Gm Global Technolgoy Operations, Inc.

Michael A Gavlak

Scott Edward Kent

David M Ebbing

Ardeean Scoccia

Brian G Wicke

Kimball C Shontz

An elliptical cross section tube of novel construction that is capable of being expanded by a conventional conical tool of the type used to expand round cross section tubes. The tube is also reinforced by integral internal webs. The unexpanded tube cross section has concave lengthwise channels and concave internal webs that are all internally tangent to a circle representing a cross section of the expansion tool's conical head. As the head of the tool is pushed through the tube, it pushes the channels out into the fin hole while flattening the webs. The tube is thus mechanically bonded to the tube, and is left with a pair of internal reinforcing webs.

Method for mechanically expanding elliptical tubes

A method of eliminating odor in a heat pump system of a vehicle includes the steps of detecting removal of the vehicle passengers and ignition key after use of the cooling mode or air conditioning of the passenger compartment heat exchanger, operating the blower, reversing the flow of refrigerant in the heat pump to place the passenger compartment heat exchanger in heating mode to remove latent moisture to eliminate odor therefrom.

Method of odor elimination on A/C heat pump systems

A leak detector has a dual sensitivity due to two thresholds, a first established by a standard leak of the test gas representing the smallest leak to be detected, and the second as a fraction of the first one. A variable autozero level is used to compensate for background but is limited in its range to prevent masking of the leak by the autozero level. When measured gas concentration in excess of the autozero level exceeds the second threshold, the autozero value is held at a fixed value and an annuciator produces a signal as a function of the concentration so that the maximum concentration and the leak site can be found. When the leak site is found, the operator selects the first threshold for comparison with the gas concentration in excess of the held autozero value to determine whether the leak exceeds the rejection level.

Leak detector method establishing two different threshold levels

A receiver dehydrator for a refrigeration system for heating and cooling accommodates flow in either direction. It comprises a canister with openings near the top for coupling to refrigerant lines, and tubes inside the canister extending from the openings to tube mouths at the bottom of the canister for either intake or withdrawal of liquid. A baffle between the mouths allows liquid passage from either mouth to the other but inhibits flow of gas bubbles. The baffle has many perforations for liquid flow and an inclined vane outside each opening directs rising bubbles away from the perforations to encourage migration to the top of the canister. Alternate perforations have vanes on opposite sides of the baffle for gas-liquid separation in either flow direction. A desiccant bag between each tube mouth and the baffle further aids in such migration.

Bi-flow receiver/dehydrator for refrigeration system

A composite piston for an automotive air conditioning compressor is provided having an aluminum shank or piston rod, a reinforced plastic piston head and a steel ball for engaging a socket plate or the like. The shank has a distal end that has a slight reverse taper and a knurled surface for providing attachment to the plastic head that is molded thereon. The proximal end of the shank has a barrel to which the steel ball is press fitted. The shank is provided with a first collar adjacent the knurled distal end of the shank and a second collar adjacent to and intermediate the first collar and the proximal end of the shank. The first collar provides a seal for the mold cavity into which plastic is injected to form the piston head over the knurled surface of the shank. The second collar provides a support for the press fit operation of the steel ball onto the distal end of the shank.

Growing community of inventors

Buffalo, NY, United States of America

Michael A Gavlak