Improvements in Machinery for Scarfing or Cutting to a Slope the Ends of Leather Strips which are to be Joined One to Another, and for Roughening the Surface of such Sloping Cuts.

摘要

26,236. Sargeant, E. F. Nov. 12. Bevelling; trimming and roughening surfaces.- Relates to improvements in machines for scarfing leather, of the type described in Specification 5800/09, and consists especially in the provision of means whereby the various operations are in sequence automatically effected. Other improvements relate to the construction and operation of the presser-feet for holding down the leather in front of the sliding knife, and to the mounting of this knife and the revolving knife used for roughening the surface of the sloping cut. The flat knife a, Fig. 1, is trunnioned in brackets a6, loosely mounted on the side bars a7. The inclination of the knife is adjusted by a hand-operated eccentric device. The presser-device comprises a series of spring-controlled presser-feet a, or rollers 12, mounted in a cross-bar a11 secured to the side bars a7. The presser-feet are raised and lowered by the engagement with vamps a15 on the knife support of an angle-piece a14, which supports the bolts a12 of the presser-feet spindles. The knife is preferably made in two portions, each extending half-way across the bed, and adapted to be adjusted independently of the other to secure the inclination that best suits the character of leather to be cut. Depression of a treadle b15, Fig. 2, serves to raise the weighted ends of the levers b3, and consequently through link b1 the back clamp b, thereby facilitating the introduction of the work. The treadle is then lowered to allow the lever b3 to press the sections of the table b8 against the knife a and to lower the clamp b on to the work. A treadle e12 is then operated and locked to effect the coupling of a drum e', Fig. 1, with a friction drive. This drum operates in sequence by a chain e, (1) the oscillation of a lever c3 on a shaft c4, which through chains c2 and levers c1 operates screws for clamping from each side, the sections of the table b8, (2) the actuation of a clamp d, d1 through the oscillation of a lever d4 about a spindle d5, and, (3) the traverse of the side bars a7 through the movement of a pulley e6 connected to a cross-head on the bars a7 by links e7. The initial movement of the cross-head a11 on the side bars serves to free the angle-piece a", Fig. 6, from the ramps a15 thereby allowing the presser feet to take up their position immediately in front of the knife. In this position, the cross-head is coupled by a suitable catch with the knife bracket, which thereafter partakes of the movement of the crosshead. As the knife approaches the end of its cut, the back clamp b is raised to clear the knife &c. by the oscillation of bell - crank levers b5, which are actuated through links b4 from the rear crosshead and through links b6 raise the levers b3 and the back clamp b. When the knife e a reaches the end of its stroke, the lever which operated the friction drum e1 is released,and. through the agency of springs or weights, the various operations of parts resulting from the friction drive are reversed. Suitable catches are provided for locking the knife brackets a6 until the presser-feet reach their operative or inoperative positions, as the case may be. When the knife a has returned to its original position, a catch on the rear cross-head frees a belt-striking bar, carrying a belt-shifting fork so arranged as firstly to drive the shaft from which is driven the spindle of the revolving cutter used for trimming and roughening the surface of the sloping cut, and secondly to actuate the screw for imparting the traverse to the saddle of this cutter. Specification 19,975/06 is referred to in this connexion. At the end of this movement, the rotation of the cutter is stopped, and the saddle screw reversed. The vertical spindle of this cutter is so mounted as to allow its pivotal movement about an axis parallel with the saddle screw to adapt it to the varying inclinations of the sloping cuts and about an axis at right-angles to this, to allow the cutter, at the end of its operation, to be swung automatically or otherwise clear of the path of the sliding knife &c. Means are indicated for preventing the knife a from digging into the leather during the latter part of its cut by automatically altering the inclination of the knife during its traverse through the material.