Improvements in the manufacture of moulds for rubber teats / [Martin Dunphy Armstrong].

  • Armstrong, Martin Dunphy.
Date:
1901
Catalogue details

Licence: Public Domain Mark

Credit: Improvements in the manufacture of moulds for rubber teats / [Martin Dunphy Armstrong]. Source: Wellcome Collection.

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    A.D. 1900 N° 20,689 Date of Application, 16th Nov-, 1900 Complete Specification Left, 14th Aug., 1901—Accepted, 14th Sept, 1901 PROVISIONAL SPECIFICATION. Improvements in the Manufacture of Moulds for Rubber Teats. We, Martin Dunphy Armstrong, of Leonard House, 25 Hampton Road, Forest Gate, in the County of Essex, Commercial Traveller, and John Dowell, of 88 Bishopsgate Street Within, in the City of London, Drug Merchant and Sundry- man, do hereby declare the nature of this invention to be as follows:— 5 This invention relates to the manufacture of moulds upon which indiarubber teats are made. Teats having plain interior surfaces are commonly made on glass moulds, but for teats with corrugated interior surfaces such as are described in the Specifi¬ cation of the above named Martin Dunphy Armstrong’s invention for which 10 Letters Patent have been granted to him dated July 14th 1892, No. 12962—it has not hitherto been found practicable to obtain glass moulds, and such teats have hitherto been made on metal moulds, each of which has been first formed with a plain surface and in which the depressions or grooves to correspond with, and form, the corrugated surface of the teat have been afterwards cut. 15 The advantage which would accrue from the use of glass moulds instead of metal ones has long been obvious, and various manufacturers of glass goods have been employed by the said Martin Dunphy Armstrong to make such moulds and experiments for this purpose have extended over several years, but their endeavours to produce them have been up till now unsuccessful, the technical 20 difficulties attending the production of them being found to be too great. Now the said John Dowell has discovered a method by which such glass moulds possessing all the necessary qualities of regularity of form and perfection of polish of surface and other requisite qualities can be produced on a commercial scald and at a satisfactory cost, and tliis invention will supply a much felt want, and 25 render the production of such teats easier and cheaper than heretofore. According to this invention we make a metal matrix in one solid piece with a cavitv the internal surface of which is of the necessary shape and configuration and polish to produce the glass moulds required, and in order to produce such metal moulds we proceed as follows :— 30 We first prepare a steel punch or male of shape to exactly correspond with the interior of the teat to be ultimately produced, or in other words it is. of the same shape and size as the glass moulds which are to be made, and. is slightly taper¬ ing so that the steel punch may be withdrawn from the cavity it produces. This punch is highly polished both on its general surface and in the grooves which 35 serve to form the corrugations and is tempered and hardened. A block of softer metal, copper for instance answers the purpose well, is next prepared and placed in a press and the before mentioned steel punch, or male, is brought down on it and subjected to great pressure, by which an indentation is produced in the softer metal. This is repeated again and again, and the steel 40 male from time to time as may be necessary, is re-heated and surface hardened and again applied to the block of softer . metal until the former has been driven in to the latter to its full depth and an internal or female die or matrix is formed which has taken an exact impression of the polished surface and corrugations of the male. One result of the great pressure to which 45 the matrix has been subjected is that the internal surface has become compressed, [Price Sd.']