| 摘要 |
334,545. Arnold, C., (Dual Speedometer Co.). May 1, 1929. Index hands and pointers; indicating maximum movements.-In a speedometer the indicating needle, which pushes the maximum indicating needle locked by a ratchet and pawl, but released by a push, before it, may be optionally locked to indicate an instantaneous speed, or two normally indicating hands, one of which may be locked to show the speed at any instant, may be employed, the locking being accomplished by local or remote control. A maximum hand 20, free on spindle 12, has a lug 21 to engage the normally indicating pointer 13 and is retained in maximum position by a ratchet 24 and pawl 23. Fig. 1, the pawl releasing the hand 20, which flies back to zero under the action of the spring 22, when the push 29 is pressed to rotate the bell crank lever 25; or, in a modification, an arm of the lever 25 may be the pawl. Rotation by an external thumb screw of the stem 16 and its eccentric pin 15 raises the collar 14 fixed to the spindle 9, thus unmeshing the gears 10, 11 and causing the normally indicating hand 13 to become fixed at a position corresponding to a certain speed. A spring 19 pressing on spindle 16 keeps it in its respective positions, while the spring 18 tends to mesh again the wheels 10, 11. In a modification, Fig. 10, the indicating hand 13<1> fixed to a collar 38 free on the spindle 12<1>, the speed of which is required, meshes with the hub 35 by a projection 37 fitting into a hole in the hub, and when reading pushes the lug 21<1> and hand 20<1> before it, as before, for the maximum reading. To fix the needles 13' at any instant the hand 49 is rotated. Rising on the cam 50 it lifts the stem 46, the springs 47 and its arm 40 which is forked around the collar 38, thus lifting the collar and the hand 13<1> out of mesh with the driving hub 35. In another modification, the spindle 12<11>, Fig. 13. directly actuates the index hand 13<11>, which as before operates the maximum hand 20". An extra index hand 59 integral with a collar 38' free on spindle, 12<11> meshes with it by means of a projection fitting into the spindle hub as in the previous modification, and is unmeshed to indicate a speed by rotating the spindle 62, the cam 61 at its end raising the spring 40<1> and the fork 39<1> which lifts the collar 38<1>. The stem 62 may be operated bv a thumb screw lever 63 attached to its end externally or said lever 63 may be connected to a " Bowden " wire and operated remotely by a lever or foot pedal. |
