Abstract: A saw blade for a two-blade, contra-reciprocating saw has two strips spot welded together. Teeth are formed by scallops cut along an edge of each strip with lands between these scallops. Abrasive grit, such as tungsten carbide chips, is brazed on the teeth except on the sides of the teeth which rub against each other as the blades reciprocate. The main cutting surfaces are the lands which are longer on one strip than the other. The arrangement is useful for cutting masonry and metal products and reduces stresses on the blade.

Abstract: A saw blade comprises a support member having at least one edge, and, spaced along that edge, a series of slots in each of which is secured a saw tooth and in which a portion of the tooth is located within the slot and a further portion extends beyond the slot to overlie a portion of a surface of the support member.Part of the slot and a part of the tooth may be sector-shaped, each slot may include an entry portion with side edges and a base edge or edges, and the tip of the sector-shaped part is located centrally of the base edge, the sector-shaped part communicating with the entry portion via an opening in the base edge whose sides are rounded and which are a tight fit with a mating portion of a tooth, the remainder of a tooth fitting into the slot with some clearance.The invention also extends to a tooth for the saw blade, the tooth having a cutting portion and a body portion to locate in said slot.

Abstract: A programmable test station automatically performs static tests of electrical and pneumatic systems of jet aircraft engines. The test station automatically stimulates the systems to be tested on each engine and measures their response. A programmable data acquisition computer controls both stimuli and measurement, and generates data. The station is operatively connected to a plurality of engines simultaneously and tests certain systems on each in accordance with station user commands. The station includes a voice generator which permits the computer to "speak" to the station user for the purpose of receiving instructions and for communicating instruction acknowledgements and requests.