switches may be momentary under actuation, or the switches may be latched in the actuated condition. The switch contacts generally function to control the energization of various electrical or electromechanical devices, or motors. Most commonly, the actuator mechanism units of these switches are of the pushbuttom type as distinguished from the "turn button" type.

The types of installations in which these pushbutton switches are utilized are so varied that the manufacturer thereof is forced to cope with the problem of providing a large number of socalled specials." As used in the art, the latter term is intended to signify switches having particular operating characteristics which because of the limited number of applications in which they may be used without significant modification therein require that these switches be manufactured in uneconomical small lots. In order to obtain economies of manufacture, it thus becomes necessary for a manufacturer to minimize the number of so-called specials" he has to provide to adequately satisfy the needs of his customers. Accordingly, attempts have been made in the prior art to design a switch having greater universality of application. To this end. such a switch should utilize standard components such that the operating characteristics of the switch are susceptible to being changed merely through the selection and utilization therein of given ones of the aforesaid standard components.

In addition to providing such a switch having the aforementioned functional flexibility, it has also been found desirable to reduce the size of these switches, i.e., miniaturize them in an effort to reduce the space needed to mount the switch in a given installation. Where a plurality of such switches are employed in a machine panel, etc., reducing the size of each switch of course also produces a significant increased saving in the amount of space which must normally be set aside to be used as the switch station. Thus, the increased functional flexibility should be achieved while at the same time providing the desired miniaturization of the switch.

Since a large number of these switches are intended to be used in installations wherein the operating parts thereof if not protected could be subjected to detrimental effects attributable to environmental conditions, it is also desirable that the switches be made oiltight. That is, the switches must be provided with means to prevent the entrance therein of oil, water coolant, dirt, and grime which comprise the primary environmental hazards which the switch may encounter in many installations. These contaminants must be sealed against entering the switch enclosure if the switch is to possess the desired reliability of operation.

OBJECTS OF THE INVENTION It is therefore an object of the present invention to provide a novel and improved manually operated electrical switch of the type having a pushbutton form of actuating mechanism which switch because of its great functional flexibility substantially obviates the heretofore existing need for specially designed switches.

It is another object of the present invention to provide such a manually operated electrical switch of the type having a pushbutton form of actuating mechanism which switch by employing a printed circuit card to make and break circuit allows inexpensive circuit modification to be accomplished by means of merely etching the circuit in a different pattern.

Yet another object of the present invention is to provide such a manually operated electrical switch having a novel and improved form of pushbutton-actuating mechanism.

A further object of the present invention is to provide such a manually operated electrical switch of the type having a pushbutton form of actuating mechanism which switch is miniature in size and effective and reliable in operation.

A still further object of the present invention is to provide such a manually operated electrical switch of the type having a pushbutton form of actuating mechanism which switch may readily be provided with a sealed construction so as to render the switch oiltight, i.e., impervious to contamination by oil, water coolant, dirt and grime.

SUMMARY OF THE INVENTION In accordance with a preferred form of the invention there is provided a miniature square oiltight pushbutton switch which is formed of a multipart elongated square housing one end of which receives and is closed by a contact and terminal supporting base plug, and the other end of which is formed as an externally threaded cylindrical portion having a cylindrical bore. A hollow cylindrical bushing is received for reciprocal movement within the cylindrical bore. A flange on the inner end of the bushing retains the bushing in the housing. A twopiece knob assembly formed of a base and a lens cap is secured preferably by frictional engagement to the outer end of the bushing. A bore is provided in the base for receiving an electrical lamp which illuminates the lens. The inner wall of the square segment of the housing is formed with a cylindrical bore surrounded by a plurality of alternately arranged splines and slots, alternate slots having barriers therein. The splines and slots cooperate with splines on the flanged portion of the bushing and legs on a ratchet member such that the flanged portion and the ratchet member may reciprocate in the housing and the ratchet member may also rotate. A printed circuit card bears against the ratchet member to move the bushing to its extended position. The ends of the splines in the housing which face toward the base plug provide cam surfaces which cooperate with follower surfaces at the ends of the legs on the ratchet member to effect indexing rotation of the ratchet member in response to depression and release of the knob assembly. When the knob assembly is intentionally depressed and released, the ratchet member and the printed circuit card are latched in the depressed position in response to rotation of the ratchet splines into the slots having barriers therein. Subsequent depression and release of the knob assembly effects further rotation of the ratchet member so that its splines enter the slots without barriers permitting retraction of the ratchet member and the printed circuit card.

The invention will be more fully understood from the following detailed description and its scope will be pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a manually operated electrical switch of the type having a pushbutton form of actuating mechanism in accordance with the present invention;

FIG. 2 is an enlarged sectional view of the manually operated electrical switch of FIG. 1 in accordance with the present invention;

FIG. 3 is a sectional view of the upper portion of the housing of the manually operated electrical switch of FIG. 2 illustrated removed therefrom;

FIG. 4 is an elevational view of the ratchet member of the manually operated electrical switch of FIG. 2 illustrated removed therefrom; and

FIG. 5 is a fragmentary sectional view of the upper portion of the housing of FIG. 3 and the ratchet member of FIG. 4 illustrated in the assembled condition in accordance with the present invention.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to FIG. 1 of the drawing, the invention as illustrated therein comprises a miniature square oiltight pushbutton switch, generally designated by reference numeral 10, and

including a substantially square multipart elongated housing 11 preferably made of a suitable nonmetallic insulating material of a type well-known to those skilled in the art. In accordance with the preferred embodiment of the invention, the elongated housing 11 viewed with reference to FIG. 1 comprises an upper portion 12 of substantially square configuration and a lower portion 13 also of square configuration. As best seen in FIG. 2 of the drawing, for purposes of assembling the upper portion 12 of the housing and the lower portion 13 thereof together, each of the

portions

12 and 13 is provided at one end thereof with a mating flange I4 and 15, respectively, which in the assembled condition functions to interlock the

portions

12 and 13 together by means of a frictional fit. However in addition, to ensure that the housing 11 is rendered oiltight as well as to provide a securer interconnection between the

portions

12 and 13, the surface of the housing 11 adjoining where the

portions

12 and 13 meet, i.e., where the mating flanges l4 and 15 thereof interlock, preferably is sealed by suitable means (not shown) against entrance into the housing 11 of such contaminants as oil, water coolant, dirt, and grime.

The other end of lower portion 13 of the substantially square multipart elongated housing 11 from that to which upper portion 12 is secured receives and is closed by a contact and terminal supporting base plug 16. The base plug 16 is preferably provided with a pair of inwardly extended triangular-shaped projections 17, which as can be seen with reference to FIG. 2 of the drawings, are positioned in juxtaposed engaging relation with the inner surface of lower housing portion 13 when the base plug 16 is received in the lower housing portion 13. The projections 17 are suitably located on the base plug 16 such that the spacing therebetween corresponds essentially to the spacing between the inner wall surfaces of the lower housing portion 13 whereby the projections 17 may serve to frictionally retain the base plug 16 positioned in the lower housing portion 13. Although as depicted in FIG. 2 of the drawings, the projections 17 comprise integral portions of the base plug 16 it is to be understood that the projections 17 may also be in the form of separate members. As in the case of the interconnection of the upper housing portion 12 and the lower housing portion 13 described previously, the base plug 16 is also sealed to the end of lower housing portion 13 by suitable means (not shown) capable of rendering the latter connection oiltight.

The base plug 16 is further provided with a plurality of slots (not shown) extending entirely through the base plug 16. A conducting member 18 formed of suitable electrically conductive material is received in each of the aforementioned slots in base plug 16 and is retained therein by suitable means against movement relative to the base plug 16. Each of the conducting members 18 is provided at one end with a terminal portion 19 which extends through the base plug 16 and as seen with reference to FIGS. 1 and 2 of the drawings projects outwardly from the base plug 16 so as to be readily accessible for purposes of making an electrical connection thereto. The other end of the conducting members 18 extending inwardly into the hollow interior of housing portion 13 comprises a contact 20 which has an inwardly extending leg portion 200 and an outwardly extending leg portion 20b such as to give the contact 20 a characteristic V-shaped like configuration. The functioning of the contact 20 will be more fully described hereinbelow.

Referring now to the upper housing portion 12 as illustrated in FIGS. 2 and 3 of the drawing, it will be seen therefrom that the upper housing portion 12 includes a lower section 21 of substantially square configuration and an upper section which is in the form of an externally threaded cylindrical section 22 having a cylindrical bore 23 which communicates with the hollow interior 24 of lower section 21 of upper housing portion 12. A portion of the inner wall segment of the lower section 21 is formed with a cylindrical bore surrounded by a plurality of alternately arranged splines 25 and slots 26, alternate slots 26 having barriers 27 therein as will be more fully described hereinafter.

A hollow cylindrical bushing 28 is received for reciprocal movement within the cylindrical bore 23 of cylindrical section 22 of upper housing portion 12. The inner end of the cylindrical bushing 28 is provided with a flange 29 whose circumference is somewhat larger than the internal dimensions of the cylindrical bore 23 and which is adapted to engage a shoulder 23a of the upper housing portion 12 whereby the flange 29 serves to retain bushing 28 in the upper housing portion 12. The flange 29 is also provided with splines 30 which cooperate with the splines 25 and slots 26 of lower section 21 of upper housing portion 12 in a manner to be described later.

Referring further to FIG. 2 of the drawings, a two-piece knob assembly 31 formed of a base 32 and a lens cap 33 is secured by frictional engagement to the outer end of the cylindrical bushing 28. The base 32 and the lens cap 33 are each provided with a

mating flange

34 and 35, respectively, which in the assembled condition function to interlock the base 32 and lens cap 33 together preferably by means of a frictional fit. The base 32 further includes a downwardly extending portion 36 which extends into the cylindrical bore 37 of cylindrical bushing 28. A bore 38 is provided in the downwardly extending portion 36 of the base 32 for receiving an electrical lamp 39 which illuminates the lens cap 33. The lamp 39 consists of a base 40 and a bulb 41. Although in accordance with the preferred embodiment of the invention, the knob assembly 31 id illustrated as being of two-piece construction, it is to be understood that other forms of construction might also be employed. For example, for those applications wherein it is not necessary that the pushbutton switch 10 be illuminated, the knob assembly 31 might be of a one-piece construction.

To further provide the upper housing portion 12 with an oiltight construction, cylindrical bushing 28 is provided with a groove 42 in the outer surface thereof which receives a gasket 43 in the form of a quad ring. The gasket 43 is formed from suitable resilient sealing material capable of providing a seal between the outer wall surface of the cylindrical bushing 28 and the inner wall surface of cylindrical bore 23 of the externally threaded cylindrical section 22 while at the same time permitting relative movement to occur therebetween. In addition a rubber boot may be utilized to form a seal between the knob assembly base 32 and the cylindrical bushing 28. The aforesaid rubber boot has not been illustrated in the drawing in the interest of clarity of illustration of other components of the pushbutton switch 10 and inasmuch as the use of such rubber boots being relatively common in the prior art such a use is well-known to those skilled in the art. Cylindrical bushing 28 is provided with a groove 44 into which a snap-in retaining ring is intended to be snapped in place for purposes 'of securing downward extending portion 36 of base 32 into cylindrical bushing 28.

A printed circuit card 45 is disposed within the multipart elongated housing 11 of pushbutton switch 10 with one end extending into the lower housing portion 13 in spaced relation to the base plug 16. The printed circuit card 45 is positioned approximately centrally in the housing 11 such that the contacts 20 of conducting members 18 are capable of making good electrical contact with printed conductors (not shown) formed on the printed circuit card 45. The printed conductors (not shown) are preferably arranged to provide open and closed conditions of the contacts 20 depending upon the position of the card 45 relative to the contacts 20. A pair of springs 46 (only one of which is seen in FIG. 2) located adjacent opposing inner sidewall surfaces of the lower housing portion 13 are interposed between the lower end of printed circuit card 45 as viewed with reference to FIG. 2 and the base plug 16. One end of each of the springs 46 is provided with a U'shaped clip 47 which receives the end portion of printed circuit card 45. The other end of each of the springs 46 abuts against the inner surface of base plug 16. Thus, it is seen that the pair of springs 46 spring bias the printed circuit card 45 in an upwardly direction as viewed with reference to FIG. 2, but yet permit the printed circuit card 45 to be moved downwardly against the bias of springs 46 in a manner which will be more fully described hereinafter. To guide the movement of springs 46 and thereby keep the printed circuit card 45 properly aligned, a suitable guideway (not shown) may be formed in each of the pair of aforementioned opposing inner side wall surfaces of lower housing portion 13 preferably as an integral part thereof for purposes of receiving and retaining the springs 46 therein. Such guideways may extend the entire length of lower housing portion 13.

The other end of the printed circuit card 45 extends upwardly into the cylindrical bore 37 of the cylindrical bushing 28. Accordingly, the upper end of the printed circuit card 45 as viewed with reference to FIG. 2 of the drawings is ofa narrower width than is the other end thereof. That is, whereas the bottom end portion of the printed circuit card 45 has a width which is essentially the same as the distance between the opposing sidewalls of the lower housing portion 13, the upper end portion of the printed circuit card 45 has a reduced width which is slightly less than the diameter of the cylindrical bore 37 of cylindrical bushing 28. The printed conductors formed on the printed circuit card 45 extend to the aforesaid narrow upper end portion of the printed circuit card 45. It is to be understood further that conductive patterns are printed on both sides of the printed circuit card 45 for selective engagement with the contact 20 of the conducting members 18, the latter contacts 20 preferably being bifurcated.

A U-shaped clip 48 similar in construction to the clip 47 previously described receives the upper end portion of the printed circuit card 45 and is in selective engagement with the printed conductors on the narrow portion of the card 45. The U-shaped clip 48 which is formed of electrically conductive material is suitably attached to one end of spring 49 also formed of electrically conductive material. The other end of the spring 49 bears against the saddle portion 50a of a Y- shaped electrically conductive member 50. Leg portion 50b of the Y-shaped member 50 is biased by the spring 49 into engagement with the terminal 51 of base 40 of lamp 39. As illustrated in FIG. 2 of the drawings, the U-shaped clip 48, spring 49, and Y-shaped member 50 are all housed within an inverted U-shaped hollow cylindrical member 52, the latter being provided with a suitable opening 53 located centrally in the base thereof to permit the aforementioned leg portion 50b to pass therethrough and engage the terminal 51 oflamp 39.

The cylindrical member 52 is positioned within cylindrical bore 37 of cylindrical bushing 28 and is retained therein by virtue of the biasing effect of spring 49 which bears against saddle 50a of Y-shaped member 50 and urges the leg portion 50!: thereof in an upwardly direction through the opening 53 provided in member 52. Cylindrical member 52 is further pro vided with a longitudinally extending opening 54 suitably located in a sidewall thereof which receives with a friction fit an elongated electrical conductor 55. The latter electrical conductor 55 has one end 5511 thereof in engagement with the base 40 of lamp 39 and the other end 55b thereof in engagement with a conductor printed on the circuit card 45 whereby to complete the electrical circuit between the lamp 39 and a terminal 19 in the base plug 16. More specifically, the aforementioned electrical circuit encompasses a terminal 19, a conductive spring 46, a clip 47, the latter making electrical contact with a conductor printed on the circuit card 45, the U- shaped clip 48 which is also in electrical contact with a conductor on the card 45, the spring 49, the Y-shaped member 50, terminal 51 oflamp 39, from terminal 51 through an internal connection in lamp 39 to base 40 thereof, the end portion 550 of conductor 15 and through the end portion 55b thereof to a conductor on the printed circuit card 45 which in turn is electrically connected to a clip 47 contacting conductive spring 46 therethrough to the terminal 19 thereof.

Referring now to FIGS. 2, 3, 4, and 5 of the drawing, as previously described a portion of the inner wall segment of the lower section 21 of upper housing portion 12 is formed with a cylindrical bore surrounded by a plurality of alternately arranged splines 25 and slots 26, alternate slots 26 having barriers 27 therein. This is best seen in FIGS. 3 and 5. The splines 25 and slots 26 cooperate with splines 30 on the flange 29 of cylindrical bushing 28. In addition the aforementioned splines 25 and slots 26 cooperate with a ratchet member 56.

As illustrated in FIG. 4 of the drawing, the ratchet member 56 comprises a circular base 57 from which project four upwardly extending legs 58. The latter legs 58 are preferably equally spaced around the circumference of the circular base 57, i.e., such that the legs 58 are spaced approximately apart. The ratchet member 56 further is provided with a cylindrical bore 56a to permit the narrow portion of the printed circuit card 45 to pass therethrough into the hollow interior of U- shaped member 52. The circular base 57 of ratchet member 56 is preferably supported on a Teflon washer 60 on a pair or shoulders provided on the printed circuit card 45 at the juncture where the narrow portion and the wider portion of the printed circuit card 45 meet. The Teflon washer 60 provides a self-lubricating surface against ratchet member 56 and the shoulders of the printed circuit card 45. In essence therefore, the ratchet member 56 is carried on the aforesaid shoulders of the printed circuit card 45 for movement therewith, it having been noted previously that the springs 46 bias the printed circuit card 45 in an upwardly direction as viewed with reference to FIG. 2 of the drawing. For purposes of further description of the method of operation of the pushbutton switch 10, the position of the printed circuit card 45 illustrated in FIG. 2 is considered to be the extended position thereof.

A description of the method of operation of the pushbutton switch 10 will now be set forth. With the parts of the switch 10 assuming their respective positions as illustrated in FIG. 2 of the drawing, i.e., with the printed circuit card 45 in its extended position and with the legs 58 of ratchet member 56 positioned in those slots 26 of upper housing portion 12 which have no barriers 27, the contacts 20 of conducting members 18 are in their respective open circuit positions. To actuate the pushbutton switch 10, an external force is applied to the knob assembly 31. The latter force depresses the knob assembly 31 whereby as the base 32 and lens cap 33 thereof move downwardly as viewed with reference to FIG. 2, the lamp 39 is carried therewith and the latter forces the Y-shaped member 50 to also move in a downwardly direction against the bias of spring 49 by virtue of the interengagement of leg portion 50b of Y-shaped member 50 with terminal 51 oflamp 39. At the same time cylindrical bushing 28 is also being made to move downwardly by the knob assembly 31. As the cylindrical bushing 28 moves downwardly the legs 58 of ratchet member 56 are engaged by the splines 30 provided on the flange 29 of the cylindrical bushing 28. Thus, the ratchet member 56 is caused to move downwardly relative to the sidewalls of the multipart elongated housing 11 of switch 10. This downward movement of the ratchet member 56 continues until the legs 58 thereof pass out of the slots 26 and clear the lowermost edges 25a of the splines 25 formed along the inner wall segment of lower section 21 of upper housing portion 12. As best seen with reference to FIGS. 3 and 5 of the drawing, the lowermost edges 25a of the splines 25 are provided with cam surfaces 25b. At this point it should also be noted that the downward movement of the ratchet member 56 is transmitted to the printed circuit card 45 by virtue of the circular base 57 of ratchet member 56 being carried on the aforedescribed shoulders of the printed circuit card 45. The downward movement of the printed circuit card 45 causes the springs 46 to be compressed. Further downward movement of the circuit card 45 brings the contacts 20 of conducting members 18 into contact with selective conductors printed on the card 45 whereby the contacts 20 function to provide a closed circuit form of operation.

As soon as the ratchet member 56 is permitted to once again move upwardly under the influence of the biasing force provided by compressed springs 46, i.e., once the external force applied to knob assembly 31 is removed, the follower surfaces 580 at the ends of the legs 58 of ratchet member 56 engage the cam surfaces 25b provided along the lowermost edges 25a of splines 25. As the ratchet member 56 moves up wardly, the follower surfaces 58a ride along the cam surfaces 25b causing the legs 58 and thereby the ratchet member 56 to rotate about the central axis of member 56 relative to the printed circuit card 45 and to the sidewalls of multipart elongated housing 11. The simultaneous rotation and upward movement of the ratchet member 56 continues until each of the legs 58 is rotated into juxtaposed relation with a slot 26 having a barrier 27, the slots 26 being alternately arranged with the splines 25 around the circumference of the inner wall segment ofthe lower section 21 of upper housing portion 12.

Since alternate slots 26 are provided with barriers 27, upward movement of the ratchet member 56 will be limited as a result of the shortened depth of the slots 26 caused by the existence therein of the barriers 27. The aforesaid shortened depth of the slots 26 is selected such that with the legs 58 positioned therein the ratchet member 56 and thereby the printed circuit card 45 will be prevented from moving upwardly a sufficient distance to cause the contacts 20 to break their closed circuit condition. That is, because the shoulders of the printed circuit card 45 bear against the under surface of circular base 57 of ratchet member 56, the printed circuit card 45 under the influence of springs 46 can only move upwardly the same distance as the ratchet member 56. If the upward movement of the ratchet member 56 is restrained by virtue of the engagement of follower surfaces 58a of legs 58 with the barriers 27, the upward movement of the printed circuit card 45 will likewise be restricted.

The pushbutton switch 10 will remain in its actuated position, i.e., with the legs 58 in the slots 26 having barriers 27 and with the contacts making electrical contact with printed conductors on the printed circuit card 45 whereby the contacts 20 provide closed circuit operation, until an external force is once again applied to knob assembly 31 causing the latter assembly 31 to be depressed. When this happens, the same manner of downward movement of the respective parts of the switch 10 will occur as previously described hereinabove. However, this time upon release of the external force, the follower surfaces 58a of legs 58 will cause the ratchet member 56 to be rotated into juxtaposed relation with slots 26 which are not provided with barriers 27. Accordingly, the ratchet member 56 as well as the printed circuit card 45 will move upwardly under the influence of springs 46 until the member 56 and card 45 assume their original normal positions illustrated in FIG. 2 of the drawings. As the printed circuit card 45 moves upwardly to the aforesaid position of FIG. 2 the contacts 20 break electrical contact thereby returning to an open circuit condition.

Thus, it is seen that when the knob assembly 31 is initially depressed and released, the ratchet member 56 and the printed circuit card 45 are latched in the depressed position in response to rotation of the ratchet member legs 58 into the slots 26 having barriers 27 therein. Subsequent depression and release of the knob assembly 31 effects further rotation of the ratchet member 56 so that its legs 58 enter the slots 26 without barriers 27 permitting retraction of the ratchet member 56 and the printed circuit card 45.

If it is desired to provide the pushbutton switch 10 with a momentary actuation form of operation rather than the alternate actuation form of operation which has been described hereinabove, this may be accomplished by removing the barriers 27 from the slots 26. Thus, if this is done, after each actuation of the knob assembly 31 the legs 58 will be free to move upwardly in the slots 26 to the full extent thereof rather than being restricted in movement by virtue of engagement with the barriers 27. In addition. it should also be recognized that the conductive patterns printed on the circuit card 45 may of course be modified to provide varying arrangements of normally open and normally closed contacts in order to meet the requirements of the particular application to which the pushbutton switch 10 is to be put.

Therefore, in accordance with the present invention there has been provided a novel and improved manually operated electrical switch of the type having a pushbutton form of actuating mechanism which switch because of its great functional flexibility substantially obviates the heretofore existing need for specially designed switches. This functional flexibility is achieved primarily through the use of a printed circuit card to make and break the circuit thereby allowing inexpensive circuit modification to be accomplished by means of merely etching the card in a different pattern. In addition the subject electrical switch is provided with a novel and improved form of pushbutton-actuating mechanism. All of the above features have been provided in a pushbutton switch which is miniature in size while yet being effective and reliable in operation. Finally, the pushbutton switch of the subject invention may readily be provided with a sealed construction so as to render the switch oiltight, i.e., impervious to contamination by oil, water coolant, dirt, and grime.

While only one embodiment of our invention has been shown, it will be appreciated that many modifications thereof may readily be made by those skilled in the art. For example, as alluded to earlier the lamp 39 may be omitted in those applications wherein illumination of the lens cap 33 is not required. Further, by eliminating the barriers 27 in the slots 26, the form of operation of the pushbutton switch 10 may be changed from alternate actuation to momentary actuation. Also, in accordance with the preferred embodiment of the invention, upper housing portion 12 is provided with an externally threaded cylindrical section 22, the latter being utilized to permit the switch 10 to be secured to a suitable support, but it is to be understood that other suitable means may be substituted therefor to accomplish this same purpose. We therefore intend by the appended claims to cover the above modifications as well as all other modifications which fall within the true spirit and scope of our invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. A miniature square pushbutton switch comprising:

a. a housing including a plurality of sidewalls and first and second open end walls, said housing further including a plurality of alternately arranged splines and slots formed internally in said plurality of sidewalls adjacent to said first open end wall;

b. a substantially cylindrical bushing having a flange formed at one end thereof, said flange including a plurality of splines formed thereon;

c. means mounting said substantially cylindrical bushing in said first open end wall of said housing for axial movement relative thereto and with said flange of said substantially cylindrical bushing positioned in said housing;

d. a printed circuit card having electrical circuit means formed thereon;

e. biasing means biasing said printed circuit card for axial movement within said housing relative to said plurality of sidewalls of said housing;

f. a contact and terminal supporting means supporting at least one contact and one terminal thereon, said contact and terminal supporting means being received in the opening in said housing formed by said second open end wall of said housing and being fixedly mounted therein to close said second open end wall with said contact extending inwardly into the interior of said housing in juxtaposed relation to the path of movement of said printed circuit card and with said terminal projecting outwardly of said housing and of said contact and terminal supporting means to provide easy accessibility thereto;

g. ratchet means supported on said printed circuit card within said housing adjacent to said first open end wall of said housing. said ratchet means being supported on said printed circuit card for axial movement therewith and for movement relative thereto, said ratchet means including at least one member movable into and out of said slots formed internally in said plurality of sidewalls of said housing;

h. a knob assembly fixedly attached to the other end of said substantially cylindrical bushing from said one end thereof having said flange formed thereon;

said knob assembly being movable in a first direction by the application thereto of an external force to move said substantially cylindrical bushing in said first direction and to bring said splines on said flange thereof into engagement with said member of said ratchet means to move said ratchet means and thereby said printed circuit card in said first direction thereby causing said member of said ratchet means to become disengaged from one of said slots formed internally in said plurality of sidewalls of said housing and causing said printed circuit card to move between a first position wherein said electrical circuit means of said printed circuit card is in one circuit condition relative to said contact and said terminal of said contact and terminal supporting means and a second position wherein said electrical circuit means of said printed circuit card is in another circuit condition relative to said contact and said terminal of said contact and terminal supporting means; and

. said biasing means upon removal of said external force from said knob assembly causing said printed circuit card to move in a second direction opposite from said first direction, the movement of said printed circuit card in said second direction causing said member of said ratchet means to move into engagement with one of said splines formed internally in said plurality of sidewalls of said housing, upon further movement of said ratchet means in said second direction said engagement of said member of said ratchet means and said one of said splines causing said ratchet means to move relative to said printed circuit card until said member is brought into juxtaposed relation and is thereafter inserted into another of said slots formed internally in said plurality of sidewalls ofsaid housing.

A miniature square pushbutton switch as set forth in claim 1 wherein:

said housing further includes sealing means sealing said housing from contamination by oil, water coolant, dirt, and grime;

. said knob assembly comprises a lens cap and a base fixedly secured together, said base of said knob assembly being fixedly attached to said other end of said cylindrical bushing and having a bore formed therein;

. a lamp is fixedly secured in said bore of said base of said 3. A miniature square pushbutton switch as set forth in claim 1 wherein:

barrier means are provided in alternate ones of said slots formed internally in said plurality of sidewalls of said housing; and

said barrier means when engaged by said member of said ratchet means restricts movement of said ratchet means in said second direction and thereby also restricts movement of said printed circuit card in said second direction such that said printed circuit card is latched in said second position thereof with said electrical circuit means formed on said printed circuit card being in said another circuit condition relative to said contact and said terminal of said contact and terminal supporting means.

4. A miniature square pushbutton switch as set forth in claim 1 wherein:

a. said contact and terminal supporting means supports a plurality of contacts and a plurality of terminals thereon, each of said plurality of contacts extends inwardly into the interior of said housing in juxtaposed relation to the path of movement of said printed circuit card, and each of said plurality of terminals projects outwardly of said housing and of said contact and terminal supporting means to provide easy accessibility thereto;

. said ratchet means comprises a base supported on said printed circuit card and four members substantially NUI . said biasing means comprises a pair of springs each having one end bearing against said contact and terminal supporting means and the other end bearing against said printed circuit card.

. A miniature square pushbutton switch comprising: a housing having a plurality of sidewalls and first and second open end walls, said housing including a plurality of alternately arranged splines and slots formed internally in said plurality of sidewalls adjacent to said first open end wall;

. a substantially cylindrical bushing having a flange formed at one end thereof, said flange including a plurality of splines formed thereon;

. means mounting said substantially cylindrical bushing in said first open end wall of said housing for axial movement relative thereto and with said flange of said substantially cylindrical bushing positioned in said housing;

a printed circuit card having electrical circuit means formed thereon; a pair of springs supported in said housing for biasing said printed circuit card for axial movement within said housing relative to said plurality of sidewalls of said housing;

f. a contact and terminal supporting means supporting a plurality of contacts and a plurality of terminals thereon, said contact and terminal supporting means being received in the opening in said housing formed by said second open end wall of said housing and being fixedly mounted therein to close said second open end wall with each of said plurality of contacts extending inwardly into the interior of said housing in juxtaposed relation to the path of movement of said printed circuit card and with each of said plurality of terminals projecting outwardly of said housing and of said contact and terminal supporting means to provide easy accessibility thereto;

ratchet means comprising a base supported on said printed circuit card and four members substantially equally spaced around the circumference of said base of said ratchet means, said ratchet means being supported on said printed circuit card for axial movement therewith and for movement relative thereto, each of said four members being movable into and out of said slots formed internally in said plurality of sidewalls of said housing;

. a knob assembly comprising a lens cap and a base fixedly a lamp fixedly secured in said bore of said base of said knob assembly, said lamp comprising a base and a bulb retained in said base of said lamp;

. means electrically connecting said base of said lamp to said electrical circuit means formed on said printed circuit card to complete the electrical circuit between said lamp and said printed circuit card;

. said knob assembly being movable in a first direction by the application of an external force to said lens cap of said knob assembly to move said substantially cylindrical bushing in said first direction and to bring said splines on said flange thereof into engagement with said four members of said ratchet means to move said ratchet means and thereby said printed circuit card in said first direction thereby causing said four members of said ratchet means to become disengaged from said slots formed internally in said plurality of sidewalls of said housing and causing said printed circuit card to move between a first position wherein said electrical circuit means of said printed circuit card is in one circuit condition relative to said plurality of contacts and said plurality of terminals of said contact and terminal supporting means and a second position wherein said electrical circuit means of said printed circuit card is in another circuit condition relative to said plurality of contacts and said plurality of terminals of said contact and terminal supporting means; and

. said pair of springs upon removal of said external force from said lens cap of said knob assembly causing said printed circuit card to move in a second direction opposite from said first direction, the movement of said printed circuit card in said second direction causing said four members of said ratchet means to move into engagement with said splines formed internally in said plurality of sidewalls of said housing, upon further movement of said ratchet means in said second direction said engagement of said four members of said ratchet means and said splines formed internally in said plurality of sidewalls of said housing causing said ratchet means to move relative to said printed circuit card until said four members are brought into juxtaposed relation and are thereafter inserted into others of said slots formed internally in said claim 5 wherein:

a. said housing further includes sealing means sealing said housing from contamination by oil, water coolant, dirt, and grime;

b. barrier means are provided in alternate ones of said slots formed internally in said plurality of sidewalls of said housing; and

c. said barrier means when engaged by at least one of said four members of said ratchet means restricts movement of said ratchet means in said second direction and thereby also restricts movement of said printed circuit card in said second direction such that said printed circuit card is latched in said second position thereof with said electrical circuit means formed on said printed circuit card being in said another circuit condition relative to said plurality of contacts and said plurality of terminals of said contact and terminal-supporting means.

Claims

1. A miniature square pushbutton switch comprising: a. a housing including a plurality of sidewalls and first and second open end walls, said housing further including a plurality of alternately arranged splines and slots formed internally in said plurality of sidewalls adjacent to said first open end wall; b. a substantially cylindrical bushing having a flange formed at one end thereof, said flange including a plurality of splines formed thereon; c. means mounting said substantially cylindrical bushing in said first open end wall of said housing for axial movement relative thereto and with said flange of said substantially cylindrical bushing positioned in said housing; d. a printed circuit card having electrical circuit means formed thereon; e. biasing means biasing said printed circuit card for axial movement within said housing relative to said plurality of sidewalls of said housing; f. a contact and terminal supporting means supporting at least one contact and one terminal thereon, said contact and terminal supporting means being received in the opening in said housing formed by said second open end wall of said housing and being fixedly mounted therein to close said second open end wall with said contact extending inwardly into the interior of said housing in juxtaposed relation to the path of movement of said printed circuit card and with said terminal projecting outwardly of said housing and of said contact and terminal supporting means to provide easy accessibility thereto; g. ratchet means supported on said printed circuit card within said housing adjacent to said first open end wall of said housing, said ratchet means being supported on said printed circuit card for axial movement therewith and for movement relative thereto, said ratchet means including at least one member movable into and out of said slots formed internally in said plurality of sidewalls of said hOusing; h. a knob assembly fixedly attached to the other end of said substantially cylindrical bushing from said one end thereof having said flange formed thereon; i. said knob assembly being movable in a first direction by the application thereto of an external force to move said substantially cylindrical bushing in said first direction and to bring said splines on said flange thereof into engagement with said member of said ratchet means to move said ratchet means and thereby said printed circuit card in said first direction thereby causing said member of said ratchet means to become disengaged from one of said slots formed internally in said plurality of sidewalls of said housing and causing said printed circuit card to move between a first position wherein said electrical circuit means of said printed circuit card is in one circuit condition relative to said contact and said terminal of said contact and terminal supporting means and a second position wherein said electrical circuit means of said printed circuit card is in another circuit condition relative to said contact and said terminal of said contact and terminal supporting means; and j. said biasing means upon removal of said external force from said knob assembly causing said printed circuit card to move in a second direction opposite from said first direction, the movement of said printed circuit card in said second direction causing said member of said ratchet means to move into engagement with one of said splines formed internally in said plurality of sidewalls of said housing, upon further movement of said ratchet means in said second direction said engagement of said member of said ratchet means and said one of said splines causing said ratchet means to move relative to said printed circuit card until said member is brought into juxtaposed relation and is thereafter inserted into another of said slots formed internally in said plurality of sidewalls of said housing.

2. A miniature square pushbutton switch as set forth in claim 1 wherein: a. said housing further includes sealing means sealing said housing from contamination by oil, water coolant, dirt, and grime; b. said knob assembly comprises a lens cap and a base fixedly secured together, said base of said knob assembly being fixedly attached to said other end of said cylindrical bushing and having a bore formed therein; c. a lamp is fixedly secured in said bore of said base of said knob assembly, said lamp comprising a base and a bulb retained in said base of said lamp; and d. means electrically connecting said base of said lamp to said electrical circuit means formed on said printed circuit card to complete the electrical circuit between said lamp and said printed circuit card.

3. A miniature square pushbutton switch as set forth in claim 1 wherein: a. barrier means are provided in alternate ones of said slots formed internally in said plurality of sidewalls of said housing; and b. said barrier means when engaged by said member of said ratchet means restricts movement of said ratchet means in said second direction and thereby also restricts movement of said printed circuit card in said second direction such that said printed circuit card is latched in said second position thereof with said electrical circuit means formed on said printed circuit card being in said another circuit condition relative to said contact and said terminal of said contact and terminal supporting means.

4. A miniature square pushbutton switch as set forth in claim 1 wherein: a. said contact and terminal supporting means supports a plurality of contacts and a plurality of terminals thereon, each of said plurality of contacts extends inwardly into the interior of said housing in juxtaposed relation to the path of movement of said printed circuit card, and each of said plurality of terminals projects outwardly of said housing and of said contact and terminal supporting means to provide easy accessibility thereto; b. said Ratchet means comprises a base supported on said printed circuit card and four members substantially equally spaced around the circumference of said base of said ratchet means, each of said four members being movable into and out of said slots formed internally in said plurality of sidewalls of said housing; and c. said biasing means comprises a pair of springs each having one end bearing against said contact and terminal supporting means and the other end bearing against said printed circuit card.

5. A miniature square pushbutton switch comprising: a. a housing having a plurality of sidewalls and first and second open end walls, said housing including a plurality of alternately arranged splines and slots formed internally in said plurality of sidewalls adjacent to said first open end wall; b. a substantially cylindrical bushing having a flange formed at one end thereof, said flange including a plurality of splines formed thereon; c. means mounting said substantially cylindrical bushing in said first open end wall of said housing for axial movement relative thereto and with said flange of said substantially cylindrical bushing positioned in said housing; d. a printed circuit card having electrical circuit means formed thereon; e. a pair of springs supported in said housing for biasing said printed circuit card for axial movement within said housing relative to said plurality of sidewalls of said housing; f. a contact and terminal supporting means supporting a plurality of contacts and a plurality of terminals thereon, said contact and terminal supporting means being received in the opening in said housing formed by said second open end wall of said housing and being fixedly mounted therein to close said second open end wall with each of said plurality of contacts extending inwardly into the interior of said housing in juxtaposed relation to the path of movement of said printed circuit card and with each of said plurality of terminals projecting outwardly of said housing and of said contact and terminal supporting means to provide easy accessibility thereto; g. ratchet means comprising a base supported on said printed circuit card and four members substantially equally spaced around the circumference of said base of said ratchet means, said ratchet means being supported on said printed circuit card for axial movement therewith and for movement relative thereto, each of said four members being movable into and out of said slots formed internally in said plurality of sidewalls of said housing; h. a knob assembly comprising a lens cap and a base fixedly secured together, said base of said knob assembly being fixedly attached to the other end of said substantially cylindrical bushing from said one end thereof having said flange formed thereon and said base of said knob assembly having a bore formed therein; i. a lamp fixedly secured in said bore of said base of said knob assembly, said lamp comprising a base and a bulb retained in said base of said lamp; j. means electrically connecting said base of said lamp to said electrical circuit means formed on said printed circuit card to complete the electrical circuit between said lamp and said printed circuit card; k. said knob assembly being movable in a first direction by the application of an external force to said lens cap of said knob assembly to move said substantially cylindrical bushing in said first direction and to bring said splines on said flange thereof into engagement with said four members of said ratchet means to move said ratchet means and thereby said printed circuit card in said first direction thereby causing said four members of said ratchet means to become disengaged from said slots formed internally in said plurality of sidewalls of said housing and causing said printed circuit card to move between a first position wherein said electrical circuit means of said printed circuit card is in one circuit condition relative to said plurality of contacts and said plUrality of terminals of said contact and terminal supporting means and a second position wherein said electrical circuit means of said printed circuit card is in another circuit condition relative to said plurality of contacts and said plurality of terminals of said contact and terminal supporting means; and l. said pair of springs upon removal of said external force from said lens cap of said knob assembly causing said printed circuit card to move in a second direction opposite from said first direction, the movement of said printed circuit card in said second direction causing said four members of said ratchet means to move into engagement with said splines formed internally in said plurality of sidewalls of said housing, upon further movement of said ratchet means in said second direction said engagement of said four members of said ratchet means and said splines formed internally in said plurality of sidewalls of said housing causing said ratchet means to move relative to said printed circuit card until said four members are brought into juxtaposed relation and are thereafter inserted into others of said slots formed internally in said plurality of sidewalls of said housing.

6. A miniature square pushbutton switch as set forth in claim 5 wherein: a. said housing further includes sealing means sealing said housing from contamination by oil, water coolant, dirt, and grime; b. barrier means are provided in alternate ones of said slots formed internally in said plurality of sidewalls of said housing; and c. said barrier means when engaged by at least one of said four members of said ratchet means restricts movement of said ratchet means in said second direction and thereby also restricts movement of said printed circuit card in said second direction such that said printed circuit card is latched in said second position thereof with said electrical circuit means formed on said printed circuit card being in said another circuit condition relative to said plurality of contacts and said plurality of terminals of said contact and terminal-supporting means.