US 3898401 A
A speed change position detecting device in an automatic transmission for an automobile, comprising a turning shaft adapted to turn in response to a control rod and to manipulate a manual valve, a cam plate fixed to the turning shaft and having protuberant cams thereon, push rods engageable with any of the protuberant cams at various shift positions of the cam plate as are set by the control rod for regulation of the speed change ranges of the transmission, an opposed contact system switch having a plurality of switch means which are selectively closed when the push rods are engaged with and pressed by the protuberant cams, and means to settle the switch on the housing of the transmission.
Description (OCR text may contain errors)
United States Patent [191 Noba et a1.
[451 Aug. 5, 1975 TRANSMISSION CONTROLLED, SPEED CHANGE POSITION DETECTING SWITCH DEVICE  Inventors: Motoi Noba, Toyota; I-Iatsuyoshi Yoshida, Toyoake, both of Japan  Appl. No.: 398,813
 Foreign Application Priority Data 200/61.54, 61.56, 61.85-61.91, 153 L, 153 LB, 166 BE, 166 BE, 168 B, 159 R, 27 R, 30 R, 38 C, 159 R; 123/179 K  References Cited UNITED STATES PATENTS 2,324,819 7/1943 Butzbach 123/179 K 2,602,126 7/1952 Morrison.... 200/153 L X 2,970,199 l/196l Dull et al. 200/153 L t 3 i l4 3,047,682 7/1962 Hults 200/159 X 3,049,599 8/1962 Eck et a1 200/153 LB X 3,198,893 8/1965 Mapelsden 200/153 L X 3,404,244 10/1968 Amis, Jr. et a1... 200/159 R 3,410,970 ll/1968 Raab ZOO/61.91 3,584,172 6/1971 Owen ZOO/153 L 3,624,330 11/1971 Bognar et a1 200/159 R 3,637,961 l/1972 Fiddler et a1. l ZOO/61.86 3,637,962 1/1972 Fiddler et a1. ZOO/61.86 3,705,964 12/1972 Romanowski et a1 200/38 C X Primary Examiner-James R. Scott Attorney, Agent, or FirmStevens, Davis, Miller & Mosher  ABSTRACT A speed change position detecting device in an automatic transmission for an automobile, comprising a turning shaft adapted to turn in response to a control rod and to manipulate a manual valve, a cam plate fixed to the turning shaft and having protuberant cams thereon, push rods engageable with any of the protuberant cams at various shift positions of the cam plate as are set by the control rod for regulation of the speed change ranges of the transmission, an opposed contact system switch having a plurality of switch means which are selectively closed when the push rods are engaged with and pressed by the protuberant cams, and means to settle the switch on the housing of the transmission.
5 Claims, 14 Drawing Figures IO 7 I A a-se nun 90 g 8 PATENTEDAUG 51915 3,839,401
SHEET i a liwa 1 PATENTEDAUB 51915 3,898,401
SHEET 3 FIG. I4
TRANSMISSION CONTROLLED, SPEED CHANGE POSITION DETECTING SWITCH DEVICE The present invention relates to a device which detects a speed change position in an automatic transmis sion for use mainly in vehicles.
In a vehicle with an automatic transmission, for example, an automobile with a torque converter, a detecting switch for each position of the operating range of the automatic transmission has heretofore been additionally provided. Since the switch is mounted on the linkage of a shift lever, it is liable to an erroneous operation on account of the shaking of the linkage. There has also been made a proposal in which the detecting switch is mounted directly on the transmission. Since, however, the switch is actuated in the slide system, the proposed measure has the disadvantages that the burning and wear of contacts are prone to occur and that a large error of angle in the case of utilizing the turning motion is prone to induce an error in the detecting position.
The principal object of the present invention is to provide a speed change position detecting device in an automatic transmission in which a cam plate is turned directly by a turning shaft for manipulating a manual valve, to actuate the respective switching means through the corresponding push rods, whereby the change-over time of the manual valve and the operating time of each switch can be reliably made coincident, any erroneous operation attributed to, for example, the mounting play of the member of the angular error can be perfectly eliminated, and the speed change position can be accurately detected.
Another object of the present invention is to provide a speed change position detecting device in an automatic transmission according to which the whole device is equipped directly on the housing of the transmission, the settlement of the mounting position can be easily made by the combination between an aperture and a boss or the like, and adjustments at the actuation of switching means are made unnecessary by fabricating protuberant cams and push rods at precise positions, whereby the maintenance and control are made remarkably simple.
Still another object of the present invention is to provide a speed change position detecting device in an automatic transmission which adopts a switch of the so called opposed contact system in which switching means are actuated by means of push rods, whereby the burning, wear etc. of contacts can be satisfactorily prevented, and a stable operation is effected over a long period of time.
Other objects and aspects of the invention will become apparent from the following detailed description of embodiments taken with reference to the accompanying drawings, in which:
FIG. 1 is a schematic vertical section of a speed change position detecting device in an automatic transmission according to the present invention;
FIGS. 2 to 7 are schematic plan views showing the positional relations between protuberant cams and push rods in various speed change ranges of the automatic transmission, among which:
FIG. 2 shows the state of the parking (P) range,
FIG. 3 shows the state of the reverse (R) range,
FIG. 4 shows the state of the neutral (N) range,
FIG. 5 shows the state of the (D range including the first to third speeds,
FIG. 6 shows the state of the (D range including the first and second speeds, and
FIG. 7 shows the state of the (L) range including only the first speed; and
FIGS. 8 to I4 are explanatory views of a sealed switch which is a switch of the opposed contact system as is mounted on the speed change position detecting device according to the present invention, among which:
FIG. 8 is a plan view, partly broken away, of the sealed switch,
FIG. 9 is a bottom view of the sealed switch,
FIG. 10 is a side view in which an insulating body constituting the sealed switch is sectioned along a line I0-I0 in FIG. 8, while a cover member is sectioned along a line I010' in FIG. 8,
FIG. 11 is a plan view of the insulating body,
FIG. 12 is a side sectional view taken along a line I2-I2 in FIG. 11,
FIG. 13 is a plan view with bridging contact pieces omitted from FIG. 11, and
FIG. 14 is a perspective view of the bridging contact piece.
As shown in FIG. 1, the speed change position detecting device in an automatic transmission according to the present invention has a turning shaft 3, for manipulating a manual valve, mounted on a bracket 2 which is provided at a housing 1 of the transmission. At an end of the turning shaft 3, a lever 4 is secured. A control rod 5 joining to a shift lever is engagedly secured to the lever 4.
Thus, when the shift lever is manipulated for the regulation of speed change ranges, namely, for the selection of an operating range, the turning shaft 3 is turned by an angle of turning corresponding to the manipulation, and a manual valve lever 6 is moved.
The bracket 2 is formed with a switch mounting hole 7 and a locating aperture 8. In the switch mounting hole 7, there is a fitted and fixed the lower part of a cover member 9 which constitutes a sealed switch being a switch of the opposed contact system. In the locating aperture 8, there is fittedly inserted a boss 10 which is provided at the upper part of the cover member 9.
The cover member 9 is provided at its lower part with a reduced diameter portion, and is formed into a T- shaped configuration in longitudinal section. The upper part covers an insulating body constituting the sealed switch as will be stated below, while the lower part formed into the cylindrical portion 9a covers push rods.
The mounting position of the sealed switch S relative to the housing I of the transmission is settled by the ac tion between the switching mounting hole 7 as well as the locating aperture 8 and the cylindrical portion 9a as well as the boss 10 fittedly inserted into them.
The sealed switch being the opposed contact system switch is constructed as illustrated in FIGS. 8 to 14.
In the figures, reference numeral 20 designates the aforesaid insulating body which is made of a synthetic resin and which has the shape of a shallow roundbox consisting of a botton wall 21 and a peripheral wall 22. Placed on the end face of the peripheral wall 22 is the peripheral edge of a flexible rubber partition plate 24 which closes the opening portion of the body 20. The cylindrical portion 9a at the lower part of the cover member 9 is joined onto the rubber partition plate 24. The outer periphery of the peripheral wall 22 is fitted into the upper part of the cover member 9.
The upper end edge part 25 of the cover member 9 is bent into a stepped part 26 formed in the peripheral wall 22. An O-ring 27 is interposed between the stepped part 26 and the end edge part 25, to provide sealing.
The rubber partition plate 24 has its peripheral edge tightly held between and fixed by the end face of the peripheral wall 22 and the cylindrical portion 9a of the cover member 9, so that a sealed chamber 28 is defined in the insulating body 20.
As shown in FIG. 13, several pairs of terminals 29a, 29b and 29c are inserted through the bottom wall 21 of the insulating body 20 in a manner to be annularly arrayed. The end faces of the respective terminals are made fixed contacts 30a, 3b and 300. Protuberant portions 31, the adjacent ones of which hold each pair of the fixed contacts 30a, 30b or 300 therebetween, are formed on the inside surface of the bottom wall 21.
The protuberant portions 31 constitute vertical motion guides 33a, 33b and 330 for bridging contact pieces 32a, 32b and 320 as will be stated below.
A pin-like projection 34 slightly lower than the peripheral wall 22 is provided at the center of the bottom wall 21. Spring receiving holes 35a, 36a; 35b, 36b; and 350, 360 are formed between the paired fixed contacts 30a and 30a, 30b and 30b, and 300 and 30c, respectively, so as to present a substantially inverted T contact in the longitudinal section of the bottom wall. A coiled spring 37 is fitted into each of the spring receiving holes.
As illustrated in FIG. 14, the bridging contact pieces 32a, 32b and 32c are formed into the substantially inverted T shape. They are loosely fitted to the vertical motion guides 33a, 33b and 330 referred to above. Each bridging contact piece is formed with contact projections 38 corresponding to the pair of the fixed contacts. As shown in FIG. 10 and FIG. 12, such bridging contact piece is held in pressed contact with the inside surface of the rubber partition plate 24 so that the coiled springs 37 are contacted with the lower surface of the bridging contact piece.
In the cylindrical portion 9a of the cover member 9, sliding holes 39a, 39b and 39c substantially corresponding to the spring receiving holes 36a, 36b and 360 are penetratingly provided. The outer end part of each sliding hole has its diameter reduced, to form a shoulder portion 40.
Shown at 41 are the second push rods which are loosely fitted in the sliding holes 39a, 39b and 39c and below the shoulder portions 40 thereof (as viewed in FIG. 10). At the inner ends of the second push rods 41, there are formed pressing projections 42 which correspond individually to. the bridging contact pieces 32a, 32b and 320 through the rubber partition plate 24. The part of each second push rod 41 above the pressing projection 42 is made a cylinder. in which a self-return spring 43 is loosely inserted.
Reference numerals l1, l2 and 13 indicate the first' push rods which protrude out of the sliding holes 39a, 39b and 390, respectively. An expanded diameter portion 44 of each first push rod at its part inserted inwardly from the shoulder portion 40 is loosely fitted into the cylindrical part of the second push rod 41, and is held in contact with the self-return spring 43.
To the cylindrical portion or the reduced diameter portion 9a of the cover member 9, a rubber packing 45 is fittedly secured. Further, an O-ring 46 is fitted to the peripheral part of the cylindrical portion 9a as is close to the outer end thereof. Thus, the insertion of the reduced diameter portion into, for example, an oil chamber can be met.
With the sealed switch being the opposed contact system switch of the above construction, the state illustrated in FIG. 10 is established so that the second push rods 41 are elastically contacted with the rubber partition plate 24 by the elastically expanding action of the self-return springs 43, and that the first push rods 11, I2 and 13 have the enlarged diameter portions 44 elastically supported on the inside surfaces of the shoulder portions 40.
When any of the first push rods 11, 12 and 13 is depressed, the self-return spring 43 contacted with the particular first push rod is resiliently contracted. Simultaneously therewith, the second push rod 41 is elastically pressed to cause the rubber partition plate 24 to bend inwardly. Any of the bridging contact pieces 32a, 32b and 320 that is held in contact with the bending part moves in the sealed chamber 28 against the urging force of the springs 37, and is brought into contact with the corresponding fixed contact pair 30a, 30b or 300, to give rise to the operation of switch on. At that time, the pin-shaped projection 34 prevents the bending of the rubber partition plate 24 from exerting any influence on the other bridging contact pieces.
In accordance with the sealed switch in the speed change position detecting device of the present invention, a plurality of switch means in which the bridging contact pieces are separably provided in opposition to the fixed contact pairs are sealedly disposed in the sealed chamber whose one side is closed by the rubber partition plate. The switching operation of the required switch means can be induced in such way that the rubber partition plate is bent by the selective depression of the plural self-returning push rods which correspond to the respective bridging contact pieces through the rubber partition plate. In this case, the bridging contact pieces of the other switch means hold the elastic contact to the inner surface of the rubber partition plate by the resilience of the springs. In consequence, even if they undergo slight movements in position under the influence of the bending of the partition plate, there is quite no fear of the occurrence of any erroneous operation of the switch as is attributed to the positional movements. Owing to the antagonism between the springs acting for the respective bridging contact pieces and the rubber partition plate to be depressed at the different positions by the plural push rods, the plural switch means can be accommodated in the single sealed chamber in the manner of preventing any erroneous operation, and the construction for sealing the respective switch means can be made simple.
As previously set forth, at the cylindrical portion 9a of the cover member 9, the three push rods ll, 12 and 13 are elastically protruded in different phases and normally downwardly. When each push rod is pressed upwards, the switch means corresponding thereto is held in the contacted state. The push rods 11, 12 and 13 are arranged above the position of the extending part of the manual valve lever 6.
On the upper surface of the front end of the manual valve lever 6, there is fixed a cam plate 14, on which a plurality of protuberant earns 15, 16, 17 and 18 are provided concentrically at different diameters. The respective protuberant cams are constructed so that when the manual valve lever 6 is turned for the selection of the operating range, they can be selectively contacted with any of the push rodsll, 12 and 13 so as to press it upwards. I
Now, lets consider the case of athree-speed automatic transmission. The push rod 11 'actuates the switch means for turning a starter circuit on,. the push rod 12 actuates the switch means for turning a back-up light circuiton, and the push rod 13 actuates the switch means for turning a seat belt warning circuit on. The automatic transmission has the speed change ranges regulated into thesix ones of a range (P) being the parking range,'a range (R) being the reverse range, a range (N) being the neutral range, a-range (D including the first to third speeds; arange (D including the first and second: speeds, and a range (L) including only the first speed. Upon manipulation of the shift lever, the manual. valve V is changed-over, and the respective operating ranges are selected Since the cam plate 14 is fixed to the front end of the manual valve lever 6, the foregoing protuberantcams 15, 16, 17 and 18. move by the same turning angle as the turning angle of the lever 6 at the change-over of the manual valve V, and engagethe respective push rods as stated below.
When, as illustrated in FIG. 2, the control rod 5 is moved in the direction of an arrow X and the manual valve V is regulated to the (P) range, the cam plate 14 moves by the same phase, to establish the state in which the protuberant cam 15 presses the push rod 15, while the other protuberant earns 16, 17 and 18 and the push rods 12 and 13 are not engaged. Owing to the pressing of the push rod 11, the starter circuit is brought into the on state, and the automobile can be started at any time.
When, as illustrated in FIG. 3, the manual valve V is regulated to the (R) range, there is established the state in which the protuberant cam 17 presses the push rod 12, the other protuberant cams and push rods are not engaged, the back-up light circuit is made on, and back-up lights can be lit at any time.
Further, when the manual valve V is regulated to the (N) range as in FIG. 4, the protuberant cam 16 presses the push rod 11 again, the other protuberant cams and push rods are not engaged, and the starter circuit is brought into the on state.
Illustrated in FIG. 5 is a case where the manual valve V is regulated to the (D range. In this case, the protuberant cam 18 presses the push rod 13, the other protuberant cams and push rods are not engaged, the seat belt warning circuit is brought into the on state, and the control is so made that unless a seat belt is put on, the starting of the automobile etc. are impossible.
The protuberant cam 18 is formed so as to have a long stroke. Whether the manual valve V is regulated to the (D range as illustrated in FIG. 6 or it is regulated to the (L) range as illustrated in FIG. 7, the protuberant cam 18 and the push rod 13 engage, whereas the other protuberant cams and push rods do not engage.
As a result, the push rod 11 is pressed and the starter circuit is brought into the on state only in the ranges (P) and (N), and the starter circuit is maintained in the *off" state in the other ranges. There is accordingly prevented such inconvenience that when the shift lever is erroneously manipulated at the non-operating time of the engine to locate the manual valve V at any range (D (D,), (L) or (R), a starting button is depressed, so the vehicle is rapidly started to cause an unforeseen accident. Similarly, the back-up lights are prevented from being lit in the ranges other than the (R) range. Thecontrol can be made so that the seat belt warning circuit may not operate in the ranges other than the (-D,),-(-D and (L) ranges, and that unless the seat belt is put on, the starting of the vehicle may be impossible in these ranges (D (D and (L).
What is claimed is:
1. A speed'change position detecting device for an automatic transmission comprising:
a valve movable to change the operating range of an automatic transmission among park, reverse, neutrail and forward positions;
a rotatable shaft;
manual shift lever connected to said shaft to turn the same;
a valve lever interconnecting said shaft to said valve 7 vso that the valve is moved in response to turning of said shaft by said shift lever;
a switch means mounting said switch on the housing of the transmission and in a position to present movable contacts in the vicinity of the path of movement of said valve lever; and
a cam plate integral with said valve lever, said plate having a plurality of cams arranged concentrically but in different radii so as to coact with said movable contacts as said cam plate moves with said valve lever.
2. The speed change position detecting device according to claim 1, wherein the mounting means of said contact switch to said housing comprises a bracket provided at said housing of said transmission, a mounting hole for said switch as is formed in said bracket, and a locating aperture formed in said bracket, and wherein said opposed contact system switch is fittedly fixed into said mounting hole, while a box provided at said switch is fittedly inserted into said locating aperture, whereby the mounting position of said switch on said housing is fixed.
3. The speed change position detecting device according to claim 1, wherein the switch comprises:
an insulating body which is shaped into a shallow box,
a cover member which is applied and fixed to an opening part of said insulating body,
a flexible rubber partition plate which is extended over said opening part of said insulating body,
a sealed chamber which is defined by an inside surface of said rubber partition plate and said insulating body in such manner that said rubber partition plate is held by and between said opening part and said cover member,
a plurality of pairs of fixed contacts which are disposed in said sealed chamber,
bridging contact pieces which are opposed to the respective pairs of fixed contacts and which separably correspond to said respective pairs of fixed contacts, and
self-returning push rods which are disposed in said cover member so as to individually correspond to the respective bridging contact pieces through said rubber partition plate.
4. The speed change position detecting device according to claim 3, wherein said insulating body comprises:
a bottom wall,
a peripheral wall,
a plurality of pairs of terminals which are penetratingly inserted through said bottom wall in a manner to be annularly arrayed and whose internal end faces comprising said fixed contacts,
protuberant portions formed on an inside surface of said bottom wall so that the adjacent ones hold said each pair of fixed contacts therebetween,
said protuberant portions constituting vertical motion guides for said bridging contact pieces,
a pin-shaped projection which is formed at the center of said bottom wall so as to be slightly lower than said peripheral wall,
spring receiving holes which are protrusively provided between said each pair of fixed contacts,
coiled springs which are fittedly inserted into said spring receiving holes, and
contact projections which are provided at said each bridging contact piece in correspondence with said respective fixed contacts,
said bridging contact pieces being pressedly contacted with said inside surface of said rubber partition plate.
5. The speed change position detecting device according to claim 3, wherein said cover member comprises:
sliding holes which are penetratingly provided in correspondence with spring receiving holes,
each of said sliding holes having the diameter of its outer end part reduced to form a shoulder portion,
a second push rod which is loosely fitted into a part of said each sliding hole below said shoulder portion,
pressing projections which are formed at inner ends of said second push rods in a manner to individually correspond to said bridging contact pieces through said rubber partition plate,
a part of said each second push rod above said pressing projection being made a cylindrical portion,
a self-returning spring which is loosely inserted into said each cylindrical portion, and
a first push rod which is protruded out of said each sliding hole,
said each first push rod having an enlarged diameter portion, at its part inserted inwardly from said shoulder portion, loosely inserted into said cylindrical portion of said second push rod and thus being held in, contact with said self-returning spring.