Loosening screws, also known as loosening screws, spring screws, or non loosening screws, are riveted or expanded on the mounting plate, and fastened to the position of the plate by screws. As the name suggests, screws that are not loose are easy to understand as being both loose and not falling off, and are commonly used in various fields such as power technology and switches. Loose screws are used to fix the position of the screw fastening plate to the plate by expanding rivets. When in use, they can be directly locked with tools or manually tightened to achieve convenient connection between plates without the need for additional separate screw assembly.
At present, the majority of screws on the market that do not come loose use a tight fit between plastic washers and threads to prevent detachment. This involves forcibly inserting the threaded part into the inner hole of a plastic washer that is smaller than the thread, and utilizing the elastic recovery of the plastic to prevent the screw from coming out.
This approach has the following drawbacks:
1. Forcefully assembling may cause plastic damage and pose a risk of detachment.
2. Plastic damage may lead to the production of plastic shavings and their attachment to threads.
3. The assembly method of plastic gaskets and outer sleeves is adhesive bonding. The adhesive backing method used for ordinary screws generally does not have high temperature resistance, while the operating environment temperature of electronic products can generally reach 60 degrees or higher, which may cause adhesive backing failure; There is also a risk of softening and deformation of plastics when used in high-temperature environments.
4. The market's demand for environmental protection of products is increasing day by day. From the control of cadmium free to flame retardant additives, to RoHS, to halogen-free requirements, the environmental risks of plastic products are far greater than those of metal structured products.
On the other hand, traditional screws that cannot be loosened are often unable to be tightened by hand due to insufficient friction, or require specific tools to lock, which limits their applicability.
Technical implementation elements:
The purpose of this utility model is to provide a non loosening screw, which replaces traditional plastic washers with an inner sleeve made of metal material, avoiding plastic damage caused by forced assembly and softening deformation during use in high temperature environments. The use of metal material reduces environmental protection risks; When in use, the friction is increased by straightening the pattern, which can be easily tightened by hand, locked with a straight or cross screwdriver, and even tightened with a pin as a lever, making it widely applicable.
In order to achieve the above objectives, the technical solution adopted by the present utility model is: a non loosening screw, comprising a screw, a spring, an outer sleeve, and an inner sleeve. The upper section of the screw is fitted with a spring, and the lower section passes through the cooperating outer sleeve and inner sleeve in sequence. The upper end of the spring contacts the screw head, and the lower end contacts the outer sleeve. The screw comprises a head, which extends downward to form a step, a rod, and a threaded part in sequence. The upper end of the head is provided with a screw groove, and the center position is arc-shaped concave. The screw groove is in a cross shape without edge sealing. The outer edge surface of the head is provided with straightening patterns, and the middle part is provided with a through pin hole.