ULTRA-MINIATURE PNEUMATIC ELBOW FITTING FITS CRITICAL MEDICAL PRODUCT TO A "TEE"

In today's business world, engineers are challenged to design products that are faster, lighter and smaller. Successful products are often the ones that provide the desired functions in the smallest overall package.

The development of Beswick's ultraminiature, low profile, adjustable position elbow fitting is an example of the miniaturization trend. The development of this elbow fitting was initiated by a telephone call from a desperate design engineer at a large medical company. Their need was immediate. Every day that passed without a solution increased the customer's financial loss.

ULTRA-MINIATURE FIXED POSITION ELBOW

Beswick design engineers identified with the customer's sense of urgency and immediately got to work. An innovative design was required and a clean sheet approach was undertaken. The first solution was an ultra-miniature, fixed-position elbow fitting (called the MLA series) with a built-in hose barb. The built-in hose barb feature was accomplished by soldering the barb to the fitting body.

This concept, joining the hose barb to the fitting body, eliminated the need for the body to be big enough to accept a female (internal) thread and allowed the selection of a 5/16 in. hexagonal body instead of a larger rectangular body. The resulting design reduced installed height by 44%, and reduced volume by more than 70% compared to conventional designs.

The MLA prototype was delivered to the customer and low volume production was initiated. The fitting physically fit into the application; however, because it was a fixed position design, the customer soon found that the hose barb did not always line up in the proper orientation after installation.

ULTRA-MINIATURE ADJUSTABLE POSITION ELBOW TO THE RESCUE

Beswick engineers went back to the drawing board. The application required an adjustable position fitting. How would this be achieved in such a small package? The answer was found by nesting the head of the screw stud into the 5/16 in. hexagonal body of the fitting. This approach allowed Beswick to maintain the 0.281 in. installed height. Beswick was also able to retain the leaktight O-ring seal design by incorporating a precision machined gland under the head of the screw stud. This fitting was named the MLAS series and, as with the MLA series elbows, the hose barb was joined to the fitting body with a solder joint.

The space saving features of the MLAS fitting make it the smallest 10-32 threaded adjustable position elbow in the world. It can be used in tight areas when nothing else will fit. Another benefit is its minimal weight: it weighs only 0.11 oz.

EVOLUTION OF THE DESIGN TO MEET VOLUME PRODUCTION

The MLAS elbow fitting met the customer's requirements and those of the regulatory agency. A large order was placed and Beswick was given the green light to begin immediate production. Now that the design was resolved, the focus shifted to meeting production schedules.

NEXT GENERATION ELBOW FITTINGS

The success of the MLAS elbow fitting lead to development of the SMLS series elbows. The SMLS is slightly larger than the MLAS fitting but is easier to manufacture, especially in stainless steel alloys. The concepts pioneered in the development of the MLAS elbow have also been applied to the design of an even smaller M3 metric threaded elbow fitting.