Valve limit switch with dome indicator

Abstract

The application discloses a valve limit switch with a dome indicator, which is characterized by comprising a shell and a dome indicator; the dome indicator comprises a cover and an indicating ball; the cover comprises a cover main body and an annular convex edge; the shell top is provided with an annular step; the annular convex edge is arranged on the bottom wall of the annular step; an annular groove is formed in the side circumferential wall of the annular step; the annular groove is provided with a plurality of telescopic rods which are uniformly distributed along the circumference of the annular step, respectively arranged along the radial direction of the annular step, respectively extended out of the annular groove and downwardly pressed to fix the annular step; the shell top is further provided with a telescopic driving mechanism; the telescopic driving mechanism is used for driving the plurality of telescopic rods to respectively telescopically extend along the radial direction of the annular step, so that the plurality of telescopic rods are respectively extended out of the annular groove or retracted into the annular groove.

Description

Technical Field

[0001] This invention relates to a valve limit switch that facilitates adjustment of a dome indicator. Background Technology

[0002] A valve limit switch is an industrial automation field instrument used to detect the open / closed status of a valve and provide feedback signals to the control system. A dome indicator is often installed on the top of the valve limit switch housing to facilitate viewing the valve's open / closed position. The dome indicator typically consists of an indicator ball and a housing, with the housing usually secured to the valve limit switch housing by multiple bolts. However, during initial installation or reinstallation of the valve limit switch, the dome indicator needs to be adjusted, requiring the housing to be unlocked first, and then locked again after adjustment. This necessitates repeatedly removing and installing multiple bolts, which is inconvenient. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a valve limit switch for convenient adjustment of a dome indicator, comprising: a housing, and a dome indicator disposed on the top of the housing; the dome indicator includes: an outer cover covering the top of the housing, and an indicator ball disposed within the outer cover; the outer cover includes: a hemispherical cover body covering the indicator ball, and a flat annular protrusion extending from the bottom end of the cover body; the top of the housing is provided with a flat annular step coaxial with the rotation axis of the indicator ball for placing the annular protrusion; the annular protrusion is flatly placed on the annular step. On the annular bottom wall; the annular side wall of the annular step is provided with an annular groove (the inner ring of the annular groove is open and the outer ring is closed) that is coaxial with the annular step and faces the indicator ball; the annular groove is provided with a plurality of telescopic rods that are evenly distributed along the circumference of the annular step, respectively arranged radially along the annular step, and respectively extend out of the annular groove and press down to fix the annular step; the top of the housing is also provided with a telescopic drive mechanism; the telescopic drive mechanism is used to drive the plurality of telescopic rods to extend and retract radially along the annular step, so that the plurality of telescopic rods extend out of the annular groove or retract into the annular groove respectively.

[0004] Preferably, the telescopic drive mechanism includes: an air supply channel and a single vertical main slide groove provided on the top of the housing around the annular groove, a main slider and a cylindrical airbag provided in the main slide groove, a single vertical threaded through hole opened at the top of the housing and connected to the top of the main slide groove at the bottom, a single vertical bolt installed in the threaded through hole, and an annular airbag, multiple support sliders and multiple support slide grooves all located in the annular groove. The cylindrical airbag is placed vertically and its bottom end is fixedly connected to the bottom end of the main slide groove; the main slider is located above the cylindrical airbag, and its bottom end is fixedly connected to the top end of the cylindrical airbag, and the main slider slides in conjunction with the main slide groove (the main slide groove is used to guide the main slider to move vertically); the bolt passes through the threaded through hole (the bolt and the threaded through hole are threadedly connected) and extends into the main slide groove, and the bottom end of the bolt presses down on the main slider and puts the cylindrical airbag in a contracted state; The annular airbag is placed horizontally and coaxial with the annular step. The outer ring of the annular airbag is fixedly connected to the outer ring of the annular groove, and the annular airbag is in an inflated state. The multiple telescopic rods and multiple sliding blocks are all located in the inner ring of the annular airbag, and the multiple telescopic rods and multiple sliding blocks correspond one-to-one. The inner end of each telescopic rod is fixedly connected to the inner ring of the annular airbag through the corresponding sliding block. The multiple sliding grooves correspond one-to-one with the multiple sliding blocks. Each sliding block slides in contact with its corresponding sliding groove. Each sliding groove guides the corresponding sliding block to move radially along the annular groove. The multiple sliding grooves are evenly distributed circumferentially along the annular groove, and each sliding groove is arranged radially along the annular groove. The outer ring of the annular airbag is connected to the bottom of the cylindrical airbag through an air delivery channel.

[0005] Preferably, the cylindrical airbag is further provided with a vertical main spring for driving the main slider to move upward; the bottom end of the main spring is fixedly connected to the bottom end of the cylindrical airbag, the top end of the main spring is fixedly connected to the top end of the cylindrical airbag, and the main spring is always in a compressed state.

[0006] Preferably, the annular airbag is further provided with multiple support springs; the multiple support springs correspond one-to-one with the multiple support sliders, and each support spring is used to drive the corresponding support slider to move along the corresponding support groove to the outer ring of the annular groove (i.e., move away from the annular convex edge); the multiple support springs are evenly distributed along the circumference of the annular groove, each support spring is arranged radially along the annular groove, and each support spring is always in a stretched state.

[0007] Preferably, a flat elastic sealing ring is provided between the annular bottom wall and the annular protrusion of the annular step, and the elastic sealing ring is pressed against the annular bottom wall of the annular step by the annular protrusion.

[0008] Preferably, the outer ring of the annular convex edge has an upwardly convex first arc-shaped chamfer at its top; the outer ends of the plurality of telescopic rods each have a downwardly convex second arc-shaped chamfer at their bottom; and the second arc-shaped chamfers of the plurality of telescopic rods all cooperate with the first arc-shaped chamfer of the annular convex edge.

[0009] The advantages and beneficial effects of the present invention are as follows: It provides a valve limit switch that is convenient for adjusting the dome indicator. When unlocking the outer cover, only one bolt needs to be unscrewed, and when locking the outer cover, only one bolt needs to be screwed on. This makes it easier to unlock and lock the outer cover, so as to facilitate the adjustment of the dome indicator after unlocking the outer cover, and to lock the outer cover again after adjusting the dome indicator.

[0010] This invention has the following characteristics: 1) Under normal conditions, the multiple telescopic rods extend out of the annular groove and press down to fix the annular step. The multiple telescopic rods are evenly distributed around the annular step and are arranged radially along the annular step. This can stably press the annular convex edge and the elastic sealing ring onto the annular bottom wall of the annular step, thereby achieving reliable locking of the outer cover. 2) When the outer cover needs to be unlocked (such as during the initial installation or reinstallation of a valve limit switch, when the dome indicator needs to be adjusted, the outer cover needs to be unlocked first), unscrew the bolt from the threaded through hole. The main spring will drive the main slider to move upward, and each branch spring will drive its corresponding branch slider to move along its corresponding branch groove towards the outer ring of the annular groove (i.e., move away from the annular convex edge). This causes the annular airbag to contract and the cylindrical airbag to expand (the contraction of the annular airbag inflates the cylindrical airbag through the air supply channel). Each telescopic rod is driven by its corresponding branch slider to retract into the annular groove, i.e., each telescopic rod disengages from the annular convex edge, thus unlocking the outer cover. After the outer cover is unlocked, the dome indicator can be adjusted (adjusting the outer cover and / or the indicator ball). 3) After the dome indicator is adjusted, place the annular convex edge flat on the bottom wall of the annular step again; then screw the single bolt into the threaded through hole again, and let the bolt extend into the main slide groove to press down the main slider and cause the cylindrical airbag to contract. The contraction of the cylindrical airbag will inflate the annular airbag through the air supply channel, causing the annular airbag to expand. The expansion of the annular airbag will drive each support slider to move along the corresponding support slide groove towards the inner circle of the annular groove (i.e., towards the direction closer to the annular convex edge). Then, each telescopic rod will be driven by the corresponding support slider to extend out of the annular groove until each telescopic rod once again presses the annular convex edge and the elastic sealing ring stably against the bottom wall of the annular step, thus achieving reliable locking of the outer cover again. This ensures that the outer cover is not accidentally moved, thereby ensuring that the dome indicator can be used normally. 4) When each telescopic rod extends out of the annular groove, the lower convex second arc chamfer at the bottom of the outer end of each telescopic rod matches the upper convex first arc chamfer at the top of the outer ring of the annular convex edge. This facilitates the contact and pressing of each telescopic rod with the annular convex edge when it extends out of the annular groove, making the locking action of the outer cover smoother. Attached Figure Description

[0011] Figure 1 This is a front view of the invention when the outer cover is locked; Figure 2 This is a top view of the invention when the outer cover is locked; Figure 3 This is a front view of the invention after the outer cover is unlocked; Figure 4 This is a top view of the invention after the outer cover is unlocked. Detailed Implementation

[0012] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0013] The specific technical solution of this invention is as follows: like Figure 1 and Figure 2 As shown, the present invention provides a valve limit switch for convenient adjustment of a dome indicator, comprising: a housing 1, and a dome indicator disposed on the top of the housing 1; the dome indicator comprises: an outer cover 2 covering the top of the housing 1, and an indicator ball 3 disposed in the outer cover 2; the outer cover 2 comprises: a hemispherical cover body 21 covering the indicator ball 3, and a flat annular protrusion 22 extending from the bottom end of the cover body 21; The top of the housing 1 is provided around the indicator ball 3; a flat annular step 11, coaxial with the axis of rotation of the indicator ball 3, is used to place an annular protrusion 22; the annular protrusion 22 is flatly placed on the annular bottom wall of the annular step 11; an annular groove 12, coaxial with the annular step 11 and opening towards the indicator ball 3, is provided on the annular side wall of the annular step 11 (the inner ring of the annular groove 12 is open and the outer ring is closed); a plurality of telescopic rods 41 are provided in the annular groove 12, which are evenly distributed around the annular step 11, arranged radially along the annular step 11, and extend out of the annular groove 12 and press down to fix the annular step 11; the top of the housing 1 is also provided with a telescopic drive mechanism; the telescopic drive mechanism is used to drive the plurality of telescopic rods 41 to extend and retract radially along the annular step 11, so that the plurality of telescopic rods 41 extend out of the annular groove 12 or retract into the annular groove 12 respectively. The telescopic drive mechanism includes: an air supply channel 13 and a single vertical main slide groove 14 arranged on the top of the housing 1 around the annular groove 12, a main slider 51 and a cylindrical airbag 52 arranged in the main slide groove 14, a single vertical threaded through hole 15 opened at the top of the housing 1 and connected to the top of the main slide groove 14 at the bottom, a single vertical bolt 6 installed in the threaded through hole 15, and an annular airbag 43, multiple support sliders 42 and multiple support slide grooves 16 all located in the annular groove 12; The cylindrical airbag 52 is vertically positioned and its bottom end is fixedly connected to the bottom end of the main slide groove 14; the main slider 51 is located above the cylindrical airbag 52, and its bottom end is fixedly connected to the top end of the cylindrical airbag 52, and the main slider 51 is slidably engaged with the main slide groove 14 (the main slide groove 14 is used to guide the main slider 51 to move vertically); the bolt 6 passes through the threaded through hole 15 (the bolt 6 is threadedly engaged with the threaded through hole 15) and extends into the main slide groove 14, and the bottom end of the bolt 6 presses down on the main slider 51 and causes the cylindrical airbag 52 to be in a contracted state; The annular airbag 43 is placed horizontally and coaxial with the annular step 11. The outer ring of the annular airbag 43 is fixedly connected to the outer ring of the annular groove 12, and the annular airbag 43 is in an inflated state. The plurality of telescopic rods 41 and the plurality of support blocks 42 are all located in the inner ring of the annular airbag 43, and the plurality of telescopic rods 41 and the plurality of support blocks 42 correspond one-to-one. The inner end of each telescopic rod 41 is fixedly connected to the inner ring of the annular airbag 43 through the corresponding support block 42. The plurality of support grooves 16 correspond one-to-one with the plurality of support blocks 42. Each support block 42 slides in cooperation with the corresponding support groove 16. Each support groove 16 is used to guide the corresponding support block 42 to move radially along the annular groove 12. The plurality of support grooves 16 are evenly distributed around the annular groove 12, and each support groove 16 is arranged radially along the annular groove 12. The outer ring of the annular airbag 43 is connected to the bottom end of the cylindrical airbag 52 through the air supply channel 13; The cylindrical airbag 52 is also provided with a vertical main spring 53 for driving the main slider 51 to move upward; the bottom end of the main spring 53 is fixedly connected to the bottom end of the cylindrical airbag 52, the top end of the main spring 53 is fixedly connected to the top end of the cylindrical airbag 52, and the main spring 53 is always in a compressed state. The annular airbag 43 is also provided with a plurality of support springs 44; the plurality of support springs 44 correspond one-to-one with the plurality of support sliders 42, and each support spring 44 is used to drive the corresponding support slider 42 to move along the corresponding support groove 16 to the outer ring of the annular groove 12 (that is, to move away from the annular convex edge 22); the plurality of support springs 44 are evenly distributed around the annular groove 12, and each support spring 44 is arranged radially along the annular groove 12, and each support spring 44 is always in a stretched state. A flat elastic sealing ring 7 is also provided between the annular bottom wall and the annular protrusion 22 of the annular step 11, and the elastic sealing ring 7 is pressed against the annular bottom wall of the annular step 11 by the annular protrusion 22. The outer ring of the annular convex edge 22 has an upwardly convex first arc-shaped chamfer 81 at its top; the outer ends of the plurality of telescopic rods 41 are respectively provided with downwardly convex second arc-shaped chamfers 82; and the second arc-shaped chamfers 82 of the plurality of telescopic rods 41 all cooperate with the first arc-shaped chamfer 81 of the annular convex edge 22.

[0014] The valve limit switch of the present invention can easily unlock and lock the outer cover 2, so as to facilitate the adjustment of the dome indicator after unlocking the outer cover 2, and the locking of the outer cover 2 again after adjusting the dome indicator; the specific operation method for unlocking and locking the outer cover 2 is as follows: Figure 1 and Figure 2As shown, under normal conditions, the multiple telescopic rods 41 extend out of the annular groove 12 and press down to fix the annular step 11. The multiple telescopic rods 41 are evenly distributed around the annular step 11, and the multiple telescopic rods 41 are arranged radially along the annular step 11. This can stably press the annular convex edge 22 and the elastic sealing ring 7 onto the annular bottom wall of the annular step 11, thereby achieving reliable locking of the outer cover 2. When it is necessary to unlock the outer cover 2 (such as when adjusting the dome indicator during the initial installation or reinstallation of the valve limit switch), unscrew the bolt 6 from the threaded through hole 15. The main spring 53 will drive the main slider 51 to move upward, and each branch spring 44 will drive the corresponding branch slider 42 to move along the corresponding branch groove 16 towards the outer ring of the annular groove 12 (i.e., move away from the annular convex edge 22). As a result, the annular airbag 43 contracts and the cylindrical airbag 52 expands (the contraction of the annular airbag 43 will inflate the cylindrical airbag 52 through the air supply channel 13, causing the cylindrical airbag 52 to expand). Furthermore, each telescopic rod 41 is driven by its corresponding branch slider 42 to retract into the annular groove 12, i.e., each telescopic rod 41 disengages from the annular convex edge 22, thus unlocking the outer cover 2. Figure 3 and Figure 4 As shown; after the outer cover 2 is unlocked, the dome indicator can be adjusted (adjust the outer cover 2 and / or the indicator ball 3). After the dome indicator is adjusted, the annular convex edge 22 is placed flat on the annular bottom wall of the annular step 11 again. Then, the single bolt 6 is screwed into the threaded through hole 15 again, and the bolt 6 is inserted into the main slide groove 14 to press down the main slider 51 and cause the cylindrical airbag 52 to contract. The contraction of the cylindrical airbag 52 will inflate the annular airbag 43 through the air supply channel 13, causing the annular airbag 43 to expand. The expansion of the annular airbag 43 will drive each support slider 42 to move along the corresponding support slide groove 16 towards the inner circle of the annular groove 12 (i.e., towards the direction closer to the annular convex edge 22). Then, each telescopic rod 41 is driven by the corresponding support slider 42 to extend out of the annular groove 12 until each telescopic rod 41 once again stably presses the annular convex edge 22 and the elastic sealing ring 7 onto the annular bottom wall of the annular step 11, thus achieving reliable locking of the outer cover 2 again. Figure 1 and Figure 2 As shown, this ensures that the outer cover 2 is not accidentally moved, thereby ensuring that the dome indicator can be used normally; Furthermore, when each telescopic rod 41 extends out of the annular groove 12, the lower convex second arc chamfer 82 at the bottom of the outer end of each telescopic rod 41 matches the upper convex first arc chamfer 81 at the top of the outer ring of the annular convex edge 22. This facilitates the contact and pressing of each telescopic rod 41 with the annular groove 12 when it extends out, making the locking action of the outer cover 2 smoother. In addition, when one hand tightens the bolt 6 to lock the outer cover 2 again, the other hand presses down on the outer cover 2, which further makes the locking action of the outer cover 2 smoother.

[0015] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A valve limit switch for convenient adjustment of a dome indicator, characterized in that, The device includes a housing and a dome indicator; the dome indicator includes an outer cover and an indicator ball; the outer cover includes a cover body and an annular convex edge; characterized in that the top of the housing is provided with an annular step; the annular convex edge is placed on the bottom wall of the annular step; an annular groove is formed on the side wall of the annular step; the annular groove is provided with a plurality of telescopic rods: evenly distributed along the circumference of the annular step, respectively arranged radially along the annular step, respectively extending out of the annular groove and pressing down to fix the annular step; the top of the housing is also provided with a telescopic drive mechanism; the telescopic drive mechanism is used to drive the plurality of telescopic rods to extend and retract radially along the annular step, so that the plurality of telescopic rods respectively extend out of the annular groove or retract into the annular groove.

2. The valve limit switch for convenient adjustment of the dome indicator according to claim 1, characterized in that, The telescopic drive mechanism includes: an air supply channel and a vertical main slide groove arranged around the annular groove at the top of the housing; a main slider and a cylindrical airbag arranged in the main slide groove; a threaded through hole opened at the top of the housing and communicating with the main slide groove; a bolt installed in the threaded through hole; and an annular airbag, multiple support sliders, and multiple support slide grooves all located in the annular groove. The bottom end of the cylindrical airbag is fixedly connected to the bottom end of the main slide groove; the main slider is fixedly connected to the top end of the cylindrical airbag; the bolt presses down on the main slider and puts the cylindrical airbag in a contracted state; The outer ring of the annular airbag is fixedly connected to the outer ring of the annular groove, and the annular airbag is in an inflated state; the multiple telescopic rods and multiple support blocks correspond one-to-one, and the inner end of each telescopic rod is fixedly connected to the inner ring of the annular airbag through the corresponding support block; the multiple support grooves and multiple support blocks correspond one-to-one, and each support groove is used to guide the corresponding support block to move radially along the annular groove. The outer ring of the annular airbag is connected to the bottom of the cylindrical airbag through an air delivery channel.

3. The valve limit switch for convenient adjustment of the dome indicator according to claim 2, characterized in that, The cylindrical airbag is also equipped with a main spring for driving the main slider to move upward.

4. The valve limit switch for convenient adjustment of the dome indicator according to claim 2, characterized in that, The annular airbag is also provided with multiple support springs; each of the multiple support springs corresponds to one of the multiple support sliders, and each support spring is used to drive the corresponding support slider to move towards the outer ring of the annular groove.

5. The valve limit switch for convenient adjustment of the dome indicator according to claim 1, characterized in that, An elastic sealing ring is also provided between the bottom wall of the annular step and the annular protrusion.

6. The valve limit switch for convenient adjustment of the dome indicator according to claim 1, characterized in that, The outer ring of the annular convex edge has an upwardly convex first arc-shaped chamfer at its top; the outer ends of the plurality of telescopic rods each have a downwardly convex second arc-shaped chamfer at their bottom; and the second arc-shaped chamfers of the plurality of telescopic rods all cooperate with the first arc-shaped chamfer of the annular convex edge.

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