BACKGROUND OF THE INVENTION
PULL-APART SAFETY SWITCH WITH MAGNETIC In one embodiment, the cover is held magnetically to MEANS FOR MACHINES the mount and in another, it is held in place by spring
Another objective of the invention is to provide that 5 the conductor is part of the cover and is magnetically The invention is adapted for use wherever it is de- held in its first relationship and another objective is to sired to prevent the operation of a machine if its opera- enable the second relationship of the conductor where tor is not in a position in which the machine can be con- the safety switches are of the normally open type, to be trolled to meet certain standards such as performance effected by resilient means, magnetically, or by combiand safety. While the invention can be used in so con- 10 nations thereof, the conductor being movably positrolling a wide range of machines, it is herein discussed tioned within the mount.
with particular reference to vehicles, especially such Yet another objective of the invention is to provide vehicles as motorcycles, motor boats, particularly those a pull-apart switch that has first, second, and third equipped with outboard motors, and snowmobiles. contacts. When the first and third contacts are included
The invention is herein discussed primarily in con- 15 in a control circuit, first relationship circuit control is nection with its use in vehicles such as those specifi- provided. When the first and second leads are included cally referred to and as stopping their engines. in a control circuit, second relationship circuit control
Even in vehicles where the throttles are self-closing, 's provided, they may become stuck for various reasons and remain 20 A further objective of the invention is to provide pullopen. This is particularly true in the case of snowmo- aPart switches of the last named type in which there are biles whose throttle-operating cables often become fro- three conducting contacts in the mount each having an zen. If this happens when the operator has been thrown appropriate one of the leads secured thereto and with from his snowmobile, the snowmobile continues in mo- the contacts separated by magnets which are of the cetion at a speed depending, of course, on the position in 25 ramic type and hence nonconductors. The third which the throttle is caught. Even when the speed of contact has an arm within the mount engageable with the vehicle is moderate, the snowmobile may be de- the second contact but spTMg-biased out of contact stroyed or badly damaged. There have been occasions therewith. The cover includes a conductor interconwhere injuries and even deaths were caused by run- nectinS a" three contacts when 11 ls secured to the away snowmobiles, for one example, at a race track 30 mount so that m first relationship control, the con
, ... , ... , . ■ trolled circuit is opened when the cover is pulled from
when a runaway snowmobile killed a spectator. , . r r ,,
T-, ui u u • J A i the mount. In second relationship circuit control, the
The problem has been recognized and one solution v . . .
utilizes a switch to short out the spark when a sensor detects excessive accelerator cable tensions indicating that it has become frozen.
THE PRESENT INVENTION
magnetic field as applied to the switch arm is insufficiently strong to overcome the spring bias until the 35 cover is pulled from the mount.
SHORT DESCRIPTION OF THE DRAWINGS
, . , , . , , , - In the accompanying drawings, several embodiments
In accordance with the invention, the problems of „ „ ^ • J iL •
, , ■' , . , of safety switches in accordance with the invention are
preventing the continued operation of a machine when ^Q shown and
its operator is not in a predetermined location is met by p,G , js a perspective view of a snowmobile to the
means of a pull-apart switch havmg a fixed mount, usu- instrument panei0f which the mount of a safety switch
ally secured to the machine and a cover attached to the of the norma„y closed type is secured and the flexible
mount in a manner enabling it to be pulled therefrom. member of its cover attached to the clothing of the op
The cover has a flexible member whose free end is to 45 erator
be pulled if the operator moves or is moved from his nG] 2 is a plan view of the safety gwitch whh jts
position. At least in the case of vehicles, the free end cover attached
is attachable to the operator and of such length that his FIQ 3 is a se'ction taken approximateiy aiong the in.
normal movements do not result in the cover being dicated lines 3 3 of FIG. 2
pulled free of the mount. 50 FIG. 4 is a section similar to FIG. 3 taken transversely
The mount is provided with two contacts connect- of a norrnany open safety switch in accordance with the
able to the ends of the lead that controls the operation invention
of the machine, a motor circuit or an ignition circuit. piG. 5 is a like view but with the cover pulled free of
The switch also includes a conductor and means releas- the mount and the switch closed;
ably holding it in a first relationship with the contacts 55 FIG 6 is a section) similar to FIG. 4, of a normally
when the cover is attached to the mount and providing open safety switch in accordance with another embodi
a second relationship with the contacts when the cover ment of the invention;
is pulled free. In one relationship, the conductor is FIG. 7 is a like view but with the cover pulled free
seated against the contacts to interconnect the lead and the switch closed;
ends and in the other relationship, the conductor is 60 FIG. 8 is an elevational view of another normally spaced from the contacts. In one of the two named rela- closed switch in accordance with the invention; tionships the control lead is operative to maintain the FIG. 9 is a section taken approximately along the inmachine in operation, the first or normally closed rela- dicated lines 9—9 of FIG. 8;
tionship if the machine is powered by an electric motor ^ FIG. 10 is a view showing the inside surfaces of the or an engine whose ignition system includes a generator cover and the mount;
and the second or normally open relationship if the ig- FIG. 11 is a section, taken lengthwise of another em
nition system of an engine includes a magneto. bodiment of the invention that may function as either