Abstract: A control unit having a condition selector, an electrical switch having an actuator unit provided with an adjustable movement differential, a condition responsive device for actuating the switch when the condition responsive device senses certain conditions selected by the selector, and a lever arrangement carried by the unit and being operatively associated with the actuator unit of the switch and the device whereby the device can actuate the switch by the lever arrangement, the lever arrangement having a first adjustable lever operatively interconnected to the selector and acting as a main range lever. The first lever is operatively interconnected to the condition responsive device and to the actuator unit of the switch. The lever arrangement has a second adjustable lever operatively interconnected to the selector and to the actuator unit of the switch for adjusting the movement differential of the actuator unit of the switch.

Abstract: A reversing valve construction having a housing provided with a movable valve member therein that is interconnected to a piston unit having opposed piston heads that define a main chamber of the housing therebetween. The housing has end portions respectively cooperating with the piston heads to define a pair of opposed control chambers therewith, the end portions respectively having valve seats leading to the control chambers in directions substantially transverse to the direction of movement of the piston unit in the housing. Each piston head has a flexible seal member secured between a front disc member and a backing plate of the respective piston head so that an integral peripheral skirt of that seal member is urged into sliding and sealing engagement with an internal peripheral surface of the housing by an annular resilient O-ring member carried by the respective piston head and radially engaging and urging its respective skirt radially outwardly into the sliding and sealing engagement.

Abstract: A reversing valve construction having a housing provided with a chamber carrying a movable valve member therein that controls ports of a valve seat of the housing through the relative position of a cavity of the valve member relative to the ports, a one piece flexible sealing skirt being carried by the valve member and extending outwardly therefrom in a cantilevered manner adjacent the valve seat so as adapted to be exposed to fluid pressure in the chamber that will act directly thereon and cause the flexible skirt to flex and engage the valve seat in a manner to tend to sealingly conform to the contour of the valve seat and thereby seal the cavity to the valve seat while permitting sliding movement therebetween. A spring in the housing acts on the flexible skirt to urge the same toward the valve seat.

Abstract: A reversing valve construction having a housing provided with a movable valve member therein that is interconnected to a piston unit having opposed piston heads that define a main chamber of the housing therebetween. The housing has opposed ends respectively cooperating with the piston heads to define a pair of opposed control chambers therebetween, the ends respectively having valve seats leading to the control chambers. Each piston head has a flexible seal member secured between a front disc member and a backing plate of the respective piston head so that an integral peripheral skirt of that seal member is urged into sliding and sealing engagement with an internal peripheral surface of the housing by an annular resilient O-ring member carried by the respective piston head and radially engaging and urging its respective skirt radially outwardly into the sliding and sealing engagement. Such seal member for each piston head can be adapted to close a valve seat carried by a respective end of the housing.

Abstract: A control unit having a condition selector, an electrical switch, having an actuator unit provided with an adjustable movement differential a condition responsive device for actuating the switch when the condition responsive device senses certain conditions selected by the selector, and a lever arrangement carried by the unit and being operatively associated with the actuator unit of the switch and the device whereby the device can actuate the switch by the lever arrangement, the lever arrangement having a first adjustable lever operatively interconnected to the selector and acting as a main range lever. The first lever is operatively interconnected to the condition responsive device and to the actuator unit of the switch. The lever arrangement has a second adjustable lever operatively interconnected to the selector for and to the actuator unit of the switch adjusting the movement differential of the actuator unit of the switch.

Abstract: A reversing valve construction having a housing provided with a chamber carrying a movable valve member therein that controls ports of a valve seat of the housing through the relative position of a cavity of the valve member relative to the ports, a one-piece flexible sealing skirt being carried by the valve member and extending outwardly therefrom in a cantilevered manner adjacent the valve seat so as adapted to be exposed to fluid pressure in the chamber that will act directly thereon and cause the flexible skirt to flex and engage the valve seat in a manner to tend to sealingly conform to the contour of the valve seat and thereby seal the cavity to the valve seat while permitting sliding movement therebetween. A spring in the housing acts on the flexible skirt to urge the same toward the valve seat.

Abstract: A reversing valve construction having a housing provided with a chamber carrying a movable piston-like valve member therein that controls ports of a valve seat of the housing through the relative position of a cavity of the valve member relative to the ports. The ports comprise first, second and third ports disposed in spaced apart and straight line relation and the cavity bridges the first and second ports while exposing the chamber to the third port when the valve member is in one position thereof and bridges the second and third ports while exposing the chamber to the first port when the valve member is in another position thereof. A flexible sealing annular member is disposed between the valve member and the valve seat and surrounding the cavity to seal the cavity of the valve member to the valve seat while permitting sliding movement therebetween.

Abstract: A switch construction having a support carrying switch contacts and an electrical coil that has an armature operatively associated with the switch contacts to cause a switching operation therewith when the coil is energized to attract the armature from a first position thereof to a second position thereof relative to the coil. A mechanical spring arrangement is operatively associated with the armature to continuously resist the movement thereof from the first position thereof to the second position thereof with an increasing force that overcomes the increasing pull in force of the energized coil on the armature before the armature reaches its zero gap with the energized coil whereby the spring arrangement prevents the armature from reaching its zero gap and thereby causes the switch construction to be relatively noiseless in the operation thereof.

Abstract: A differential piston type reversing valve construction having a housing body provided with a high pressure chamber that has a valve member slideable therein for selectively interconnecting said high pressure chamber to either port of a pair of ports interrupting a valve seat of the housing body while interconnecting a low pressure port of the valve seat to the other port of the pair of ports, the valve member having a small piston member and a large piston member interconnected thereto and being disposed spaced from each other to define an intermediate chamber therebetween. The small piston member has one side thereof exposed to the high pressure chamber and the large piston member has one side thereof exposed to a control chamber of the housing body.

Abstract: A reversing valve construction having a housing provided with a movable valve member therein that is interconnected to a piston unit having opposed piston heads that define a main chamber of the housing therebetween. The housing has opposed ends respectively cooperating with the piston heads to define a pair of opposed control chambers therebetween, the ends respectively having valve seats leading to the control chambers. Each piston head has a flexible seal member secured between a front disc member and a backing plate of the respective piston head so that an integral peripheral skirt of that seal member is urged into sliding and sealing engagement with an internal peripheral surface of the housing by an annular resilient O-ring member carried by the respective piston head and radially engaging and urging its respective skirt radially outwardly into the sliding and sealing engagement. Such seal member for each piston head can be adapted to close a valve seat carried by a respective end of the housing.

Abstract: A control unit having a condition selector, an electrical switch having an actuator unit provided with an adjustable movement differential, a condition responsive device for actuating the switch when the condition responsive device senses certain conditions selected by the selector, and a lever arrangement carried by the unit and being operatively associated with the actuator unit of the switch and the device whereby the device can actuate the switch by the lever arrangement, the lever arrangement having a first adjustable lever operatively interconnected to the selector and acting as a main range lever. The first lever is operatively interconnected to the condition responsive device and to the actuator unit of the switch. The lever arrangement has a second adjustable lever operatively interconnected to the selector and to the actuator unit of the switch for adjusting the movement differential of the actuator unit of the switch.

Abstract: A reversing valve construction having a housing provided with a chamber carrying a movable piston-like valve member therein that controls ports of a valve seat of the housing through the relative position of a passage of the valve member relative to the ports. A one-piece flexible sealing skirt is carried by the valve member and extends outwardly therefrom in a cantilevered manner adjacent the valve seat means so as to be adapted to be exposed to fluid pressure in the chamber that will act directly thereon and cause the flexible skirt to flex and engage the valve seat means in a manner to tend to sealingly conform to the contour of the valve seat means and thereby seal the passage means of the valve member to the valve seat means while permitting sliding movement therebetween.

Abstract: A reversing valve construction having a housing provided with a chamber carrying a movable valve member therein that controls ports of a valve seat of the housing through the relative position of a cavity of the valve member relative to the ports, a one-piece flexible sealing skirt being carried by the valve member and extending outwardly therefrom in a cantilevered manner adjacent the valve seat so as adapted to be exposed to fluid pressure in the chamber that will act directly thereon and cause the flexible skirt to flex and engage the valve seat in a manner to tend to sealingly conform to the contour of the valve seat and thereby seal the cavity to the valve seat while permitting sliding movement therebetween. A spring in the housing acts on the flexible skirt to urge the same toward the valve seat.

Abstract: A reversing valve construction having a housing provided with a chamber carrying a movable piston-like valve member therein that controls ports of a valve seat of the housing through the relative position of a cavity of the valve member relative to the ports. The ports comprise first, second and third ports that all face in the same direction at the valve seat and are disposed in spaced apart and straight line relation and the cavity faces the ports and bridges the first and second ports while exposing the chamber to the third port when the valve member is in one position thereof and bridges the second and third ports while exposing the chamber to the first port when the valve member is in another position thereof. A flexible sealing annular member is disposed between the valve member and the valve seat and surrounding the cavity to be movable relative thereto to seal the cavity of the valve member to the valve seat while permitting sliding movement therebetween.

Abstract: A reversing valve construction having a housing provided with a chamber carrying a movable piston-like valve member therein that controls ports of a valve seat of the housing through the relative position of a cavity of the valve member relative to the ports. The ports comprise first, second and third ports disposed in spaced apart and straight line relation and the cavity bridges the first and second ports while exposing the chamber to the third port when the valve member is in one position thereof and bridges the second and third ports while exposing the chamber to the first port when the valve member is in another position thereof. A flexible sealing annular member is disposed between the valve member and the valve seat and surrounding the cavity to seal the cavity of the valve member to the valve seat while permitting sliding movement therebetween.

Abstract: A reversing valve construction having a housing carrying a movable piston-like valve member therein that controls ports of a valve seat of the housing provided with a chamber through the relative position of a cavity of the valve member relative to the ports. The ports comprise first, second and third ports disposed in spaced apart and straight line relation and the cavity bridges the first and second ports while exposing the chamber to the third port when the valve member is in one position thereof and bridges the second and third ports while exposing the chamber to the first port when the valve member is in another position thereof. A flexible sealing annular member is disposed between the valve member and the valve seat and surrounding the cavity to seal the cavity of the valve member to the valve seat while permitting sliding movement therebetween.

Abstract: A reversing valve construction having a housing provided with a chamber carrying a movable piston-like valve member therein that controls ports of a valve seat of the housing through the relative position of a passage of the valve member relative to the ports. A one-piece flexible sealing skirt is carried by the valve member and extends outwardly therefrom in a cantilevered manner adjacent the valve seat means so as to be adapted to be exposed to fluid pressure in the chamber that will act directly thereon and cause the flexible skirt to flex and engage the valve seat means in a manner to tend to sealingly conform to the contour of the valve seat means and thereby seal the passage means of the valve member to the valve seat means while permitting sliding movement therebetween.

Abstract: A double throw electrical switch construction having a housing carrying a movable actuator unit for moving a snap switch blade of the housing over center to snap a contact portion of the blade between a pair of spaced contact stops carried by the housing with a contact force being sustained at the "trip point" of the switch construction by an actuator spring of the actuator unit being moved over center before the blade is moved over center by the snap movement of the actuator spring. The actuator unit includes an actuator plunger having lost motion means directly acting against the actuator spring whereby the actuator spring can move relative to the actuator plunger through the lost motion means thereof when the actuator plunger moves the actuator spring over center in either direction thereof.

Abstract: A reversing valve construction having a housing provided with a chamber carrying a movable piston-like valve member therein that controls ports of a valve seat of the housing through the relative position of a cavity of the valve member relative to the ports. The ports comprise first, second and third ports disposed in spaced apart and straight line relation and the cavity bridges the first and second ports while exposing the chamber to the third port when the valve member is in one position thereof and bridges the second and third ports while exposing the chamber to the first port when the valve member is in another position thereof. A flexible annular sealing member is disposed between the valve member and the valve seat and surrounding the cavity of the valve member to seal the cavity of the valve member to the valve seat while permitting sliding movement therebetween.

Abstract: A double throw electrical switch construction having a housing carrying a movable actuator unit for moving a snap switch blade of the housing over center to snap a contact portion of the blade between a pair of spaced contact stops carried by the housing with a contact force being sustained at the "trip point" of the switch construction by an actuator spring of the actuator unit being moved over center before the blade is moved over center by the snap movement of the actuator spring. The actuator unit includes an actuator plunger having lost motion means directly acting against the actuator spring whereby the actuator spring can move relative to the actuator plunger through the lost motion means thereof when the actuator plunger moves the actuator spring over center in either direction thereof.