Patent GB-227176-A (GB)
Title: Improvements in road-contouring and like apparatus
IPC: G01C7/04
Filed: 1923-10-08
Abstract: 227,176. Evans, W. E., (Williams, J. H.). Oct. 8, 1923. Road-contouring apparatus; ocurse-recording apparatus.- In apparatus for recording the configuration of a path over which it is moved, and in which the length of the path is measured by rolling along it a wheel of known circumference, or by the number of revolutions of a propeller &c., a driving element rotated from the wheel &c. engages a driven surface capable of movement in two directions at right-angles to each other, the angular disposition of the driven surface in relation to the driving element being controlled by a pendulum, or by a gyroscopic compass &c. so as to control the resultant direction of movement of the driven surface. The driven surface may itself constitute the record surface or it may be geared to a second surface on which the record is made. In the form shown in Figs. 1, 3 and 4 a wheeled carriage a supports a platform b which carries a bracket b<2> having lugs b' between which is supported a bearing b<4> for the apparatus, cushioning-springs b<6> being interposed between this bearing and the bracket. The frame c of the apparatus is mounted to slide vertically in the bearing b<4> and is supported by a spring b<7>. This frame forms a bearing for a spindle d to one end of which is secured a pendulum e while the other end carries a bracket g formed at its free end with a transverse member g<1>, the end brackets g<2> of which support a rod g<3> on which the record drum h is slidably and rotatably mounted, the rod being preferably of angular section and engaging by means of rollers with a sleeve on which the drum is rotatably carried. Also seated in the brackets g<2> is a support g<4> on which is slidably mounted a stylus carrier i. The frame c has an extension c<2> carrying bearing-brackets c<3> in which is mounted the driving wheel f which frictionally engages the drum h, this wheel being driven by one of the wheels a<3> of the carriage, through the gearing shown in Fig. 1. This gearing includes change wheels l<5>, l<6> to permit of variation in the horizontal scale of the record. The point of contact of the wheel f and drum h lies in the axis of the spindle d so that rotation of the wheel around this axis due to changing inclination of the road will vary the magnitudes of the two component movements of the drum. For varying the vertical scale of the record the stylus carrier is caused to be moved to a variable extent by the drum when the latter moves axially, the direction of movement of the carrier being opposite to that of the drum. The carrier for the drum has an extension j<1> carrying a pin engaging one end of a slotted lever k<1>, the other end of which is engaged by a pin on the stylus carrier. The fulcrum k<2> of the lever is carried by a slide-bar k<5>, adjustment of which varies the ratio between the arms of the lever. Alternatively the members i, j may carry racks connected together by change wheels. The pendulum is preferably of compound form, arranged so that the moments of inertia of the parts above and below the axis of suspension are equal. In the modification shown in Fig. 10 the record surface t is separate from the driven sur. face r and receives a movement of rotation onlv. The drums r, t and the stylus carrier w are carried by a frame q which is suspended from the pendulum spindle supported in the bearing p. The friction driving-wheel s rotates the drum r which is keyed to its spindle r<1> so as to be slidable thereon. The spindle r<1> and the spindle t' carrying the drum t are provided with pinions r<2>, t<3> connected by change wheels so that the horizontal scale of the record can be varied. The drum r has an extension r<3> fitted at its lower end with a disc r<4> engaging rollers w<3>, w<5> on the carrier w. The stylus w<8> thus receives the axial movements of the drum r. In a further modification the friction wheel is supported by the pendulum spindle, the driven surface then receiving the angular movements of the carriage. The apparatus may also be adapted for obtaining a profile from a curve of a trigonometrical function obtained by apparatus such as described in Specification 191,437. In this case the drum carrier may carry a pointer adapted to be traversed along the curve so as to cause the carrier to receive angular movements relatively to the friction driving-disc.