Removing Sag from Couch Spring
A couch spring of the type shown in the sketch sagged considerably, making it ineffective. The sag was taken up by bending the sections of wire with a monkey wrench, so that the entire spring was stiffened almost as satisfactorily as when new. Care must be taken that the wires are bent uniformly so that the strain is evenly distributed.
¶An eggshell may be balanced on the edge of a knife if the egg is “blown,” and then partly filled with sand.
An Effective Combination Lock Easily Made
By E. F. STRONG
The combination lock described has been used for years on lockers and letter boxes in a large public building. The details of a lock with three disks are given, and in Fig. 4 the use of two disks is suggested. The lock is made as follows: From a piece of ³⁄₁₆ or ¹⁄₄-in. hard wood, saw out three disks, A, Fig. 1, from 1 to 4 in. in diameter, according to the size of lock desired. For one with 2-in. disks, as shown, cut slots, B, ¹⁄₂ in. wide and deep, in the edge of the disks. For axles use ³⁄₈ by 2-in. hardwood dowels, C, with a six-penny headless wire nail in one end, leaving about ¹⁄₄ in. of it exposed.
Fig. 1
Fig. 2
Fig. 3
Fig. 4
This Wooden Combination Lock Gives Good Service and is Easily Made
The case of the lock is shown in Fig. 1. It is made large enough to mount the disks, as shown. Around the edges of the inside surface of the lid fasten strips a trifle thicker than the disks. Place the disks in the positions shown, drilling small holes in the baseboard for the nail axles. The bolts, D, and the piece, E, are made of hard wood, fastened with a lap joint. On each side of the bar, D, fasten cleats, F, to hold it in position. The handle, H, moves in a slot in the lid, and is fixed to the bar, E.
The door, or lid, on which the lock is to be used, is provided with openings, J, as shown in Fig. 3. The axles C, project through openings, as bearings. When the windows J, through which the combinations are read, are made, place the ends of the bolts in the slots of the disks and screw the lock in position. Mark on each disk the point exactly in the center of the window, enabling one to work the combination temporarily. To lock the device, push the handle to the left and turn the axles. To unlock it, turn the axles until the pencil marks appear in the middle of the windows, and throw the bolts.
Next make paper dials, K, of a diameter as shown in Fig. 2. Divide the circumference into from 50 to 100 equal parts, according to the size of the dial, and draw radii, as shown. Number at least every fifth point. To the face of each disk, A, with small thumb tacks, fasten one of the dials, placing the combination numbers selected exactly over the pencil marks made in setting the temporary combination. Verify the combination before locking it. Unless the slots in the disks are a little wider than the ends of the bolts, the combination must be very closely adjusted. An aid in setting the combination is a line on the glass or a point of black paper, as shown in Fig. 2. The combination may be changed by setting the dials in new positions. The large number of combinations possible makes it very difficult to obtain the combination. For most purposes, two disks are sufficient in a lock of this kind.
¶A convenient method of supporting a garden-hose nozzle is to tie a loose knot in the end of the hose, arranging the nozzle to spray as desired.