U.S. patent number 3,787,647 [Application Number 05/123,987] was granted by the patent office on 1974-01-22 for conducting fluid type gravity safety switch with spiral contacts.
Invention is credited to Benjamin F. Hughes.
United States Patent |
3,787,647 |
Hughes |
January 22, 1974 |
CONDUCTING FLUID TYPE GRAVITY SAFETY SWITCH WITH SPIRAL
CONTACTS
Abstract
An improved gravity operated switch includes a movable
electrically conductive member in a housing normally on a central
seat when in a normal horizontal position out of the circuit. When
the housing is tilted, the movable conductive member moves out of
the seat to bridge a pair of fixed spaced electrical contacts in an
associated electrical circuit to control the flow of fuel to the
engine of the vehicles, ignition, or other engine control
components. The switch has particular utility in engine powered
vehicles, such as tractors.
Inventors: |
Hughes; Benjamin F. (Morris,
AL) |
Family
ID: |
22412098 |
Appl.
No.: |
05/123,987 |
Filed: |
July 7, 1972 |
Current U.S.
Class: |
200/61.47;
200/233; 200/220; 200/235 |
Current CPC
Class: |
H01H
29/20 (20130101) |
Current International
Class: |
H01H
29/00 (20060101); H01H 29/20 (20060101); H01h
035/02 () |
Field of
Search: |
;200/61.47,220,233,235 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Scott; James R.
Claims
1. An improved gravity switch combination for protecting a vehicle
subject to tilting at an unsafe operating angle, comprising in
combination: a housing mountable in a fixed position on said
vehicle; an external circuit; said housing including a lower
insulative base member with a slanted multi-U shaped groove
configuration having a central recess or seat portion and an upper
complementary cover member containing a fixed contact array
disposed on the base member in operative relationship such that a
flowable blobule may bridge the fixed contact array at a desired
position; an electrically conductive fluid globule flowable down an
incline by gravity, normally seated on said seat portion; each of
said groove configuration having a distal end receivable of said
globule; a pair of electrically conductive spaced fixed contact
elements in each of said distal ends connectable in said external
circuit, whereby said external circuit is closed when bridged by
said globule, thereby responsive to predetermined degrees of tilt
the engine ignition and other
2. A switch combination of claim 1, in which said distal ends are
connected to said external circuit operatively, and in which said
contact elements are each flexible and of spiral shape providing
sufficient flexibility for engagement with said globule when the
globule is in a bridged position.
3. A switch combination of claim 2, in which said fluid globule
includes mercury and other electrically-conductive metal granules
in a
4. A switch combination of claim 3, in which said housing base
member includes siad multi-U shaped groove configuration shaped in
a ray-configuration of radially outwardly-extending grooves from
the central recess or seat, such that the globule moves by pull of
gravity to bridge the contacts of at least one of the grooves when
the housing is tilted in
5. A switch combination of claim 4, in which said external circuit
includes a solenoid coil structure operatively closable of a fuel
supply-line valve of an automobile engine, the coil structure being
operatively connected to said contact elements such that the coil
becomes energized when said
6. A switch combination of claim 5, in which the external circuit
includes an ignition circuit operatively connected to break circuit
when the globule bridges the contacts and to re-establish circuit
when thereafter
7. A switch combination of claim 6, further including a second
external circuit comprising the foot and seat circuit having a
solenoid coil arranged to close a fuel line supply to an engine of
a vehicle, and being operatively connected to said contact elements
such that the second external circuit's solenoid coil is energized
when said globule bridges said contact elements and is de-energized
when the globule moves-off the
8. A switch combination of claim 7, in which said second external
circuit is operatively arranged such that when said globule bridges
said contacts the circuit thereof is grounded and is thereafter
de-energized when said globule is no longer ground-bridg-ing the
contacts.
Description
IMPROVED GRAVITY SAFETY SWITCH
The improvements relate to the construction and the function of my
U.S. Pat. No. 3,599,745, also to the teaching of prior art, such as
taught by Hadley et al, U.S. Pat. No. 1,858,191, and others who
taught having a switch with a movable electrical member in a
housing bridging a pair of fixed spaced contacts, connected to an
outside external control circuit closed being bridged by the
globule while the switch is in a normal horizontal position. When
tilted beyond a predetermined angle, the globule would move off the
contacts opening the circuits. It was also taught when the above
circuit was open by the movement of the globule, the globule would
move to bridge a pair of spaced fixed contacts in the same switch
connected to an associated control circuit to close this last named
circuit in an effort to control the fuel supply, and or ignition,
when employed on an engine on a machine. When employed in the above
manner the engine will misfire due to vibration of the engine, and
when the machine is traveling on rough surfaces which causes the
globule of mercury to bounce and move off the contacts momentarily
causing the misfire.
The main object of this invention is to correct the above faults by
having a mercury globule out of the circuit when in a normal
operating position, when tilted this globule will move to bridge
the contacts in the switch to close the circuit, thereby
controlling the flow of fuel to the engine, ignition or other
engine control components.
Another object is to stabilize the globule by having a superficial
analgam, a mixture of silver or gold dust making the globule more
stable, and by having a spiral contact points that flex with the
globule when bridged to give better contact during vibration.
Another object is to have a safety switch to protect all vehicles,
tractors, cars, trucks, snowmobiles, beach buggies and the like,
and such as power mowers, both the riding and the push type to
ground the ignition when tilted, to prevent the engine starting
while changing the blade, etc., to prevent an accident.
Another object is to have switches constructed so that engine
vibrations, and traveling on rough surfaces will seldom, if ever,
cause the globule to bounce to bridge the contacts momentarily, by
having strictures, and having the wings and the travel space from
the central region to the outer contact points the proper
length.
The invention will be explained in further detail in conjunction
with the drawings.
FIG. 1 is a sectional view taken substantially on line 1--1 of FIG.
2 of a first switch embodiment of the invention with the wings
slanting upward about 40.degree. from horizontal.
FIG. 2 is a side view taken substantially on line 2--2 of FIG. 1,
dotted lines shows the wing in a tilted position with an
amalgamated globule of mercury bridging the pair of contacts.
FIG. 3 is a vertical section view taken substantially on line 3--3
of FIG. 4 illustrating a second switch embodiment of the
invention.
FIG. 4 is a horizontal cross sectional view taken on line 4--4 of
FIG. 3.
FIG. 5 is a similar view of FIG. 3 showing the second switch in a
tilted position with space globule travel having a stricture formed
by the protruding dome.
FIG. 6 is a vertical sectional view similar to that of FIG. 3
showing the two parts of the second switch separated, to be fitted
together and sealed.
FIG. 7 shows a first circuit employing a gravity switch protecting
a vehicle by cutting off fuel supply of its engine.
FIG. 8 shows a second circuit employing a gravity switch for
protecting a vehicle employing a diesel engine for power by cutting
off its fuel supply.
FIG. 9 is a diagram of a third circuit employing a gravity switch
to control the ignition of the engine of a vehicle.
Referring first to FIGS. 1 and 2 there is shown a switch S1 having
a housing 10 made of hermetically sealed insulative material and
formed with three tubular wings 11, 12, 13. The wings axially slant
upward from a common intersection forming a pocket seal 14 in a
central region in which is normally seated a fluid globule 15
consisting of mercury and silver dust or granules making a
superficial amalgam. A pair of spiral fixed spaced electrical
contacts 16, 17, 18 are in the tips of winds 11, 12, 13. These
contacts are provided with electrical leads 19', 19" which extend
outward of the projections 20, 21, 22 formed in the bottom of the
wing tips. The switch is in a normally horizontal position when all
of the wing tips are horizontal. If the switch is tilted beyond a
predetermined angle as illustrated by dotted lines in FIG. 2, the
amalgamted mercury globule rolls out of pocket seat 14 and into one
of the wings to bridge the contacts therein. If an electrical
circuit is connected externally to leads 19', 19", the pairs of
contacts 16, 17, 18 of this circuit will be closed when globule 15
bridges any one of the contacts 16, 17, 18. If the switch is
connected as illustrated in FIGS. 7, 8, 9 to any of the circuits
C1, C2, C3, this will control the flow of fuel to the engine of the
vehicle, ignition, or other engine control components. Other wings
could be added if desired and strictures in the tubular wings could
also be added.
Switch S2 is shown in FIGS. 3-6. It has a hermetically sealed
somewhat cylindrical housing 23, formed with a cylindrical outer
housing 24 having a dome or a top part 25 with an inside portion
protruding downward resembling inverted cone 26. Concentrically and
horizontally surrounding this cone inside of housing 24 is a pair
of spaced fixed concentric electrical conductive ring contacts 27
to which leads 34, 34' are connected and extend out of projection
28. A circular flat base 29 with mounting holes 30 completes the
enclosure On the base inside is an elevated table 31 formed with a
concaved conical seat 32 on which globule 15a is normally seated. A
conical travel space 33 is formed, having a stricture between the
dome 25 and seat 32 for globule 15a to travel to bridge contacts 27
when tilted beyond a predetermined angle. If leads 34, 34' are
connected to an external circuit the circuit will be closed,
closing off the flow of fuel to the engine, ignition or activating
other engine control components.
FIG. 7 shows schematically how an improved gravity switch S2 can be
connected in a control circuit C1 for protecting a vehicle.
In switch S2 globule 15a is normally on seat 32. One lead 34 is
connected to line wire 35 which terminates at terminal 36 of
battery 37. The other terminal 38 of the battery is grounded at its
terminal 38 of coil 40. The other lead 34' of switch S2 is
connected to lead wire 39 connected to coil 40 of a normally open
solenoid valve 41 terminating at the ground. If the vehicle tilts
to an unsafe angle globule 15a will move to bridge contacts 27
closing the circuit. This will energize coil 40 to close valve 41
to close off the fuel supply through fuel line 42 to the engine of
the vehicle which will stop the engine. The engine can be
re-started when the switch resumes a normal horizontal position.
Switch S1 can be substituted for switch S2 to obtain the same
results. There are no on-off switches in this circuit C1 which can
be used on most vehicles.
FIG. 8 shows how switch S2a can be used for protecting a vehicle
employing a diesel engine.
In circuit C2 employing gravity switch S2a, glouble 15a is normally
disposed on seat 32. One lead 34 is connected to line wire 43 which
in turn is connected to coil 44 of a solenoid operated valve 45.
The valve is located in the fuel supply line 46 to the engine if
the vehicle ports a and b are normally open. When energized port b
is closed to close off fuel to the engine, port c is opened to by
pass drain line 47 leading back to main line through port a that
remains open, releasing the fuel pressure and thereby stopping the
engine. The other lead 34' of S2a is connected to line wire 48 and
to terminal 49 of switch S3, a double pole double throw selector
switch. This switch gives the operator a choice to sit or to stand.
The other terminal 50 of selector S3 is connected to line wire 51
which terminates at terminal 52 of battery 53. The other terminal
54 is grounded at its terminal of coil 44. Underseat 55 is
supported by springs 56. On bar 57 is gravity switch S2b in a
tilted position. Bar 57 is pivotally mounted on brackets 58 to seat
55 and also to bracket 59 on base 60. Switch S2c leads 34', 34" are
terminally connected to selector switch S3. Foot switch S2c is
pivotally mounted on bar 57a on bracket 58a under treadle 61
supported by spring 62 and pivot end 63 on base 64 and bracket 59a
in a tilted closed position. Leads 34", 34'" terminate at selector
switch S3, thereby connecting switches S2a and S2b in parallel to
wires 48 and 51 and to switch S2a in series with coil 44. The
driver closes selector switch S3 to energize the circuit and sits
on seat 55 thereby de-engergizing the circuit which is now in a
normal operating position. If the vehicle tilts excessively at an
unsafe angle globule 15a will bridge contacts 27 to close the
circuit energizing coil 44 to close off the fuel supply to the
engine which will then stop. The engine can be re-started when the
vehicle resumes a normal position. The same results occurs if the
driver leaves seat 55 or if the driver selects the foot switch S2c
and removes his foot from treadle 61. Selector switch S3 should be
opened when the driver leaves the vehicle to prevent battery
rundown. Switch S1 could be substituted for S2a, S2b or S2c to
obtain the same result. Solenoid valve 41 in circuit C1 could be
substituted for solenoid valve 45 in circuit C2, with the same
result.
FIG. 9 shows another circuit C3 which is arranged to cut off power
from the ignition when the vehicle tilts at a dangerous angle. Seat
switch S2d is identical to switch S2a in circuit C2, the parts
being numbered identically. Seat 55 is mounted on springs 56 and
switch S2e is secured pivotally on bars 57 by bracket 58 to seat
and bracket 59 to base 60. The foot switch could also be used in
this circuit C3 as shown in circuit C2. Seat switch S2e is disposed
in an axially tilted position. Lead 34" is connected to resistor R2
and is grounded while lead 34 is connected to line wire 65 which is
connected to on-off switch S4. Line wire 65 terminates at terminal
66 on battery 67 while the other terminal 68 of the battery is
grounded at its terminal and spark plug 75. Line wire 69 is
connected to on-off switch S4 and to the ignition coil 70 of the
vehicle engine. The high voltage output line 71 of coil 70 is
connected to rotary contact 72 of distributor 73 and contacts 74
are connected to spark plugs 75 of the engine. Lead 34' of switch
SP is connected to resistor R1 and is grounded and lead 34 is
connected to line wire 69. The resistors R1, R2 should have an
ohmic value as to the resistance of the circuit to protect the
circuit wire when grounded from over heating.
If the vehicle tilts excessively at an unsafe angle, glouble 15a
will move to bridge contacts 27 to close the circuit. This will
ground the circuit and de-energized it to stop the engine. This
engine can be restarted when the vehicle resumes a normal
horizontal position. Other circuits are obvious to those skilled in
the art such as connecting line wire 69 from the ignition coil of
circuit C3 of FIG. 9 to line wire 39 in circuit C1 of FIG. 7 on a
vehicle employing power from an ignition engine to control the fuel
and ignition. When tilted beyond a safe operating angle, glouble
15a will bridge contacts 27 to close the circuit energizing coil 40
of valve 41 to shut off the fuel supply to stop the engine. This
will ground the ignition through coil 40. It would also stop the
engine; hence, a double safety feature.
Another circuit using S2 is to connect one lead 34 at any point of
an ignition circuit with grounded lead 34' to stop the engine when
tilted. Fuses, triper fuses, circuit breakers, relay, time-delay
relays, could be used, arranged to open the ignition circuit when
the switch is tilted or inverted in an upset to cut-off the fuel
supply and open the ignition circuit to stop the engine and prevent
a possible fire. While but certain preferred embodiments of the
invention are shown it will be apparent that the invention is
capable of further variations and modification without departing
from the scope of the invention as defined by the claims appended
hereto.
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