Process and equipment for stretching of leather
OwnerJiri Dokoupilinventor
Life of this patent
Estimating the term…
Abstract
A process for stretching leather and similar flat materials, characterized by at least one part of an initial surface of a piece of leather is placed on a bearing surface which is slidable with respect to the leather, the piece of leather being loaded with pressure forces, which are spread over at least one part of the bearing surface, working in the direction of the bearing surface, and the stretching forces for stretching the leather under strain relative to the bearing surface are put into effect over at least one part of a second surface of the piece of leather and being at least approximately tangential with reference to a leather surface as well as at least approximately polydirectional in the direction of the edge of the leather piece.
Claims22
Process for stretching leather and similar flat materials, characterized by the following steps:
- a) placing an initial surface (L1) of a piece of leather (L) at least partly on a bearing surface (AF) that is substantially stationary during leather stretching so as to slidably support the leather;
- b) loading the piece of leather with pressure forces (Pa) spread over the bearing surface and acting in a direction towards said bearing surface;
- c) stretching the leather while slidably supported on said substantially stationary bearing surface by means of stretching forces (Ps), said stretching forces being put into effect at least partly over a second surface (L2) of the piece of leather and acting at least approximately tangential to said second surface (L2);
- d) said stretching forces (Ps) further acting at least approximately polydirectionally and distributed over the perimeter of the piece of leather towards the outer margin thereof;
- e) said bearing surface (AF) being substantially stationary during stretching of the leather and slidable relative to the leather so as not to participate in said stretching.
Facility for stretching leather and similar flat materials in a process including the steps of placing a piece of leather at least partly into a stretching device, loading the piece of leather with pressure forces spread over the leather piece, stretching the leather by means of stretching forces, said stretching forces acting at least approximately tangential to the leather as well as polydirectionally and distributedly over the perimeter of the piece of leather towards the outer margin thereof, said facility including:
- a) a bearing appliance (TRV1, TRV2) for receiving the leather (L), said appliance including a bearing surface (AF) that is substantially stationary during leather stretching and which is slidable relative to an initial surface (L1) of the leather piece during stretching thereof;
- b) a stretching device (STV) arranged opposite said bearing surface (AF) and including stretching means (ASW) acting on a second leather surface (L2) at least approximately tangentially thereto;
- c) said stretching means (ASW) acting on said second leather surface (L2) polydirectionally and distributedly over the perimeter of the piece of leather towards the outer margin thereof;
- d) said bearing surface (AF) during stretching of the leather being substantially stationary but slidable relative to the leather so as not to participate in said stretching.
Dependencies are inferred from the claim text.