AMERICAN INSTITUTE. 



113 



through the hole N, wmcling it round the baron which the "tension-screw" F 

 acts, so as to give more or less tension, as required. The " tension-screAv " acts 

 in the nut P, which is riveted on the fixed arm. The " presser," the foot of which 

 holds the cloth in place for working, is regulated as to pressure by the " lift-cam " 

 A, the stiffness of the cam being maintained by the *' spring " E. is a regulating 

 screw, by which the elasticity of the spring E is regulated, so as to increase or 

 lessen the stiffness of the lift-cam A. The spool which carries the supply of thread 

 is shown at H. It is free to turn on a wire passing through its centre, and is pre- 

 vented from rising by a weight, G, placed on it. 



Figure 2. 



In fig. 2, A represents the thumb-screw, which, be- 

 ing movable, is used to alter the stitch to any required 

 length. B represents the feed-wheel, which moves the 

 fabric along, either fast or slow, as the machine may 

 Figure 3. i,q run^ t^g length of the stitch made tliipending upon 



the position of the thumb-screw A; a is the cam by which the feed-wheel is moved; 

 6 is a cam for moving the shuttle-bar; while C is the cam by which the needle-bar 

 is worked — the whole being put in motion by the shaft of the flj^-whccl. The 

 feed-wheel is moved by a short shaft, one end of which connects with a cam. The 

 bite is such that slipping is an utter impossibility. Fig. 3 shows Bradshaw's 

 shuttle, which is now used by most sewing machine manufacturers who make the 

 lock-stitch, and without which no mac}iine can be made for general, and especially 

 for heavy purposes. ISilver and bronze niedals awarded. 



Grover 4* Baker''s Sewing Machities. 

 Grover & Baker, No. 495 Broadway. 



This machine was invented in 1851. Its most striking peculiarities are, that it 

 ■works with two needles, and without noise. 



Fig. 1 illustrates the whole machine, except the sliding-plates and part of the 

 bed-plate, which have been removed to show the working parts. Fig. 2 shows an 

 end view. A is the bed-plate, B is the arm which carries the cloth-presser, a, 

 whose office is to hold the fabric while the vertical needle, h, passes through it, 

 carrying the thread from a spindle, K. The threads are fed from two common 

 spools, firmly fastened on spindles, by cone screws, q, and the requisite tensions 

 [Am. Inst.] 8 . 



