Tensionable elastic screen bottom

Claim 2

A screen bottom, comprising a sieve plate member having sieve openings and zones devoid of sieve openings, a supporting tackle member having parallel elongated strips and hooks at the ends of said strips, said hooks being connected to opposite ends of said plate member, said two members having different elastic qualities and in their untensioned state the less elastic of the two members lies in arched arrangement relatively to the more elastic of the two members and is larger in length than the more elastic member, and upon tensioning of the screen bottom the one of said members which was initially the smaller in length and more elastic is extended to the length of the other one of said members which was initially the larger in length and less elastic member.

Claim 3

A device in accordance with claim 1, wherein said strips form a single hanging down curve extending between the hooks.

Claim 4

A device in accordance with claim 1, comprising a second finer elastic sieving botTom located above the first-mentioned sieving bottom, the two sieving bottoms and said strips extending when tensioned parallel to each other.

Claim 5

A device in accordance with claim 1, wherein said strips extend wave-like above said sieve bottom.

Claim 6

A device in accordance with claim 1, comprising holders fixed to said sieve bottom by vulcanization or glueing and carrying said strips.

Claim 7

A device in accordance with claim 1, wherein said sieve bottom consists of flexible fine weave of bronze or spring steel, said strips being elastic.

Claim 8

A device in accordance with claim 1, wherein said strips consist of a material which is elastic but less elastic than the material of which said sieve bottom is made.

Claim 9

A device in accordance with claim 7, wherein said strips consist of stretchable material consisting of spring steel binder or plastic.

Claim 10

A device in accordance with claim 8 wherein said strips consist of a flexible material consisting of Perlon, steel strips or weaves.

Claim 11

A screen bottom, comprising a sieve plate member having sieve openings and zones devoid of sieve openings, a supporting tackle member having parallel elongated strips, said strips forming a plurality of hanging down curves extending between alternate zones, a plurality of transverse supporting members located below said strips, said transverse supporting members being located from the group of materials consisting of plastics, wood, pressed wood and light metal means connecting said transverse supporting members to said strips and to said sieve plate along said zones, said supporting tackle member further having hooks connected to opposite ends of said sieve plate member, said sieve plate member and said supporting tackle member having different elastic qualities and in their untensioned state the less elastic of the two members lies in arched arrangement relatively to the more elastic of the two members and is larger in length than the more elastic member, and upon tensioning of the screen bottom the one of said members which was initially the smaller in length and more elastic is extended to the length of the other one of said members which was initially the larger in length and less elastic member.

Claim 12

A screen bottom, comprising a sieve plate member having sieve openings and zones devoid of sieve openings, a supporting tackle member having parallel elongated strips, said strips forming a plurality of hanging down curves extending between alternate zones, a plurality of transverse supporting members located below said strips, said transverse supporting members being located from the group of materials consisting of plastics, wood, pressed wood and light metal means connecting said transverse supporting members to said strips and to said sieve plate along said zones, said supporting tackle member further having hooks connected to opposite ends of said sieve plate member, said sieve plate member and said supporting tackle member having different elastic qualities and in their untensioned state the less elastic of the two members lies in arched arrangement relatively to the more elastic of the two members and is larger in length than the more elastic member, and upon tensioning of the screen bottom the one of said members which was initially the smaller in length and more elastic is extended to the length of the other one of said members which was initially the larger in length and less elastic member.

Claim 13

A device in accordance with claim 10, wherein said transverse supporting members are fixed solely to said strips, said transverse supporting members engaging the lower surface of said sieve bottom in the zones devoid of openings when said strips are tensioned.

Claim 14

A device in accordance with claim 10, wherein said transverse supporting members are fixed to said strips and to the lower surface of said sieve, said transverse supporting members extending along said zones.

Claim 15

A device in accordance with claim 1, comprising holders carried by said sieve bottom, and pins carried by said strips and adapted to engage said holders to connect said sieve bottom with said strips.

Claim 16

A device in accordance with claim 10, wherein said strips consist of pivoted non-elastic sections.

Claim 17

A device in accordance with claim 10, comprising angular clamps connecting said strips with said sieve bottom.

Claim 18

A device in accordance with claim 10, wherein said strips are connected to said transverse supporting members on top and bottom, the top connections extending substantially in the plane of said sieve bottom when the sieve bottom is tensioned.