Patent GB-104351-A (GB)
Title: An Improved Machine for Grinding & Lapping Slip and Gap Gauges & the like.
Inventor: PITTER WALTER CHARLES
IPC: B24B35/00
Filed: 1916-02-01
Abstract: 104,351. Pitter, W. C. Feb. 1, 1916. Block, rubber, and like apparatus. - For grinding lapping slip and gap gauges and other such narrow flat objects, one or more laps extending at all times completely across one dimension of the work are connected to move bodily with a bodily movable structure, means being provided for moving the structure and also for imparting a further movement to the laps relative to the structure such that the laps shall pass over the whole surface of the work at each of their movements relative tn the structure. For soft work, files may be used in place of the laps. As shown in Fig. 1, a gap gauge 5 held by an electromagnetic chuck 6 is operated upon by laps 3, 4, which are carried by rods 7, 8 connected by sleeves 11 to to crank-pins 12 on wheels 13 upon slides 14, the wheels being actuated by chain gearing from the driving-shaft 30, and the slides reciprocated by connecting-rods 20 arranged between the eccentric pins 21 of disks 22 and the spindles of the sprocket-wheels 18. The laps are pressed by springs 9, 10 against hardened strips or guides 1, 2 upon adjustable parts 46, which at one edge bear against an upstanding member 49 upon the table or base-plate of the machine. The slide guides 17 and the driving-shaft 30 are adjustable together vertically, and the shaft 23 is similarly adjustable with the lower shaft from which it is driven. The guides 1, 2 may each comprise two wedge-shaped parts adapted to be adjusted relatively to one another. When it is desired to move the laps away from the work, one pair of sleeves may be slid from coupling position and the other pair used as hinges for the laps. For grinding the ends of slip gauges, one or more guides are arranged between the laps, and springs are fitted on each rod to press the laps towards each other and against the guide or guides. Adjustable parallel slips may be used for setting the work in the chuck in line with the guides, or the guides may be fitted with coils so that, when electric current is switched on, the guides are held to the table in any desired position. For lapping one side only of a number of thin slip gauges, the apparatus shown in Fig. 7 is employed. The work 61 is held by an electro-magnetic chuck 56 and is operated upon by a single lap 62, which rests on fixed guides 63, 64. The chuck has a long straight edge 57 so that it can be accurately placed in relation to the guides. Crank-pins 65 and a connecting-rod 75 connected to the slide 67 impart the compound motion to the lap. Bevel or other gearing may be used in place of chains. Electro-magnetic chucks and work-holders. - The chuck preferably used for holding the work consists of two units 43, 44 drawn together by one or more springs 45 and each provided with a coil wound upon it, so that when the work is placed between the units and the current switched on, the units and work become a horseshoe magnet firmly held to the table or base-plate. Instead of holding the work between the chuck members, it may be held by an auxiliary chuck adapted to be laid upon the electro-magnetic chuck and operating as an armature to the poles of the magnet.