Mechanical expansion shaft combined with expansion key return device

Abstract

A kind of mechanical expansion shaft combination expansion key return device related to mechanical industry product, see drawing, it is mainly by 1-expansion shaft cylinder, 2-return compression spring, 3-locking screw, 4-expansion key one, 5-internal hexagonal cylindrical head screw, 6-expansion key two composition, 7 is the sleeve to be expanded.The characteristics are: the combination expansion key of return device is formed by expansion key one and expansion key two after being loaded into expansion shaft cylinder by key groove on expansion shaft cylinder respectively, and is coupled by screw, the length of the bottom of combination expansion key is greater than the axial length of key groove on expansion shaft cylinder, so as to limit the maximum stroke of outer expansion of combination expansion key, and ensure that combination expansion key will not be separated from expansion shaft cylinder, it is more durable, safe and reliable than the current external expansion key return device.

Description

Technical Field

[0001] This utility model relates to the improvement of mechanical expansion shafts for products in the machinery industry. Background Technology

[0002] Appendix Figure 1 This is a simplified structural diagram of a current mechanical expansion shaft, with attached... Figure 2 It is attached Figure 1 The enlarged view of the key return device at point A is based on my utility model patent for "High-Precision Winding Expansion Shaft" granted in 2007. This patented product has been recognized by the market and widely used for more than ten years. It mainly consists of: 1-drive nut, 2-pull rod, 3-compression spring, 4-expansion core, 5-expansion key, 6-expansion shaft sleeve, and 7-return leaf spring. Its working principle is as follows: turning the drive nut forces the pull rod to compress the compression spring. The elastic force of the compression spring passes through the expansion core, the expansion key, and finally tightens the sleeve 8. When the sleeve is to be loosened, simply turn the drive nut to release the elastic force of the compression spring. At this time, the expansion key retracts under the action of the return leaf spring. The key return device of the expansion shaft consists of two return leaf springs mounted outside the expansion shaft cylinder, which press against the bosses at both ends of the expansion key. The return leaf springs can only force the expansion key to retract within a certain elastic range, but cannot control the maximum stroke when the expansion key expands. The maximum stroke of the expansion key can only be controlled by the external sleeve. Therefore, when a section of the expansion shaft is not fitted with a sleeve, the maximum stroke of the expansion key in that section cannot be controlled. This causes the return leaf springs pressing against the bosses at both ends of the expansion key to fail or break due to excessive deformation when the expansion key expands too much, eventually causing the expansion key to fall off. If the expansion shaft is rotating at this time, the expansion key will fly out, causing a safety accident. Therefore, the key return device must be improved so that it can not only meet the requirement of smooth retraction of the expansion key, but also effectively control the maximum stroke when the expansion key expands. Summary of the Invention

[0003] The purpose of this utility model is to provide a return device for a mechanical expansion shaft combined with an expansion key. It mainly consists of an expansion shaft cylinder, an expansion key one, an expansion key two, a return spring, and screws. The expansion key one and expansion key two are inserted into the expansion shaft cylinder one after the other from the keyway. After they are fitted together, they are combined into one piece with screws. In this way, it and the expansion shaft cylinder form a structure with a large bottom and a small opening, which can control the maximum stroke of the expansion key and prevent the expansion key from falling off or flying out. Then, return springs are placed in the screw holes on both sides of the keyway of the expansion shaft cylinder and set screws are screwed in to adjust the return pressure of the expansion key.

[0004] The technical solution adopted by this utility model to solve the technical problem is: a return device for a mechanical expansion shaft combined expansion key, which mainly consists of an expansion shaft cylinder, expansion key one, expansion key two, a return compression spring and screws. The feature is that: the combined expansion key of the return device is formed by expansion key one and expansion key two being installed into the expansion shaft cylinder through the keyway on the expansion shaft cylinder and then connected by screws. The length of the bottom of the combined expansion key is greater than the axial length of the keyway on the expansion shaft cylinder, thereby limiting the maximum stroke of the combined expansion key and ensuring that the combined expansion key will not detach from the expansion shaft cylinder.

[0005] The beneficial effects of this utility model are: the mechanical expansion shaft assembly expansion key return device, which is composed of an expansion shaft cylinder, expansion key one, expansion key two, return spring and screw with the above-mentioned features, not only maintains the reliable expansion and contraction function of the expansion key, but also effectively controls the maximum stroke of the expansion key's external expansion, avoiding the expansion key from falling off or flying out. It is more durable and safer than the existing external return device of mechanical expansion shaft. Attached Figure Description

[0006] Appendix Figure 1 This is a simplified structural diagram of a current mechanical expansion shaft.

[0007] Appendix Figure 2 It is attached Figure 1 Enlarged view of the key return device at point A.

[0008] Appendix Figure 3 This is a simplified structural diagram of the mechanical expansion shaft utilizing this invention.

[0009] Appendix Figure 4 It is attached Figure 3 Enlarged view of this utility model at point A in the middle. Detailed Implementation

[0010] Appendix Figure 3 Appendix Figure 4 This is a preferred embodiment of the present invention. In the figure, 1-expansion cylinder, 2-return spring, 3-set screw, 4-expansion key one, 5-internal hexagon head screw, 6-expansion key two, 7-expansion sleeve. It is assembled as follows: First, insert expansion key one into the keyway of the expansion cylinder, ensuring the upper part of the large end of the expansion key is flush against one side of the keyway. Then, insert expansion key two into the keyway of the expansion cylinder. After they are in contact with expansion key one, use an internal hexagon head screw to combine them. Next, place return springs into the screw holes on both sides of the keyway of the expansion cylinder and screw in the set screws. Adjust the return pressure of the expansion keys to complete the assembly.

Claims

1. A return device for a mechanically expanded shaft assembly with an expanded key, mainly composed of an expanded shaft cylinder, an expanded key one, an expanded key two, a return spring, and a screw, characterized in that: The combined expansion key of the reset device is formed by expansion key one and expansion key two which are coupled by screws after being respectively installed into the key groove of the expansion shaft cylinder, and the length of the bottom of the combined expansion key is greater than the axial length of the key groove of the expansion shaft cylinder.

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