Abstract: A device to be worn by a person such as an athlete to protect the knee from external objects and to afford strength for the knee joint.It comprises a thigh member and a calf member as well as a pair of arms extending from each of such members toward the knee joint and on opposite sides of the knee. Each adjacent pair of arms is connected together by a hub member which extends through an opening in one arm and is fastened to the other arm. A washer is mounted between the arms and is formed with an abutment to be engaged by a limit-stop on one of the arms.The thigh and calf members each comprises a pliable member as well as a flexible cellular material. The cellular material is provided with a tab which extends through a slot in the pliable material such that as the pliable material is firmly attached to the wearer, the tabs can be pulled to straighten the cellular material against the leg. This prevents gathering of the cellular material and also permits of adjustment for varying leg sizes.

Abstract: A drain ditch digging attachment which is used with a back-hoe and which is provided with a generally V-shaped bucket for removing ground to form an elongated drainage ditch down or along a slope. The attachment has a long transverse reinforcing bar across the bucket and extending beyond the opposite ends thereof, such extensions having ground cutting and moving members such that the attachment not only digs the ditch but also forms the edges or sides of the ditch in one single pass of the attachment without the need for additional manual labor.

Abstract: An anti-siphon fluid tank adaptor to prevent the insertion of a siphoning tube while nonetheless permitting rapid filling of the tank.The adaptor comprises an extension firmly secured to the tank and a tubular sleeve firmly welded to the extension and having an end portion within the tank covered with a conically-shaped member. The sleeve is provided with several holes about the circumference of the sleeve and one end of the extension is provided with means for receiving a cap for closing the entire adaptor.

Abstract: A bearing system, for joint or hinge point bearings, employing a spherical bearing wherein the ball member is provided with oppositely disposed flat side walls and the bearing race therefore is formed with a longitudinal slot whereby the ball member can be inserted into the race. A sleeve, which is secured to a supporting or operating member during installation, is provided about the race and the sleeve and race are formed with mating splines which enable the spherical bearing assembly to reciprocatably move relative to the sleeve.Suitable lubricating channels are provided, and sealing rings are installed at the outer margins of the bearing ball and race members to retain the lubricant in place and to prevent the ingress of foreign material.

Abstract: A therapeutic pool system whereby a safer and more comfortable air circulation system is provided.In detail, it comprises a fluid circulation system which circulates the fluid, usually water, from the pool through a skimmer, filter and heater back to the pool. In addition, there is an air circulation system whereby air is taken from above the water in the skimmer, intermixed with the circulating water and returned to the pool to provide a healthful, comfortable experience for people using the pool.

Abstract: A hydraulically operated folding mechanism for ground working implements wherein substantially rectilinear movement of the piston rod of a hydraulic actuator causes one section of the implement to rotate substantially 180.degree. relative to another section thereof. This enables a relatively large implement to be made small and compact for purposes of storage and transport. It further includes members for permitting the several sections to pivot relative to each other when in operating position so that the implement can conform to the contour of the ground and locking structure which prevents such pivotal movement as soon as the folding mechanism becomes operative.

Abstract: A blind fastener wherein a push-pull type setting tool is employed for pulling a stem into a predetermined position relative to a sleeve, and a two element shear washer is provided to fail at a predetermined shear load as created by the compressive load on the sleeve and the reaction tensile pull on the stem. Failure of the shear washer drives a locking collar between the stem and sleeve.The shear washer comprises a pair of concentric but axially offset elements joined together by an annular shear web which, upon shear failure allows one of the elements to drive an annular locking collar between the stem and sleeve. Such shear washer together with the rivet sleeve are serially placed under compression to counteract the tensile force applied to the stem.

Abstract: A VLF navigation system suitable for highly accurate worldwide aircraft navigation utilizing existing VLF transmitting stations on a "dead reckoning" basis with initial and intermediate fixes. The system is enabled to utilize all existing VLF transmitting stations regardless of station frequency by novel receiver phase-locked loop means which normalizes all station frequencies to phase coherent independent data signals of a common working frequency. In one form of the invention, utilizing hyperbolic coordinates, both RF stations of each station pair utilized for computation are such VLF transmitting stations; while in another form of the invention, utilizing Rho-Rho coordinates, one RF station of each station pair is an on-board frequency standard normalized to the common working frequency, and the other station of each pair is one of the VLF transmitting stations.