CN115855579A

CN115855579A - Food detection equipment

Info

Publication number: CN115855579A
Application number: CN202310173939.7A
Authority: CN
Inventors: 侯旭明; 朱林; 张晓磊; 杨云; 常彩彩
Original assignee: Shandong Hengcheng Testing Technology Co ltd
Current assignee: Shandong Hengcheng Testing Technology Co ltd
Priority date: 2023-02-28
Filing date: 2023-02-28
Publication date: 2023-03-28
Anticipated expiration: 2043-02-28
Also published as: CN115855579B

Abstract

The invention is suitable for the technical field of food detection, and provides food detection equipment, which comprises a detection frame, a plurality of sampling assemblies and a sliding piece, wherein the sampling assemblies are arranged on the detection frame in a rotating mode through threads; the sliding pipe is in sliding fit with the sliding rod; the peripheral side surface of the sliding pipe is provided with a connecting pipe in a penetrating way; a piston rod is in sliding fit with the inside of the connecting pipe; a connecting spring is arranged between the piston rod and the connecting pipe; a threaded pipe penetrates through the sampling barrel; the threaded pipe is in threaded rotation fit with the screw rod; the side surface of the sampling barrel is symmetrically provided with positioning pipes; the piston rod is in inserting fit with the positioning tube. The device drives each group of gear synchronous rotation through rotating the ring gear to drive each group of puddler and rotate together with the puddler that corresponds in step, realize treating the intensive mixing of sample liquid food, prevent to influence the accuracy of test result because of the sediment, realize the sample to the upper and middle, lower floor of the different degree of depth sample through the cooperation between each part, improve the accuracy to liquid food sample data.

Description

Food detection equipment

Technical Field

The invention relates to the technical field of food detection, in particular to food detection equipment.

Background

The food detection takes a product as a main line, and physical and chemical index detection as a teaching item, and comprises food sensory detection, milk and dairy product quality detection, beverage product quality detection, wine product quality detection, vegetable oil quality detection and meat and egg product quality detection, wherein the food safety detection is an important basis for guaranteeing the food safety and the like. The existing common food detection sampling devices are also divided into a plurality of types due to different food types and different inspection occasions.

When liquid food such as soup or water containing additives is sampled and detected, a sampling device in the prior art often needs to manually scoop certain components of the liquid food, the food is fed into a sampling bottle after scooping, the sampling bottle is sealed and stored finally, and when the same liquid food is sampled, different depths of the same liquid food need to be sampled; meanwhile, in the actual operation process, the situation that the sampled food needs to be kept in a non-precipitation state for sampling exists, and because the liquid food is easy to precipitate, the liquid food needs to be manually stirred before being sampled, so that the sampled sample keeps a uniformly mixed state, time and labor are consumed by manual stirring, and the stirring effect is general. Therefore, in order to solve the above problems, it is desirable to provide a food detection sampling device.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide food detection equipment which drives all groups of gears to synchronously rotate through rotating a toothed ring, so that all groups of stirring rods are driven to synchronously rotate together with corresponding stirring rods, the liquid food to be sampled is fully stirred, the influence on the accuracy of a test result due to precipitation is prevented, meanwhile, the upper layer, the middle layer and the lower layer of samples with different depths are sampled through the matching among all parts, and the accuracy of liquid food sampling data is improved.

In order to achieve the purpose, the invention provides the following technical scheme:

a food detection device comprises a detection frame and a plurality of sampling assemblies, wherein the sampling assemblies are rotatably arranged on the detection frame through threads; the detection frame comprises a fixing plate; the bottom surface of the fixed plate is provided with a screw rod in a penetrating and rotating mode; the bottom surface of the fixed plate is positioned on two sides of the screw rod and is symmetrically and fixedly connected with sliding rods; pressing air bags are arranged on the surfaces of the fixing plates; further comprising: a slider slidably disposed on the inspection frame, the slider comprising: the sliding pipes are arranged oppositely and are in sliding fit with the sliding rods; a connecting pipe penetrates through the peripheral side surface of the sliding pipe; a piston rod is in sliding fit with the inside of the connecting pipe; a connecting spring is arranged between the piston rod and the connecting pipe; the two sliding pipes are fixedly connected through the arc pipes; the sliding pipe is hollow and is respectively communicated with the arc-shaped pipe and the connecting pipe; an air conveying hose is arranged between the arc-shaped pipe and the pressing air bag; the sampling assembly comprises a sampling barrel; a threaded pipe penetrates through the sampling barrel; the threaded pipe is in threaded rotation fit with the screw rod; positioning pipes are symmetrically arranged on the peripheral side of the sampling barrel; the piston rod is in plug-in fit with the positioning tube.

The invention is further configured to: the surface of the fixing plate is fixedly connected with a C-shaped plate right above the pressing air bag; a pressing plate is in sliding fit with the inner wall of the C-shaped plate; an extrusion spring is arranged between the pressing plate and the inner top of the C-shaped plate; the side surface of the pressing plate is fixedly connected with a shifting plate.

The invention is further configured to: an annular handle is arranged at the top end of the screw rod; and a stop block is arranged at the bottom end of the two sliding rods.

The invention is further configured to: the inner wall of the sampling barrel is in sliding fit with a piston ring; the piston ring is in sliding fit with the peripheral side face of the threaded pipe; reset springs are symmetrically arranged between the piston ring and the inner bottom surface of the sampling barrel; an infusion tube is arranged on the circumferential side surface of the sampling barrel and is close to the inner bottom surface in a penetrating way.

The invention is further configured to: the surface of the piston ring is provided with an annular iron block; the annular iron block is in sliding fit with the threaded pipe; the periphery side of the threaded pipe is located at the top of the sampling barrel and is fixedly connected with an annular electromagnetic chuck.

The invention is further configured to: a normally open reset button switch is arranged in the positioning tube; a flexible battery pack for supplying power to the annular electromagnetic chuck is arranged on the inner peripheral side surface of the sampling barrel close to the inner top of the sampling barrel; the normally-open reset button switch is electrically connected with the flexible battery pack; a threading groove is formed in the sampling barrel; and an elastic diaphragm for preventing water is arranged in the positioning pipe.

The invention is further configured to: the peripheral side surfaces of the fixed plates are provided with connecting plates; a toothed ring is rotationally matched between the connecting plates; the surface of the connecting plate is provided with a stirring rod in a penetrating and rotating manner; the circumferential side surfaces of the stirring rods are provided with stirring rods; the end part of the stirring rod is fixedly connected with a gear; each gear is meshed and matched with the gear ring.

The invention is further configured to: a transverse handle rod is arranged on the side surface of the connecting plate; the surface of the gear ring is fixedly connected with a vertical handle rod; the side surface of the periphery of the gear ring is provided with an annular limiting rail; the surface of each connecting plate is provided with an annular rotary groove; the inner wall of the annular rotary groove is provided with an annular limiting groove; the annular limiting rail is in running fit with the annular limiting groove.

The invention has the advantages that:

1. according to the invention, each group of sliding parts is moved to a position close to a corresponding sampling assembly, the pressing plate is driven to tightly press and deform the pressing air bag under the elastic acting force of the extrusion spring, at the moment, the connecting spring is stretched, air in the pressing air bag enters the connecting pipe through the air conveying hose and the sliding pipe, the piston rod is pushed to be inserted into the positioning pipe on the sampling barrel, one group of piston rods props against the normally open reset button switch, so that the annular electromagnetic chuck is powered off, and the piston ring is pushed to tightly prop against the inner bottom surface of the sampling barrel under the acting force of the reset spring; repeating the operation to complete the assembly of each group of sampling barrels and the corresponding sliding parts; the assembly process is simple, and the operation is convenient.

2. According to the invention, the check block on the assembled slide bar of the detection frame extends into the bottom of a sample container to be detected, the annular handle is rotated to drive the screw rod to rotate, so that each group of sampling assemblies and the corresponding sliding part are driven to descend along the slide bar together, when the upper layer sampling assembly descends to the upper part of a sample, the corresponding shifting plate is shifted upwards, the corresponding pressing air bag resets, under the elastic resetting acting force of the connecting spring, the piston rod is pulled out of the positioning tube, the piston rod is separated from the normally open resetting button switch and resets into the connecting tube, the sliding part slides down along the slide bar, at the moment, the annular electromagnetic chuck is electrified, the annular iron block is attracted to drive the piston ring to ascend, and the upper layer sample is drawn into the sampling barrel through the infusion tube; by repeating the operation, the sampling of the upper layer, the middle layer and the lower layer of samples with different depths is realized, and the accuracy of the liquid food sampling data is improved.

3. According to the invention, the assembled check block on the slide rod of the detection frame extends into the bottom of the container of the sample to be detected, when the sample to be sampled is kept in a non-deposition state, the toothed ring can be rotated before sampling, all groups of gears are driven to synchronously rotate, so that all groups of stirring rods and corresponding stirring rods are driven to synchronously rotate, the liquid food to be sampled is fully stirred, samples at different depths are synchronously sampled and then detected, the accuracy of a test result is prevented from being influenced by deposition, the detection numerical value is averaged, and the accuracy of liquid food sampling data is improved.

Drawings

FIG. 1 is a schematic structural view of a food inspection apparatus according to the present invention;

FIG. 2 is a schematic structural diagram of the inspection rack of the present invention;

FIG. 3 is a schematic view of the bottom view of the inspection stand according to the present invention;

FIG. 4 is a schematic structural view of a sampling assembly of the present invention;

FIG. 5 is a schematic view of the slider of the present invention;

in the figure: 1. a detection frame; 2. a sampling assembly; 3. a fixing plate; 4. a screw rod; 5. a slide bar; 6. pressing the air bag; 7. a slider; 8. a slide pipe; 9. a connecting pipe; 10. a piston rod; 11. a connecting spring; 12. an arc tube; 13. a gas hose; 14. a sampling barrel; 15. a threaded pipe; 16. a positioning tube; 17. a C-shaped plate; 18. a pressing plate; 19. a compression spring; 20. dialing a plate; 21. an annular handle; 22. a stopper; 23. a piston ring; 24. a return spring; 25. a transfusion tube; 26. an annular iron block; 27. an annular electromagnetic chuck; 28. a normally open reset button switch; 29. a flexible battery pack; 30. a threading slot; 31. an elastic diaphragm; 32. a connecting plate; 33. a toothed ring; 34. a stirring rod; 35. a stirring rod; 36. a gear; 37. a transverse handle bar; 38. a vertical handle bar; 39. annular spacing rail.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

It is noted that, unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

In the present invention, unless stated to the contrary, the use of the terms "upper and lower" are generally used with respect to the orientation shown in the drawings, or with respect to the vertical, vertical or gravitational direction; likewise, for ease of understanding and description, "left and right" are generally to the left and right as shown in the drawings; "inner and outer" refer to the inner and outer relative to the profile of the respective member itself, but the above directional terms are not intended to limit the present invention.

Example one

Referring to fig. 1-5, the first embodiment provides the following technical solutions:

concretely, the food detection equipment comprises a detection frame 1, a plurality of sampling assemblies 2 which are arranged on the detection frame 1 in a threaded rotating mode, and a sliding piece 7 which is arranged on the detection frame 1 in a sliding mode; the slider 7 includes: two oppositely arranged slide pipes 8 and arc pipes 12; the sliding pipe 8 is in sliding fit with the sliding rod 5; the side surface of the periphery of the sliding pipe 8 is provided with a connecting pipe 9 in a penetrating way; a piston rod 10 is in sliding fit with the inside of the connecting pipe 9; a connecting spring 11 is arranged between the piston rod 10 and the connecting pipe 9; the two sliding pipes 8 are fixedly connected through an arc-shaped pipe 12; the slide pipe 8 is hollow and is respectively communicated with the arc pipe 12 and the connecting pipe 9; a gas transmission hose 13 is arranged between the arc-shaped pipe 12 and the pressing air bag 6; the sampling assembly 2 comprises a sampling barrel 14; a threaded pipe 15 penetrates through the sampling barrel 14; the threaded pipe 15 is in threaded rotation fit with the screw rod 4; the side surface of the circumference of the sampling barrel 14 is symmetrically provided with a positioning tube 16; the piston rod 10 is in plug fit with the positioning tube 16.

The working principle of the first embodiment is as follows:

the telescopic motion of the piston rod 10 is controlled by matching the pressing air bag 6 with the connecting spring 11, when the piston rod 10 extends out, the piston rod is inserted into the positioning tube 16, the quick assembly of the sliding part 7 and the sampling assembly 2 is realized, the sampling assembly 2 can move up and down along with the rotation of the screw rod 4, meanwhile, a piston rod 10 is tightly pressed against a normally open reset button switch 28, the annular electromagnetic suction disc 27 is powered off, and under the elastic reset acting force of the reset spring 24, the piston ring 23 is driven to be tightly pressed against the inner bottom surface of the sampling barrel 14; when the piston rod 10 retracts and resets, the piston rod is separated from the normally-open reset button switch 28 and the positioning tube 16 in sequence, so that the annular electromagnetic chuck 27 is electrified, the piston ring 23 is attracted to ascend, the reset spring 24 is extruded, and the upper-layer liquid sample is pumped into the sampling barrel 14 through the liquid conveying tube 25, thereby completing the sampling work of the sampling assembly 2.

Example two

Referring to fig. 2-5, the second embodiment is an improvement of the first embodiment, specifically, a C-shaped plate 17 is fixedly connected to the surface of the fixing plate 3 directly above the pressing airbag 6; a pressing plate 18 is in sliding fit between the inner walls of the C-shaped plates 17; an extrusion spring 19 is arranged between the pressing plate 18 and the inner top of the C-shaped plate 17; the side surface of the pressing plate 18 is fixedly connected with a poking plate 20; the top end of the screw rod 4 is provided with an annular handle 21; the bottom ends of the two slide bars 5 are provided with a stop block 22; the inner wall of the sampling barrel 14 is in sliding fit with a piston ring 23; the piston ring 23 is in sliding fit with the peripheral side surface of the threaded pipe 15; reset springs 24 are symmetrically arranged between the piston ring 23 and the inner bottom surface of the sampling barrel 14; a transfusion pipe 25 is arranged on the circumferential side surface of the sampling barrel 14 near the inner bottom surface in a penetrating way; the surface of the piston ring 23 is provided with an annular iron block 26; the annular iron block 26 is in sliding fit with the threaded pipe 15; the peripheral side surface of the threaded pipe 15 is fixedly connected with an annular electromagnetic chuck 27 at the top part in the sampling barrel 14; a normally open reset button switch 28 is arranged in the positioning tube 16; a flexible battery pack 29 for supplying power to the annular electromagnetic chuck 27 is arranged on the inner peripheral side surface of the sampling barrel 14 close to the inner top part of the sampling barrel; the normally open reset button switch 28 is electrically connected with the flexible battery pack 29; a threading groove 30 is formed in the sampling barrel 14; an elastic diaphragm 31 for waterproofing is provided inside one positioning tube 16.

The second embodiment has the working principle that:

the assembling process comprises the following steps: by moving each set of sliding parts 7 to a position close to the corresponding sampling assembly 2, in an initial state, the pressing spring 19 presses the pressing air bag 6 through the pressing plate 18 (the pressing air bag 6 is in a compressed state), the pressing plate 18 is driven to press the pressing air bag 6 to deform under the elastic acting force of the pressing spring 19, at the moment, the connecting spring 11 is stretched, air inside the pressing air bag 6 enters the connecting pipe 9 through the air conveying hose 13 and the sliding pipe 8, the piston rod 10 is pushed to be inserted into the positioning pipe 16 on the sampling barrel 14, the normally open reset button switch 28 is pushed by one set of piston rods 10, the annular electromagnetic suction cup 27 is powered off, and the piston ring 23 is pushed to be tightly abutted against the inner bottom surface of the sampling barrel 14 under the acting force of the reset spring 24; the above operations are repeated to complete the assembly of each group of sampling buckets 14 and the corresponding slide 7.

Positioning and sampling: the assembled detection frame 1 is characterized in that a stop block 22 on a sliding rod 5 extends into the bottom of a sample container to be detected, an annular handle 21 is rotated to drive a screw rod 4 to rotate, so that each group of sampling assemblies 2 and corresponding sliding parts 7 are driven to descend along the sliding rod 5, when an upper layer of sampling assembly 2 descends to the upper position of a sample, a corresponding shifting plate 20 is shifted upwards, a corresponding pressing air bag 6 resets, under the elastic resetting acting force of a connecting spring 11, a piston rod 10 is pulled out of a positioning pipe 16 to be separated from a normally open resetting button switch 28 and reset into a connecting pipe 9, the sliding part 7 slides down along the sliding rod 5, the upper layer of sampling assembly 2 can only rotate along with the rotation of the screw rod 4 and cannot perform ascending and descending movement, at the moment, an annular electromagnetic suction disc 27 is powered on, an annular iron block 26 is attracted to drive a piston ring 23 to ascend, and the upper layer of sample is pumped into a sampling barrel 14 through a liquid conveying pipe 25; and repeating the operation to realize the sampling of the upper, middle and lower layers of samples with different depths.

And (3) detection process: and respectively putting the upper, middle and lower layers of liquid food samples taken out from the liquid samples into the three groups of detection test tubes, adding consistent detection reagents, observing the specific reflection of the three groups of detection test tubes, and carrying out food detection.

EXAMPLE III

Referring to fig. 2, the third embodiment is an improvement of the first embodiment, specifically, the fixing plate 3 is provided with connecting plates 32 on the peripheral side; a toothed ring 33 is rotationally matched between the connecting plates 32; the surface of the connecting plate 32 is provided with a stirring rod 34 in a penetrating and rotating way; the stirring rods 35 are arranged on the peripheral side surfaces of the stirring rods 34; the end of the stirring rod 34 is fixedly connected with a gear 36; each gear 36 is meshed with the gear ring 33; a transverse handle rod 37 is arranged on the side surface of the connecting plate 32; the surface of the toothed ring 33 is fixedly connected with a vertical handle rod 38; the peripheral side surface of the gear ring 33 is provided with an annular limit rail 39; the surface of each connecting plate 32 is provided with an annular rotary groove; the inner wall of the annular rotary groove is provided with an annular limiting groove; the annular limit rail 39 is in running fit with the annular limit groove.

The working principle of the third embodiment is as follows:

need keep the situation of carrying out the sampling under the non-sedimentation state to sampling food, through rotating vertical handle pole 38 and then drive ring gear 33 and rotate along the annular rotary tank on each connecting plate 32, thereby drive each group's puddler 34 synchronous rotation, then drive each stirring rod 35 that corresponds of group and treat and detect liquid food sample and stir, prevent that liquid food sample from taking place to deposit the accuracy that influences the detection, carry out the sampling of the different degree of depth according to above-mentioned embodiment, carry out food detection, detect numerical value and get the average value, the accuracy of detecting has been improved.

It is to be understood that the above-described embodiments are only a few, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular is intended to include the plural unless the context clearly dictates otherwise, and it should be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of features, steps, operations, devices, components, and/or combinations thereof.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.

Claims

1. A food detection device comprises a detection frame (1) and a plurality of sampling assemblies (2) which are arranged on the detection frame (1) in a threaded rotating manner; the method is characterized in that: the detection frame (1) comprises a fixing plate (3); the bottom surface of the fixed plate (3) is provided with a screw rod (4) in a penetrating and rotating way; the bottom surface of the fixed plate (3) is positioned at two sides of the screw rod (4) and is symmetrically and fixedly connected with slide rods (5); pressing air bags (6) are arranged on the surfaces of the fixing plates (3);

the sliding part (7) is arranged on the detection frame (1) in a sliding manner, and the sliding part (7) comprises:

the sliding tubes (8) are arranged oppositely, and the sliding tubes (8) are in sliding fit with the sliding rods (5); a connecting pipe (9) penetrates through the peripheral side surface of the sliding pipe (8); a piston rod (10) is in sliding fit with the inside of the connecting pipe (9); a connecting spring (11) is arranged between the piston rod (10) and the connecting pipe (9); the two sliding pipes (8) are fixedly connected through the arc-shaped pipes (12); the sliding pipe (8) is hollow and is respectively communicated with the arc-shaped pipe (12) and the connecting pipe (9); an air hose (13) is arranged between the arc-shaped pipe (12) and the pressing air bag (6);

the sampling assembly (2) comprises a sampling bucket (14); a threaded pipe (15) penetrates through the sampling barrel (14); the threaded pipe (15) is in threaded rotation fit with the screw rod (4); the circumferential side surface of the sampling barrel (14) is symmetrically provided with positioning pipes (16); the piston rod (10) is in plug fit with the positioning tube (16).

2. The food testing apparatus of claim 1, wherein: a C-shaped plate (17) is fixedly connected to the surface of the fixing plate (3) right above the pressing air bag (6); a pressing plate (18) is in sliding fit with the inner wall of the C-shaped plate (17); an extrusion spring (19) is arranged between the pressing plate (18) and the inner top of the C-shaped plate (17); the side surface of the pressing plate (18) is fixedly connected with a shifting plate (20).

3. The food testing apparatus of claim 1, wherein: the top end of the screw rod (4) is provided with an annular handle (21); the bottom ends of the two sliding rods (5) are provided with a stop block (22).

4. The food testing apparatus of claim 1, wherein: a piston ring (23) is in sliding fit with the inner wall of the sampling barrel (14); the piston ring (23) is in sliding fit with the peripheral side face of the threaded pipe (15); reset springs (24) are symmetrically arranged between the piston ring (23) and the inner bottom surface of the sampling barrel (14); an infusion tube (25) is arranged on the circumferential side surface of the sampling barrel (14) near the inner bottom surface in a penetrating way.

5. The food detection apparatus of claim 4, wherein: an annular iron block (26) is arranged on the surface of the piston ring (23); the annular iron block (26) is in sliding fit with the threaded pipe (15); the periphery side of the threaded pipe (15) is positioned at the inner top of the sampling barrel (14) and is fixedly connected with an annular electromagnetic chuck (27).

6. The food testing apparatus of claim 5, wherein: a normally open reset button switch (28) is arranged in the positioning tube (16); a flexible battery pack (29) for supplying power to the annular electromagnetic chuck (27) is arranged on the inner peripheral side surface of the sampling barrel (14) close to the inner top part of the sampling barrel; the normally open reset button switch (28) is electrically connected with the flexible battery pack (29); a threading groove (30) is formed in the sampling barrel (14); an elastic diaphragm (31) for water prevention is arranged inside the positioning tube (16).

7. The food testing apparatus of claim 1, wherein: the peripheral side surfaces of the fixed plates (3) are provided with connecting plates (32); a toothed ring (33) is rotationally matched between the connecting plates (32); the surface of the connecting plate (32) is provided with a stirring rod (34) in a penetrating and rotating way; the circumferential side surfaces of the stirring rods (34) are provided with stirring rods (35); a gear (36) is fixedly connected to the end part of the stirring rod (34); each gear (36) is meshed with the gear ring (33).

8. The food testing device of claim 7, wherein: a transverse handle rod (37) is arranged on the side surface of the connecting plate (32); the surface of the gear ring (33) is fixedly connected with a vertical handle rod (38); the side surface of the periphery of the gear ring (33) is provided with an annular limit rail (39); the surface of each connecting plate (32) is provided with an annular rotary groove; the inner wall of the annular rotary groove is provided with an annular limiting groove; the annular limiting rail (39) is in running fit with the annular limiting groove.