Anti-sticking travel switch contact protection structure
By introducing a dustproof mechanism into the limit switch, the problem of jamming caused by oil and dust entering is solved, ensuring the normal operation of the limit switch and extending its service life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NINGBO HUAYU MOTOR CO LTD
- Filing Date
- 2025-06-20
- Publication Date
- 2026-07-21
AI Technical Summary
When traditional limit switches are used in harsh environments, they are prone to jamming due to oil and dust entering the gap between the elastic telescopic rod and the housing, which affects sensitivity and service life.
A dustproof mechanism was designed, including a front cover, a rear cover, and a telescopic sleeve, which respectively protect the front and rear ends of the elastic telescopic rod from dust. The mechanism is also secured by positioning posts, positioning holes, and clamping components to prevent impurities from entering the gaps.
It effectively prevents dust and oil from entering, reduces the probability of jamming, ensures the normal function of the limit switch, and extends its service life.
Smart Images
Figure CN224536900U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of limit switch technology, and in particular to a limit switch contact protection structure to prevent jamming. Background Technology
[0002] Limit switches, a type of position switch (also known as a limit device), are commonly used low-current control electrical appliances. They utilize the impact of moving parts in production machinery to actuate their contacts, thereby connecting or disconnecting the control circuit to achieve a specific control purpose. Typically, these switches are used to limit the position or travel of mechanical movement, causing the machinery to automatically stop, reverse, change speed, or automatically reciprocate at a certain position or travel. A similar limit switch is disclosed in utility model patent CN205315811U. Traditional limit switches mainly consist of a housing and an elastic telescopic rod located at the front end of the housing. Because limit switches are often used in production workshops with harsh environments, after a period of time, a certain amount of oil and dust can enter the gaps between the telescopic rod and the housing, increasing the damping of the telescopic rod and thus reducing the sensitivity of the limit switch and affecting its service life. Therefore, improvements are needed. Utility Model Content
[0003] This invention addresses the shortcomings of existing technologies by providing a limit switch contact protection structure that prevents jamming. This structure effectively prevents external dust, oil, and other impurities from entering the gap between the elastic telescopic rod and the housing, thereby reducing the risk of jamming of the elastic telescopic rod.
[0004] To solve the above-mentioned technical problems, the present invention provides a solution through the following technical method:
[0005] A limit switch contact protection structure for preventing jamming includes a housing and an elastic telescopic rod disposed on the front side of the housing. A dustproof mechanism is provided between the elastic telescopic rod and the housing. The dustproof mechanism includes a front cover sleeved on the front end of the elastic telescopic rod, a rear cover mounted on the housing, and a telescopic sleeve disposed between the front cover and the rear cover and sleeved on the elastic telescopic rod.
[0006] Using the above solution, the dustproof mechanism can block the gap between the elastic telescopic rod and the housing, preventing external dust, oil, and other impurities from entering the gap, thereby reducing the probability of the limit switch jamming. The front and rear covers can respectively prevent dust from entering the front and rear ends of the elastic telescopic rod. The telescopic sleeve can not only prevent dust but also maintain the smoothness of the elastic telescopic rod's extension and retraction, thus ensuring the normal functioning of the limit switch.
[0007] Preferably, the end of the elastic telescopic rod is provided with a hemispherical head, and the front cover is a hemispherical shell.
[0008] By adopting the above solution, the elastic telescopic rod with the front cover can accurately identify the compression of the object without causing damage to the object's surface, thereby improving the performance of the limit switch.
[0009] Preferably, the end of the elastic telescopic rod is provided with a positioning hole, and the inner side wall of the front cover is provided with a positioning pin that is inserted into the positioning hole.
[0010] By adopting the above solution, the insertion and engagement between the positioning post and the positioning hole can realize the positioning between the front cover and the elastic telescopic rod, thereby completing the pre-positioning between the dustproof mechanism and the elastic telescopic rod, making the installation of the dustproof mechanism more efficient and convenient.
[0011] Preferably, the cross-section of the positioning post is non-circular, and the cross-sectional shape of the positioning hole is consistent with that of the positioning post.
[0012] By adopting the above solution, the fit between the positioning post with a non-spherical cross-section and the positioning hole can play a role in limiting rotation, making the pre-positioning between the dustproof mechanism and the elastic telescopic rod more accurate, and further improving the installation efficiency and convenience of the dustproof mechanism.
[0013] As a preferred option, the telescopic sleeve is an organ pipe.
[0014] The above solution results in a simple and mature bellows tube structure that has both a certain resistance to compression and the ability to achieve stable expansion and contraction, thus ensuring the performance of the expansion sleeve.
[0015] Preferably, the front end of the housing is provided with a connecting seat for the elastic telescopic rod to slide through, and the rear cover is sleeved on the connecting seat.
[0016] Preferably, both ends of the connector are provided with positioning elements, and both sides of the rear cover are provided with clamping components that clamp and fix the rear cover to the two positioning elements respectively to prevent the rear cover from detaching from the connector.
[0017] The above solution allows the rear cover to be stably installed on the connecting base, while also being easy to disassemble, thus facilitating the cleaning and replacement of the dustproof mechanism.
[0018] Preferably, the end of the positioning member away from the housing is provided with protrusions on both sides, and the clamping assembly includes an elastic positioning clamp that clamps the protruding part of the protrusion and a connecting member that connects the elastic positioning clamp and the rear cover.
[0019] By adopting the above solution, the connection stability between the clamping component and the positioning component can be further improved, and the disassembly efficiency and convenience of both can be effectively improved.
[0020] Preferably, the protrusion is cylindrical, with its outer circumferential surface protruding from the outer wall of the positioning member.
[0021] Using the above solution, the cylindrical outer circumferential surface has a guiding function, which can facilitate the elastic positioning clamp to detach from the protrusion and ensure the stability of the two after docking.
[0022] Preferably, both clamping ends of the elastic positioning clamp are provided with convex guide arc surfaces.
[0023] Using the above scheme, the convex guide arc surface has a guiding function. During the insertion of the protruding part, the elastic positioning clamp, in conjunction with the outer circumference of the protruding part, drives the elastic positioning clamp to automatically open, facilitating its entry. After the elastic positioning clamp is aligned with the protruding part, it automatically returns to its original position under its own elastic force, thus completing the positioning and preventing it from detaching from the positioning part. This effectively improves the installation efficiency and convenience of the elastic positioning clamp.
[0024] This utility model, by adopting the above technical solutions, has significant technical effects: the dustproof mechanism can block the gap between the elastic telescopic rod and the housing to prevent external dust, oil, and other impurities from entering the gap, thereby reducing the probability of the limit switch jamming. The front and rear covers can respectively prevent dust from entering the front and rear ends of the elastic telescopic rod. The telescopic sleeve can not only prevent dust but also maintain the smoothness of the elastic telescopic rod's extension and retraction, thus ensuring the normal functioning of the limit switch. Attached Figure Description
[0025] Figure 1 This is a schematic diagram of the structure of this embodiment. Figure 1 ;
[0026] Figure 2 for Figure 1 An enlarged schematic diagram of part A shown;
[0027] Figure 3 This is a schematic diagram of the structure of this embodiment. Figure 2 ;
[0028] Figure 4 for Figure 3 An enlarged schematic diagram of part B is shown below;
[0029] Figure 5 This is a schematic diagram of the dustproof mechanism in this embodiment;
[0030] Figure 6 for Figure 5 An enlarged schematic diagram of section C shown.
[0031] The parts referred to by the numbers in the above attached figures are as follows: 1. Housing; 2. Elastic telescopic rod; 3. Dustproof mechanism; 4. Front cover; 5. Rear cover; 6. Telescopic sleeve; 7. Hemispherical head; 8. Positioning hole; 9. Positioning post; 10. Connecting seat; 11. Positioning component; 12. Clamping assembly; 13. Protrusion; 14. Elastic positioning clamp; 15. Connecting component; 16. Guide arc surface; 17. Enclosure plate; 18. End cap; 19. Clearance groove. Detailed Implementation
[0032] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.
[0033] like Figures 1 to 6 As shown, this embodiment discloses an anti-jamming limit switch contact protection structure, including a housing 1 and an elastic telescopic rod 2 disposed on the front side of the housing 1. The specific telescopic structure of the elastic telescopic rod 2 is prior art and does not involve the technical improvement of this utility model, so it will not be described in detail. A dustproof mechanism 3 is provided between the elastic telescopic rod 2 and the housing 1. The dustproof mechanism 3 includes a rigid front cover 4 sleeved on the front end of the elastic telescopic rod 2, a rigid rear cover 5 installed on the housing 1, and a telescopic sleeve 6 integrally disposed between the front cover 4 and the rear cover 5 and sleeved on the elastic telescopic rod 2. Specifically, the end of the elastic telescopic rod 2 is provided with a hemispherical head 7, and the front cover 4 is a hemispherical housing 1 to accommodate the hemispherical head 7, thereby improving the fit between the front cover 4 and the end of the elastic telescopic rod 2. The telescopic sleeve 6 is an accordion tube, which can extend and retract with the elastic telescopic rod 2, thereby ensuring the normal operation of the limit switch.
[0034] To achieve pre-positioning between the front cover 4 and the elastic positioning post 9, a positioning hole 8 is provided at the end of the elastic telescopic rod 2, and a positioning post 9 is provided on the inner side wall of the front cover 4, which is inserted into the positioning hole 8. The cross-section of the positioning post 9 is non-circular, and the cross-sectional shape of the positioning hole 8 is consistent with the cross-section of the positioning post 9, so as to limit rotation and thus effectively improve the pre-positioning effect.
[0035] To improve the installation stability of the rear cover 5, a connecting seat 10 is integrally provided at the center of the front end of the housing 1 for the elastic telescopic rod 2 to slide through. The rear cover 5 is sleeved on the connecting seat 10. Specifically, the rear cover 5 includes a surrounding plate 17 surrounding the outer wall of the connecting seat 10 and an end cap 18 integrally provided at the port of the surrounding plate 17 and covering the end face of the connecting seat 10. Positioning members 11 are fixed at both ends of the connecting seat 10. Both sides of the surrounding plate 17 and near the edge of the housing 1 are provided with clearance grooves 19 for the two positioning members 11 to engage. Both sides of the rear cover 5 are provided with clamping components 12 that clamp and fix to the two positioning members 11 respectively to prevent the rear cover 5 from detaching from the connecting seat 10.
[0036] In this embodiment, the end of the positioning member 11 furthest from the housing 1 is provided with a protruding part 13 on both sides. The protruding part 13 is cylindrical, and its outer peripheral surface protrudes from the outer side wall of the positioning member 11. The width of the clearance groove 19 is equal to or slightly larger than the outer diameter of the protruding part 13, so that the protruding part 13 can smoothly enter the clearance groove 19, thereby allowing the rear cover 5 to fit tightly with the connecting seat 10. The clamping assembly 12 includes an elastic positioning clamp 14 that clamps the protruding part of the protruding part 13 and a connecting part 15 integrally connected between the elastic positioning clamp 14 and the rear cover 5. The elastic positioning clamp 14 is preferably made of stainless steel plate bent, so it has better elasticity and corrosion resistance. Both clamping ends of the elastic positioning clamp 14 are provided with protruding guide arc surfaces 16, thereby facilitating the docking of the elastic positioning clamp 14 with the positioning clamp.
[0037] The specific usage process is as follows:
[0038] When installing the dustproof mechanism 3, first compress the distance between the front cover 4 and the rear cover 5 so that the positioning pin 9 on the inner side of the front cover 4 protrudes. Then, insert the positioning pin 9 into the positioning hole 8 at the end of the elastic telescopic rod 2 to complete the pre-positioning of the front cover 4 and the elastic telescopic rod 2. Then, slide the rear cover 5 backward onto the connecting seat 10 of the housing 1 to lengthen the telescopic sleeve 6, and align the clearance grooves 19 on both sides of the rear cover 5 with the positioning members 11 on both sides of the connecting seat 10. At the same time, drive the elastic positioning clips 14 on both sides of the rear cover 5 to fix the protrusions 13 clamped on the two positioning members 11, thereby completing the fixation of the cover 5 and the connecting seat 10.
[0039] After installation, when an object presses against the elastic telescopic rod 2, the telescopic sleeve 6 retracts accordingly. Conversely, when the elastic telescopic rod 2 returns to its original position, the telescopic sleeve 6 extends accordingly. During this process, the dustproof mechanism 3 prevents external impurities from entering the gap between the elastic telescopic rod 2 and the housing 1, thereby reducing the probability of the elastic telescopic rod 2 getting stuck and extending the service life of the limit switch.
[0040] When disassembling the dustproof mechanism 3, first overcome the elastic force of the elastic positioning clips 14 to pull the rear cover 5 forward, so that the two elastic positioning clips 14 separate from the corresponding positioning parts 11, thereby releasing the lock between the rear cover 5 and the housing 1. Then, reverse the above installation process.
Claims
1. A limit switch contact protection structure to prevent jamming, comprising a housing (1) and an elastic telescopic rod (2) disposed on the front side of the housing (1), characterized in that: A dustproof mechanism (3) is provided between the elastic telescopic rod (2) and the housing (1). The dustproof mechanism (3) includes a front cover (4) sleeved on the front end of the elastic telescopic rod (2), a rear cover (5) installed on the housing (1), and a telescopic sleeve (6) provided between the front cover (4) and the rear cover (5) and sleeved on the elastic telescopic rod (2).
2. The anti-jamming limit switch contact protection structure according to claim 1, characterized in that: The end of the elastic telescopic rod (2) is provided with a hemispherical head (7), and the front cover (4) is a hemispherical shell (1).
3. The anti-jamming limit switch contact protection structure according to claim 1 or 2, characterized in that: The end of the elastic telescopic rod (2) is provided with a positioning hole (8), and the inner side wall of the front cover (4) is provided with a positioning pin (9) that is inserted into the positioning hole (8).
4. The anti-jamming limit switch contact protection structure according to claim 3, characterized in that: The cross-section of the positioning post (9) is non-circular, and the cross-sectional shape of the positioning hole (8) is consistent with that of the positioning post (9).
5. A limit switch contact protection structure for preventing jamming according to claim 1 or 2, characterized in that: The telescopic sleeve (6) is an organ pipe.
6. A limit switch contact protection structure for preventing jamming according to claim 1 or 2, characterized in that: The front end of the housing (1) is provided with a connecting seat (10) for the elastic telescopic rod (2) to slide through, and the rear cover (5) is sleeved on the connecting seat (10).
7. The anti-jamming limit switch contact protection structure according to claim 6, characterized in that: Both ends of the connecting seat (10) are provided with positioning elements (11), and both sides of the rear cover (5) are provided with clamping components (12) that are respectively clamped and fixed to the two positioning elements (11) to prevent the rear cover (5) from detaching from the connecting seat (10).
8. The anti-jamming limit switch contact protection structure according to claim 7, characterized in that: The positioning member (11) has a protrusion (13) with two outward protrusions at one end away from the housing (1). The clamping assembly (12) includes an elastic positioning clamp (14) clamping the protruding part of the protrusion (13) and a connecting member (15) connecting the elastic positioning clamp (14) and the rear cover (5).
9. The anti-jamming limit switch contact protection structure according to claim 8, characterized in that: The protrusion (13) is cylindrical, and its outer circumference protrudes from the outer wall of the positioning member (11).
10. The anti-jamming limit switch contact protection structure according to claim 8, characterized in that: Both clamping ends of the elastic positioning clamp (14) are provided with outwardly protruding guide arc surfaces (16).