Abstract: An electronic teaching device for teaching addition and subtraction to students in the primary grades. The device is of simple construction utilizing digital electronic components. The invention utilizes an enclosure or box which invites students to use the device as a toy or game while facilitating learning of simple mathematical tables. In the preferred embodiment the student gains access to the box, and a reward, which may be placed inside it, if he correctly completes a simple algebraic equation which had previously been setup by a teacher.

Abstract: An apparatus for forming pocket welts is disclosed. The upper portion of the external breast pocket of men and women's sport and suit jackets are frequently constructed by making a cut in the breast of the jacket and connecting a pocket to the inward side of the jacket fabric. A pocket welt is joined to the exterior of the breast, just below the cut and along its sides to form a top portion of the completed pocket. The pocket welt is constructed using a precut piece of fabric which is positioned by an operator on a template, which forms a portion of the apparatus. The fabric is secured by a vacuum and is folded by the operator along lines determined by the template. Subsequent to folding, a precut fusing material may be positioned by the operator over the fabric. The apparatus is then actuated by the operator causing the fabric and fusing to be folded and pressed, automatically. If fusing is used, the temperature of the platens may be set sufficiently high so as to cause the fusing to bond to the fabric.

Abstract: An end closure for honeycomb structures is disclosed. The end closure effectively provides for the sealing of the end of a honeycomb structure in order to prevent moisture from entering and propagating into the structure. The invention includes a structure and method for closing the end of a honeycomb structure with a molded closure. A foam adhesive, in combination with a tape adhesive, forces the tape adhesive to conform to the shape of the irregular honeycomb core, thereby providing an effective bond and seal of the honeycomb face.

Abstract: A load limiter or a crash attenuation device based on wire bending principals is disclosed. Excessive tensile shocks, such as the accelerative forces imposed on a low stretch load restraint in a helicopter if it crashes, are absorbed by forcing a bifurcated double coil to successively bend and straighten as it travels through a pair of wire guides in response to the forces being transmitted into the limiter by the load restraint. The reaction force absorbed is a function of the wire diameter and stiffness while the reaction stroke is a function of the number of turns in the coil reels. The device further has an adjustment mechanism so it can easily be adapted to a wide variety of design conditions without changing the basic configuration of the limiter.

Abstract: An apparatus or guide to aid in inserting the needle of syringes and the like into body conduits such as veins, is disclosed. The apparatus includes a pair of members which are placed on the opposite sides of a vein, parallel to the longitudinal axis thereof, thereby preventing lateral movement of the vein while it is being pierced by the needle. In an embodiment of the invention a guide is provided to aid in inserting the needle to the desired depth.

Abstract: A mechanism for use in a strapping apparatus including a pair of like rolls which have meshing gears as flanges and which are rotated by a drive means through a clutch system to both feed and tension strap without stopping or reversing the drive means. Strap is laced about and nipped by the rolls and, as the rolls rotate at the same speed and the roll flanges travel with the strap, abrasion along the strap sides and edges is avoided.

Abstract: A family of airfoils for use in rotary wing aircraft, particularly helicopters, is disclosed. The family is characterized by having a maximum c.sub.1.sbsb.max at M=0.4 and maximum delay in drag divergence while maintaining zero lift pitching moment levels c.sub.m.sbsb.o correctable within the range of -0.01 to +0.01. The present family of airfoils provide high lift at maximum angle of attack when the blade is retreating and maximum delay in drag rise or drag divergence when the blade is advancing. The airfoil section of the family enable a helicopter rotor to counteract, more efficiently, the rolling moment which would otherwise be induced by a rotorcraft's forward flight; this is achieved by the present family of airfoils while maintaining the airfoil sectional pitching moment coefficient at or about zero thereby enabling the blade in which the airfoil sections are incorporated to impose minimum structural loads on the rotorcraft's control system.

Abstract: A method of forming ceramic fiber and metal composite structures is disclosed. The method is particularly useful in forming such structures having a complex shape. Fibers are coated with an investment grade sticky wax as a fugitive organic binder. Aluminium oxide coated with a sticky wax binder have been found to have greater flexibility than the fibers alone or fibers coated with other binders. The coated fibers are then laid up into a preform of the desired shape. The preform is elevated to a moderate temperature prior to pressure compaction. The preform may be combined with other preforms to form a more complex shape. The preform is then installed in a casting mold and elevated to a temperature sufficient to remove the sticky wax binder. Molten metal is then introduced into the mold where it fills the voids created by the removal of the sticky wax. Subsequent to cooling, the fiber and metal composite material is removed from the casting mold.

Abstract: A protective device for sharpened cutting edges is disclosed. A sheath apparatus adapted to be connected, and secured, to the opposite ends of a blade for a rotary lawn mower is described. The invention provides protection for the user thereof when attaching or detaching rotary lawn mower blades or during the sharpening of such blades.

Abstract: An electromagnetic system is provided to monitor the activity of a ferrous debris detector of the type which uses electric discharges to automatically disintegrate magnetically concentrated accumulations of micron sized wear particles in hydraulic systems. The data provided are used to detect instances of abnormal wear as shown by either an unusually large number of such discharges or an excessive rate of discharge. Where such abnormality occurs the monitor will provide an audiovisual alarm to warn of the problem in time to prevent catastrophic failure of the system.

Abstract: An integrated transmission and helicopter rotor head is disclosed. Lift and bending moments generated by the rotating hub are carried by non-rotating support structure. The rotating rotor shaft is adapted to carry only torque loads. Partial gear reduction takes place above the rotor shaft, thereby reducing its torque loading. The invention includes a planet gear assembly wherein the ring gear is connected to the rotating hub, while the rotor drive shaft causes rotation of the sun gear. The hub swashplate is located above the hub with its control rods passing through the planet gear assembly.

Abstract: A support structure for thin wall, lightweight, ducts which are commonly used in aircraft is disclosed. The support structure, a clamp, has a split, circular body with a tapered separation. A support bracket is connected to the body of the clamp which permits mounting to a bulkhead. The split circular body of the clamp is designed in a manner which allows for quick mounting and dismounting the duct without the use of tools. The split line is at an angle with respect to the longitudinal axis of the clamp. The clamp will grip the duct tight enough to prevent movement between the duct and the support without damaging the duct.

Abstract: A split ring grommet for use in routing electrical cables, and the like, through aircraft bulkheads is disclosed. The grommet has a flange which is formed at one end thereof and tabs on its outer surface. The grommet is designed so that when it is inserted into the hole in a bulkhead the tab and flange engage the edge of the bulkhead which forms the periphery of the hole. A clamp is provided for securing the opposing faces of the split ring grommet. The clamp slips over the non-flanged end of the grommet and has locking members which fit into slots in the grommet on either side of the opposing faces. The tabs and locking members are spring biased so as to insure a tight fit between the grommet and the bulkhead. Electrical cables, hydraulic tubing and the like are secured by straps which engage both the cables and the grommet.

Abstract: An optical fluid level monitor is disclosed. It comprises a plurality of prismatic sensors disposed in a linear array for measuring the levels of fluids, such as oil, in sumps of aircraft and helicopter engines and other closed containers. In use each of the sensors is sequentially pulsed by an integral light source. If the detector is above the fluid level it appears bright, if below it appears bright, if below it appears dark, this difference being caused by an integral light detector device. Counting circuits are provided to determine the number of bright sensors and electronically convert this into a fluid volume for display purposes. A presettable low volume alarm is also included as is a correction circuit to compensate for volume changes caused by heating of the fluid in use.

Abstract: An apparatus for removing entrapped gas and selectively removing and detecting particles above a predetermined size in an oil lubrication system is described. The oil enters tangentially at the top of an outer cylinder and is caused to cyclonically work its way down to the bottom of the cylinder. The oil is then forced to reverse its flow and travel up along an inner cylinder. The centrifugal force fields created by such flow cause entrapped gas to coalesce in the center of the flow pattern from which point it can be vented from the system. It also causes heavier particles, which are used by the apparatus to detect impending failure, to be thrown out of the flow pattern into a detection cavity positioned at the bottom of the outer cylinder at its periphery while lighter particles remain suspended in the fluid. A conventional magnetic sensor is contained within the cavity to capture the separated particles for subsequent removal from the system and signal their presence to the operator of the system.

Abstract: A low cost apparatus adapted to permit shelf type vending machines adapted to sell small items such as candy bars to be modified so that larger items such as cakes and pies can be sold therefrom. The apparatus comprises a panel which fits onto a shelf of the machine so as to widen it to accomodate such larger items. Ease of assembly is assured by having the panel engage the shelf with a pair of runners which engage the sides of said shelf and hold it in place with a friction fit.

Abstract: A game board apparatus adapted to play a wide variety of optionally chosen games. The apparatus includes a game board having an elevated rectangular coordinate gridded playing area adapted to cooperate with various playing pieces and space limiters to create an almost infinite variety of playing patterns. The apparatus further includes playing pieces adapted to be used for playing word games, traveling games and the like and a random piece selector designed to increase the element of luck while still placing a premium on playing skill.

Abstract: A semi-articulated flexstrap for use in connecting a rotor blade to the hub of a helicopter rotor is disclosed. The flexstrap includes a series of straps which alternatingly crisscross at a point between the blade and hub. The straps are substantially parallel to the plane of rotation of the rotor at the crossover point and unrestrained so as to permit relative movement between the straps. The relative movement of the straps of articulation of the flexstrap in the plane of rotation of the rotor permits lead lag motion of the rotor blade to occur.

Abstract: An electromagnetic system is provided to capture ferrous particles in a circulating fluid medium and provide analog and digital data which relate both to the mass of any significant individual particles captured and the total mass of such particles accumulated in a given time for subsequent retrieval. A periodic self checking capability is also included to determine if the system is functioning normally.