US 3179765 A
Description (OCR text may contain errors)
A ril 20, 1965 R. M. DYKSTERHOUSE 3,179,765
SWITCH PARTICULARLY ADAPTED FOR SPEEDOMETER SOLENOID ACTUATION Filed Jan. 25, 1962 2 Sheets-Sheet 1 April 1965 R. M. DYKSTERHOUSE 3,179,765
SWITCH PARTICULARLY ADAPTED FOR SPEEDOMETER SOLENOID ACTUATION Filed Jan. 25, 1962 2 Sheets-Sheet 2 United States Patent SWlTCI-I PARTICULARLY ADAPTED FGR SPEEDOMETER SQLENQID ACTUATHON Robert M. Dylrsterhouse, Charles/nix, Mich, assignor, by mesne assignments, to Circuit Controls Corporation,
Petoskey, Mich, a corporation of Michigan Filed Jan. 25, 1962, Ser. No. 168,6b2
3 Claims. (Cl. 200-6158) case or housing is also important because it provides a a direct means for linkage with a speedometer control element or the like. The manually operable control element is selectively engageable with the operating pin of the switch as the control element is moved in .a tubular sleeve. Movement of the control member causes selected shouldering of the switch operating pin thereby closing the contactorof the switch. When the speedometer control element is moved :away from shouldering engagement the switchleaf, in obedience to release pressure upon the operating pin, returns the contacts to an open position with a quick pick oif from the contactor. Simultaneously, the pin, in following relationship with the control member repositions itself for repetitive operation.
Many mechanical, electrical, pneumatic and hydraulic devices require a compound form of control as for example, where a limited lineal movement is necessary from a position remote from the actual work and where an electrical circuit, for example, must be coordinated with the mechanical or lineal motion. An example occurs in trucks where the selection of a new speed range of gearing requires the energization of a separate speedometer. One portion of the action is mechanical or lineal. The
other portion of the action is electrically controlled. In
general, such situations are met by providing a limit switch which is energized or tie-energized upon motion would result in a labyrinth of wiring clutter. Ideally such controls should be located proximate to a central control panel adjacent to the location of the control element which must be manually acted upon by the driver, for example.
The present switch is particularly adapted for inside location at a selected position along the line served by a push-pull cable connection as exemplified in Bowden wire systems. The switch employs a straddle casing which hosts neatly upon a tubular sheath in ferrule encasing an actuating piston tor reciprocatingthe central control wire in a Bowden wire structure. The piggy-back construction adapts the switch for easy original installation and replacement .or service; While especially adapted to use with transmission selection mechanisms for speedometer fsole'noid actuation, the switch of the present invention has innumerable other ,uses where Bowden wire actuation re- 'quires coordinated electrical energization and deenergizalice tion. Further, the present invention utilizes a switch spring action completely adequate for pin return without auxiliary spring return and doing so over a long life because of its great simplicity and minimum throw. In addition, the particular leaf spring action is very last in avoidance of arcing at closing and opening of the contacts.
In usage the switches have shown excellent trouble free longevity outliving the Bowden wire systems into which they are integrated.
Accordingly the principal object of the present invention is to provide a unique switch unit for straddle positioning.
Another object is to provide a micro-type switch for integrating with a Bowden wire actuating system coordihating electrical control with lineal movement at or adjacent to the lineal actuation control member.
Another object is to provide a unique fast acting switch 7 structure wherein the case prov-ides a stop limiting full throw of the contact actuating leaf. and wherein the light spring action in the leaf accomplishes following return of the actuating pin without auxiliary springs or mechanism.
Still another object is to provide a suitable switch having long life characteristics which'is simple to fabricate and easy to install and maintain.-
Other objects including overall adaptability to coordinating Bowden wire actuation with selected actuation of electrical circuits and attendant economics resulting from the availability of such deviceswill beincreasingly clear as the description proceeds.
In the drawings:
FIGURE 1 is a side elevation view of a Bowden wire tubular ferrule and showing the switch of the present invention in piggy-back position 'astraddle the ferrule.
FIGURE 2 is another side elevation view and illustrates the ferrule of FIGURE 1 with a portion removed to illustrate the Bowden wire actuating piston reciprocably in the terrule.
FIGURE 3 is a partial cut away portion indicating piston engagement with the switch actuating pin causing selected movement of said pin.
FIGURE 4 is a top plan view of the switch in mounted position and in hidden edge indicating the position of the opening through the ferrule wall.
FIGURE 5 is a full cross section elevation view taken on the line V--V of FIGURE 4 and indicating the simple case construction dimensionally restricting the throw of the leaf spring element and indicating the switch in the open position.
FIGURE 6 is a detail of the cross section shown in FIGURE 5 and indicating the piston engagement and movement of the actuating pin to close the switch contacts.
FIGURE 7 is an exploded perspective view indicating the extreme simplicity of the switch.
General description In general the present invention comprises a leaf spring type actuation structure positioned by an upper encasement and housing member, both of these elements being prepared as by molding from high dielectric strength resin material. ,Upper and lower as thus used has reference to the FIGURE 1 orientation of the structure and as will be appreciated, this positioning may be reversed since the structure is operative from any selected location. The casing is adapted for straddle mounting over a tubular member, as for example a ferrule guiding reciprocating lineal movement of a piston element. A transverse opening is provided through the wall of the ferrule member and the actuation pin of the switch then depends or extends into the tube transversely of the axis of the tube.
This extension is adequate so long as it provides for an actuating interference with the lineally moving member or piston element. Location of the switch in straddle position is selected in accord with a desired point in lineal movement where coordinated electrical circuits require coordinated energization or deenergization. Overrun movement has no eifect on the switch provided the piston is of uniform cylindrical diameter. Selected upsets on the piston may be provided to establish zones of energization and deenergization where this is required since the actuating pin maintains following contact with the piston.
Until contact, as between piston element and switch pin, the switch occupies a normal (open or closed-shown open) position biased by the actuating leaf mechanism. The switch leaf actuating mechanism is moved against this bias by movement of the pin in accord with the piston engagement. Here the switch case provides an insulating blockage or limit to overrun of throw. This movement of the leaf urges a snap action contact movement in avoidance of arcing at the contacts. The leaf actuation structure and contactors are contained in two strips of flat spring stock as ordinarily selected for electrical equipment such as beryllium-copper alloys having good fatigue resistance and excellent conductive characteristics. Intermediate the two leaf elements an insulating block is provided for spaced retention of the leaf elements at one end and leaf elements and spaces are in turn sandwiched between the upper and lower insulating case elements.
The elimination of full throw by the leaf assures good operating bias on the actuating pin, gives excellent fast break action at the contactors and provides a longer life than anticipated in most bow type spring switches. Further, the switch is easily installed and easily integrated into existing wiring harness arrangement. It has proved very serviceable with Bowden wire type devices.
Specific description Referring to the drawings and particularly to FIGURE 1 thereof, a switch 11 in pig-a-back relation to a tubular ferrule 12 is shown in accord with the present invention. Electrical leads 13 and 14 are shown entering the switch cover 15, the leads 13 and 14 being generally parallel to the tubular ferrule 12. The base portion 16 of the switch 11 is provided with clevis legs 17 which straddle the tubular ferrule 12. An actuating pin 18 intermediate the clevis legs 17, and extending transversely through the base member 16, is provided which depends into the axial cavity of the tubular ferrule 12. As will beseen, the actuating pin 18 is biased axially so as to resiliently follow the movement of a member guided by the guide ferrule 12. As shown in FIGURE 1, the resilient bias has been overcome and the pin 18 is fully extended into the switch 11.
By reference to FIGURE 2 the guide ferrule 12 has been cut away to reveal its tubular character and the control piston element 19 is shown in the cavity 241 of the tubular ferrule 12. As will be appreciated, the piston element 19 is reciprocable axially in the ferrule 12 as by manual push-pull action on the control knob 21 secured to the piston element 19, limited in its travel by shouldering engagement with the ferrule 12.
Such an arrangement is characteristic of Bowden wire remote control cable actuating arrangements and the piston 19 is shown connected to a cable element 22 which reciprocates in accord with the piston 19 and correspondingly moves lineally in the sheath 23. A grommet element 24 establishes a crimp sleeve connection with the sheath 23. The sheath 23 as will be appreciated is flexible and houses the cable leading to a remote connection with mechanism (not shown) to be acted upon by the lineal stroke of the cable or core piece 22. Where, for example, the cable or core piece 22 activates a separate transmission, it is desirable that cooperating gauges and indicators, as for example, speedometers and solenoids therefor be energized. Other functions may also require electrical coordination but the specific application is mentioned as typical. By reference to FIGURE 3 the actuation of the switch 11 is understood in reference to the relationship between the actuating pin 18 and the piston 19 in the guide sleeve or ferrule 12. The actuating pin 13 radially depends into the cavity 20 of the ferrule 12 and through the opening 25 provided through the tubular wall of the ferrule 12. The pin 18 hence depends into an interference position with the stroke of the piston 19. The tip 26 of the pin 18 is rounded so as to accomplish radial and axial movement as the chamfer 27 on the end of the piston 19 engages the pin 18. The pin 18 is thus deflected against a resilient bias as will be seen as the description proceeds to accomplish selected energization or deenergization of the circuit served by the switch 11. The resilient bias on the pin 18 continues so that contact as between pin 13 and barrel of piston 1% is maintained. When the piston 19 is withdrawn from contact with pin 18, the pin 18 is returned to its initial rest position as shown in full line in the FIGURE 3.
In FIGURE 4 the switch 11 is shown in top plan view astraddle the ferrule 12 with the depending legs 17 flanking the ferrule 12 so as to locate the actuator 18 in register with the opening 25 defined in the ferrule 12 so as to provide an interference contact as between the pin 18 and the piston 19. Fasteners 28, such as rivets or screws, secure the cover 15 to the base member 16.
In the cross section as shown in FIGURE 5, the switch 11 is opened up along its elongate axis to reveal the switch cavity 29 as defined between the cover element 15 over the base member 16. The clevis legs 17 depend from and are integral with the base 16. Registering openings 30 through the legs 17 provide simple clamp means as by a fastener (not shown) passing through both and bearing on the ferrule 12. The cover 15 is made from insulating material which is cast or otherwise molded as from resin materials such as the urea formaldehydes, nylon or the like having adequate dimensional stability. The cover 15 is molded to close over the base 16 and shoulder thereagainst. Cradle-like bracket extension 31 and 32 at each end of the base 16 provide for locatably mounting the switch 11 to the ferrule 12 as previously seen. The cover 15 is also provided with a stop extension 33 in axial register with the actuating pin 18. This, as will be seen, limits full throw of the switch. In addition, a boss 34 is integrally and internally provided at one end of the cover 15. The base member 16 provides a platform-like bottom 35 to the switch 11 and the opening 36 is provided transversely therethrough intermediate the legs 17, the opening 36 journalling the pin 18 which extends therethrough. A first contact carrying lead plate 37 rests registrably on the platform surface 35 of the base 16. The plate 37 is an elongate flat piece of conducting material electrically connected to the lead 14 at one end and provided with a first contactor 38. A second contact carrying lead plate 39, having an integral bow portion 40, is positioned in substantially spaced apart parallel register with the first contact plate 37. The bow 40 is positioned in register with the pin 13 on one side and the abutment or stop 33 on the other side. As will be appreciated, the stop 33 thus limits the amount of movement of the second plate 39 at the free end 41 thereof by limiting movement of the how 40. The free end 4-1 of the plate 39 carries the contactor 42 which is hence movable with movement imparted by the bow 49 oscillating in accord with movement of the pin 18. The second contactor plate 39 is of the leaf spring type and the bow 40 is formed by parallel elongate slots 43 (FIGURE 7) provided in the plate 39, the bow portion as, intermediate the slots 43 then being deformed to provide a selected bow spring bias acting upon the entire leaf. The action of the moving contact plate 39 is best understood when it is appreciated that the end 44 thereof, opposite the free end 41, is fixed in spaced parallel register with the corresponding end of the first contactor plate 37.
Spacing is by means of spacer block 45 comprising an insulating wafer between the movable contactor element 39 and the fixed contactor plate 37. One of the fasteners 28 is thus seen to pass transversely through the cover 15, second contactor plate 39, spacer 45, first contactor plate 3! and base 16. Parallel registry is hence maintained by the fastener 28 and the limiting confines of the switch case comprising cover and base 16. The boss 34 of the cover 15 thus bears upon the sandwich arrangement of contactor carrying elements spaced apart by the spacers 45. The lead 13 thus passes into the switch cavity 29 and is electrically connected to the leaf spring contactor element 39 adjacent the spacer 45.
By reference to FIGURE 6 the detail view shows the contacts 42 and 38 in closed position in contrast to the open switch position shown in FIGURE 5. In FIGURE 6 the switch 11 is positioned astraddle the ferrule 12 and the pin 18 extending through the opening 36 in the base 16, and through the opening 25 in the ferrule 12 has been moved by action of the piston 19 so as to overcome the spring bias of the bow .40 thereby causing the leaf spring element 39 to snap closed toward the contactor plate 37 bringing the contactors 42" and 38 into conducting relationship. In this action the amount of movement of the bow 40 toward full over center throw is limited by the stop 33 thus maintaining closure of the contacts 42 and 38 while axially exerting spring pressure on the pin 18 urging it into following contact with the piston 19. Hence, as the piston 19 is backed oif from contact with the pin 18, the switch 11 snaps open as in FIGURE 5, the pin 18 then radially extends into the opening in the ferrule 12. Hence, as will be appreciated, the positioning of the pin 18 and the attendant location of the switch 11 admits of considerable coordination with lineal piston movement by the simple expedient of location of the straddler switch 11 at a selected location along the ferrule 12.
The simplicity of the switch 11 is best understood by reference to FIGURE 7 where the switch 11 of the present invention is shown in exploded view. Four cast or molded insulating elements are required, the cover 15, the base 16, the spacer 45 and the pin 18. The conducting contactor carrying elements 37 and 39 are easily attachable to leads 14 and 13, respectively, with spacer 45 located therebetwcen and the whole switch 11 is then assembled by dropping the pin 18 through the opening 46 transversely through the contactor plate 37, the head 47 on the pin limiting drop through, and then closing the whole switch mechanism between the base 16 and cover 15 and fastening the whole by use of fasteners 28. Flank shoulders 48 in the cover 15 assure alignment of the electrical conducting members along with the locator elements 49 and 50 in the base 16. These locator elements 49 and 50 index the position of the contactor plate 37 on assembly. Step 51, provided at one end of the platform surface 35, provides an insulating relief for the lead 14 serving the plate 37 when viewed in cooperation with the spacer 45. A similar step 52 is provided in the spacer 45 to insulate and accommodate the lead 13 connecting with the second contactor plate 39.
The switch 11, in summation, is thus seen as a compact and simple structure wherein only two moving parts are involved and wherein the leaf spring element is limited against full throw with resulting long life and dual function. In this connection the bow serves to move the contactor into and out of conducting relation with its fixed counterpart and also serves to relieve the pin when overcoming bias is relieved. The elements of the switch 11 are easily and economically fabricated and the resultant switch product supplies a long felt need for electrical coordination with lineal acting mechanical components such as Bowden wire systems. Installation and selection of switch location is very simple by the mere radial piercing, for example, of a Bowden wire guide sleeve or ferrule. Replacement and repair is easily accomplished. Switch performance is very good and contact pressures as between the pin 18 and piston 19 are minimal so that wear at this point is no problem. Fabricating of the switch requires no special skills and assembly is relatively fool-proof. By securing elements 37 and 39 to wire harness and field assembling these elements to form the switch 11 it is possible, where desirable, to attain ultimate installation advantage.
Having thus described my invention those skilled in the art will readily perceive additional modifications, changes, and improvements therein and such modifications, changes, and improvements therein are intended to be included herein limited only by the scope of the hereinafter appended claims.
1. A switch comprising:
(a) a base member of insulating material and provided with a platform portion and depending clevis portion;
(15) a cover member of insulating material registrably positioned to cover said base member and shoulder thereagainst while defining therewith a mechanism cavity;
(c) a fiat contact plate secured to said platform portion of said base member and held by said base and said cover against movement;
(d) a flat leaf spring contact element having an integral bow portion, said leaf spring contact element positioned in said cavity defined by said base and said cover and in substantial parallel registry with said flat contact plate;
(e) a spacer block provided at one end of said cover member and spacing apart said flat contact plate and said flat leaf spring contact element at one end;
(1) an actuating pin transversely through said base and between said clevis depending from said base in biased contact with said bow portion of said leaf spring contact element and having positively limited axial movement said axial movement in one direction depressing said how portion of said leaf spring contact element thereby accomplishing a snap action engagement between said flat contact plate and said leaf spring contact element.
2. The structure of claim 1 and including: a member lineally between said clevis depending from said base in an interference path with said actuating pin and overcoming said bias applied by said integral bow portion to said pin, thereby selectively operating said leaf spring contact element.
3. The switch structure of claim 1 and including:
(a) a guide ferrule lineally between said clevis and in compact parallel relationship with said base member; and
(b) a piston reciprocable in said guide ferrule, said piston in an interference path with said actuating pin and overcoming said bias applied by said integral bow portion to said actuating pin, so as to selectively operate said leaf spring contact element.
References Cited by the Examiner UNITED STATES PATENTS 1,561,432 11/25 Hitchcock 248-230 1,826,105 10/31 Veale 200-161 2,448,230 8/48 Miller 200-67 2,545,264 3/51 Davis 200-67 2,700,079 1/ 5 5 Haydon 200-67 2,790,863 4/57 Towle 200-161 2,838,622 6/58 Bachi 200-153 2,840,65 6 6/ 5 8 Roeser 200-67 3,120,590 2/ 64 Dahlin 200-67 BERNARD A. GILHEANY, Primary Examiner. ROBERT K. SCHAEFER, Examiner.