Patent GB-210913-A (GB)
Title: Improvements in or relating to gradient meters, clinometers and the like
IPC: G01C9/08
Filed: 1922-11-28
Abstract: 210,913. Lynden, Robert Aernout, Baron van. Nov. 28, 1922. Clinometers. - A gradient indicator or clinometer for use on moving vehicles &c. and having a gravity-actuated indicator, is provided with means for applying or indicating the corrections for errors due to the acceleration of the vehicle &c., the said means being actuated from a member which is rotated at a speed proportional to that of the vehicle. Speed and distance indicators may also be actuated by the same member. The apparatus is contained in a casing A divided by a partition A<1>, and, in the form shown in Figs. 1 and 2, comprises a shaft D rotated at a speed proportional to that of the vehicle and geared to a shaft D<3> to which are secured the blades E<1> of an impeller E which directs a fluid stream through an aperture E<3> on to a turbine wheel F secured to a shaft F<1>. In order that the force acting on the wheel F may be proportional to the speed of the impeller, the aperture E<3> is controlled by a spring E <4> Fig. 4, which is acted upon by the fluid so as progressively to close the aperture as the speed increases. The spindle F<1> is connected by gears F<2>, G<1>, G<2>, G<3> to a spindle G<4> to which is secured a drum G containing a coiled constraining-spring. The angular movements of the spindles F<1>, G<4> are thus proportional to the speed of the vehicle and the drum may be marked with speed graduations visible through a window A<4>. The spindle F<1> is extended downwardly through a partition C<2> and carries a disc H to which are secured the pinions H<1> constituting the planet members of an epicyclic differential gear. The sun member is carried by a tube, J<1> which is freely mounted on the spindle F<1> and is provided with paddles J<2> which resist rotation of the tube. The internally-toothed annulus K is also provided with external teeth gearing with a wheel K<1> carried by a drum K<2> mounted on a spindle R<3> which also carries a pinion R<4> gearing with a segmental gear L<1> carried by the pendulum L which constitutes the indicating means for the clinometer. The drum k<2> is graduated in terms of gradients &c. Acceleration of the mounting causes rotation of the spindle F<1> and this, owing to the resistant force due to the paddles, tends to cause rotation of the ring K and pinion K<4>. The pendulum also tends to swing due to its inertia under the influence of acceleration and so to rotate the pinion K<4>, and the parts are so arranged that the net rotation of the pinion K<4> is zero so long as the gradient remains constant. The drum K<2> thus indicates changes of gradient only. The shaft D may be arranged to operate a mileage indicator B<1>. Several modifications are described. For example, a differential gear of the bevelpinion type may be .used instead of the epicyclic gear. Further instead of the corrective force being applied to the pendulum, the pendulum may swing freely over a scale which is moved by the differential mechanism; or the scale may be fixed and a separate pointer may be moved to indicate the correction required. Moreover, the impeller may be omitted, the speedometer drum being actuated by the shaft D<3> through a differential gear similar to that shown in Figs. 1 and 2. Further, a fluid-slip or dashpot device may be substituted for the paddles J<2>.