Abstract: An improved preheater for a clothes dryer delivers hot exhausted air from a dryer through a loop of tubing within a box-like housing for heat exchange with ambient air drawn through the housing. Valving is provided for selectively drawing ambient air to the housing either from conditioned space near the dryer, or from solar-heated attic space. The hottest run of the tubing loop is located downstream in the ambient air flow. In one form the box has a flanged open front for attachment over an air inlet grate located in the rear of a dryer. In another form, the box is separated from the dryer and an adapter is used to carry the preheated air to an air inlet of a dryer.

Abstract: A strap is woven back and forth through six openings in a body member to form two pockets, one for the thumb and the second for the remaining four fingers, and the ends of the straps are secured through cooperative Velcro-type fasteners to the two strap portions forming the two pockets. The body member may be used by right- or left-handed persons by simply turning it over whereby the front-ball side for a right-hand user now becomes the rear-hand side for a left-hand user.

Abstract: The upper post section of a batting tee is strengthened and/or repaired by a solid plug being positioned in the open upper end and a sleeve initially rolled up is unrolled downwardly and around the post upper end.

Abstract: A pitching target is provided and includes a self-supporting frame having an elongated top crossbar supported above a support surface by legs at each end of the crossbar. A screen having a strike zone depicted thereon is attached to the crossbar so as to hang freely therefrom. A trough is positioned beneath the screen so as to receive balls impacting on the screen falling downwardly therefrom.

Abstract: An unlasted shoe construction of the sandal type in which an upper is formed from one-piece of flexible material with vamp tabs and instep tabs integral therewith so that the tabs will be fully clear of the connection of the upper with a bottom. The instep tabs are provided to afford places to attach an instep strap and a heel strap to complete the sandal construction.

Abstract: A travelling wave tube has an output lead passing through a tubular output arm to a cap provided at the end of the arm. The cap has a cylindrical wall of ceramic material and is completed by a flanged plate of metal, to which said output lead is attached. When coupled to a waveguide, the travelling wave tube output arm enters an entry hole in one wall of the waveguide while the cap thereof abuts a matching ridge provided on the interior of the opposite wall of the waveguide. A small recess in the ridge locates the cap, the cylindrical wall of which acts as a window through which travelling wave tube output may pass into the interior of said waveguide.

Abstract: The portable softball pitching mound of the present invention comprises a Fiberglas shell member having forward and rearward ends and opposite side portions. A pitching rubber is detachably mounted upon the upper surface of the shell member. The upper surface area of the shell member behind the pitching rubber is substantially flat and coplanar with the upper surface of the rubber. The area of the shell immediately adjacent to the forward edge of the rubber slopes forwardly and downwardly to form a push-off area terminating in a less inclined downwardly sloping resilient drag area extending to the forward edge of the shell member. The distance from the forward edge of the pitching rubber to the forward edge of the shell member is less than the length of a pitcher's stride. The shell is constructed of reinforced Fiberglas and the upper surface is covered with a layer of artificial turf.

Abstract: A travelling wave tube arrangement is provided in which in order to support and cool the collector thereof the latter is cradled between two slabs of beryllium oxide attached to the walls of a channel in a block of copper, which walls are inclined in V-fashion. A further slab of beryllium oxide is provided above the collector. This last mentioned slab is attached to a flexible copper alloy wall which is dependent from a copper alloy plate which extends across the top of the channel. The plate is brazed to the block. A screw passing through the plate exerts pressure upon said flexible wall which in turn urges the beryllium oxide plate carried thereby towards the collector thus pressing the latter between the three beryllium oxide plates to form a electrically insulating support of good thermal conductivity.

Abstract: Preparation of nitrodiarylamine by reacting alkali metal hydroxide, activated aromatic amine and nitrohaloarene is described.

Abstract: Forming nitrodiarylamines by reacting the formyl derivative of an aromatic amine, a nitrohaloarene, and a proton abstractor which is sodium carbonate or bicarbonate with or without a reaction promoting amount of a compound of potassium, cesium, rubidium or mixture thereof.