SLIDE SWITCH IN A DUAL IN-LINE PACKAGE CONFIGURATION

Abstract: A dual in-line package switch comprises a base (10), a slider (11) and a cover (12). The base (10) comprises in-line terminals (13-18) and on its upper part corresponding contact pins (21-26). The slider (11) comprises teeth (55, 56) to con­ tact the pins (21-26) and a handle (39) for moving the slider to its different positions. The top (12) has an opening (62) for access to the handle (39). The base (10) has a detent (29) on its upper surface and the slider (11) has on its bottom surface a pair of detent receiving recesses (36, 37), each complemen­ tary to the detent. The detent and the complementary re­ cesses act as limits for two positions of the slider.

Description: The invention relates to miniature slide switches of a DIP configuration. The DIP configuration is prevalent in many electronic applications and slide switches of this configuration are known. For example U.S. Patent 4,075,442 issued February 21, 1978 to Fukuda et al for Miniature Slide Switch Assembly having Flexible Detent on Movable Actuator or Fixed Housing, discloses a slide switch having a base member in which a slide member of the switch reciprocates. The base is furnished with recesses in above on the surface of the base member and a matching projection on the slide. A detent action then takes place between the projection and the semicircular recesses in operation to fix the position of the slide in accordance with the desired switch connections. The recesses are off centre and are located to the side of the base. Other patents relating to DIP switches are, for example, U.S. Patent 4,119,823 to Matsueda et al, October 10, 1978 for an Electrical Switch which shows individual switch settings for individual pairs of terminals. U.S. Patent 4,168,404 to Lockard September 18, 1979 for Impedance Programming DIP Switch Assembly also allows individual switching of pairs of terminals in a DIP switching arrangement. U.S. Patent 4,332,987 to Hoffman for a DIP switch shows a slide body means in a DIP switch which is receivable in and movable along a channel. U.S. Patent 4, 352, 966 to English et al, October 5, 1982 for a Slide Switch discloses a base with a bearing surface. A slider has switch arms which are deformably biased freely over confronting cam surface of contacting projections extending from a housing. U.S. Patent 4,376,234 to Liagaud, March 8, 1983 for a DIP switch shows a base, pairs of legs from the base, and slide contacts for each pair of legs. US-A-3,947,391, which is closest prior art, describes a slide switch having a base, a slider and a cover. The bottom of the slider is well spaced from the base; contacts in the slider project freely downwardly from shallow recesses, and detents are provided on the slider which are long, deflectable projections. According to the invention, there is provided an electrical switch comprising a base having pairs of electrical terminals extending downwardly from the base in a dual in-line package configuration in two parallel longitudinal rows and contact pins connected to the terminals, extending upwardly from the base in two parallel longitudinally extending rows; a slider longitudinally slidable in the direction of the rows and supporting an elongated contact having laterally spaced downwardly extending teeth selectively to mate with and make bridging electrical connection with some of the pins upwardly extending from the base in correspondence to the longitudinal position of the slider relative to the base, the slider having on its upper surface a means for imparting sliding motion to the slider in the longitudinal direction; and a cover extending over the base and capturing the slider between the cover and the base, the cover having a longitudinal aperture on the upper part of the cover to afford access to the slider sliding motion imparting means; characterised in that the contact can be passed downwardly into and retained within a through aperture in the slider and has ends thereof seated in recesses alongside the aperture in the slider; and the base has on its upper surface a detent, and the slider has on its bottom surface a pair of detent receiving recesses, the detent and each recess of the pair being complementary for maintaining the slider firmly in one of two selected positions, the detent being held operatively in position by the cover acting against the slider, the detent of the base and each recess of the slider being located symmetrically with respect to and on the longitudinal centre line between the upwardly extending pins of the base. The slide switch described has the merit of avoiding any torque in its detent action with respect to a longitudinal vertical plane of symmetry, such torque being inherent in for example the Fukuda detent which is constructed to act on one side of the slide of the slide switch. The various objects, advantages and novel features of the invention will be more fully understood from the following detailed description of an embodiment of the invention when read in connection with the accompanying drawings in which like reference numerals refer to like parts and in which:- Figure 1 is a perspective view of an embodiment of the invention; Figure 2 is a top view of the embodiment of Figure 1 with the cover and slider removed, showing the base; Figure 3 is a sectional view of the base of Figure 2 taken along the lines 3-3 of Figure 2; Figure 4 is a partial side view of the base of Figure 2; Figure 5 is a top view of the slider of Figure 1, with the top removed; Figure 6 is a bottom view of the slider of Figure 5; Figure 7 is a sectional view taken along the lines 7-7 of Figure 6; Figure 8 is a sectional view along the lines 8-8 of Figure 6; Figure 9 is a partial sectional view along the lines 9-9 of Figure 6 with addition of a pin in place; Figure 10 is an enlarged partial side perspective view showing the deformable hold down tabs; Figure 11 is an enlarged partial side perspective view showing the support pads; and Figure 12 is an enlarged side perspective view of the inverted U-shaped contact. Referring to Figure 1, a slide switch embodying the invention comprises a base 10, a slider 11, and a cover 12. Terminals 13a through 18a are paired respectively with terminals 13b through 18b, and extend downwardly from the base 10 in a dual in-line configuration (only one 'a' contact of each pair is visible in Figure 1. Referring to Figures 2, 3 and 4, each terminal such as 16a, 16b extend through a base floor 19 of the base 10 and then upwards from the upper surface of base floor 19 to form respectively contact pins 21a through 26a which are paired respectively with contact pins 21b through 26b (see Figure 2). A peripheral ledge 28 (Figures 2, 3 and 4) surround the upper part of base floor 19. A detent 29 is raised on the central upper surface of base floor 19 symmetrically along a median longitudinal line 31. The detent 29 which may be an embossment, is also symmetrical with respect to a transverse central line (not shown). A continuous connection interconnects respective contacts 21a-26a and 21b-26b respectively through internal passageways 30, with respective contacts 13a-16a, and 13b-16b. Vertical grooves 32 along the side of the base floor 19 permit the bending in closely to the base member of the contacts as 16a of Figure 3 as they emerge from the base floor 19, permitting the intermediate part of terminals 33 to lay flat without obtruding from the base member horizontally. The contact pins 21a through 26a, and 21b through 26b, all extend vertically to the same height above the base floor 19. Referring to Figures 5 through 8, the slider 11 comprises a slider element 35 having a bottom 34, and a generally rectangular bore 38 in the bottom 34 of slider element 35, which surrounds a pair of detent receiving recesses 36 and 37. Each recess 36, 37 is complementary in form to the detent 29 on the base 10. The slider 11 has an upwardly extending handle or means of movement 39. Apertures 41, 42 are formed in the slider element 35, one on each side of the longitudinal axis of symmetry. In rectangular apertures 44, 45, 46 and 47 (44 and 45 being on one side of the axis 31 in Figures 5 and 6, and 46 and 47 being on the other side) are downwardly extending contacts 48 through 51 respectively. Only one downwardly extending contact need be described as the others are similar and arranged in their respective apertures in a similar manner, symmetrically longitudinally and transversely. In Figure 5, contact 48 is a single piece of metal having two horizontally longitudinal extensions 53, 54 and secured in the top of the slider element by deformable pads 82. Two winglike portions 55, 56 of contact 48 adjoin the extensions 53, 54 respectively, and these winglike portions in turn are connected to the top of a bridging portion 57. The winglike portions 55 and 56 at their sides are bent downwards at the margins of the rectangular aperture 44. Thus, in Figure 6 the winglike portion 55 finally terminates in a pair of teeth contacts 55a and 55b, and the winglike portion 56 finally terminates in a pair of teeth contacts 56a and 56b. Figures 7 and 10 also show a pair 71 of deformable hold down tabs 72 and 73 on the surface 74 of the slider which are deformed by ultrasonic thermal displacement to hold the contacts in the recesses so that there is no pitch or movement of the contact which is independently suspended and captured in the slider recess and slot. The cover 12 comprises an inverted box-like portion 61, open at the bottom which fits down over the assembly of slider 11 and base 10, so that the bottom margin of inverted box-like portion 61 rests on the ledge 28, and may be then ultrasonically welded to the peripheral ledge. A rectangular aperture 62 on the top 61, is open to access handle 39. The inner sidewalls of the box-like portion 61 enclose closely the slider to permit the slider longitudinal motion only, the top of the box-like portion 61 preventing upward movement of the slider 11. In Figure 10 there is a plurality of deformable hold-down tabs 72 and 73 before deformation and before the contacts have been included in their appropriate recesses. In Figure 11 there are numerous pairs of pads 81 of support pads 82 on the surface 74 of the slider which may support the cover. Figure 12 highlights a U-shaped contact 90 which has two pairs 91 and 92 of downwardly extending teeth 93, 94, 95 and 96 which are longitudinally connected to each other by a generally semicircular elongated connector 97. On the upper surface 98 of the contact 90, is an elongated rib 99 which supports the contact. At each opposite end 101 and 102 of the contact there is a generally flat square member 103 and 104 which has a semicircular recess 105 and 106 which acts to seat the contact in the slider and a rectangular member 107 and 108 protruding from each square member. To assemble the switch the slider 11 is placed on top of the base 10 with the pairs of teeth gripping or engaging the corresponding contact pins, as shown in Figure 9 with a pin 25a grasped. Thus, for example, teeth 55a and 55b may clasp or engage pin 21a. In this position, pin 21a is engaged between teeth 55a and 55b, and pin 22a is engaged between teeth 56a and 56b. In this fashion the teeth of downwardly extending contact 49 clasp the pins 24a and 25a. In this initial position the teeth of contact 48 engage and short circuit the pins 21a and 22a, the teeth of contact 49 engage and short circuit the pins 24a and 25a, the teeth of contact 50 engage and short circuit the pins 21b and 22b. The top is now put in place and affixed by ultrasonic welding or the like at the ledge 28. When in place, the handle 39 is accessible and the switch slider may be slid to either position. In the other position the teeth of contact 48 engage pins 22a and 23a, the teeth of contact 49 engage pins 25a and 26a, the teeth of contact 50 engage the pins 22b and 23b, and the teeth of contact 51 engage the contact pins 25b and 26b. As the contact 48, 49, 50 and 51 are each respectively, a single conductor, the effect is to bridge and short circuit, as noted above, the pins engaged by the teeth of any contact at any time. The initial position, of course, may be that described for the second position of the slider described above. In each of the selected positions a detent action is secured by the co-operation of the base detent and one of the slider recesses, the slider being held down by the cover or top 12. Briefly, electrically we have a slide switch which either short circuits contacts 13a to 14a, 16a to 17a, 13b to 14b, and 16b to 17b in one switch position, or in the other switch position short circuits contacts 14a to 15a, 17a to 18a, 14b and 15b, and 17b to 18b. The description herein uses up and down, top and bottom, solely for ease of description. It will be understood that orientation of the switch is not significant. Applicants' detent is slight and the complementrary or matching recesses in the slider provided herein is sufficient to give the desired detent action. Even though the top bears lightly against the slider, there is sufficient natural resilience of the material to allow the detent action to occur. Moreover, the symmetry and simplicity of the arrangement of the present invention leads to an easy and simple manufacturing process.

Claims: An electrical switch comprising a base (10) having pairs of electrical terminals (13-18) extending downwardly from the base (10) in a dual in-line package configuration in two parallel longitudinal rows and contact pins (21-26) connected to the terminals (13-18), extending upwardly from the base in two parallel longitudinally extending rows; a slider (11) longitudinally slidable in the direction of the rows and supporting an elongated contact (90) having laterally spaced downwardly extending teeth (55, 56) selectively to mate with and make bridging electrical connection with some of the pins (21-26) upwardly extending from the base (10) in correspondence to the longitudinal position of the slider (11) relative to the base (10), the slider (11) having on its upper surface a means (39) for imparting sliding motion to the slider (11) in the longitudinal direction; and a cover (12) extending over the base (10) and capturing the slider (11) between the cover (12) and the base (10), the cover (12) having a longitudinal aperture (62) on the upper part of the cover (12) to afford access to the slider sliding motion imparting means (39); characterised in that the contact (90) can be passed downwardly into and retained within a through aperture (44-47) in the slider (11) and has ends (103, 104) thereof seated in recesses (110) alongside the aperture (44-47) in the slider (11); and the base (10) has on its upper surface a detent (29), and the slider has on its bottom surface a pair of detent receiving recesses (36, 37), the detent (29) and each recess (36, 37) of the pair being complementary for maintaining the slider (11) firmly in one of two selected positions, the detent (29) being held operatively in position by the cover (12) acting against the slider (11), the detent (29) of the base (10) and each recess (36, 37) of the slider (11) being located symmetrically with respect to and on the longitudinal centre line between the upwardly extending pins (21-26) of the base (10). An electrical switch according to claim 1, characterised in that ends (103, 104) of the contact (90) are held in the recesses (110) by deformation of hold down tabs (72, 73) on the surface of the slider. An electrical switch according to claim 1, characterised in that the slider has a plurality of support pads (82) for supporting the cover (12) on the upper surface of the slider (11). An electrical switch according to claim 1, characterised in that the detent (29) of the base (10) is an embossment which is complementary to the recesses (36, 37). An electrical switch according to claim 4, characterised in that each recess (36, 37) is located symmetrically on either side of a centre line transverse to the longitudinal centre line of the slider (11). An electrical switch according to claim 1 characterised in that the contact (90) comprises two pairs of downwardly extending teeth (93-96) connected longitudinally by a generally semicircular elongated member (97), the contact having on its upper surface an elongated supporting rib (99); and a protrusion (103, 104) at each opposite end of the said contact.

Inventors: BOULAIS, DENNIS R., STOKOE, PHILIP T.
Applicants: ALCO ELECTRONIC PRODUCTS, INC.
Application year: 1986
Main classification: H01H15
IPC codes: H01H15