Patent GB-451950-A (GB)
Title: A method of and apparatus for cutting samples from the sheets of gasholders
IPC: G01N1/04
Filed: 1935-02-13
Abstract: 451,950. Drilling-machines. CUTLER, S., 39, Victoria Street, Westminster. Feb. 13, 1935, Nos. 4609 and 10511. [Class 83 (iii)] Apparatus for restricting the escape of gas when cutting sample discs from gas holders, comprises an open ended cover chamber held through interposed sealing means against the holder and provided with a gas light passage through which the cutting tool can be actuated. In one form the fluid tight casing 12, Fig. 1, is cylindrical in shape and carries a number of semi-flexible arms 15 to which electromagnets 16 are attached for securing the casing to a gasholder 11. A flange 17 on the casing receives a packing ring such as an inflatable rubber tube 18 to make a gas tight joint with the holder 11. A manually operable self-feeding drilling machine 14 is suspended within the casing 12 by means of a lug 28 slidably engaging a rod 29 screwing in the cover of the casing at 31 and supported by a bracket 30. A window 36 of celluloid &c. is inserted on the top of the casing and an aperture 32 at the bottom connects with a flexible sleeve 34 through which the operator may insert his arm for manipulation of the drilling apparatus &c. In operation, a small hole 37 is drilled in the gasholder 11 and a central combined drill and tap 38 on the machine is wedged in the hole to receive the cutting thrust. The casing 12 is then placed over the machine and held by the electromagnets 16. The operator next passes his arm through the flexible sleeve 34 and inserts the rod 29 through the lug 28 and into the bracket 30 to support the machine. A lateral shaft 26 is next moved to cause a socket thereon to engage the driving spindle of the machine, the shaft 26 having a crank handle on the outside of the casing 12 and passing through a bearing in a flexible bellows attached to the casing to allow axial movement of the shaft for engagement with and disengagement from the machine spindle. On rotation of the crank handle an annular cutter 38a cuts out a disc from the gasholder which remains fixed on the central cutter 38 after severance. The operator then slides the machine along the rod 29 into an extension 13 of the casing 12 and applies a cover plate, previously placed in the casing 12, to seal the hole in the gasholder, this plate being secured by an internal cross-bar and bolt. The magnets 16 may then be de-energized and the casing removed. A eye 39 on the upper arm 15 provides for an additional support for the casing by means of a suspension attached to the gasholder. The magnets may be attached to a resilient annulus carrying bolts for engaging the flange 17. In a modification the magnets 16 are replaced by suction cups attached to a resilient annulus carrying a ring of bolts engaging the flange 17 to clamp the casing 12 against the gasholder, each cup being provided with a stem and nut by which it may be evacuated. In a further modification the casing 12 may be surrounded by an annular chamber connected to an exhausting pump or like source of low pressure. In another form the casing consists of a hard rubber cone 60, Fig. 5, provided with a sealing ring 62 of resilient rubber. The cone is held against the gasholder 11 by means of three pins 63 engaging a metal ring 85 and screwing in a pressure plate 64 attached to a yoke 65 which is secured to the gas holder by its slotted ends 66 and bolts 70. The bolts 70 are attached to unsymmetrical cross-bars 71 which are passed through holes previously formed in the gasholder, the holes being sealed by closely fitting stepped washers 69. An annular cutter 77 having teeth 78 secured thereto is screwed to a shank passing through a brass bush 75 in the cone 60 and carrying a ratchet gear 79 to which is attached a screwed stem 80 and feed nut 81. A centring pin 83 on the cutter carries a pivoted latch 84 which retains the disc cut from the gasholder. The cone 60 and yoke 65 must be removed before the hole formed in the gasholder can be sealed with a plate and cross-bar. The yoke 65 may be attached to the gasholder by permanent or electromagnets. Reference has been directed by the Comptroller to Specifications 236,315, [Class 83 (iii)], 339,945, [Class 68 (ii)], 354,422, and 413,600.