US3781743A - Manual reset for a switch device - Google Patents

Abstract

A condition responsive switching device has a manual reset provision in which a pressure responsive actuator has a pin providing an output force to be applied against a moveable contact blade of a switch. A wedging member is spring biased between the base and the blade so that upon movement of the moveable blade to an open switch position, the wedging member is moved along adjacent to the blade to hold the blade and thus the contact in an open switch position. After the pressure responsive actuator returns to the normal position, a reset operation is accomplished by a pivoting reset driver which is operated upon pushing a reset button to slide the wedging member against its bias spring back to an initial position to allow the moveable blade to move to a closed switch position.

Description

United States Patent [1 1 Kolbow Dec. 25, 1973 MANUAL RESET FOR A SWITCH DEVICE Primary Examiner--Robert K. Schaefer Assistant ExaminerRobert A. Vanderhye [75] Inventor. ilsltzzgld P. Kolbow, Minneapolis, Atmmey Lam0nt B Koontz et al- [73] Assignee: Honeywell lnc., Minneapolis, Minn. ABSTRACT [22] Filed; June 27, 1972 A condition responsive switching device has a manual reset provision in which a pressure responsive actuator PP 4 266,796 has a pin providing an output force to be applied against a moveable contact blade of a switch. A wedg- 52 U.S. Cl. 337/118, 200/83 2; ing member is Spring biased between the base and the 51 Int. Cl. lll0llh 37/36, HOlh 71/58 blade 80 that p movement of the moveable blade [58] Field of Search 200/83 2, 153 H; to an Open Switch position, the wedgihg member is 335/26. 337/56, 91, 118 130, 5 343, 35 moved along adjacent to the blade to hold the blade and thus the contact in an open switch position. After [56] References Cited the pressure responsive actuator returns to the normal UNITED STATES PATENTS position, a reset operation is accomplished by a pivoting reset driver which is operated upon pushing a reset g et 231 button to slide the we'dging member against its bias 1 2 2 2 '6 X I spring back to an initial position to allow the moveable blade to move to-a closed switch position.

6 Claims, 3 Drawing Figures 20 I3 ll 3| 32 1 MANUAL RESET FOR A SWITCH DEVICE BACKGROUND AND SUMMARY OF THE INVENTION In a co-pending application of Elwyn H. Olson Ser. No. 266,797, filed June 27, 1972, for Manual Reset For A Switch Device, a control device is disclosed having a snap action condition responsive actuator for moving a switch to an open position with a means for maintaining the switch in the open position until a manual reset operation takes place. While such control devices having manual reset are broadly old, the Olson device provides for a biasing member against the moveable contact blade so that when the blade is lifted from a first to a second position to open the switch by the actuator, a removal of the output force provided by the ac tuator results in the moveable blade being held in the second position. The manual reset operation is accomplished by a reset driver for removing the force supplied by the biasing member to allow the moveable contact blade to return to the first position.

The present invention provides for an improved control device having a biasing member with a resetting operation. A Wedging biasing member is mounted between the base and the moveable contact blade to slide under the force of a biasing spring along the surface of the blade to continuably apply a loading in a direction in line with a main actuator output member. Upon the moveable contact being lifted by the output member, the Wedging member slides along the blade to hold the blade in an open switch position even though the output member of the actuator returns to a normal position. The resetting operation is accomplished by a reset driver which engages the Wedging member to slide it back to the initial position to allow the moveable blade to move to a closed switch position.

FIG. 1 is a partial cross sectional side view of the switch device showing the Wedging member spring biased against a moveable contact blade;

FIG. 2 is a partial cut-away end view of the device of FIG. 1 showing the reset driver for engaging the wedging member; i i

FIG. 3 is a partial cross sectional view of the device as shown'in FIG. 1 with the Wedging member in a position to hold the moveable contact blade in an open switch position.

DESCRIPTION OF THE INVENTION Referring to FIG. 1, the control device has a base to which is connected an actuator means 11 of a pressure responsive snap acting type as shown in the M. E. Russell, U.S. Pat. 2,840,669 issued June 24, 1958. A pressure through a fluid filled tube 12 connected to a remote condition responsive device or bulb 16 provides a pressure to move the output member or pin 13 upwardly upon a condition or the temperature of the remote bulb exceeding some predetermined value.

Connected to the base is a fixed switch contact 20 electrically connected to a terminal 21. A moveable switch contact 22 is connected to a contact support member or resilient blade 24 attached to base 10 and terminal 25. Blade 24 is inclined with respect to a surface 26 of base 10. When contact 22 engages contact 20 an electrical circuit is completed between terminals 21 and 25.

A contact blade, Wedging member 31 is slidably, moveable between surface 26 of the base and resilient inclined blade 24 and is biased in a normal or first position to the left against blade 24 by a spring 32. The force of spring 32 is sufficient to maintain Wedging member 31 biased against blade 24 but not sufficient by itself to provide the force or loading to lift the blade from the position, as shown in FIG. I to open the switch. Wedging member 31 moves to a second position, shown in FIG. 3, when blade 24 is raised by output member 13.

A reset driver member or button 33 is pivoted on base portion or cover 10a at 34 and has a pair of extremities and 51 for engaging the outer ends 36 and 37 of Wedging member 31 when the reset driver is pushed to the dotted line position.

As shown in FIG. 2 Wedging member 31 has a pair of connected portions, 52 and 53 for engaging the underside of blade 24. Portions 52 and 53 are connected at 55 to form a U shape so that when the Wedging member moves to the left under blade 24, portions 52 and 53 straddle pin 13 as shown in FIG. 3. Reset driver 33 engages the extremities 52 and 53 of the Wedging member at outer ends 37 and 36 which are higher to insure that extremities 50 and 51 engage the ends to move member 31 to the right as shown in FIG. 1.

OPERATION OF THE INVENTION As shown in FIG. I, the control device is in a switch close position with an electrical circuit existing between terminals 21 and 25. Upon an increase in the temperature of bulb 16 above a predetermined temperature, actuator 11 causes pin 13 to move upwardly to lift the moveable blade 24 to a position as shown in FIG. 3 to open the electrical circuit. Wedging member 31 is driven by spring 32 to the position as shown in FIG. 3 even though the Wedging member is biased against blade 24. The force on the blade by the wedging member is insufficient to lift the blade until pin 13 pro vides the additional upward force.

Upon the return of the temperature to a normal value, pin 13 returns to the position as shown in FIG. 1; however, Wedging member 31 remains in the position as shown in FIG. 3 to hold contact 22 in its raised position and thus the switch open. Since blade 24 and the base are substantially parallel there is little or no force tending to drive Wedging member 31 from its holding position. Upon the operation of the reset driver 33 from the position as shown in FIG. 1 to the dashed line position, the reset driver moves Wedging member 31 back to the position as shown in FIG. 1 to allow moveable contact blade 24 to be lowered to a switch closed position for normal operation.

The Wedging member 31 slides between the base 10 and moveable contact blade 24 to continually engage the blade under the force of spring 32. With such an invention, the change in dimensions due to tolerance build-ups during manufacture of such a device is of little consequence as Wedging member 31 is free to move along the blade until the blade 24 is engaged regardless of any variance in the normal position until an additional force or loading is applied by pin 13 to the blade, the force due to Wedging member 31 is insufficient to lift the blade. Such an invention provides for ease of manufacture as the tolerances of the dimensions of the parts associated with the improved resetting mechanism need not be maintained within any close degree of accuracy and yet a control device is provided with a simple resetting mechanism.

The embodiments of the invention in which an exclusive property or right is claimed are defined as follows:

1. In a control device, a base,

actuator means attached to said base and adapted to be responsive to a change in value of a condition, switch means on said base having a moveable contact support member for moving a switch contact to open and close an electrical circuit, said contact support member being inclined with respect to an adjacent surface of said base, connection means operably connecting said actuator means to said switch means for moving said contact support member from a first position to a second position upon a predetermined change in value of the condition, wedging means positioned in a first position between said moveable contact support member and said surface of the base, said wedging means tending to bias said contact support member in a direction from said first to said second position, said bias being insufficient to move said contact support member to said second position so that when said contact support member moves to said second position in response to said actuator means, said wedging means moves to a second position to hold said moveable contact support member in said second position, and reset means operably connected to said wedging means to slide said wedging means from said second position to said first position to free said moveable contact support member from said second position. 2. The invention of claim 1 wherein, said moveable contact support member is a resilient blade attached at one end to said base and having a switch contact at its opposite end, and

said wedging means comprises a member mounted between said base and said blade and biased to slide along said blade as said blade moves from said first to said second position.

3. The invention of claim 2, wherein,

said reset means comprises a lever pivotally connected to said base and having extremities for engaging said wedging member to slide said wedging member from said second to said first position so as to not hold said blade in said second position.

4. The invention of claim 1, wherein,

said contact support member is a resilient blade supporting a switch contact of said switch means,

said connection means comprises a pin engaging said blade of said switch means to lift the blade to said second position, andsaid wedging means comprises a U-shaped member which is biased by a spring to apply a force to said blade which is insufficient to move said blade to said second position, said U-shaped member being arranged to straddle said pin when said pin moves to apply a force to the blade which is sufficient to move said blade to said second position.

5. The invention of claim 4, wherein,

said U-shaped member has two in line surfaces on opposite sides thereof for engaging said blade continuously throughout its movement from said first position to said second position.

6. The invention of claim 4 wherein,

said U-shaped member in said first position applies a force to said blade regardless of any variance in said first position of said blade.

Claims (6)

1. In a control device, a base, actuator means attached to said base and adapted to be responsive to a change in value of a condition, switch means on said base having a moveable contact support member for moving a switch contact to open and close an electrical circuit, said contact support member being inclined with respect to an adjacent surface of said base, connection means operably connecting said actuator means to said switch means for moving said contact support member from a first position to a second position upon a predetermined change in value of the condition, wedging means positioned in a first position between said moveable contact support member and said surface of the base, said wedging means tending to bias said contact support member in a direction from said first to said second position, said bias being insufficient to move said contact support member to said second position so that when said contact support member moves to said second position in response to said actuator means, said wedging means moves to a second position to hold said moveable contact support member in said second position, and reset means operably connected to said wedging means to slide said wedging means from said second position to said first position to free said moveable contact support member from said second position.

2. The invention of claim 1 wherein, said moveable contact support member is a resilient blade attached at one end to said base and having a switch contact at its opposite end, and said wedging means comprises a member mounted between said base and said blade and biased to slide along said blade as said blade moves from said first to said second position.

3. The invention of claim 2, wherein, said reset means comprises a lever pivotally connected to said base and having extremities for engaging said wedging member to slide said wedging member from said second to said first position so as to not hold said blade in said second position.

4. The invention of claim 1, wherein, said contact support member is a resilient blade supporting a switch contact of said switch means, said connection means comprises a pin engaging said blade of said switch means to lift the blade to said second position, and said wedging means comprises a U-shaped member which is biased by a spring to apply a force to said blade which is insufficient to move said blade to said second position, said U-shaped member being arranged to straddle said pin when said pin moves to apply a force to the blade which is sufficient to move said blade to said second position.

5. The invention of claim 4, wherein, said U-shaped member has two in line surfaces on opposite sides thereof for engaging said blade continuously throughout its movement from said first position to said second position.

6. The invention of claim 4 wherein, said U-shaped member in said first position applies a force to said blade regardless of any variance in said first position of said blade.

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