GB2032065A

GB2032065A - Inertia actuator

Info

Publication number: GB2032065A
Application number: GB7840473A
Authority: GB
Original assignee: Lees I D M
Current assignee: Lees I D M
Priority date: 1978-10-13
Filing date: 1978-10-13
Publication date: 1980-04-30
Also published as: GB2032065B

Abstract

An actuator, intended for installation on a road vehicle or aircraft so as to be operative to switch off the fuel supply, operate a fire extinguisher, inflate a passenger protection bag and/or disconnect a battery, upon the vehicle or aircraft being arrested suddenly, e.g. as a result of impact or collision, comprises a ball 53 arranged between two opposed spring-loaded cups 37, 50, the cup 37 being connected, by way of a lost-motion connection 38, 39 to a retainer member 24, 26 which serves to block a bolt or plunger 27 against movement under the stress of a spring 32. Upon the ball 53 being displaced by inertia from between the cups 37, 50, the bolt or plunger 27 is released. Adjustment of the force retaining the ball 53 can be effected by means of a plug 43 containing a spring 46 loading shank 47 of the cup 50. <IMAGE>

Description

SPECIFICATION Inertia actuator This invention concerns an inertia actuator for use, for example, on a road vehicle or aircraft as part of a safety system serving to render the vehicle or aircraft less susceptible to consequential catastrophe or calamity (such as fire or explosion) after being involved in an impact or collision.

It is well known that it is imperative to take precautionary action in relation to a motor vehicle which has been involved in an accident, for instance by disconnecting the battery from the electrical circuitry of the vehicle, and/or switching off the fuel supply to the vehicle's engine.

However, in practice when an accident occurs this precautionary action is frequently overlooked both by people who may actually have been involved in the occurrence by having been passengers in the vehicle(s) concerned and by any bystanders or others nearby. As a result, efforts may be made to assist persons who may have been hurt or incapacitated in the accident, heedless of the very real risk of the possibility of fire or explosion which could add catastrophically to the consequences of the occurrence.

An object of the invention is to provide a form of actuator which can be incorporated into a motor vehicle, aircraft or the like and which can be arranged, upon occurrence of an impact or collision, to initiate appropriate precautionary operations to minimise consequential risks, subsequent to the impact or collision.

With this object in view, the present invention provides an inertia-operated actuator comprising a bolt or plunger, loaded resiliently towards an operative position, but retained in an inoperative position against its loading by a retainer member held in a retaining position by the presence of a ball located between two cups at least one of which is spring loaded, the ball being displaceable from between the cups by inertia to permit the retainer member to move to a releasing position in which it releases the bolt or plunger to move to its operative position.

Preferably both of the cups are resiliently loaded towards one another, one of said cups being carried by a stem extending into a cavity in the retainer member, a first spring within said cavity serving to load the respective cup towards the ball and the retainer member towards the retaining position. The said retainer member may have a second spring, of lesser strength than the first spring, acting thereon to load the retainer member towards the bail.

A lost motion connection may be provided between the said stem and the retainer member, this being provided by a pin in the retainer member extending through a slot in the stem.

The other of the cups may conveniently be provided on a shank projecting into a respective cavity in a plug, a respective spring being provided in this cavity to load the respective cup towards the ball, and the plug being adjustable to vary the spring loading of the cup against the ball.

The shank may have a lost motion connection with the plug by way of a pin fixed in the plug and extending through a slot in the shank.

A locking nut may be provided for locking the plug in its adjusted position.

The invention will be described further, by way of example, with reference to the accompanying drawing in which the single figure is a crosssectional elevation of a preferred embodiment of the inertia-operated actuator, it being understood that the following description is illustrative, and not limitative, of the scope of the invention.

As illustrated in the drawing, the preferred embodiment of the actuator of the invention comprises a housing, indicated generally by the reference numeral 10 and comprising two parts 11 and 12 bolted together at flanges 13, 14 and defining an interior space 1 5 with opposed tubular extensions 16 and 1 7 extending away from each other at opposite sides of said space 1 5.

The extension 1 6 has, at its end remote from the space 15, an enlargement 1 8 to the interior 1 9 of which access can be had by way of a closure cap 20 which is a friction fit in an opening 21.

A screw thread 22 is provided in the inner surface of the extension 16 adjacent its junction with the enlargement 18, to receive a hollow guide nut 23 which serves as an axial guide for one end of a tubular retainer member 24 the other end of which is formed with a flange 25 which is a sliding fit in the interior of the extension 16.A retainer peg 26 is formed integrally on the end of the retainer member 24 so as to project into the interior of the enlargement 1 8 and cooperate with a bolt or plunger 27 extending perpendicularly to the extension 1 6 and guided through an opening 28 in one side of the enlargement 18 and a guide nut 29 screwed into a hole 30 in the opposite side of the enlargement 1 8. This hole 30 is large enough to permit passage therethrough of a tabular spring cover 31 carried by the bolt or plunger 27 and locating in place a helical compression spring 32 which, by engaging by one end against the wall of the enlargement in the region of the opening 28 and by the other end against the bottom of the cover 31, loads the bolt or plunger 27 to the right as viewed in the drawing.It will be understood, therefore, that the guide nut 29 is provided to enable the assembly of the bolt or plunger 27 with its spring cover 31 and spring 32 to be assembled in place in the enlargement 1 8. It will be appreciated also that in the illustrated position of the retainer member 24, the retainer peg 26 retains the bolt or plunger 27 in a cocked position, with the helical spring 32 compressed, by projecting into the path of movement of the cover 31 and being abutted by the bottom of the cover 31. A collar 33, integral with the bolt or plunger 27, serves to limit the extent of possible movement to the right (as viewed in the drawing) of the bolt or plunger 27 by abutment against the guide nut 29.This collar 33 is not essential and can be omitted, in which case the possible movement of the bolt or plunger 27 will be determined by abutment of the cover 31 against the nut 29.

The interior cavity 34 within the tubular retainer member 24 accommodates a first spring 35 associated with said retainer member 24, as well as one end of a stem 36 the other end of which has a first cup 37 and the retainer member 24 is provided by a pin 38 fixed in the flange 25 of the member 24 and extending through a slot 39 in the stem 36. A second spring 40 associated with the retainer member 24 surrounds the latter and abuts by one end against the guide nut 23 and by the other end against the flange 25. The stem 36 extends into the interior space 1 5 through a guide hole 41 in a web 42 separating such space 1 5 from the interior of the extension 1 6.

The extension 1 7 is internally threaded to accommodate a threaded plug 43 which has an internal cavity 44 axially aligned with the cavity 34 in the retainer member 24 and which is provided with a lock nut 45 to enable it to be locked in place once it has been screwed a desired distance into the extension 1 7. The cavity 44 accommodates a respective helical spring 46 and one end of a shank 47 which protrudes through a hole 48 in a web 49 dividing the interior of the extension 1 7 from the interior space 1 5 and terminates in a second cup 50 which faces the cup 37. A pin 51 fixed in the plug 43 and extending through a slot 52 in the shank 47 provides a lost motion connection between the cup 50 and the plug 43.

A ball 53 is accommodated in the interior space 1 5 and is located between the two cups 37 and 50, and as shown the assembled arrangement of the actuator is such that the retainer member 24 is located with the peg 26 blocking the bolt or plunger 27 against movement under the influence of the spring 32, adjustment of the extent to which the plug 43 is screwed in permitting this to be achieved.

The actuator, as illustrated, will be installed, for example, in a motor vehicle, such as a motor car, in the engine compartment, and the bolt or plunger 27 can be coupled, as desired, to perform any of a number of possible precautionary operations upon operation of the actuator. For instance it may be connected at one end to a fuel shut-off valve and at its other end to a batterydisconnecting switch arranged so as to isolate the vehicle's battery completely at a position close to the battery's terminals. Additionally or alternatively, it could be coupled to fireextinguishing apparatus in the engine compartment and/or to passenger safety equipment such as inflatable impact-cushioning bag installations in the passenger compartment of the vehicle and/or a visual or audible alarm.Fixing of the actuator in place can be effected, for instance, by a bracket (not shown) attached by using one or more of the bolts which clamp the flanges 1 3 and 14 together, or by an appropriate bracket (not shown) formed integrally with the housing 10.

The spring-loading of the cups 37, 50 is such that with normal motions of the vehicle on which the actuator is installed, the ball 53 will be retained therebetween. However, upon the occurrence of a severe impact, which may take place in any substantially horizontal direction relative to the orientation of the vehicle, the ball 53 will be caused, by inertia, to jerk out of its position retained between the two cups 37, 50 with the result that the spring 40 is able to move the retainer member 24 away from the bolt or plunger 27. The peg 26 is therefore disengaged from the cover 31, so that the spring 32 can then exert itself and cause substantially instantaneous movement of the bolt or plunger 27 to the right to actuate the safety apparatus to which it is coupled.

The invention is not confined to the precise details of the foregoing example, and variations may be made thereto. Thus, for example, arrangements are possible in which only one of the cups 37, 50 is spring-loaded, the other being fixedly disposed. Other arrangements are possible.

Claims

1. An inertia-operated actuator comprising a bolt or plunger, loaded resiliently towards an operative position, but retained in an inoperative position against its loading by a retainer member held in a retaining position by the presence of a ball located between two cups of which at least one is spring loaded, the ball being displaceable from between the cups by inertia to permit the retainer member to move to a releasing position in which it releases the bolt or plunger to move to its operative position.

2. An actuator as claimed in claim 1 wherein both of the cups are resiliently loaded towards one another.

3. An actuator as claimed in claim 2 wherein one of the cups is carried by a stem extending into a cavity in the retainer member, a first spring within said cavity serving to load the respective cup towards the ball and the retainer towards the retaining position.

4. An actuator as claimed in claim 3 wherein the retainer member has a second spring, of lesser strength than the first spring, acting thereon to load the retainer member towards the ball.

5. An actuator as claimed in claim 3 or 4 wherein a lost motion connection is provided between the stem and the retainer member.

6. An actuator as claimed in claim 5 wherein the lost motion connection is provided by a pin in the retainer member extending through a slot in the stem.

7. An actuator as claimed in any of claims 3 to 6 wherein the other of the cups is provided on a shank projecting into a respective cavity in a plug, a respective spring being provided in this cavity to load the respective cup towards the ball, the plug being adjustable to vary the spring loading of the respective cup against the ball.

8. An actuator as claimed in claim 7 wherein the shank has a lost motion connection with the plug.

9. An actuator as claimed in claim 8 wherein the said lost motion connection between the shank and the plug is provided by way of a pin fixed in the plug and extending through a slot in the shank.

10. An actuator as claimed in claim 7, 8 or 9 wherein a locking nut is provided for locking the plug in its adjusted position.

11. An inertia-operated actuator substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.

1 2. A motor vehicle having electrical circuitry connected to a battery to be supplied with current by said battery, characterised by the provision of an inertia-operated actuator as claimed in any preceding claim, disposed to cause connection of the battery from the circuitry.

1 3. A motor vehicle characterised by the provision of an inertia-operated actuator as claimed in any of claims 1 to 11, disposed to shut off fuel supply to the engine, to operate a fire extinguisher, operate an inflatable impactcushioning bag installation in the passenger compartment of the vehicle, and/or to provide a visual or audible alarm.