Improvements in and relating to portable and hand held cutting machines

Abstract

Abstract 326,852. Williams, E. Dec. 19, 1928. Drilling and milling machines.-In a portable hand-held cutting machine for operating on any material or for surgical purposes, a casing containing the bearings and shafting &c. for the cutter is removably attached to a second casing containing a power unit or flexible shaftingt by means of a male and female coupling comprising a tapered portion and a parallel centring portion. The driving shafts are also provided with male and female couplings so that they may be connected and disconnected simultaneously with the casings and without the aid of tools. As applied to a rotary cutter machine, the cutter 12 is formed integral with or is attached to a shaft 14 rotated through bevel gearing 9 from a shaft 10 united by a sliding coupling 23A to a shaft 23 driven by a motor 2A. The power-unit 2A has a nozzle extension 31B connected thereto by a screwed ring 5, the extension being provided with parallel and tapered .bores for receiving the similarly shaped end 18 of the casing 18A which carries the bearings for the driving shafts. A key 19A may be provided for preventing relative rotation of the parts of the coupling 18 and the coupling is secured by a screwed ring 20 having projections 21 for rotation by hand. The casing 18A is interchangeable for others of different kind and may be replaced by a straight casing carrying a cutter co-axial with the shaft 23 for drilling &c. 'The lower portion 26 of the cutter-casing 18A may be made separate from the upper portion and angularly adjustable thereon to vary the inclination of the cutter 12, rack teeth being provided on the portion 26 and a hand-rotated pinion on the portion 18A to enable the adjustment to be effected. An additional bevel gear is then provided in the train 9 to enable the drive to be maintained in all positions. A spring guide 15, 17, adjustable by a screw 16, may be provided for assisting the control of the cutter and regulating the depth of cut. The coupling 18 may be secured to the casing of a flexible shaft which is formed similarly to the member 31B. The motor 2A is slidably secured in a non-circular recess of the casing 2 by means of the screwed ring 5 and a removable cover 43 and may be cooled by air circulation through holes 7 in the casing. Tubular extensions 8 may be provided on the casing to protect the electric conductors for the motor and projections 8A are provided for hand grip of the casing. The securing ring 20 for the coupling 18 mav screw on this portion of the coupling instead of on the portion 31B and the portion 31B may be formed integral with the base of the power unit. Milling-cutters.-The rotary cutter 12 has a flange wider than its central portion and may be provided with teeth on the inner, outer and side faces of the flange. Specifications 263.580 and 272,591 are referred to.

Inventors

No inventors recorded.

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