GB967670A - Improvements relating to adhesive strength testing machines - Google Patents

Abstract

967,670. Testing adhesion. SONDES PLACE RESEARCH LABORATORIES Ltd. May 14,1962 [April 17, 1961], No. 13776/61. Heading G1S. Apparatus for testing adhesion by measuring the force required to strip adhesive tape from a plate at a constant predetermined speed comprises a hollow slotted pillar 2 guiding a weighted body 3 suspended by a cable 5 within the pillar, the weight 3 being manually raised to an initial position by drum 8 (Fig. 2) and handle 11 and then allowed to fall under gravity, but at a constant speed controlled by a motor 14. The tape is stuck to a plate that can be releasably secured to the weight 3 the lower end of the tape being doubled back on itself and fastened to a nail 33 in bracket 34 fixed to the operating member 27 of a dial gauge 26; the upper end of the member 27 is fixed to a leaf spring 28 (Fig. 3) fast with the housing 7. Thus as the weight 3 falls, the tape is stripped upwardly from it, the deflection of leaf-spring 28 being a measure of the force and indicated in force units on the dial gauge. During the fall of weight 3 a notched drum 17 rotates (nearly) once operating the arm 19 of a microswitch 20 at inch increments of the fall to operate a warning light for the operator to take a reading of the force. The travel of weight 3 is limited by an escapement 23 co-operating with a pin 22. A one-way clutch prevents slip against the controlling motor 14 during fall of the weight 3, but allows manual raising of the weight.