US2747034A - Three-position push button switch - Google Patents

Description

May 22. 1956 H. w. MACHON EI'AL 2,747,034

THREE-POSITION PUSH BUTTON SWITCH Filed July 16, 1953 4 Sheets-Sheet l eoowHM+ A RNEYS May 22, 1956 H. w. MACHON ETAL 2,747,034

THREE-POSITION PUSH BUTTON SWITCH Filed July 16, 1955 4 Sheets-Sheet 2 ATTORNEYS May 22, 1956 H. W. MACHON ETAL THREE-POSITION PUSH BUTTON SWITCH 4 Sheets-Sheet 5 Filed July 16, 1953 INVENTORS #565616? 14/. 4440/04! J'OJEP/l R M46/V4A 0 BY mt I tT I bRNEZYS ii hired States Patent THREE-PUSZTEQN QUTTQ'EFI WlTCli Application July 16, 1'253, Serial No, 368,268

6 Ciaims. (Ci. Ebb-16) The present invention relates generally to switches and, in particular, to switches of the push button type.

The primary object of the present invention is to provide an improved double throw switch of the push button type having normally closed contacts and normally open contacts, and to provide in said switch means for the closing of the normally open contacts before the opening of the normally closed contacts.

Pursuant to the foregoing objects, it is another object of the present invention to provide a momentary contact push button switch having a normal or released position wherein one set of contacts is closed and a second set of contacts is open, an intermediate position wherein all the contacts are closed, and a fully depressed position wherein the normally closed contacts are open and the normally open contacts are closed.

A further object is the provision of a momentary contact push button switch of generally simplified and improved construction which, however, is efiicient in operation.

The above and other objects, features and advantages of the present invention will be more fully understood from the following description considered in connection with the accompanying illustrative drawings.

In the drawings:

Fig. 1 is a side view of a switch embodying the present invention, the switch being in normal or released condition thereof;

Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1.;

Fig. 3 is sectional view taken on the line 33 of Fig. 2;

Fig. 4 is a view similar to Fig. 3, the switch being in an intermediate position thereof;

Fig. 5 is aview similar to Figs. 3 and 4, the switch being in the fully depressed position thereof;

Fig. 6 is sectional view taken on the line 66 of Fig, 3-;v

Fig. 7 is a sectional view taken on. the line 77 of Fig fig and Fig. 8 is aview of the back of the switch.

Referring now to the drawings in detail, the switch 10 of the present invention comprises a hollow casing 12 formed of suitable insulation material and provided with contacts M-1.4 and 24-.-24 which are secured therein, as illustrated and described in Patent No. 2,543,090, to P. Ballou and assigned to the assignee hereof. As shown herein, the normally closed switch contacts 14 are carriedby metal strips 16 whichare secured in position by companion terminal screws 18 which are removably threaded into companion metallic socket members 20 se curedin companion lateral portions 22 of the casing body 12. Similarly; the normally open contacts 24 are carried by metallic strips 26 secured by screws 28 threaded into companion metallic socket members 30, mounted in companion lateral portions 32 of the casing body 22. It will be understood that the internally threaded socket members; 2i): and, are secured in the casing 12 during the molding operation for forming said casing part.

2,747,034 atented May 22, 1956 The normally closed contacts 14 are releasably engaged by the companion contacts 34 carried by the movable bridging contact member 36 which consists of a rigid metal strip, and the normally open contacts 24 are relea-sably engaged by companion contacts 38 carried by the movable bridging contact member 49 which consists of a rigid metal strip shaped as best illustrated in Figs. 3, 4, and 5.

in order to effect the operation of the contact bridging members 36 and 4t provision is made for the insulation button assembly 42 which, as here shown, is provided with a mushroom head 44 which is secured to a circular body member or operating part as by the securing element 46. it will be understood that the member 45 and the head 44 are each preferably formed of a suitable insulating material, the securing element 46 being preferably molded in part db and engaged in a preferably metallic insert id molded in the head 4-4. The button part 45 is provided with a preferably circular recess 5% which constitutes a seat for one end of a spring 52, the function of which is hereinafter described in detail. The button part is also provided with a projecting stem 54- which is provided, as here shown, with a metallic insert 56, preferably molded therein, in which there is threadedly engaged a bolt 58 which projects from the free end of the stem 54. It will be noted that the casing 12 is suitably apertured, as at 6t and that the stem 54 is disposed for slidable movement within said aperture 6% longitudinally of the casing 12. A preferably circular collar 62. is provided on the casing 12 and surrounds the aperture 6% therein. A washer 64 is mounted within the casing wall 13 about the aperture 6t and it will be noted that the stem 54 extends through the washer 6d and that the coiled compression spring 52 is disposed about the stem 5 the lower end of the spring abutting the washer 64, and the upper end thereof being seated in the recess 5%, as previously indicated. Consequently, it will be understood that the spring 52 biases the button assembly 42, and consequently the stem 54 and the bolt 53, to the normal switch released position thereof illustrated in Fig. 3.

At the head 66 thereof, the bolt 53 is provided with a lock washer 68 on which is mounted a washer 70, the bolt 5s extending through said washer 79. A tube or sleeve 72, formed of a suitable insulating material, is mounted on the insulation washer 7d, it being noted that the contact bridging members 36 and 4d are both mounted for slidable movement relative to the tube 72 which extends through the central openings 37 and 41, respectively, thereof. A coil compression spring 74 is disposed about the tube 72, the lower end of the spring abutting the bridging member 40, and the upper end of the spring mounting an insulation washer 76 which is slidably movable relative to the tube 72. An additional insulation washer 78 is seated at the upper end of the tube '72 and also abuts the free end of the projection 54 of the button assembly 42. It will be seen that with such an arrangement, the movable contact and detent assembly can be easily and rapidly assembled by arranging the parts in the described manner and then tightening bolt 58 into the threaded portion of insert 56.

Fig. 3 illustrates the normal or released position of the push button switch 10. It will be noted that in said condition of the switch, the spring 52 is expanded and retains the push button 4-2 in the fully retracted position thereof illustrated in said figure. in this position of the push button, the washer '78 abuts the inner surface 80 of the casing 12 and serves as a detent to limit the movement of the push button outwardly of the casing. In addition, it will be noted that the contacts 33 carried by thecontact bridging member 46, are disengaged from the companion contacts 24, and that the contacts 34 of the contact bridging 36 are in engagement with the companion. contacts 14 to close a circuit therethrough. it will be understood that in said position of the push button switch, the spring 74 is partially compressed and biases the bridging member 36 against the contacts 14 through the medium of the washer 76, it being understood that the force exerted by the spring 52 is greater than that exerted by the spring 74. When the push button assembly 42 is pushed inwardly toward the casing 12, from the fully retracted position thereof illustrated in Fig. 3, to the intermediate or partially projected position illustrated in Fig. 4, it will be noted that the washer 78, which is urged farther into the casing 12 by the stem 54, stops short of engagement with the bridging member 36, so that the latter remains in position to retain the switch closed at the contacts 14 thereof. However, said movement of the push button results in the movement of the bolt 58 to permit for the expansion of the partially contracted spring 74 for biasing the bridging member 40 against the contacts 24 to close the switch at said latter contacts. Therefore, it will be apparent that in the intermediate position of the switch, the latter is closed at both sets of contacts thereof. When the push button is then fully depressed from its intermediate position so that the push button assembly 42 moves to the fully retracted position thereof, as illustrated in Fig. 5, the washer 78 engages the bridging member 36 and carries the latter out of engagement with the contacts 14 to open the switch at said contacts. Said movement of the bridging member 36 causes the washer 76 to move in the same direction for fully compressing the spring 74, the bolt 58 and the sleeve 72 moving relative to the bridging member 46 to the position thereof illustrated in Fig. 5, and said bridging member remaining in engagement with the contacts 2424. Therefore, it will be apparent that in depressing the push button assembly from its released position through its intermediate position to its fully depressed position, the contacts -24 were bridged to close the switch at said contacts, before the switch was opened at the contacts 14 thereof. Upon release of the push button, from the position thereof illustrated in Fig. 5, the fully compressed spring 50 now expands to return the push button to the position thereof illustrated in Fig. 3, the washer 78, now serving as a detent element to limit outward movement of the push button assembly. During said movement,

the washer 76 engages the bridging member 40 and carries the latter out of engagement with the contacts 24. In addition, the expansion of the spring 74, from the fully compressed condition thereof illustrated in Fig. 5, biases the bridging member 36 into engagement with the contacts 14, through the medium of the washer 76, to close the switch at said latter contacts.

While we have shown and described the preferred embodiments of our invention, it will be understood that various changes may be made in the idea or principles of the invention within the scope of the appended claims.

Having thus described our invention, what we claim and desire to secure by Letters Patent is:

l. A switch comprising a casing having an axial opening extending into the interior of the casing, a pair of companion contacts carried by said casing and disposed in laterally spaced relation therein, a second pair of companion contacts carried by said casing and disposed in laterally spaced relation therein, one of said pairs of contacts being spaced from the other of said pairs of contacts longitudinally of the casing, 21 first movable bridging contact member mounted for movement in the space between said pairs to open and close said first pair of contacts, a second movable bridging contact member mounted for movement in the space between said pairs to open and close said second pair of contacts, and means for actuating said bridging contact members comprising a stem slidably movable in said opening of the casing and spring biased to a first position in which one pair of said contacts are normally open and the other of said pair of contacts are normally closed, a guide sleeve disposed in line with said stem and connected thereto for axial movement therewith, said bridging members having openings through which said sleeve extends, said bridging members being movable longitudinally of said sleeve, a detent member having an opening through which said sleeve extends, said detent member being slidably movable on said sleeve longitudinally thereof, spring means surrounding said guide sleeve and resiliently engaging and holding said detent member in engagement with one of said bridging contact members and biasing both of said bridging contact members toward their contact engaging positions, respectively, and means including said sleeve for removably connecting said bridging contact members to said stem for actuation thereby, said last mentioned means including means releasably securing said sleeve to said stem.

2. A switch comprising a casing having an axial opening extending into the interior of the casing, a pair of companion contacts carried by said casing and disposed in laterally spaced relation therein, a second pair of companion contacts carried by said casing and disposed in laterally spaced relation therein, one of said pairs of contacts being spaced from the other of said pairs of contacts longitudinally, of the casing, a first movable bridging contact member mounted for movement in the space between said pairs to open and close said first pair of contacts, a second movable bridging contact member mounted for movement in the space between said pairs to open and close said second pair of contacts, and means for actuating said bridging contact members, comprising a stem slidably movable in said opening of the casing and spring biased to a first position in which one pair of said contacts are normally open and the other of said pair of contacts are normally closed, a guide sleeve disposed in line with stem and connected thereto for axial movement therewith, said bridging members having openings through which said sleeve extends, said bridging members being movable longitudinally of said sleeve, an insulated detent member having an opening through which said sleeve extends, said detent member being slidably movable on said sleeve longitudinally thereof and insulating said bridging contact members from each other, spring means surrounding said guide sleeve and resiliently engaging and holding said detent member in engagement with one of said bridging contact members and biasing both of said bridging contact members toward their contact engaging positions, respectively, and means including said sleeve for removably connecting said bridging contact members to said stem for actuation thereby, said last mentioned means including means releasably securing said sleeve to said stem and means providing a detent for the other of said bridging contact members, said last mentioned bridging contact member being movable by said last mentioned detent and said first mentioned spring against the bias of said last mentioned spring to disengage the companion stationary contacts when the first mentioned bridging member is engaged with its companion stationary contacts and said last mentioned detent member being movable by said sleeve away from said last mentioned bridging contact member when the latter is moved into engagement with its companion stationary contact members by movement of said stem against the bias of said first mentioned spring, and detent means operatively connected to said stem and engaging said first mentioned bridging contact member to disengage the latter from the companion stationary contacts by movement of said stem against the bias of said first mentioned spring.

3. In a push-button switch including a slidable stem, a detent assembly comprising a sleeve aligned with said stem and having a detent member at each end, and a fastening member for holding said assembly in fixed relative position to said stem.

4. In a switch having a slidable stem provided with a bearing surface, two contacts, each contact having a fixed and movable contact member, and detent means for imparting motion to said movable contact members in response to movement of said stem, an improved assembly comprising a first detent member having one side abutting against said bearing surface of said shaft, a sleeve in substantial alignment with said stem and abutting at one end against the other side of said first detent member, second detent member abutting against the other end of said tube and secured to said stem, said movable contact .iembers being slidably mounted on said sleeve betv-teen said detent members, and a spring disposed between said movable contact members for mutually biasing tor for movement away from each other.

5. A push button switch comprising a housing; an internally threaded operating stem slidably mounted in said housing and having a first or normal position, a second or intermediate position and a third or fully retracted position; means for biasing said stem to said normal position, first and second sets of fixed contacts secured to said housing, a first detent member provided with apertures and abutting at one surface against the end of said stem within said housing so that said aperture is aligned with the threaded portion of said stem, a sleeve abutting at one end to said first detent member so that the hollow portion of said sleeve is aligned with said aperture in said first detent member, a second detent member having an aperture and abutting against the other end of said sleeve so that its aperture is aligned with the hollow portion of said sleeve, a bolt having its head abutting against said second detent member and its shank extending through said apertures and said hollow portion of said sleeve and being threadably secured to said threaded portion of said stern for holding said detent members and said sleeve in their defined positions, first and second contact bridging members each having a set of movable contacts and being slidably mounted on said 3 sleeve, and a spring disposed around said sleeve and between said contact bridging members for biasing both said sets of movable contacts toward their contact making positions, the parts being so positioned and proportioned that when said shaft is in said first position, said first set of movable contact members engages said first set of fixed contact members and said second sets of movable and fixed contact members are out of engagement; and when said shaft is in said second position, both said sets of movable contact members engage their associated sets of fixed contact members and when said shaft is in said third position, said first sets of movable and fixed contact members are out of engagement and said second sets of movable and fixed contact members are in engagement.

6. In a push-button switch having a housing provided with an opening therein, a stem slidably disposed within said housing opening, a detent assembly comprising a sleeve aligned with said stem and having a detent memher at each end, a bolt extending through said sleeve and threadedly engaging said stern whereby to hold said detent assembly in fixed relation to said stem, and a com pression spring operatively engaging said stem and said housing for biasing said stem to a predetermined position wherein the detent member adjacent the housing operatively engages said housing to limit movement of said stem, said stem, spring and detent assembly being assembled and disassembled by threadedly engaging and disengaging, respectively, said bolt and said stem, and means for gaining access to said bolt from outside said housing.

References Cited in the file of this patent UNITED STATES PATENTS

Images