GB384791A - Improvements in or relating to linear measuring instruments or measuring devices - Google Patents

Abstract

384,791. Measuring- wheels. JONES, L. R., Glenwater, Woodhill Avenue, Gerrards Cross, Buckinghamshire. Dec. 7, 1931, No. 33851. [Class 106 (ii).] A measuring-wheel a is freely mounted on a spindle d carried by a handle e, the spindle also having freely mounted upon it the hub f<1> of a pendulum f carrying the usual counter g and means are provided for temporarily locking the wheel and pendulum against relative rotation with respect to one another but not with respect to the spindle d. The flange of the wheel a which bears on the surface to be measured is provided with a rubber tread b. The actuating arm g<1> of the counter g is connected by a link h to one arm of a lever i pivoted on a stud on the pendulum. The other arm of the lever i carries a roller pin l which is maintained in contact with a ratchet surface m on the wheel a by means of a spring k. The surface m has three teeth and the circumference of the wheel is one yard, the teeth coming opposite pointers n in a viewing aperture o when the pointers n come opposite each zero of the members representing feet on the wheel. A plunger p attached to a cap q passes through the hollow spindle d and is connected by a chain r and cable s to a small lever t on the handle e. When the lever t is pressed down, the hub f<1> of the pendulum is forced against a friction washer u on the hub c and the wheel and pendulum are locked. In measuring the ground outside buildings, a zero on the wheel is adjusted to the pendulum and the two are locked. The zero is now placed on the ground at the commencement of the distance and the wheel rolled along the surface. For measuring floors indoors where the distance begins or terminates at the wall, the pendulum f is adjusted initially so that the pointers n are opposite a point v situated at each measurement on the wheel and equivalent to À94 of a foot. A pointer w indicates when the wheel l has just dropped off a tooth.