US3410970A

US3410970A - Neutral safety and backup light switch

Info

Publication number: US3410970A
Application number: US570237A
Authority: US
Inventors: Andrew F Raab
Original assignee: Littelfuse Inc
Current assignee: Littelfuse Inc
Priority date: 1966-08-04
Filing date: 1966-08-04
Publication date: 1968-11-12
Anticipated expiration: 1985-11-12

Description

Nov. 12, 1968 RAAB NEUTRAL SAFETY AND BACKUP LIGHT SWITCH Filed Aug. 4, 1966 4 Sheets-Sheet. 1

Nov. 12, 1968 A. F. RAAB NEUTRAL SAFETY AND BACKUP LIGHT swnca 4 Sheets-Sheet 2 I ZZZ/2722?? dzzdrewflfiaab 74 Filed Aug. 4, 1966 Nov. 12, 1968 A. F. RAAB 3,410,970

NEUTRAL SAFETY AND BACKUP, LIGHT SWITCH Filed Aug. 4, 1966 4 Sheets-Sheet 5 Nov. 12, 1968 A. F. RAAB 3,410,970

.NEUTRAL SAFETY AND BACKUP LIGHT SWITCH Filed Aug. 4, 1966 4 Sheets-Sheet 4 United States Patent 3,410,970 NEUTRAL SAFETY AND BACKUP LIGHT SWITCH Andrew F. Raah, Chicago, Ill., assignor, by mesne assignments, to Littelfuse Inc., a corporation of Texas Filed Aug. 4, 1966, Ser. No. 570,237 16 Claims. (Cl. ZOO-61.91)

ABSTRACT OF THE DISCLOSURE A neutral safety and backup light switch apparatus is provided for incorporation in an automatic transmission apparatus of an automotive vehicle also having engine starting means and backup light means, the automatic transmission apparatus including a transmission casing and a transmission means in said casing having a control member movable to park, reverse, neutral and forward positions in accordance with the operating conditions of the transmission means. The neutral safety and backup light switch apparatus is mounted within the transmission casing and operated by the control member therein and it provides for external electrical connection to the engine starting means and the backup light means. Where the automatic transmission apparatus also includes electrical- 1y operated control devices within the transmission casing, such as a cruise control, a variable pitch control, a direct downshift control, or the like, the switch apparatus of this invention may also make external electrical connections thereto.

The principal object of this invention is to provide a neutral safety and backup light switch for incorporation in such a transmission casing for such purposes.

Briefly, the switch apparatus of this invention includes a hollow casing member which is located within the transmission casing, which has a substantially flat inner reference surface and which has a hollow tubular extension extending outwardly from the housing member through an opening in the transmission casing exteriorly of the transmission casing, the tubular extension having an outer end closure wall. Means, preferably an O-ring, seals the tubular extension in the opening in the transmission casing.

A plurality of contact terminals, having contact surfaces substantially flush with the substantially flat inner reference surface of the housing member, have terminal extensions extending outwardly through openings in the end closure wall of the tubular extension for external electrical connection to the engine starting means and the backup light means for the automotive vehicle. The hollow housing member has a cover member having an elongated guide slot therein, and a carrier is slidably movable between the hollow housing member and the carrier, the carrier having an operating extension extending through the elongated guide slot in the cover member. Contacts are carried by the carrier and they are slidable along the substantially fiat inner reference surface of the housing member for sequentially engaging the contact surfaces of the contact terminals as the carrier is moved along the guide slot. A link interconnects the control member of the automatic transmission means and the operating extension of the carrier for longitudinally moving the carrier along the guide slot as the control member is moved to provide electrical connections through the contacts of the carrier and the contact terminals of the housing member to the engine starting means when the control member is in park and neutral positions and to the backup light means when the control member is in reverse position.

3,410,970 Patented Nov. 12, 1968 "ice Where the transmission apparatus includes electrical control means within the transmission casing, such as the aforementioned cruise control, variable pitch control, direct downshift control, or the like, one or more terminal connectors may extend outwardly through the hollow tubular extension and through openings in the end closure wall of the hollow tubular extension for making external electrical connections to such electrical control means.

Preferably, the hollow tubular extension extends from the substantially flat inner reference surface of the housing member, and a locating plug is secured in the tubular extension, the locating plug having a substantially flat inner reference surface which is substantially flush with and which forms part of the substantially flat inner reference surface of the housing member. The contact surfaces of the terminal contacts are received in and are substantially flush with the substantially flat inner reference surface of the locating plug and, hence, with the substantially fiat inner reference surface of the housing member. The terminal extensions of the contact terminals extend outwardly through openings in the locating'plug as well as through the openings in the end closure wall of the tubular extension. The one or more terminal connectors are received in the housing member and the locating plug adjacent the substantially flat inner reference surfaces thereof and they extend outwardly through openings in the locating plug and also through the openings in the end closure wall of the tubular extensions. Thus, the locating plug and the end closure wall of the tubular extension provide for accurate positioning of the contact terminals and the terminal connectors.

The terminal extensions of the contact terminals and the terminal connectors are secured and sealed in the tubular extension and in the openings in the end closure wall of the tubular extension by an apoxy resin, the outer portions of the openings in the end closure wall being provided with lip seals to confine and prevent escape of the epoxy resin through the openings.

Further objects of this invention reside in the details of construction of the switch apparatus and the cooperative relationships between the component parts thereof and with the automatic transmission apparatus with which it is used. 5

Other objects and adavntages of this invention will become apaprent to those skilled in the art upon reference to the accompanying specification, claims and drawings in which:

FIG. 1 is a sectional view through a portion of an automatic transmission apparatus illustrating the switch apparatus of this invention applied thereto;

FIG. 2 is an elevational view of the automatic transmission apparatus with a portion of the casing thereof broken away to more clearly illustrate the switch apparatus;

FIG. 3 is a perspective view of the switch apparatus of this invention;

FIG. 4 is a vertical sectional view through the switch apparatus with the cover portion of the housing and the carrier removed;

FIG. 5 is a vertical sectional view through the apparatus taken substantially along the line 55 of FIG. 4;

FIG. 6 is a perspective view of the cover portion of the switch apparatus;

FIG. 7 is an enlarged elevational view of the carrier of the switch apparatus;

FIG. 8 is a vertical sectional view through the carrier taken subtsantially along the line 88 of FIG. 7;

FIG. 9 is a perspective view of one of the contact means carried by the carrier;

FIG. is an elevational view of the inside of the hollow housing portion of the switch apparatus;

FIG. 11 is a sectional view taken substantially along line 11-11 of FIG. 10;

FIG. 12 is an enlarged sectional and perspective view of one of the openings in the end closure wall of the tubular extension of the housing portion of the switch apparatus;

FIG. 13 comprises exploded perspective views of the contact terminals and terminal connectors for making external electrical connections;

FIG. 14 is a plan view of the locating plug which is secured in the tubular extension of the housing portion;

FIG. 15 is a sectional view through the locating plug taken substantially along the line 15-15 of FIG. 14; and

FIG. 16 is a partial sectional view through the closure plug taken substantially along the line 16-16 of FIG. 14 but showing a contact terminal mounted therein.

Referring first to FIGS. 1 and 2, the neutral safety and backup light switch apparatus of this invention is generally designated at 10 and it is shown mounted in an automatic transmission apparatus 11. The automatic transmission apparatus includes a casing 12 in which a control member 13 is pivotally mounted on a pivot 14. The control member 13 is movable to park, reverse, neutral and forward positions such as drive and low in accordance with the operating conditions of the transmission means. The control member 13 has a part 15 thereof provided with a plurality of detent notches which are engaged by a follower 16 carried by a spring 17 for releasably holding the control member 13 in its various positions such as park, reverse, neutral, drive and low. A link 18 is connected to the control member 13 and is provided with a hook 19 receivable in a slot 36 of the carrier 83 of the switch apparatus 10 for moving the carrier as the control member 13 is moved. The switch apparatus 10 is secured in place within the casing 12 by a screw 21 and the casing 12 is provided with an opening through which the tubular extension of the switch apparatus extends externally of the casing. The automatic transmission apparatus 11 may also include electrically operated control devices (not shown) within the casing 12, such as a cruise control, a variable pitch control, a direct downshift control, or the like. The switch apparatus of this invention provides for external electrical connection to the engine starting means and the backup light means (not shown) of the automotive vehicle for permitting starting of the automotive engine when the control member 13 of the automatic transmission apparatus is in park or neutral position and for operating the backup light means when the control member 13 is in the reverse position. The switch apparatus of this invention also provides for external electrical connection to the electrically operated control devices within the transmission casing 12.

Referring now to FIGS. 3 to 6 and 10 to 12, the switch apparatus of this invention includes a housing portion 25 which is preferably formed from a high temperature synthetic plastic material such as nylon or zytel or the like which is capable of withstanding temperature variations from about 20 F. to about +275 F. and which has a coefiicient of thermal expansion corresponding substantially to that of steel or the like. The housing portionis hollow and is provided with a marginal wall 26 and a substantially flat inner reference surface 27. The housing portion 25 is provided with an integral hollow tubular extension which extends from the substantially flat inner reference surface 27 and which is provided at its end with a closure end wall 29. The circumference of the tubular extension 28 is provided with an annular groove 30 for receiving an O-ring 31 for sealing the tubular extension 28 in the opening 20 in the transmission casing 12. The tubular extension is also provided with further

annular grooves

32 and 33 for receiving a cap of a connectortnot shown) which makes external electrical connection to the contact terminals and the connector terminals of the switch apparatus.

The end closure wall 29 of the tubular extension is provided with four openings 35 therethrough and a pair of other openings 36 thcrethrough. The openings 35 are for the purpose of receiving the contact terminals and the openings 36 are for the purpose of receiving the connector terminals. The inner portions of these

openings

35 and 36 are flared as indicated at 37 and the outer edges of the

openings

35 and 36 are provided with inwardly facing lip seals 38 as shown more clearly in FIG. 12. The hollow tubular extension 28 adjacent to its juncture with the housing portion 25 is recessed as indicated at for receiving a locating plug 41.

The locating plug 41 is illustrated in more detail in FIGS. 13 to 16. The locating plug 41 is also preferably made of high temperature synthetic plastic material, such as nylon or zytel or the like and it has an inner reference surface 39 which is substantally flush with the inner reference surface 27 of the housing member when it is mounted in the recess 40 in the housing member. The locating plug 41 is provided with four openings 42 therein for receiving the contact terminals. The locating plug 41 is also provided with openings 43 for receiving the connector terminals. The inner reference surface 39 of the locating plug 41 is provided with relatively deep recesses 44 adjacent the

openings

42 and 43 so as to provide clearance for the contact terminals and the connector terminals where they are bent. The inner reference surface 39 of the locating plug 41 is also provided with relatively shallow recesses 45 for receiving and locating the contact terminals and the connector terminals substantially flush with the inner reference surface of the locating plug 41 and, hence, the inner reference surface of the housing portion 25. The locating plug 41 is also provided with a tapered portion 46 and an edge opening 47 to provide an opening between the locating plug 41 and the housing portion 25 when the plug is secured in the housing portion. The locating plug 41 is also provided with an opening 48 therein substantially diametrically opposite from the opening 47 which also communicates with the interior of the tubular extension 28.

The contact terminals and the connector terminals are shown in more detail in FIG. 13. There are two contact terminals 50 and two contact terminals 54 which are received in the openings 42 in the locating plug 41 and there is a connector terminal 58 and a connector terminal 63 which are received in the openings 43 in the 10- cating plug 41. Each contact terminal 50 includes

contact surface portions

51 and 52 and a terminnal extension 53. The contact terminals 50 are inserted through two of the openings 42 and the contact surfaces 51 and 52 are received in the recesses in the locating plug 41 and are accurately guided with respect to depth by the recesses 45. The contact terminals 50 may be suitably secured in place in the locating plug 41 by a suitable epoxy resin which is received in the relatively deep recesses 44 underneath the contact surfaces 51 and 52. Each of the contact terminals 54 includes a contact surface 55 and a terminal extension 56. Here, also, the contact terminals 54 are inserted through the other two openings 42 in the locating plug 41 and the contact surfaces 55 engage the relatively shallow recesses 45 for accurately positioning the contact terminals 54 with respect to depth. As in the case of the contact terminals 50, the contact terminals 54 may be secured in place in the locating plug 41 by a suitable epoxy resin contained in the deeper recesses 44.

The connector terminal 58 includes a portion 59 which lies substantially flush with the inner reference surfaces 39 and 27 of the locating plug and the housing portion, an extension 60 extending through one of the openings 43 and a connector portion 61 extending along the inner reference surface 27 Here, the portions 59 of the connector terminal are also guided by a recess 45 in the locating plug 41 and by a. corresponding recess in the inner reference surface of the housing portion. The connector terminal 63 includes a portion 64 extending substantially flush with the inner reference surfaces 39 and 27 of the locating plug and the housing portion, an extension 65 extending through the other opening 43 in the locating plug and a terminal extension 66 lying along the inner reference surface 27 of the housing portion, the portion 64 of the connector terminal 63 being guided by the recess 45 in the locating plug 41 and by a corresponding recess in the housing portion 25. The

connector terminals

58 and 63 may be suitably secured in the locating plug 41 by epoxy resin contained in the deeper recesses 44.

The contact terminals and 54 and the

connector terminals

58 and 63 are first secured in the locating plug 41 as described above and then the assembly is inserted into the tubular extension 28, the

terminal extensions

53 and 56 of the contact terminals extending through the openings 35 in the end wall 29 and the extensions and 65 of the connector terminals extending through the openings 36. These

extensions

53, 56, 60 and 65 are tightly gripped by the lip seals 38 of the

openings

35 and 36. After the locating plug 41 is secured in the recesses 40 in the tubular extension 28, the assembly is turned so that the tubular extension 28 faces downwardly and then an epoxy resin is inserted through the openings 47 and/or 48 into the tubular extension. The epoxy resin flows into the flared portions 37 of the

openings

35 and 36 and leakage of the epoxy resin beyond the

openings

35 and 36 is prevented by the lip seals 38. The epoxy resin then solidifies and firmly holds the contact terminals and the connector terminals in place in the end closure wall 29 of the tubular extension as indicated at in FIG. 5. In this way, the contact terminals and the connector terminals are secured in place at two points in the housing to provide accurate contact placement and a precision made switch apparatus. The contact surfaces of the contact terminals are substantially flush with the substantially flat inner reference surfaces 39 and 27 of the locating plug and the housing portion so as to provide free movement of contact means carried by a carrier along such surfaces. The contact surfaces are accurately positioned and this is necessary since the make and break of the contacts by the contact means requires precision operation.

The hollow housing portion 25 is provided at its periphery with a plurality of openings 73 for receiving tabs of a cover member, with a locating wall 67 having notches for receiving the

extensions

61 and 66 of the

connector terminals

59 and 63 and a locating pin 74 to assist in locating the cover portion of the housing. The cover portion of the housing is shown at 75 in more detail in FIG. 6. It has a wall portion provided with a guide slot 76 and sides provided with tabs 77 which are bent over into the slots 73 in the housing portion for securing the cover portion to the housing portion. The pin 74 is received in an opening in the cover portion to assist in properly locating the cover portion with respect to the housing portion. The cover portion 75 also has an extension 78 provided with an opening 79 which receives the screw 21 for mounting the switch apparatus within the transmission casing 12.

The cover portion 75 is also provided with an off-set tab 80 having an insulating sheet 81 secured thereto for accommodating the

extensions

61 and 66 of the

connector terminals

58 and 63 to provide for internal electrical connection to the control means which are located within the transmission casing.

Slidably mounted between the housing portion 25 and the cover portion 75 is a carrier '83, it having a body portion 84 arranged between the housing portion 25 and the cover portion 75 and an extension 85 extending through the guide slot 76 in the cover portion 75. The extension 85 is provided with a slot 86 for receiving the hook portion 19 of the link 18 so that as the link 18 is moved by the control member 13, the carrier 83 is moved along the

inner reference sunfaces

39 and 27 of the locating plug and housing member. The carrier 83, which is shown more clearly in FIGS. 7 to 9, has a pair of

slots

87 and 88 in the inner surface thereof for receiving contact means 89 and 90, respectively. The contact means 89 and 90 are the same in construction and they each include a pair of spherical projections 91 for making contact with the contact surfaces of the contact terminals and a dimple 92 acting as a spring seat for a spring 93 received in a hole in the carrier body 84. The contact means 89 and 90 each include extensions 94 having holes 95 extending into slots 96 in the carrier body adjacent the ends of the

slots

87 and 88, the carrier body 84 having small projections 97 extending into the slots 95 for holding the contact means 89 and 90 against excessive outward movement by the springs 93. The surface of the body member 84 is provided with elongated projections 98 to limit the amount of tilting movement of the carrier between the housing portion and the cover portion as the carrier is moved along the guide slot 76. The spherical projections 91 of the contact means 89 and 90 are urged against the substantially flat inner reference surfaces of the locating plug 41 and the housing portion 87 and as the carrier is moved longitudinally of the guide slot 76, the spherical projections 91 of the contact means 89 and 90 sequentially engage the contact surfaces 51 and 52 of the contact terminals 50 and the contact surfaces 55 of the contact terminals 54. The contact means 89 of the carrier 83 bridge the contact surfaces 51 (when the carrier is moved to park position and bridge the contact surfaces 55 when the carrier is moved to reverse position. The contact means 90 bridge the contact surfaces 52 when the carrier is moved to neutral position. In this way, the engine starting means which is electrically connected through the contact terminals 50 are activated when the carrier is in park or neutral position and the back up light means are activated when the carrier is moved to reverse position.

The electrical control devices within the transmission casing, such as a cruise control, a variable pitch control, or a direct downshift control, are internally electrically connected to the

extensions

60 and 65 of the

connector terminals

59 and 63 and are externally connected to suitable switching devices by the

extensions

61 and 66 of such connector terminals. If more than two control devices within the transmission casing are to be controlled, an additional connector terminal may be inserted through a knockout 100 in the end closure wall 29 of the tubular extension, as shown in FIG. 10, through the opening 47 in the plug member 41, as shown in FIG. 5, and along a recess 101 in the reference sunface 27 of the housing portion 55 and through an additional notch in the wall portion -67 of the housing member, as shown in FIG. 4. The cover member 75 and the

connector terminals

58 and 64 are preferably formed of steel having a thermal coefficient of expansion substantially the same as that of the synthetic plastic housing portion 25, the

contact terminals

50 and 54 are preferably formed of bright dipped half hardened brass and the contact means are preferably formed of bright dipped electrolytic copper which is half hardened. By utilizing these various materials for these various parts the relationships of the parts are substantially unaffected by the aforementioned wide range of temperatures to which the switch apparatus of this invention may be subjected.

While for purposes of illustration, one form of this invention has been disclosed, other forms thereof may become apparent to those skilled in the art upon reference to this disclosure and, therefore, this invention is to be limited only by the scope of the appended claims.

I claim:

1. In an automotive vehicle having engine starting means, back up light means and an automatic transmission apparatus including a casing and a transmission means in said casing having a control member movable to park, reverse, neutral and forward positions in accordance with the operating conditions of the transmission means, the improvement comprising a neutral safety and back up light switch apparatus in said transmission casing and comprising a hollow housing member in said casing having means providing a substantially flat inner reference surface, a hollow tubular extension extending from said housing member through an opening in the transmission casing exteriorly of the casing and provided with an outer end closure wall, means sealing the hollow tubular extension in the opening in the transmission casing, a plurality of contact terminals having contact surfaces substantially flush with said substantially flat inner reference surface of said housing member and terminal extensions extending outwardly through openings in said end closure wall of said hollow tubular extension for external electrical connection to the engine starting means and the back up light means of the automotive vehicle, a cover member on said hollow housing member and having an elongated guide slot therein, a carrier slidably movable between the housing member and the cover member and having an operating extension extending through the elongated guide slot in the cover member, contacts carried by the carrier and slidable along said substantially fiat inner reference surface of said housing member for sequentially engaging the contact sunfaces of the contact terminals as the carrier is longitudinally moved along the elongated guide slot, and a link interconnecting the control member of the transmission means and the operating extension of the carrier for longitudinally moving the carrier along the guide slot as the control member is moved to provide electrical connections through the contacts of the carrier and the contact terminals of the housing member to the engine starting means when the control member is in park and neutral positions and to the back up light means when the control member is in reverse position.

2. An apparatus as defined in claim 1 wherein said hollow tubular extension extends from said substantially flat inner reference surface of said housing member, wherein a locating plug is recessed in said tubular extension and has a substantially fiat inner reference surface substantially flush with and forming part of the substantially fiat inner reference surface of said housing member, wherein said contact surfaces of said contact terminals are received in and are substantially flush with the substantially fiat inner reference surface of said locating plug, and wherein the terminal extensions of said contact terminals extend outwardly through openings in said locating plug as well as through the openings in the end closure wall of said tubular extension.

3. An apparatus as defined in claim 1 wherein the terminal extensions of said contact terminals are sealed in said tubular extension and in the openings in the end closure wall of said tubular extension by an epoxy resin.

4. An apparatus as defined in claim 3 wherein the outer portions of the openings in the end closure wall of said tubular extension are provided with lip seals to prevent escape of the epoxy resin through said openings.

5. An apparatus as defined in claim 2 wherein the terminal extensions of said contact terminals are sealed in said tubular extension between the locating plug and the end closure wall of said tubular extension and in the openings in the end closure wall of said tubular extension by an epoxy resin.

6. An apparatus as defined in claim 5 wherein the outer portions of the openings in the end closure wall of said tubular extension are provided with lip seals to prevent escape of the epoxy resin through said openings.

7. An apparatus as defined in claim 1 wherein the means for sealing the hollow tubular extension in the opening in the transmission casing comprises an annular groove in the exterior of the tubular extension and an O-ring seated in said annular groove.

8. In an apparatus as defined in claim 1 wherein the transmission apparatus also includes in the transmission casing electrical control means for the operation of the transmission means, and wherein at least one terminal connector for making external electrical connection to the electrical control means within the transmission casing extends outwardly through said hollow tubular extension and through openings in said end closure Wall of said hollow tubular extension.

9. In an apparatus as defined in claim 2 wherein the transmission apparatus also includes in the transmission casing electrical control means for the operation of the transmission means, and wherein at least one terminal connector for making external electrical connection to the electrical means within the transmission means is received in the housing member and the locating plug adjacent the substantially flat inner reference surfaces thereof and extends outwardly through openings in said locating plug and the end closure wall of said tubular extension.

10. In an apparatus as defined in claim 8 wherein the terminal extensions of said contact terminals and said at least one terminal connector are sealed in said tubular extension and in the openings in the end closure wall of said tubular extension by an epoxy resin.

11. In an apparatus as defined in claim 9 wherein the terminal extensions of said contact terminals and said at least one terminal connector are sealed in said tubular extension between the locating plug and the end closure wall of said tubular extension and in the openings in the end closure wall of said tubular extension by an epoxy resin.

12. An apparatus as defined in claim 10 wherein the outer portions of the openings in the end closure wall of said tubular extension are provided with lip seals to prevent escape of the epoxy resin through said openings.

13. An apparatus as defined in claim 11 wherein the outer portions of the openings in the end closure wall of said tubular extension are provided with lip seals to prevent escape of the epoxy resin through said openings.

14. An apparatus as defined in claim 1 wherein two laterally spaced contact surfaces are provided for each park, reverse and neutral positions and wherein the contact surfaces for the park, reverse and neutral positions are longitudinally spaced with respect to each other, and wherein the contacts carried by the carrier sequentially bridge the respective laterally spaced contact surfaces as the carrier is longitudinally moved to the park, reverse and neutral positions.

15. An apparatus as defined in claim 14 wherein the contacts carried by the carrier are spring biased toward the substantially fiat inner reference surface of the housing member and the substantially flush contact surfaces.

16. A switch apparatus comprising a hollow housing member having a wall provided with openings therethrough, the inner portions of said openings being flared and the outer portions of said openings being provided with lip seals, contact terminals having switch contact means within the housing member and terminal extensions extending outwardly through the openings in said wall and being engaged by said lip seals, and an epoxy resin in said flared openings securing and sealing said terminal extensions in said openings in said wall and being confined from external escape by said lip seals.

References Cited UNITED STATES PATENTS 2,894,089 7/1959 Newcomb 2006l.54

ROBERT K. SCHAEFER, Primary Examiner.

M. GINSBURG, Assistant Examiner.