Designer's Corner

Toy launcher

As the projectile is inserted, the bistable member stores potential energy. In response to a slight triggering force in the opposite direction, potential energy is released, ejecting the missile.

The basic invention consists of a resilient (rubber) dish with fingers or ridges. When the dish is inverted the fingers or ridges surround another member. The device is an interesting method to restrain and propel objects and can reportedly propel small foam rockets 10 ft in the air. Advantages include:

restraint and propulsion are combined into one device.

only a small force is required to separate the components.

a single simple part provides a means to guide, restrain, and actuate.

the majority of the energy input to fastening can be regained in releasing.

actuator can be integrally combined (molded in) with plastics or textiles.

The new bistable member for ejecting snap-fastener and spring-latch assemblies (Patent 5,870,806) integrates both the latching mechanism and ejecting mechanism in a single molded structure.

A continuously curved dome-shaped base portion inverts between convex and concave forms. An engaging protrusion forms a ring around the central apex of the bistable member that is wide enough to receive the head of the male portion. During inversion, the engaging protrusion moves toward the central apex to wrap around and engage the head of the male member. Upon release, recovered potential energy ejects the toy rocket.

Robert P. Black Jr., 18532 Paseo Pueblo, Saratoga, CA 95070; Tel: (408) 374-7059; Fax: (408) 374-3005; E-mail: rsblack@pacbell.net.

Dual-shaft gearhead

A dual-shaft right angle gearhead lets engineers run two drives off of the same gearbox, or improve system accuracy and repeatability by mounting a feedback device on the extra output shaft.

The DuraTRUE™90 dual shaft planetary gearhead can increase system reliability by using fewer components. With this dual shaft gearhead, designers have the flexibility to operate two axes with a single servomotor, or to use the extra output shaft as a feedback opportunity to improve system accuracy and repeatability.

Offering a backlash of 8 arc-min, the dual-shaft gearhead has a peak torque rating of 7,450 inch-lbs and a peak radial load capacity of up to 1.798 lbs. It is available in 60, 90, 115, and 142 sq mm frame sizes, and ratios of 1:1 to 500:1.

As a replacement for spiral bevel geared right angle gearheads, the design reportedly delivers higher torque and longer life in a smaller package. Targeted at such applications as pulp, paper, and textile machinery, material handling equipment, and general automation.

Anthony Trupiano, Thomson Micron, 50 Alexander Ct., Ronkonkoma, NY 11779; Tel: (516) 467-8000; Fax: (516) 467-9814; E-mail: trupiano@thomsonmail.com .

Filter head flow meter

Clever place for a flow meter: While many mobile hydraulic systems don't have in-line flow meters, all require easily accessible filters to clean the oil.

Troubleshooting a hydraulic system that isn't equipped with a flow meter, as is the case with most mobile equipment, requires opening up the system to install a flow meter or measuring fluid flow over time into a graduated cylinder. Both approaches are time consuming and messy due to spills, and conventional flow meters are bulky to "plumb" into a system.

A new piece of test equipment for measuring liquid flow mounts easily in place of the hydraulic system's low-pressure oil filter, and offers a quick and easy alternative to increase troubleshooting efficiency. To install, remove the spin-on, return line filter, and then spin on the flow meter. When troubleshooting is complete, replace the filter.

Operating on the principle of pressure differential, the filter head flow meter consists of a piston, spring, and scale, contained within a cylindrical housing. As flow enters, higher pressure on top of the piston moves the indicator down against the spring. As the indicator goes further down it exposes more of an orifice. The oil enters an inner tube and returns back up the inside of the meter and returns back into the filter head. With the meter installed technicians can check for proper flow by operating one hydraulic function at a time.

Bob Evans, Trackmobile Inc., 1602 Executive Dr., LaGrange, GA 30420; Tel: (706) 884-6651; Fax: (706) 884-0390; E-mail: trackmobile@trackmobile.com .