Robertshaw Controls Company

Other

Denis G Wolfe

Hugh J Tyler

By Linda Benton, Trust Administrator

Wilbur F Jackson, Deceased

Richard K Mitts

Joseph S Danon

Naohisa Wada

Bruce B Parsons

Richard J Berryhill

A piston and cylinder type thermal device and method of making the same are provided, the device having a cylinder member carrying a piston stem that has an outer end that projects out of the opening of an end of the cylinder member to be extended and retracted relative thereto upon changes of sensed temperature of a charge of material disposed in the cylinder member that operatively acts on a resilient stem seat disposed in the cylinder member and having an opening at one end thereof that receives an inner end of the stem therein. The stem has a lubricant thereon to tend to prevent abrasion between the stem and the seat during the extended and retracted movement therebetween. A lubricant storage unit is carried by the device and has therein a porous member with the lubricant absorbed therein and being operatively associated with the stem for applying the lubricant to the stem external of the end of the cylinder member during movement of the stem relative to the stem seat. The lubricant storage unit comprises a cup-shaped member having a closed end and an open end with the open end being telescoped on and secured to the end of the cylinder member in such a manner that the porous member is placed under axial compression between and against the end of the cylinder member and the closed end of the cup-shaped member.

Piston and cylinder type thermal device part therefor and methods of

An improved combustion detection apparatus is disclosed that can be employed in a fail-safe control circuit for a combustion apparatus to operate a shut-off valve in the fuel supply in response to the presence or absence of combustion. The improved combustion detector is an electrode assembly of a solid metal oxide member and electrodes in the form of electrical conducting coatings on opposite sides of the metal oxide member. The metal oxide has the characteristic of generating an electromotive force by transfer of oxygen ions therethrough. The combustion detector is placed in the vicinity of a flame from a pilot or main burner of the combustion apparatus. The oxygen gradient established by the burner flame and the resultant high temperature of the metal oxide member provides an instantaneous response to ignition or extinguishment of the burner flame. There is also disclosed an improved metal coating and method for its application on the metal oxide member which greatly increases its operational life over metal coatings of the prior art.

Combustion detection apparatus

There is disclosed a thermally responsive actuator useful for solenoids of electromagnetic valves and the like that includes a thermally responsive assembly of first and second metallic members that function as a thermocouple to generate an electrical voltage and also as a bimetallic operator for a switch carried within a housing of the device and operative to make and break the thermocouple circuit.

Thermally responsive actuator

There is disclosed an antifriction assembly of relative moving machine elements such as shaft and thrust bearing or screw and nut assemblies having engagement surfaces formed of materials characterized by a coefficient of friction which is inversely dependent upon compressive loading. Typical of such materials are plastics such as fluorocarbons, polyamides and/or acetal resins. The antifriction assembly utilizes the aforementioned characteristics of these materials to achieve minimal force and wear and maximum life. The shaft and thrust bearing assembly comprises a shaft having a grooved land to receive a bearing plate which has a slotted aperture to capture the shaft. The shaft and bearing are formed of the aforementioned plastics. The screw and nut assembly comprises members that are also formed of the aforementioned plastics. The screw member has external helical threads and the annular nut member has internal helical threads of the same or substantially the same pitch as the external threads and is threadably engaged on the screw member. The external and internal helical threads have distinctly different flank angles to provide a minimal length of thread engagement and a maximum of surface loading. In the preferred embodiment the thread engagement comprises a line spiral contact between the members and is obtained by providing substantially square threads on one of the members and threads with an acute flank angle on the other member.

Antifriction assemblies

There is disclosed a safety control for a pulse combustion system. In a pulse combustion process, a combustible fuel and air are introduced into a combustion chamber through check valves in pulses and ignite to generate an alternating sinusoidal pressure wave. The control system of the invention comprises rectifying the sinusoidal pressure wave to obtain therefrom a differential pressure signal and applying the pressure signal to a control circuit to position a valve in the combustible fuel supply. Any interruption in combustion within the chamber causes a cessation of the differential pressure signal and closes the control valve. The apparatus of the invention includes, as the rectification facility, a dynamic check valve having a funnel member which is longitudinally disposed in a conduit communicating between the pulse combustion chamber and a pressure responsive transducer, the latter being operatively connected to maintain the fuel supply valve open during combustion and to close the fuel supply valve upon failure of combustion within the chamber.

Pulse combustion control system

There is disclosed a thermally responsive switch that is ideally suited for responding to the ignition and extinguishment of a flame. The switch is provided with two switch poles, one that is biased normally open and the other that is biased normally closed. The response of the switch to the presence of a flame is very sensitive and precise to open the normally closed contact within a few seconds after ignition of a flame and, shortly thereafter within another controlled time period, to close the normally open contact. Upon extinguishment of the flame, the switch reverses its movement, opening the normally open contact within a short time interval, and, thereafter, closing the normally closed contact. The switch mechanism employs a thermally responsive, tube-in-tube member with the inner tube connected to a push rod which resiliently carries a switch lever. The switch lever has lateral tabs which are captured within first and second slots of brackets which are on the switch blade and which have predetermined widths to provide lost motion connections between the switch lever and the switch blade. The switch blade is biased resiliently towards the normally closed contact and this bias is laterally unbalanced to provide a stepping action of the switch lever. The switch lever also resiliently receives and is carried on the push rod whereby it accomodates thermal deformation of the tube assembly which is in excess of that necessary for the opening and closing functions of the switch.

Thermal switch

An electrical furnace has a plurality of electrical heaters and a control unit carried by a frame. A rigid lead unit is carried by the frame and has rigid lead means directly and electrically interconnected to terminals of the heaters and terminals of the control unit, the rigid lead unit itself having terminals for electrically interconnecting the rigid lead means to power source leads whereby the power source leads are directly and electrically interconnected to the terminals of the heater and the control unit by the rigid lead means without the need for auxiliary wiring. The control unit includes an electrical sequencing switch construction having a plurality of electrical switches for sequentially operating the heaters, the switch construction having a temperature sensing unit operatively interconnected to the switches for moving and holding the same in open conditions thereof when the temperature sensing unit senses a high temperature condition of the heaters.

Electrical furnace and parts therefor

The heat from an electric resistance igniter is used both (1) to start fuel flow to a burner after ignition temperature, and (2) to stop the fuel flow after a delay in the event of flame failure.

Glow coil ignition system with flame sensing

A thermal responsive switch employs a gas expansion operating member movable by changes in pressure of a gas charge in a chamber containing a carbonaceous adsorbent material formed from a compound of carbon and non-carbon component by removing the non-carbon component.

Burner system with absorbent carbon flame responsive switch

A wedging member, such as a ball, is frictionally engaged with inclined supporting ends of a pair of contact elements at a calibration temperature. The wedging member retains the positioning of the supporting ends as the temperature is changed from the calibration temperature to a hardening temperature for a hardenable material, such as an inorganic-base chemical-setting cement, for rigidly securing the supporting ends.

Method of assembling calibrated switch

An explosion resistant gas valve in which a valve actuating mechanism in the form of a bimetallic strip is operated by an electric heat motor. An explosion containment structure is provided about the electric heat motor to isolate it from the path of gas flow. A plurality of pressure relief apertures extend through the sides of the containment structure.

Explosion resistant electric heat motor gas valve

The end of an elongated resistance element, such as a molybdenum disilicide rod, is joined to a metal member which provides both electrical connection and mechanical support.

REFRACTORY RESISTOR WITH SUPPORTING TERMINAL

A thermally operated valve utilizes a member which is moved in accordance with the pressure of a gas within a chamber containing an adsorbent carbon material formed from a compound of carbon and a non-carbon component wherein the non-carbon component has been removed leaving a porous structure with cavities of sufficient size to receive and adsorb the gas.

Thermally operated valve utilizing gas adsorbent material

A thermal responsive device employs gas, such as a noble gas, with an adsorbent carbon material which is a decomposed carbonaceous compound, such as decomposed polyvinylidene chloride or decomposed polyvinylidene fluoride.

Growing community of inventors

Santa Ana, CA, United States of America

Denis G Wolfe