This is an improvement in the journal boxes of pitmen rods, connections, c, which renders them self-adjusting. All boxes require to be well fitted to their respective journals, but a certain degree of tightness is necessary, to avoid, on the one hand, the heating of the journal or box, and to prevent, on the other, the jar or re-action of the connection or pitman rod on the wrist of the crank. Our engravings fully illustrate method adopted by this inventor to effect the above objects, and we will now proceed to describe them. The connection, or pitman rod, is made in the usual manner, with strap, box in two parts, and a key or wedge to tighten the box. But instead of the key being made to be driven up by a hammer, when thought to be necessary, and then retained in its place by a set screw, a spring is applied in such a manner as to force in the key or wedge as fast as the box may wear, and thus keep the box tightened with a uniform pressure. Either a spiral or lateral spring can be used, as may be best adapted to the purpose for which the connection or pitman rod is designed. Fig. 1 represents the use of the lateral spring, and Fig. 2 the use of the spiral. A is the pitman rod, B the journal, C and D are the boxes, and E is a strap held to the shaft or pitman by the screw bolt, F. In Fig. 1, a wedge, G, equal in width with the box, is passed through between the stub end of the connection or pitman xod and the box. On this wedge rests a lateral spring, H, seoured to the connection, and regulated by a screw. The resistance through the medium of the box cannot drive back the key or wedge, for the resistance operates at right angles to the movement of the key and wedge. By practical experiment it has been found that it requires but little power on the part of the spring to force the key and wedge forward, and retain them, when the pressure of the spring is constant and uniform. At every revolution of the crank, the part of the box next to the key or wedge is relieved, and affords an opportunity for the spring to act and tighten it. In Fig. 2, the wedge, G, passes vertically through a slot in the box, and in the pitman rod, and around its end is placed the spiral spring, H, against which is screwed the nut, I so that as the box wears, the half box, C, is brought closer up to the crank pin by the pressure of the spring pulling the wedge, G, in; by tightening or loosening the screw of the spring, Fig. 1, or I, (Fig. 2,) the power of the spring can be increased or diminished. The lateral spring is most applicable to sawmills with wood pitmen rods; and both methods are found to be great savers of time, attention and friction, as well as promoting the uniform wearing of the shafts and boxes. The inventor is L. Dederick, 218 Hamilton street, Albany, N. Y., from whom any further information can be obtained. A patent was granted March 9, 1858. BURT'S MONTGOLFIERS.—These little paper balloons afford great amusement and are a' pretty sight floating in the air, either by day ornight, and they may be made the subject of an interesting scientific talk. They are sold by I. S. Clough, 231 Pearl St., New York.
This article was originally published with the title "Improved Self-Adjusting Journal Box" in Scientific American 13, 42, 332 (June 1858)