Carrier Corporation

William E Wright

John R McManus

Ross A Moyer

Nelson R Gratzer

Thaddeus J Wawro

Dale E Jackson

Charles E Whipple

Fred V Honnold

Charles Anthony Mitchell

John R Duncan

Roderick G Rohrberg

Burrows P Eaton

An integrally threaded brass insert is molded into the discharge conduit of a condensate pan such that a steel drainage pipe can be threadably engaged to the insert without causing damage to the plastic discharge conduit. Bonding between the insert and the surrounding conduit is enhanced by providing a knurled surface on the outer periphery of the insert.

Molded drain connection with insert

A slit fin heat exchanger is formed by wrapping slit fin tubing around a pair of mandrels having expanded metal cylinders thereon into a flat coil having two spaced rows of tubing. The flat coil containing the expanded metal cylinders is located on mandrels which are rotatable about spaced parallel axes with the mandrels and axes initially being in the same plane. The mandrels are rotated about their axes in opposite directions which shifts the plane in which the coil is located. The shifting of the plane of the coil moves a portion of a first row of the coil into contact with a planar portion of a platen and the second row of the coil into a nesting relationship with the portion of the first row which is in contact with the planar portion of the platen. Continued rotation of the mandrels causes folding of the portions of the coil which extends the area of nesting. The folding takes place through up to 120.degree. and the ends of the first row of the coil contacts a portion of the platen causing the formation of a knob at the end of each coil and the nesting of the coil to the ends of the coil and into the expanded metal cylinders. The expanded metal cylinders serve to support the coil throughout its functional life, as well as during the manufacturing process.

Slit fin coil and the method of making coils

Method of making coils

A method of arc welding is disclosed. Specifically, a method of pulsed direct current (DC) arc welding is disclosed wherein special pulses of positive direct current are used to weld together work pieces. The special DC pulses are capable of dissipating difficult to reduce oxides which may be present on the surfaces of the work pieces without using a flux. The method is especially useful for fluxless arc welding of aluminum, particularly thin wall aluminum tubing used in making heat exchangers for air conditioning systems.

Pulsed direct current arc welding

A method and apparatus for expanding a tubular workpiece which includes mounting the workpiece in a lower die, filling the workpiece with fluid and engaging the upper portion of the workpiece with an upper die. The upper die is moved downwardly acting to physically compress the workpiece. The dies are additionally configured to form an internal pressure cavity such that further downward displacement of the upper die creates an internal pressure forcing the workpiece outwardly into the desired end configuration.

Method for expanding tubular blanks

A control system for a pulsed DC arc welding system power supply is disclosed. The control system operates to automatically adjust the pulse width of the current pulses supplied at the arc gap by the power supply to control the power flow to the work pieces at the arc gap. An example of such a control system for a conventional pulsed DC arc welding system power supply comprises a variable resistance device connected in parallel with a normally closed time delay switch. This system is electrically connected in an impulsar control circuit of the power supply. The control system automatically changes the resistance within the conventional impulsar control circuit to provide an adjustment within the control circuit to alter the impulsar output signal which controls the pulse width of the current pulses supplied by the power supply.

Control system for pulsed DC arc welding power supply

A feedback control system for a pulsed direct current (DC) arc welding system is disclosed wherein the duty cycle of current pulses supplied by a power supply is controlled in response to resistance sensed at the arc gap of the system. The circuit comprises a voltage sensor, a high-low regulator, and a pulse width signal generator. The voltage sensor senses the voltage drop across the arc gap. This voltage is directly proportional to the resistance at the arc gap. The high-low regulator responds to the sensed voltage to generate an output signal when the voltage drop across the arc gap exceeds a high limit or is below a low limit. This output signal alters the control signal from the pulse width signal generator which controls the arc welding system power supply. The control signal from the generator is altered so that the duty cycle of the current pulses is adjusted, in response to changes in the resistance sensed at the arc gap, to maintain a constant time averaged power flow to the work pieces at the arc gap. The form of the current pulses, including peak current level, is unchanged except for the duty cycle adjustment.

Feedback control system for pulsed DC arc welding

Apparatus for use in a heat exchange unit having wound fin tubing includes a tube support having a vertical portion and multiple lateral portions, each lateral portion having an opening therein. A support tube is inserted through the openings in the lateral portions of the tube support such that runs of wound fin tubing are secured between the tube support and the support tube. A run support portion of the tube support may additionally define notches for securing the various runs of wound fin tubing. Pins or other means for securing the tubular support means are inserted into the ends of the tubular support such that the support tube is affixed to the tube support assembly. The pins are secured to either the base pan or the structural assembly of the unit providing a tube support assembly as an integral part of the heat exchange unit.

Heat exchanger tube support assembly

Apparatus for encasing a heat exchange unit. A wrapper is disclosed having solid portions for structural support of the heat exchange unit and fastening means including closure means formed on each end of the wrapper and a fastener strip which co-acts with said closure means to secure the wrapper in its appropriate position. Louver portions and solid portions of the wrapper are additionally disclosed to provide a structurally sound wrapper having spaced louver openings to allow air flow therethrough.

Wrapper for a heat exchange unit

Method of manufacturing a heat exchanger element with a plurality of helically wound coils. The tubes are wrapped about a forming drum in a parallel abutting relation to each other to form a plurality of helically wound coils. Terminal leads are provided at each end of the coil. Terminal leads at each end of the coils are bent, disposed one inwardly the other so that they are positioned tangent to the same plane, which is perpendicular to the center longitudinal axis of the coils, and then a portion of each terminal lead is cut off and joined to a header.

Method of manufacturing a heat exchanger element

An accumulator for use in a refrigerant circuit having a tube in which are formed inlet and discharge openings and a cylindrical shell which is deformed by metal spinning against the exterior surface of the tube to form a container which serves as the accumulator. A diverter is provided between the discharge opening and the inlet opening to prevent direct flow through the tube bypassing the container. A method of manufacture of the accumulator by metal spinning is also disclosed.

Refrigerant accumulator and method of manufacture thereof

Apparatus for use in a heat exchanger assembly having wound fin tubing including a spacer member having a structural portion for securing components within the heat exchanger and a series of spaced projections extending therefrom. The spaced projections define a series of U-shaped openings adapted to receive and maintain the wound fin tubing in a fixed relationship. A retainer element is mounted to enclose the openings to secure the wound fin tubing therein. On some of the projections of the spacer member are mounted tabs which are inserted through slots in the retainer element to secure the retainer element to the spacer member such that the wound fin tubing is secured within the spaced openings and such that the structural portion of the spacer member secures various components of the heat exchanger assembly.

Wound fin heat exchanger support

Apparatus for venting a plate fin coil during the ultrasonic soldering of aluminum return bend tubes to the heat exchange tubes in the coil. The apparatus includes a process snorkel member comprising a bored plug for telescoping inside an extension tube extending from an open end of a heat exchange tube forming an end of a circuit in the coil, and a venting tube defining an air conduit from the plug to the atmosphere, whereby the pressure in the interior of the plate fin coil assembly is relieved when the fin coil is immersed in the solder bath.

Growing community of inventors

East Syracuse, NY, United States of America

William E Wright