GB1422406A - Apparatus for testing golf clubs - Google Patents

Abstract

1422406 Automatic control of testing SUMITOMO RUBBER INDUSTRIES Ltd 17 May 1973 [24 May 1972] 23686/73 Heading G3N Programmed dynamic testing apparatus for a golf club comprises a club grip 4 driven by shaft 22 simulating wrist motion, shaft 22 being mounted on arm 5 pivoted on shaft 21 simulating player's arm and body motion, each motion being controlled independently of the other by a corresponding set of programmed signals to simulate a downswing of the club. Control arrangement. Desired wrist and arm angle profiles defining a desired downswing, Figs; 4, 5 (not shown), as a function of time are pre-set on a corresponding potentiometer group, Fig. 6 (not shown) as a set of voltages (E 1 - E n ) see also (#B), Fig. 8 (not shown), which are successively sampled in time under control of clock pulses (#A Fig. 8), and fed to a subtraction integrator (Fig. 6) producing the partially smoothed angle profile (#C, Fig. 8) provided by integrating, within each pulse duration, the difference, between the value of #C at the beginning of the duration held in a sample and hold circuit to form waveform (#D, Fig. 8), and the waveform (#B), waveform (#C) being fed to a corresponding position servosystem, Fig. 7 (not shown). The partially smoothed angle profile is compared with a corresponding actual angle signal derived from a corresponding potentiometer on, or belt driven by, shaft 21, or 22, the resulting error signal controlling a trigger circuit of a three phase SCR or a transistor rectifier unit, supplied by a threephase, 400 HZ, or 1 KHZ A.C. source to control a corresponding D.C. low inertia electric motor M 1 , or M 2 , possibly with reduction gear, or a corresponding electrically controlled hydraulic motor (not shown), to drive shaft 21, or 22, in accordance with the corresponding angle profile. A photo-electric pick-up (not shown) may detect club and golfball velocities. For slowmotion studies, correlated changes may be made in the integrator time constant, and the clockpulse rate. Mechanical arrangement. Motor M 1 , driven according to the desired law of arm movement (#, Fig. 4) drives shaft 21 and with it arm 5. Shaft 21 supports rotationally free pulleys 14, 15, integral with each other or coupled to rotate together, motor M 2 , driven according to the desired law of wrist motion (# Fig. 4) driving shaft 22 independently of arm rotation via pulleys 13, 15, 14, 12, and belts 16, 17. Motors M 1 , M 2 are mounted in housing 7, see also Fig. 1 (not shown) which is mounted on a frame such that it can be adjusted for tilt, and height. The club grip is held between a pair of bolted together plates (24), Fig. 3 (not shown), each with a semicircular hollow for the club grip.