Switch, in particular battery cutout switch for vehicles and the like

Information

  • Patent Grant
  • 6686551
  • Patent Number
    6,686,551
  • Date Filed
    Monday, July 15, 2002
    21 years ago
  • Date Issued
    Tuesday, February 3, 2004
    20 years ago
Abstract
A switch destined in particular for usage as a general cutout switch for batteries in low-voltage vehicle electrical systems and the like includes a supporting body carrying at least one pair of fixed electrical contacts,—a mobile element carrying at least one mobile electrical contact, cooperating with the fixed contacts and movable in a rectilinear direction between an open-contacts position and a closed-contacts position and vice versa, a rotary control member suitable for controlling the movement of the mobile element, an elastic structure that tends to push the mobile element towards the open-contacts position, mutually cooperative contact surfaces provided on the control member and on the mobile element and mutually cooperative stop mechanisms provided on the supporting body and on the rotary control member.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention refers to switch, destined in particular for usage as a general cutout switch for batteries in low-voltage vehicle electrical systems and the like.




2. Statement of the Art




Switches of this type are normally equipped with at least a pair of fixed contacts and at least one mobile contact that can be shifted, with respect to the fixed contacts, between an open position and a closed position.




Switches destined for utilization in vehicle electrical systems as battery cutouts must be capable of guaranteeing circuit interruption in emergency situations via a simple and intuitive manoeuvre, such as simply applying pressure on a knob for example.




In other applications, instead, there can exist the opposite need, i.e. that of only allowing the switch to be opened or closed by personnel in possession of a special key.




BRIEF SUMMARY OF THE INVENTION




The object of present invention is to provide a switch that is simple, robust and reliable, having a control mechanism that allows versions of the switch commanded by both knob and key to be realized.











BRIEF DESCRIPTION OF THE DRAWINGS




The present invention will now be described in detail, with reference to the enclosed drawings, which are supplied as a non limitative example and where:





FIG. 1

is a perspective view of a first form of embodiment of a switch in accordance with the invention,





FIG. 2

is a plan view of the switch in

FIG. 1

,





FIGS. 3 and 4

are sectional views along the lines III—III and IV—IV respectively, as shown in

FIG. 2

,





FIG. 5

is a perspective, cutaway view of a the switch in

FIG. 1

,





FIGS. 6 and 7

are partial sectional views illustrating the switch in

FIG. 1

in the open position and closed position respectively,





FIG. 8

is a schematic perspective illustrating the part indicated by the arrow VIII in

FIG. 2

,





FIGS. 9

,


10


,


11


and


12


are schematic plan views perpendicular to the arrow IX in

FIG. 8

, and





FIGS. 13 and 14

are partial, perspective cutaway views of a second form of embodiment of the switch in accordance with the present invention.











DETAILED DESCRIPTION OF THE INVENTION




With reference to

FIG. 1

, item


10


indicates a first form of embodiment of the switch in accordance with the invention, destined for utilization as a battery cutout for vehicles, boats and the like. The switch


10


includes a supporting body


12


in an injection moulded plastic material, from which two main electrical contacts


14


protrude. In the example of embodiment illustrated in the figure, the switch


10


is also equipped with a number of secondary, electrical spade terminals


16


. The switch


10


in accordance with the first form of embodiment of the present invention includes a control knob


18


that is used to control the opening and closing manoeuvres of the switch.




With reference to

FIGS. 3 and 4

, the terminals


14


carry a pair of fixed contacts


20


situated inside a cavity


22


in the main body


12


. The fixed contacts


20


cooperate with a mobile contact


24


carried on a mobile element


26


, mounted such that it can slide within a tubular portion


28


of the main body


12


. The mobile element


26


carries a coil spring


30


in compression that presses the mobile contact


24


against the seat


32


of the mobile element


26


. This mobile element cooperates with a prismatic guide


32


, created on the inside of the supporting body


12


(

FIG. 5

) so that it can move along the longitudinal axis


34


, but without being able to rotate around the aforesaid axis. The mobile element


26


carrying the mobile contact


24


can move between the open-contacts position illustrated in

FIG. 3 and a

closed position in which the mobile contact


24


is pressed against the fixed contacts


20


. The mobile element


26


is pushed towards the open position by the elastic force produced by the coil spring in compression


38


, coaxial with the longitudinal axis


34


and positioned between a wall


40


of the supporting body


12


and an appendage


42


of the mobile element


26


.




A small, sliding shaft


44


is arranged along the longitudinal axis


34


and carries an auxiliary mobile contact


45


that cooperates with the auxiliary fixed contacts


46


connected to the auxiliary terminals


16


. The shaft


44


is associated with a spring in compression


48


that tends to push it towards the open-contacts position. The appendage


42


of the mobile element


26


rests against the upper end of the shaft


44


in the closed-contacts position and, in turn, presses the shaft


44


in the auxiliary closed-contacts position.




With reference to

FIG. 5

, at its upper end, the mobile element


26


carries a cam-shaped surface


50


, with substantially the form of a wedge obtained from a circular profile. The mobile member


36


is preferably equipped with two or more cam-shaped surfaces


50


, angularly equidistant along the upper circumferential border of the mobile element


26


. Each of these cam-shaped surfaces


50


cooperates with a presser element


52


carried by a rotary control member


54


. The rotary control member


54


is arranged coaxially to and above the mobile element


26


and has an upper surface


56


that faces onto a seat


58


that is fixed with respect to the main body


12


and is preferably obtained as an integral part of the upper end of the tubular portion


28


. The rotary control member


54


is pushed against the seat


58


by the elastic force of the spring


38


. In fact, the load on the spring


38


pushes the mobile element


26


upward, which in turn, pushes the rotary element


54


upwards via contact between the cam-shaped surfaces


50


and the presser elements


52


. The upper surface


56


of the rotary control member


54


is equipped with at least one catch


60


that is destined to cooperate with a corresponding catch


62


present on the contact surface


58


(see FIGS.


6


and


7


). As is illustrated in

FIG. 7

, the reciprocal engagement between the catches


60


and


62


occurs when the angular position of the rotary control member


54


corresponds to the closed-contacts position, i.e. the condition in which the mobile member


26


is in its lowermost position. The rotary control member


54


is also free to move in the direction of the longitudinal axis


34


to disengage the catches


60


and


62


, and so allow the switch to return to the open-contacts position. Two or more pairs of cooperating catches


60


and


62


could be provided for on the mutually facing surfaces


56


and


58


.




With reference to

FIGS. 2 and 5

, the rotary control member


54


has an axial portion


64


that protrudes upwards and is equipped with a pair of appendages


66


that engage with respective arched grooves


68


formed inside the control knob


18


and with their centre on the longitudinal axis


34


. A return spring


69


is positioned around the appendage


64


and has its ends anchored to the supporting body


12


and control knob


18


respectively. The grooves


68


have an angular extension of approximately 90°, which corresponds to the angular travel that the control knob


18


must be subjected to in order to bring the switch from the open position to the closed position. The return spring


69


applies an elastic force to the control knob


18


that tends to make it turn in the opposite direction to that in which it must be turned in the manoeuvre to close the switch, or rather the manoeuvre that brings the switch from the open-contacts position to the closed-contacts position. The arched grooves


68


of the control knob


18


appear on the outer surface of the knob, so that the appendages


66


are visible when viewing the switch from above. Preferably, the appendages


66


should be coloured so that they are easily visible and “ON” and “OFF” indicators provided on the top surface of the knob


18


so that the state of the switch, in the respective open-contacts or closed-contacts positions, can be visually determined.




The operation of the switch in accordance with the invention will now be described, starting from the open-contacts configuration illustrated in

FIGS. 3 and 6

. In this condition, the knob


18


is in the position shown in FIG.


9


. The appendages


66


are in contact with the first end of the respective grooves


68


. As illustrated in

FIG. 6

, the position of the presser element of rotary control element


54


is level with the lowest point of the inclined surface


50


and, in consequence, the mobile element


26


is in its upper position, in which the mobile contact


24


is separated from the fixed contacts


20


. To set the switch


10


in the closed-contacts operational position, the control knob


18


is turned by approximately 90°, in a clockwise direction with reference to FIG.


9


. During this rotation, the appendages


66


are dragged into rotation around the axis


34


by contact with the ends of the grooves


68


. In consequence, the axial portion


64


carrying the appendages


66


also performs a rotation of approximately 90° and turns the rotary control member


54


by the same amount. When this rotation is complete, the configuration of the switch is that shown in

FIG. 7

, where the catch


60


is engaged with the stationary catch


62


. The rotation of the rotary control member


54


positions the presser element


52


level with the highest point of the inclined surface


50


. Since the mobile element


26


cannot rotate any further with respect to the stationary casing, this element is consequentially obliged to move downwards against the thrust of the spring under compression


38


. This downwards motion of the mobile element


26


brings the mobile contact


24


into contact with the fixed contacts


20


. The coil spring


30


keeps the mobile contact


24


pressed against the fixed contacts


20


and permits movement of the mobile contact to allow for play and tolerances. When the 90° clockwise rotation of the knob


28


is completed, with respect to the knob, the appendages


66


will be in the position illustrated in FIG.


10


. When the user releases the knob


18


, it will rotate anticlockwise under the action of the return spring


69


. The anticlockwise rotation terminates when the appendages


66


come into contact with the opposite ends of the grooves


68


, in the position shown in FIG.


11


. This position is a stable position for the knob


18


. The appendages


66


are positioned in correspondence to the “ON” sign, which indicates the closed-contacts operational state of the switch


10


.




In the closed-contacts position, the rotary control member


54


is kept in a fixed position with respect to the main body


12


by the reciprocal engagement of the teeth


60


and


62


. This engagement remains stable due to the fact that the spring


38


exerts an upward, axial thrust that keeps the rotary control member


54


pushed against the surface


58


of the main body


12


.




To return the casing to the open-contacts operational position, all that is needed is to push the control knob


18


downwards. This downward force produces a downward movement on the rotary control member


54


that disengages the catch


60


from the corresponding stationary catch


62


. As soon as the catch


60


disengages, the rotary control member


54


is free to rotate around the axis


34


. Due to the contact between the inclined surface


50


and the presser member


52


, the axial thrust of the spring


38


makes the control member


54


rotate and push the mobile element


26


upwards. Rotation of the rotary control member


54


stops when this member reaches an end stop on the stationary casing (not illustrated). During the rotation of the rotary control member


54


, the knob


18


remains stationary, thereby obtaining a relative rotation of


900


in the anticlockwise direction between the appendages


66


and the knob


18


. The switch thus returns to the configuration illustrated in

FIG. 12

, where the appendages


66


indicate the “OFF” position, corresponding to the open-contacts position. The fact that the control knob


18


can rotate and is elastically pulled in the opposite direction to that in which it is rotated to close the switch, consequently allows the operational state of the switch to be visibly checked via the appendages


66


.




In the device in accordance with the invention, the switch's control mechanism is suitable for realising both a knob-type control and a key-type control.

FIGS. 13 and 14

illustrate a variant of the switch in accordance with the invention in which the knob


18


is replaced by a control key


70


. The key control


70


has an engagement portion


72


that is inserted via a slot


74


in the tubular portion


28


of the main body


12


and that engages with a seat


76


realised on the upper surface of


56


of the rotary control member


54


. Part of the control portion


72


extends beyond the upper surface


56


in order to form the catch


60


, as in the previously described solution. In the situation where the switch


10


is open, the seat


76


of the rotary control member


54


is aligned with the slot in the main body and the key can be inserted or removed from the switch. To close the switch, the key


70


must be inserted and turned clockwise until the tooth


60


engages with the corresponding tooth formed on the surface


58


of the main body. In this condition, the switch is closed and the key


70


cannot be extracted. To open the switch, it is sufficient to simply push the key


70


downwards. Following downwards pressure on the key, the rotary control member


54


rotates in the anticlockwise direction, returning to its position that corresponds to the open-contacts position. The operational state of the switch is indicated by the position of the key


70


. The switch in this variant of the invention can only be closed by someone possessing the specific key, which could be advantageous from the antitheft viewpoint for example.




The key can only be extracted when the switch is open and hence the absence of the key indicates that the switch is open.



Claims
  • 1. A switch, in particular a battery cutout switch for vehicles including:a supporting body carrying at least one pair of fixed electrical contacts, a mobile element carrying at least one mobile electrical contact, cooperating with said fixed contacts and movable in a rectilinear direction between an open-contacts position and a closed-contacts position and vice versa, a rotary control member suitable for controlling the movement of the mobile element towards the closed-contacts position, elastic means that tend to push the mobile element towards the open-contacts position, mutually cooperative contact surfaces provided on the rotary control member and on the mobile element for transforming the rotary motion of the rotary control member into linear motion of the mobile element, and mutually cooperative stop mechanisms provided on the supporting body and on the rotary control member for holding the rotary control member in a blocked position corresponding to the closed-contacts position, said stop mechanisms being formed to disengage when the rotary control member is subjected to movement in the axial direction.
  • 2. A switch according to claim 1, wherein said mutually cooperative contact surfaces include at least one inclined surface with a circumferential profile.
  • 3. A switch according to claim 1, wherein said stop mechanisms include a pair of teeth formed on mutually facing heads of the rotary control member and a main body.
  • 4. A switch according to claim 1, including at least one auxiliary mobile contact carried on a sliding shaft cooperating with an end portion of said mobile element.
  • 5. A switch according to claim 1, wherein said rotary control member cooperates with a control knob that can rotate and move linearly.
  • 6. A switch according to claim 5, wherein the rotary control member is connected to a pair of appendages that engage with respective circular-shaped grooves formed on a facing surface of said control knob, said appendages indicating the operational state (ON or OFF) of the switch.
  • 7. A switch according to claim 6, including elastic means of return positioned between the control knob and the main body, which applies torque to the control knob that tends to make it rotate in the opposite direction to that in which the knob is turned for closing the switch.
  • 8. A switch according to claim 1, wherein said rotary control member is associated with a removable control key.
  • 9. A switch according to claim 8, wherein said key includes at least one of said stop mechanisms for holding the rotary control member in the said blocked position.
Priority Claims (1)
Number Date Country Kind
01122729 Sep 2001 EP
US Referenced Citations (10)
Number Name Date Kind
1889175 Evans Nov 1932 A
2377250 Lawson May 1945 A
4538036 Heinrich et al. Aug 1985 A
5310974 Churchill et al. May 1994 A
5593022 Schaeffer et al. Jan 1997 A
5624023 Chasen et al. Apr 1997 A
5744873 Hasegawa et al. Apr 1998 A
6444932 Resmalm Sep 2002 B1
6512189 Schuberth et al. Jan 2003 B1
6520267 Funfer et al. Feb 2003 B2
Foreign Referenced Citations (3)
Number Date Country
0645791 Mar 1995 EP
0685783 Dec 1995 EP
2046023 Nov 1980 GB