US2843687A

US2843687A - Safety switch

Info

Publication number: US2843687A
Application number: US601194A
Authority: US
Inventors: Frank W Murphy
Original assignee: Individual
Current assignee: Individual
Priority date: 1956-07-31
Filing date: 1956-07-31
Publication date: 1958-07-15
Anticipated expiration: 1975-07-15

Description

July 15, 1958 F. w. MURPHY 2,843,687

' SAFETY SWITCH Filed July 31, 1956.

INVENIOR RWMW hI;

ATTORNE S United States Patent SAFETY SWITCH Frank W. Murphy, Tulsa,'0kla.

Application July 31, 1956, Serial No. 601,194

' Claims. Cl. 200-56) The present invention relates to safety switches, and more particularly to such switches combined with a gauge and responsive to conditions of said gauge.

The primary object of the invention is to provide .a safety switch which is actuated by the movable gauge indicator upon a predetermined movement thereof.

Another object of the invention is to provide a safety switch of the class described above having means to adjust the position of the switch so as to vary the condition under which the switch will operate.

A further object of the invention is to provide a safety switch of the class described above which is inexpensive to manufacture, simple to use, and completely effective and accurate in its operation.

Other objects and advantages will become apparent in the following specification when considered in the light of the attached drawings, in which:

Figure l is a plan view of the invention with parts broken away in section for clarity of illustration.

Figure 2 is a fragmentary enlarged vertical crosssection taken along the line 22 of Figure 1, looking in the direction indicated.

Figure 3 is a diagrammatic view of the invention illustrating the electrical circuit used therewith.

Figure 4 is a plan view of the switch support blank used with the invention.

Referring now to the drawings in detail wherein like reference characters indicate like parts throughout the several figures, the reference numeral indicates generally a combined safety switch and gauge constructed in accordance with the invention.

The combination gauge and safety switch 10 comprises a generally cylindrical body 11 having a bottom wall 12,

a dial 13 positioned in vertically spaced relation to the bottom 12, a glass 14 positioned above the dial 13, and a glass retainer ring 15 securing the glass 14 to the cylindrical body 11. An indicator hand 16 is pivoted at 17 in the cylindrical body 11 and has secured thereto beneath the dial 13 an actuating pin 18, as best seen in Figure l.

The indicator hand 16 is adapted to swing on the pivot 17 carrying the actuating pin 18 therewith. The indicator hand 16 is adapted to be driven by any suitable means (not shown) in response to pressure changes, temperature changes, or any other measured phenomenon.

A switch plate, generally indicated at 19, rests on the bottom 12 of the cylindrical body 11 and is pivoted thereto by means of a pivot bolt 20 extending through a bore 21 in one end of the switch plate 19. The opposite end of the switch plate 19 is provided with a generally U-shaped bracket 22 having an outer vertical wall 23 carrying a vertically extending slot 24 therein. The switch plate 19 is provided with a laterally extending support 25 having a bore 26 extending'therethrough.

An arm 27 is provided with a horizontal fiange 28 having a pivot bolt 29 extending therethrough into the bore 26 of the extension 25 to pivotally mount the arm 27 to the extension 25. The end of the arm 27 opposite the flange 28 is provided with an offset extensionSfl which is adapted to engage the actuating pin 18 carried by the indicator hand 16, as best shown in Figure 1.

A micro switch 31 is secured .to the switch plate 19 by means of 'bolts 32 extending therethrough and into bores 33 in the switch plate 19. The micro switch 31 is of conventional construction and has a plurality of terminal connectors '34, 35 and 36 on one end thereof, a conventional swinging switch arm 37 'interiorly thereof, and a switch arm actuating pin 38 extending through the side Wall of the micro switch 31 to engage the arm 27, as best seen in Figure 1.

The cylindrical body 11 has a flattened portion 3.9 formed in one side thereof with a bore 40 extending therethrough. A bolt 41 having a head 42 on the outer end thereof extends through the bore 40 into the cylindrical body 11 and through the slot 24 in the outer wall 23 of the U-shaped bracket 22. A head 43 is formed on the inner end of the bolt 41 and is positioned behind the vertical wall 23 so as to rotatably secure the bolt 41 to the bracket 22.

A nut 44 is engaged on the bolt 41 exteriorly of the cylindrical body 11 in engagement therewith so that the nut 44 engages a shoulder 45 on the body 11 so as to be held against turning. A coil spring 46 is positioned about the bolt 41 interiorly of the body 11 having one end thereof in engagement with the body 11 and the other end thereof in engagement with the vertical wall 23 of the bracket 22.

As can be readily seen by reference to Figure l, the bolt 41 by means of head 42 will swing the switch plate 19 about the pivot 20 to move the switch actuating bar 38 toward and away from the actuating pin 18. The spring 46 will normally maintain the nut 45 in tight engagement with the body 11 so that the switch 31 will be normally maintained in the innermost position permitted by the nut 45.

In the use and operation of the invention, the indicator hand 16 in response to exterior forces rotates on the pivot 17 carrying the actuating pin 18 therewith. The actuating pin 18 in contact with the offset portion 30 of the arm 27 causes the arm 27 to pivot about the pivot 29 moving the switch arm 38 so as to actuate the switch 31 and break a circuit existing between the

contacts

34 and 36.

As the indicator hand 16 reverses its direction of movement, the indicator pin 18 will permit the arm 27 to move away from the switch 31 so that the switch will again close the circuit between the

contacts

34 and 36.

In the event that the indicator hand 16 continues to travel after the arm 27 has pivoted to it fullest extent on the pivot 29, the switch plate 19 will swing on the pivot 20 against the tension of the spring 46 to move the switch 31 permitting the arm 27 as far as is necessary by the movement of the actuating pin 18.

It should be noted that the switch 31 can be utilized to actuate a motor 47 through a battery 48 utilizing the

contacts

34 and 36 so that the breaking of the circuit between the

contacts

34 and 36 will cause the motor 47 to cease to run. Obviously, the use of the

contacts

34 and 35 will establish a circuit upon movement of the switch arm 37 when such an action is desired.

Having thus described the preferred embodiment of the invention, it should be understood that numerous structural modifications and adaptations may be resorted to without departing from the scope of the appended claims.

What is claimed is:

1. A combined gauge and safety switch comprising a gauge body, an indicator hand pivotally mounted in said gauge body, a switch pivotally mounted to said gauge body for movement in a direction toward said indicator hand, a switch actuating arm pivotally carried by said switch for movement in a direction toward said indicator hand, a switch actuating arm actuating pin carried by said indicator hand for .moving said actuating arm to switch actuating position upon movement of said indicator hand.

2. A device as claimed in claim 1 wherein said switch is biased toward said indicator hand by means of a spring biasing means.

3. A device as claimed in claim 2 wherein a screw threaded adjusting means is associated with said switch and said spring biasing means to adjust the pivotal position of said switch.

4. A safety switch for gauges of the type having a gauge body and a pivoted indicator hand comprising a 15 switch pivotally mounted in said gauge body, means including a spring for normally maintaining said pivoted switch in one position, a switch actuating arm pivoted to said switch, .an actuating pin carried by the indicator hand of said gauge and engaging said actuating arm whereby rotational movement of said hand will pivot said actuating arm on said switch actuating said switch, said spring biasing means permitting pivotal movement of said switch thereagainst upon pivotal action of said indicator hand beyond that necessary to actuate said switch.

5. A device as claimed in claim 4 wherein said adjusting means for said switch extends through said body for operation exteriorly of said body.

References Cited in the file of this patent UNITED STATES PATENTS