Patent GB-465874-A (GB)
Title: Method of and means for trueing grinding discs
IPC: B24B53/08
Filed: 1935-08-12
Abstract: 465,874. Trueing grinding - discs. ZAHNRADFABRIK FRIEDRICHSHAFEN AKT.-GES. Aug. 12, 1935, No. 22682. Convention date, Aug. 13, 1934. Addition to 454,089. [Classes 60 and 124] A profiled grinding-disc for grinding helical gear teeth of involute form is trued by a diamond &c. tool which is guided, by means of a template, along a path corresponding to the involute curve of the tooth flanks, and either the template being given simultaneously a movement along a screw path around an axis corresponding to the axis of the gear to be ground, or the template being stationary and the tool given a movement along lines of simultaneous contact between two co-operating side flanks of the teeth of mating gears. Apparatus for carrying out the movements first mentioned above comprises a shaft 40, Figs. 2, 2a and 4, mounted between the centres of the work-slide of a gear grinding machine, the shaft having mounted thereon a casing 39, 41, 42 carrying two involute templates 43, pivoted at 44 to the casing and adjustable by eccentric bolts 46 and springs 45 ; the casing also carries an involute shaped guide pin 70 in engagement with a bar 71 set at the helical angle of the gear on the machine frame. On the templates 43 rest pins or rollers 50 on a frame 51 comprising relatively adjustable parts 51<1>, 52, the frame also having arms 52<1> resting on the shaft 40 or on the hubs 411, 421 of the casing 39, the parts being held down by springs 49. The frame 51 has pivoted thereon a trueing tool holder 23 adjustable by a screw 58 and an arcuate slot 61 to the required helical angle, and the holder 23 has a knife edge 59 in line with the axis of the trueing-tool 13 and adapted to engage a knife edge in line with the axis of the grinding - disc undergoing treatment. A spring 60 pulls the frame 51 so that a bolt 55 thereon engages the wall 42 of the casing 39, and a weaker spring 48 resting against a collar 40<1> on shaft 40 presses the casing 39 axially of the shaft. In operation, the work slide of the machine is moved along the bed, the guide pin 70 engaging the bar 71 so as to give the casing a screw movement, whilst at the same time the frame 51 is swung in the direction of the arrow, Figs. 2 and 2a, so that the pins 50 move over the templates 43. Apparatus for carrying out the modified movements referred to above comprises a template 93, Fig. 5, of involute form adjustably secured to the machine frame, the trueing-tool holder 23 having a long arm 86 pivoted at 87, 88 to a member 89 angularly adjustable about a pivot 90 on an adjustable frame 91, 96. This frame carries a pin or roller 92 bearing on the template and has two arms 97, 971 pressed by a spring 99 on opposite sides of a shaft 102 mounted in the work-slide centres ; a knife edge 105 in line with the axis of the diamond 13 engages a knife edge 106 in line with the axis of the grinding-disc 1. In operation, the frames 91, 86 are swung round the shaft 102 in the direction of the arrow, the knife edges being held in contact during the movements. In a modified construction of this form of apparatus, Fig. 8, two fixed adjustable templates 117 are employed, and the trueing-tool holder 86 is pivoted to a member 107 angularly adjustable about a pivot 108 on a frame 109 having arms 115 resting on a shaft 119 mounted between the work-slide centres and rollers 116 held down on the template by springs 118 ; knife edges 105, 106 are provided as in the other constructions described. The Specification as open to inspection under Sect. 91 comprises also two constructional forms wherein the involute templates are omitted, the trueing-tool being constrained to move in the desired path by linkwork. This subject-matter does not appear in the Specification as accepted.