Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H35/00—Switches operated by change of a physical condition
  • H01H35/14—Switches operated by change of acceleration, e.g. by shock or vibration, inertia switch
  • H01H35/141—Details
  • H01H35/143—Resetting means

Definitions

• This invention relates to an inertia switch device for opening or closing electrical contacts in response to movement of the device .
• Devices of this kind are known in which an inertia mass held in an operative position by a spring or a magnet is freed by an acceleration or a deceleration of a pre ⁇ determined intensity to effect the opening or closing of the electrical contacts.
• Such devices are usually mounted in a vehicle in a position such that they respond to acceleration or deceleration in a horizontal direc ⁇ tion, so that if the vehicle is subject to an impact from the front, the side, or the rear, the electrical contacts are operated. It is a disadvantage of such devices that they may not be capable of being easily reset to their original, unoperated, condition.
• An object of this invention is to provide an inertia switch device which mitigates this disadvantage.
• an inertia switch device comprises an an inertia mass which is movable from a rest position when the device is subjected to an applied acceleration or deceleration in a horizontal plane, a first electrical contact movable between a first stable position in which it engages a second electrical contact and a second stable position in which it no longer engages the second electrical
• OMPI IPO contact support means having a bifurcated portion for carrying a bifurcated portion of the first electrical contact
• operating means engageable by the inertia mass on movement of the inertia mass as a result of the applied acceleration or deceleration exceeding a thres ⁇ hold value, to move the first electrical contact from the first to the second stable position, or vice versa
• the operating means comprising a first limb which is struck by the inertia mass when the threshold value is exceeded and a second limb having a bifurcated portion which is pivotally mounted on the support means, resi ⁇ lient biassing means which lie within the bifurcated portions and connect the first electrical contact and the second limb so as to bias the first electrical contact towards the first or second stable position depending on the position of the second limb, and resetting means ' comprising an operating member- movable to operate the resilient biassing means and thereby return the first electrical contact to its original stable position.
• the operating member may be arranged to actuate a linkage which bears against the resilient biassing means to return the first electrical contact to its original stable position.
• the operating member is arranged to actuate a cranked lever which bears against the resilient biassing means to return the first electrical contact to its original stable position.
• the resilient biassing means may comprise a helical tension spring hooked at opposite ends into respective holes in the first electrical contact and the second limb of the operating means.
• the inertia mass, the electrical contacts, the operating means and the resilient biassing means may be accommo ⁇ dated in a housing and the operating member may extend out of the housing by an amount which provides a visual indication as to whether or not the operating means have been struck by the inertia mass.
• an inertia switch device comprises an inertia mass which is movable from a rest position when the device is sub ⁇ jected to an applied acceleration or deceleration in a horizontal plane, electrical contacts operable by the inertia mass on movement of the inertia mass as a result of the applied acceleration or deceleration in said horizontal plane exceeding a predtermined value, and a second inertia mass which tends to maintain an initial rest position when -the device is subjected to an applied angular rotation about an axis substantially parallel to said horizontal plane and which is also arranged to operate the electrical contacts when the applied angular rotation exceeds a predetermined value.
• the inertia switch device of the invention has the advantage that the operation of the electrical contacts occurs when the angular rotation exceeds the predeter ⁇ mined value such as occurs when the vehicle rolls about its longitudinal axis.
• the second inertia mass may be slidably mounted to produce operation of the electrical contacts when the device is subjected to said applied angular rotation.
• the second inertia mass may comprise a block slidably mounted within a compartment and arranged to resist operation of the electrical contacts by a force applied in a direction, normal to the horizontal plane by peg in the compartment engaging a slot provided in the block or by a peg on the block engaging a slot provided in the compartment.
• the inertia switch device of the invention therefore has the additional advantage that it will resist operation of the electrical contacts by forces applied in a direction normal to the horizontal plane such as are caused by bumps in a road along which the vehicle is travelling.
• the second inertia mass may be pivotally mounted to produce operation of the electrical contacts when the device is subjected to said applied angular rotation.
• the second inertia mass may comprise a block pivotally mounted so as to resist operation by a force applied in a direction normal to the horizontal plane.
• the pivotally mounted block may be hemi-cylindrical and the operation . of the electrical contacts may be produced by a cam follower arranged to co-operate with a cam rotationally fast with the pivotally mounted block.
• Figure 1 is a longitudinal cross-sectional vie ' of an inertia switch device in accordance with the invention
• Figure 7 is a fragmentary perspective view of a re ⁇ taining peg shown in Figure 5 ;
• the inertia switch device 1 has a housing 2 of electrically insulating material in which are mounted two fixed electrical terminals 3 and -4 and a movable electrical contact member 5.
• the housing 2 also accommodates an inertia mass 6 responsive to acceleration or decele ⁇ ration of the device 1 acting in a substantially hori ⁇ zontal direction when the. device, is mounted in the attitude illustrated in Figure 1.
• the upper part of the movable contact member 5 is bifurcated the two limbs 26 forming the bifurcation bearing against respective indentations * in the underside of the two limbs 24.
• a contact actuating member 27, which is generally L-shaped, has a bifurcated arm 28, the limbs 29 of which are seated for pivotal movement in the indentations 25 in the upper surface of the limbs 24 of the terminal 4.
• the other arm 31 of the actuating member 27 extends over the ball 6 and rests on the upper surface of the seat 9 in which the inertia mass 6 is accommodated.
• a helical tension spring 34 hooked at opposite ends into a hole in the contact * actuating member 27 and a hole in the movable contact member 5, lies between the limbs of the bifurcations of these members 27, 4 and 5 and normally -acts to urge the movable contact member 5 against the fixed terminal 3 and to urge the arm 31 of the actuating member 27 towards the ball 6.
• a reset button 35 is slidably mounted in the housing 2 so that its lower end 36 engages a limb 58 of a linkage 59.
• the reset button 35 has a rectangular head 60 which projects from the upper wall 61 of the housing 2 and a stem 62 which extends into the interior of the housing 2 through a slot 63 formed between two upstanding shoul ⁇ ders 64 on the upper surface 61 of the housing 2.
• Abutments 65 and 66 formed on the wall of the housing act as guides for the stem 62 during sliding movement of the res.et button 35.
• the linkage 59 takes the form of a cranked lever 68 having two limbs 58 and 69 (see Figures 3 and 4) which extend substantially at right angles to each other and are located adjacent opposite ends of a shaft 70 which is pivotally mounted in the housing 2.
• the end of the limb 69 is arranged to engage the spring 34 and the end of limb 58 is provided with a notch 71 which is engaged by the lower end of the stem 62.
• the device 1 is mounted n a vehicle with the base 51 of the housing 2 in a substantially horizontal plane with the rounded portion 20 of the moving contact member 5 engaging the portion 19 of of the electrical terminal 4.
• the arm 1 of the actuating member 27 extends over the ball 6 - and rests on the upper surface of the seat 9 as seen in Figure 1-.
• the electrical terminals 3 and 4 are connected to electrical circuits (not shown) for electrically operated door locks of the vehicle or for an electrically operated supply valve in a fuel pump or a fuel supply pipe of the vehicle.
• the inertia mass 6 will ride up the sloping side 11 of the frusto-conical seat 9 and strike the arm 31 of the actuating member 27.
• the arm 31 is moved upwards until it comes to rest against a series of ribs 12 on the under ⁇ side of the upper wall 61 of the housing 2.
• the spring 34 bears against the end of the limb 58 of the cranked lever 68 causing it to rotate in an anti- clock-wise direction as seen in Figure 1 so that the end of the limb 58 bears against the lower end 36 . of the stem 62 and pushes the reset button 35 in an upward direction.
• the inertia swi-tch device 1 remains in this conditon until it is reset.
• the displacing of the reset button 35 in an upward direction provides a visual indication that the inertia mass 6 has struck the arm 31 of the actuating member 27-
• the inertia switch device 1 is reset by depressing the reset button 35 which actuates the linkage 59 and returns the mechanism to its original position.
• Depress ⁇ ing rectangular head 60 towards the wall 61 of the housing 2 causes the lower end of the stem 62 to engage the notch 61 in the end of the limb 58 of the cranked
• the inertia switch device 1 is generally similar .to that shown in Figures 1 to but differs therefrom in that it includes a furthe • inertia mass 7 responsive to angular rotation.
• the inertia mass 7 comprises a metal block 37 arranged t slide within the substantially rectangular compartment 33 within the housing 2 in response to angular rotation of device " 1 about an axis 39.
• the extent and direction of the sliding movement of the metal block 37 is con ⁇ trolled by a. peg 40. which lies within an inverted U- shaped slot 41 provided on side 42 of the metal bloc 37.
• the metal block 37 tapers towards its upper end - 4 and its broader, lower end 44 normally rests on the bottom 45 of the compartment 33.
• the peg 40 which is anchored in a wall 32 of the housing 2, normally projects into the slot 41 at a position at the apex of the inverted ⁇ and tends to keep the block 37 at or near to the bottom 45 of the com ⁇ partment 33 when the device 1 is subjected to a force applied in a vertical direction such as is caused by a bump in a road along which a vehicle is travelling.
• a force applied in a vertical direction such as is caused by a bump in a road along which a vehicle is travelling.
• the device 1 is mounted on the vehicle with the base 51 of the housing 2 in a substantially horizontal plane and the axis 39 substantially parallel to the longi ⁇ tudinal axis of the vehicle.
• the electrical terminals 3 and 4 are connected to electrical circuits (not shown) for electrically operated door locks of the vehicle or for an electrically operated supply valve in fuel supply pipe of the vehicle.
• the inertia mass 6 will ride up the sloping side 11 of the frusto-conical seat 9 and strike the arm 31 of the actuating member 27.
• the arm 31 is moved upwards until it comes to rest against a series " of ribs 72 on the underside of the upper wall 61 of housing 2. This causes the spring 34 to move "over centre” so that the rounded portion 20 of the movable contact member 5 is moved away from the vertically extending portion 19 of the electrical terminal 3.
• the electrical circuit for the electrically operated door locks or the elec ⁇ trically operated supply valve is broken, so that the door locks are released and the supply of fuel is cut off.
• the device 1 will rotat around the inertia mass 7 which tends to remain in it original rest position in space.
• the compartment 3 therefore slides around relative to the inertia mass 7, the slot 41 moving around relative to the peg 40 so tha the peg 40 eventually occupies a position along one o the arms 47 or 48 depending on the extent and th direction of the angular rotation of the vehicle.
• Th upper end 43 of the inertia mass 7 will therefore strik end portion 49 of- the arm 31 of the actuating membe 27.
• the movable contact member 5 is therefore move away from the . vertically extending portion 19 of th electrical terminal 3 to break the electrical circui for the electrically operated door locks or the elec trically operated fuel supply valve.
• the device 1 can be reset when the vehicle has bee returned to its original, upright position by depressin the reset button 35 which actuates the linkage 59 and returns the mechanism to its -original position.
• Depressing rectangular head 60 towards the wall 61 of th housing 2 causes the lower end of the stem 62 to engag the notch 61 in the end of the limb 58 of the cranked lever 68 causing it to rotate in clockwise direction.
• the end of the limb 69 bears against the spring 34 and
• the alternative form of the inertia mass 7 comprises a substantially hemi- cylindrical block 52 which is pivotally mounted for rotation about an axis 53.
• the block 52 forming the inertia mass 7 is accommodated in a compartment of the inertia device 1 similar to the compartment 38 shown in Figure 5.
• a shaft 54 which is rotationally fast with the block 52 and which provides the pivotal mounting, carries a cam 55 at one end which is arranged to co ⁇ operate with a cam follower 56 slidably mounted in the compartment.
• An abutment 57 on the upper end of the cam follower 56 is arranged to engage the end portion 49 of the arm 31 of the actuating member 27.
• the movable contact member 5 is therefore moved- away - from the vertically extending portion 19 of the electrical terminal 3 to break the electrical circuit for the electrically operated door locks or the elec ⁇ trically operated fuel supply valve. As before the device can be reset by the reset button 35.

Landscapes

• Switches Operated By Changes In Physical Conditions (AREA)
• Rotary Switch, Piano Key Switch, And Lever Switch (AREA)
• Push-Button Switches (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10506486

Family Applications (1)

Country Status (10)

Cited By (1)

Families Citing this family (8)

Citations (3)

Family Cites Families (1)

• 1979
  • 1979-07-13 GB GB7924490A patent/GB2053569B/en not_active Expired
• 1980
  • 1980-07-10 US US06/243,911 patent/US4371763A/en not_active Expired - Lifetime
  • 1980-07-10 JP JP55501428A patent/JPH024086B2/ja not_active Expired
  • 1980-07-10 WO PCT/GB1980/000117 patent/WO1981000325A1/en active IP Right Grant
  • 1980-07-10 DE DE8080901215T patent/DE3070006D1/de not_active Expired
  • 1980-07-10 BR BR8008979A patent/BR8008979A/pt not_active IP Right Cessation
  • 1980-07-10 EP EP80901215A patent/EP0038328B1/en not_active Expired
  • 1980-07-11 CA CA000355962A patent/CA1159926A/en not_active Expired
  • 1980-07-11 ES ES493345A patent/ES493345A0/es active Granted
• 1981
  • 1981-01-27 IN IN49/DEL/81A patent/IN155323B/en unknown

Patent Citations (3)

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