Patent GB-298015-A (GB)
Title: Improvements in cork-grinding machines
IPC: B27J5/00
Filed: 1928-01-10
Abstract: 298,015. Bono, S. di. Jan. 10, 1928. Corks, shaping and treating; wheels and other tools.-A machine for grinding cork-stoppers comprises a number of rotary working-holding jaws disposed about a centrally arranged drum covered with emery paper, the work pieces being moved in an orbital path round the drum while the finished articles are automatically ejected at one position and fresh work pieces inserted at another position. The base 1 is provided with a central opening 5 closed by a fixed plate 7 fitted with a sleeve 8. An annular supporting surface 6 in the frame carries a plate 9 provided with a vertical sleeve 10 carrying a toothed rim 11 engaging pinions 12 driving the work-spindles. An external cover 13 fitted with an annular rim 14 is arranged to protect the internal parts. The sleeve 8 carries on bearings 18 and thrust-bearing 23 a cylindrical body 15 fitted with a disc 16 having a tapered edge to fit the rim 14, the body 15 being rotated by means of a gear 19 driven by a pinion 20 on a vertical shaft 21. The shaft 21 is driven from a countershaft 102 through cone pulleys 103, 104, helical gearing 106, and clutch 107. The disc 16 is provided with apertures 24 which accomodate sleeves 24<1> which support the rotary workholders. Each work-holding unit comprises a sleeve 25 driven from one of the pinions 12 and carrying a gear 26 engaging a gear 29 on the lowerwork-holding jaw 30. A squared shaft 33 passes centrally through the sleeve 25 and is fitted at its upper end with an arm 39 carrying the rotatable upper work-holding dog 40. The dog 40 is normally pressed down to engage the work-piece 50 by means of a spring 38 bearing on the upper end of the shaft 33. The arrangement is such that the work centres may move angularly about the axis of the shaft 33, the work being normally urged towards the central emery drum 55 by means of a spring 45 acting on a collar 43 secured to the sleeve 24<1>. The movements of the work-holders to and from the emery drum are controlled by a central cam 49 engaged by a roller on the collar 43. The emery drum is mounted on a central shaft 51 driven from the countershaft 102 by means of a crossed belt passing over pulleys 110, 111. The cam 49 comprises a fixed portion 56 of constant height, this portion causing complete withdrawal of the work pieces for removing finished corks and positioning fresh blanks. The stepped portions 49a of the cam, Fig. 7, may be in separate portions or in one piece and are designed to give a step-by-step feed of the work-pieces to the drum. In longitudinal section the portions 49a of the cam comprise an upper portion 49b of tapering form so that by setting the cam longitudinally by means of a hand wheel 57. corks of different diameters may be produced. The lower section of the cam is of polygonal equilateral shape so as to produce corks of quadrangular section with rounded edges. The cork makes one complete rotation for each of the segments of the cam. For making tapering corks, the external surface of the drum 54 is correspondingly tapered. A shaft 59 mounted in the rim 14 is provided at its upper end with an adjustable crank-disc 60 catrrying a cylindrical box 64 connected to a flexible tube 67. An arm 65 extending from the box is provided with a jaw 68 against which two adjacent edges of a blank 50 may be placed and held by the suction of an air pump 75 driven by a belt 13 from the countershaft 102. The pump draws air through a chamber 74 communicating with a casing 77, preferably transparent, enclosing the upper part of the machine, the pump serving to remove the cork dust produced during working and also to maintain the necessary vacuum in th tube 67 to hold the corks against the mouth 68. The lower end of the shaft 59 carries an arm 69 engaged by a cam 71 on the spindle 22, the shaft being thus oscillated at the required times to carry the blank to a position opposite the jaw 30. The ejecting device comprises a bell-crank lever 79 mounted on a pivot 78, one arm carrying a leaf spring 79<1> and the other carrying a roller. The lever is normally kept against a stop 81 by a spring 73 connected to the blank-positioning means. When the finished work-piece reaches the ejecting mechanism the roller engages one of the hubs 32 and actuates the lever so that the work-piece is knocked off the jaw 30 and falls into a receptacle. In order to allow the ejecting operation the rounded end 41 of the shaft 33 passes at the finishing position on to a fixed cam strip 82, the shaft being thus raised to withdraw the centre 40 from the cork. When the rod 33 reaches its uppermost positicn it is there held by a pivoted pawl 83 engaging n a notch in the rod. As soon as a fresh blank has been positioned, the pawl 83 is tripped by a stop 84 and thus withdrawn from the rod 33 which thereupon is pressed downwards to brirg the upper centre on to the blank. The emery drum comprises a metal rim, Fig. 10, gapped at 85 and covered with a layer 86 of soft fabric such as billiard cloth. One end of the emery band 55 is gripped in a clamp 87 tightened by a screw 88 and the other end is gripped in a jaw 89, a spring 92 being provided to keep the band under tension. Means are provided for disengaging any one of the cork lathes from the emery drum without stopping the whole machine.