Cut-to-length apparatus for bias-cut tire belt ply material

Claim 1

In an apparatus for bias-cutting an elongated starting strip of rubberized tire belt ply material, which has a multiplicity of parallel cord-like reinforcing elements therein obliquely oriented at a given bias angle to the longitudinal strip dimension, into at least one relatively shorter belt ply-forming strip, with the cutting of starting strip being initiated at an interior region thereof and proceeding therefrom toward its opposite edges in a line parallel to said reinforcing elements, which apparatus includes a. a rotatable drum having a hard peripheral surface constituting an anvil for supporting the full width of a predetermined length portion of said starting strip during a cutting operation, b. a pair of non-rotary cutting blades, and c. carriage means supporting said cutting blades and mounted for reciprocal separating and approaching movements along an arcuate path spaced radially from said drum surface and included in a plane normal to said drum surface and oriented obliquely to the mid-circumferential plane of said drum at an angle corresponding to the bias angle of said reinforcing elements in said starting strip, d. each of said carriage means being arranged to move between an intermediate region of said path, in which region said cutting blades abut against each other, and a respective one of the end regions of said path, and e. said cutting blades when in abutting relation presenting a cutting edge tip configuration the parting line of which overlies said interior region of said starting strip; the improvement comprising: A. means for angularly adjusting the obliquity of said path relative to said mid-circumferential plane of said drum over a range of angles of orientation corresponding at least to a possible range of different bias angles at which said reinforcing elements may be oriented in different starting strips to be cut; B. said path having a curvature such that the spacing between said path and said drum surface normally of the latter 1. is constant lengthwise of said path in one adjusted position thereof corresponding to a selected one of said different possible bias angles, and 2. varies lengthwise of said path in all other adjusted positions thereof; C. means operatively connected with said carriage means for jointly moving the same and thus said cutting blades to effect said separating and approaching movements thereof; and D. means operatively connected with said cutting blades 1. for protracting said cutting blades from said carriage means and against said drum surface, and thus through said starting strip when the same is located on said drum surface, preparatory to a separating movement of said cutting blades, 2. for yieldingly urging said cutting blades, upon protraction thereof, into continuous contact with said drum surface during a separating movement of said cutting blades and the performance of a cutting operation, thereby to compensate for any variation in said spacing of said path from said drum surface lengthwise of said path which results when the latter is in any other than said one adjusted position thereof, and 3. for retracting said cutTing blades from said drum surface and toward said carriage means preparatory to and during an approaching movement of said cutting blades subsequent to completion of the cutting operation.