Patent GB-723092-A (GB)
Title: Improvements relating to the testing of leaf springs and the sorting of them in accordance with the result of the test
Inventor: BOWNS DESMOND EDWARD
IPC: G01N3/00
Filed: 1952-04-01
Abstract: 723,092. Testing springs. SMALL & TIDMAS, Ltd., J. C. April 1, 1952 [Jan. 1, 1951], No. 75/51. Class 106 (2). An apparatus for testing springs and sorting them in accordance with the result of the test, comprises means for temporarily holding test-pieces in which the springs are mounted, a pivoted test member adapted to engage the spring, so that the ultimate position of the pivoted test member depends upon the strength of the spring, and at least two sets of ejector or ejection control mechanisms operating in different directions, one or other of which mechanisms is selected to eject the test piece or permit its ejection according to whether the spring in the test piece causes the pivoted test member, by its ultimate position, to indicate " pass or "not pass." In the particular embodiment described, the apparatus is used for testing bobbin carriages, each bobbin, carriage 1, Fig. 1, comprising a flat plate having a large opening 2 therein in which is a curved spring 3. A shaft 6 is adapted to cause to-and-fro movements of a slide 11 feeding the carriages 1 one by one from the bottom of a stack of carriages to the testing apparatus as is shown more clearly in Fig. 2. On a shaft 7, Fig. 1, driven from the shaft 6, are cams 13, Fig. 4, causing plungers 14 to be lowered into holes 4 in each carriage, as it is moved into the testing position, to temporarily secure the carriage to the apparatus. On the shaft 6, Fig. 4, are cams 20, 21, 22. Cam 20 causes an arm 24 to be pivoted about an axis 26 in such a manner that as each carriage 1 is moved into position for testing, a test member 28 on the arm 24 is raised and when the carriage 1 is correctly located in position by the plungers 14 the cam 20 allows a weight 27 on the arm 24 to pivot the test member 28 against the spring 3. The ultimate position of the arm 24 thus depends -upon the strength of the spring 3. The cams 21 and 22 are positioned such that they are not normally in line with their followers 29, 30, see Fig. 5. That is to say, if the spring 3 being tested is of correct strength the cams 21 and 22 during their rotation do not act on the followers 29 and 30. If, however, the spring 3 is too strong, the balance member 24 is held with the weight in a higher position than is shown in Fig. 5, and the follower 29, pivoting with the arm 24, is caused to lie in the path of the cam 21. The cam 21, during its rotation, then acts on the follower 29 which moves a support member 31, normally situated below and to one side of the carriage 1, away from the carriage 1, allowing the carriage to fall at this side into a receptacle when the plungers 14 are raised and the carriage 1 displaced therefrom by a reciprocating stripping means 18. Similarly, if the spring 3 is too weak, the balance member 24 is held with the weight 27 in a lower position than is shown in Fig. 5. The resulting tilt of the arm 24 then causes the follower 30 to lie in the path of its associated cam 22 and during the rotation of the cam 22 the follower 30 causes a supporting member 32, lying opposite to the supporting member 31, to move to one side in a manner allowing the carriage to fall to that side into a second receptacle when the plungers 14 are raised. If the spring is of the correct strength neither of the supporting members 31, 32 are operated and the carriage 1 is eventually automatically moved forward to an acceptance position or a further carriage is brought into the test position. In a modification, Fig. 7, if the spring under test is too strong or too weak the resulting movement of the arm 24 causes an electrical circuit to be completed through a contact 44 or 43. When such a circuit is completed a corresponding solenoid is energized to displace the appropriate supporting member 31 or 32.