Washers are called fasteners made of various materials, mainly from metal or plastic. Their shape is most often circular, but it also happens different (square, rectangular and even polygonal). They are designed to distribute the load when tightening nuts, screws, screws, bolts, studs and other elements of threaded connections, to prevent dents and other damage, and also to ensure good electrical contact.
But there is an unusual puck. Grover has a special purpose.
Technical problem and its solution
The rapid development of mechanical engineering in the second half of the 19th century revealed a significant lack of threaded connections. Mechanical loads, vibration, and various vibrations of the moving parts of the mechanism nodes caused, in addition to fatigue damage, the threat of spontaneous reduction in the strength of their joints. The nuts and bolts were loosened, and in order to control their condition, effort and time were required. At the same time, riveted joints, which were an alternative to threaded ones, made it difficult to disassemble, and therefore maintenance of equipment, which became increasingly difficult. A special washer-grover was the solution to this problem.
Principle of operation
Everything ingenious is simple, but works flawlessly. The Grover washer is a single coil of spring or a ring with a slot, slightly curved so that the gap diverges in the direction that prevents the rotation of the nut when it is unscrewed. During the forward stroke, nothing interferes with the movement of the fastener assembly consisting of a bolt (screw or stud) and nut. But when you try to rotate it in the opposite direction, a sharp edge digs into the metal and complicates this action.
Where did the name “Grover” come from?
There are two main versions of why a spring grover washer is called that. According to the first, the name of the inventor turned out to be immortalized. In favor of this assumption is the fact that until the beginning of the fifties the word "Grover" in the Soviet technical documentation was written with a capital letter. After the campaign against foreign words began in the USSR, according to the linguists of the time, who only littered the “great and mighty,” transistors began to be called triodes, resistors as resistors, and the washer-grover was renamed to spring, or in extreme cases, it was recommended to write this capitalized term.
The second variant of the origin of the term is based on its alleged relationship with the English word “Grow”, meaning “growth”. If you think figuratively, then the stronger the fastening is clamped, the more it is resisted, due to its spring nature, the washer-grover. And when unscrewing it straightens, and its maximum transverse size increases, that is, grows.
All fasteners manufactured in our country are strictly standardized. The Grover washer is no exception. GOST 6402-70 clearly regulates the mechanical properties of "spring washers", the materials from which they are made, and the geometric dimensions by which they are made. This is not surprising, the safety of a complex machine may depend on this, at first glance, secondary assembly unit .