Screw cap container
10597200 ยท 2020-03-24
Assignee
Inventors
- Noriyuki Asakawa (Tokyo, JP)
- Tatsuharu Ida (Tokyo, JP)
- Takumi SUGIZAKI (Tokyo, JP)
- Shigeru Hayakawa (Tokyo, JP)
Cpc classification
B65D1/0246
PERFORMING OPERATIONS; TRANSPORTING
B65D41/0414
PERFORMING OPERATIONS; TRANSPORTING
B65D41/04
PERFORMING OPERATIONS; TRANSPORTING
B65D41/0428
PERFORMING OPERATIONS; TRANSPORTING
B65D41/0421
PERFORMING OPERATIONS; TRANSPORTING
International classification
B65D41/04
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A screw cap container including a container main body and a screw cap. The container main body includes a mouth tubular portion, which is provided with slope screw portions. The slope screw portions include: upper screw protrusions disposed at three or more different positions; lower long screw protrusions having left end positions same as left end positions of the upper screw protrusions, and each having a length longer than a length of each upper screw protrusion; and oblique screw protrusions extending obliquely from right ends of the lower long screw protrusions and each being connected to a left end of a different one of the upper screw protrusions. The screw cap includes a top wall and an outer circumferential wall. The outer circumferential wall is provided with cap screw protrusions disposed in the same number as the number of the upper screw protrusions.
Claims
1. A screw cap container comprising a container main body and a screw cap, wherein the container main body includes a mouth tubular portion, which is provided on an outer circumference thereof with slope screw portions configured to be screwed to the screw cap, the slope screw portions include: upper screw protrusions disposed at three or more different positions at an equal interval in a top view thereof; lower long screw protrusions having left end positions same as left end positions of the upper screw protrusions, being disposed a predetermined height below and in parallel with the upper screw protrusions, and each having a length longer than a length of each upper screw protrusion; and oblique screw protrusions extending obliquely relative to the lower long screw protrusions in an upper right direction from right ends of the lower long screw protrusions and each being connected to a left end of a different one of the upper screw protrusions, the screw cap includes a top wall and an outer circumferential wall suspended from an outer edge of the top wall, and the outer circumferential wall is provided on an inner circumference thereof with cap screw protrusions disposed at an equal interval and at an equal height in the same number as the number of the upper screw protrusions and thus configured to be screwed with the slope screw portions of the container main body.
2. The screw cap container according to claim 1, wherein the slope screw portions include: the upper screw protrusions disposed at four or more even number of positions; and partial gaps in which no oblique screw protrusions and no lower long screw protrusions are present, the gaps being defined between one of the upper screw protrusions and another one of the upper screw protrusions located adjacent thereto at two different positions at an interval of 180 in the top view thereof.
3. The screw cap container according to claim 1, wherein the cap screw protrusions are disposed at positions above a middle of a vertical height of the inner circumference of the outer circumferential wall, thereby permitting the screw cap to be placed deeply.
4. The screw cap container according to claim 1, wherein the screw cap includes a sealing tubular portion suspended from a back surface of the top wall, and the sealing tubular portion is provided on an inner side of a lower end thereof with an inner ring in a suspended manner, the inner ring being configured to be inserted in an inner circumference of the mouth tubular portion of the container main body and seal an inside of the container main body at the time of capping.
5. The screw cap container according to claim 4, wherein the sealing tubular portion is further provided on an outer side of the lower end thereof with a contact ring in a suspended manner, the contact ring being deformable and having a tip portion configured to tightly contact an upper surface of the mouth tubular portion of the container main body at the time of capping.
6. The screw cap container according to claim 1, wherein the slope screw portions further include engagement protrusions disposed between the upper screw protrusions and the lower long screw protrusions, and the cap screw protrusions of the screw cap are provided with engagement recesses.
7. The screw cap container according to claim 1, wherein the mouth tubular portion of the container main body is further provided on the outer circumference thereof with a neck ring, the neck ring is provided on an outer circumference thereof with an outward engagement ridge, and the outer circumferential wall of the screw cap is further provided on the inner circumference thereof with an inward engagement ridge.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) In the accompanying drawings:
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DETAILED DESCRIPTION
(18) The following describes a screw cap container of the present disclosure with reference to the drawings of preferred embodiments.
Embodiment 1
(19) In the description below, in a top view as illustrated in
(20) In
(21) As illustrated in
(22) As illustrated in
(23) As illustrated in
(24) As illustrated in
(25) In the present embodiment, the inclined wall 11 is disposed between the top wall 10 and the outer circumferential wall 12. However, the inclined wall 11 may be omitted, and the outer circumferential wall 12 may be provided in a suspended manner directly from the outer edge of the top wall 10.
(26) The outer circumferential wall 12 is provided, in an upper portion of an inner circumference thereof, with an annular protrusion 14. The outer circumferential wall 12 is also provided, in portions thereof that are located below the annular protrusion 14, with the cap screw protrusions 15a, 15b, 15c, and 15d, which each have a length in the circumferential direction of 30 to 40 (preferably approximately 34). The cap screw protrusions 15a, 15b, 15c, and 15d are disposed at an (equal) interval of 90 in the circumferential direction at four different positions that are located at a height from a lower end of the outer circumferential wall 12.
(27) In the present embodiment, the cap screw protrusions 15a etc. are disposed at the four positions. However, it is to be noted that the cap screw protrusions 15a etc. need to be disposed in the same number as the number of the disposed upper screw protrusions 4a etc.
(28) Additionally, a portion of the inner circumference of the outer circumferential wall 12 that is located below the cap screw protrusions 15a, 15b, 15c, and 15d forms an engagement surface 12a, which is configured to come into sliding contact with outer surfaces of the slope screw portions 2.
(29) The cap screw protrusions 15a, 15b, 15c, and 15d has a width , which is defined to be the interval (height) between the upper screw protrusions 4a, 4b, 4c, and 4d and the lower long screw protrusions 5a, 5b, 5c, and 5d of the slope screw portions 2 of the container main body A so that the cap screw protrusions 15a, 15b, 15c, and 15d are engaged therebetween.
(30) The cap screw protrusions 15a, 15b, 15c, and 15d have lower surfaces that extend horizontally or obliquely downward gently toward a rotational direction at the time of capping in a manner such that the lower surfaces are parallel with upper surfaces of the upper screw protrusions 4a, 4b, 4c, and 4d. The cap screw protrusions 15a, 15b, 15c, and 15d each also have an upper surface that extends obliquely further downward (with a tapering width) toward the rotational direction at the time of capping with respect to the corresponding lower surface.
(31) As illustrated in
(32) In the present embodiment, the cap B includes the sealing tubular portion 13 to seal the inside of the container main body A. However, the sealing tubular portion 13 may be omitted when a sealing member, such as a packing, is provided in the mouth tubular portion 1 of the container main body A.
(33) Next, a description is given of modes of use and advantageous effects of the present embodiment.
(34) In the container used in the present embodiment, the mouth tubular portion 1 has a relatively large diameter of 76 mm.
(35) When the screw cap B is placed from above on the mouth tubular portion 1 of the container main body A, the screw cap B is displaced downward, with the engagement surface 12a on the inner circumference of the outer circumferential wall 12 being in sliding contact with the outer circumferences of the slope screw portions 2 of the container main body A.
(36) Suppose, for example, that the screw cap B is placed, with the cap screw protrusion 15a being located at a position corresponding to an angle between 0 and 30 in the section a with respected to the container main body A. In this case, as illustrated in
(37) Consequently, the cap screw protrusions 15a, 15b, 15c, and 15d evenly abut against the upper screw protrusions 4a, 4b, 4c, and 4d, disposed at an interval of 90, of the slope screw portions 2. This permits the screw cap B to be always placed horizontally with respect to the mouth tubular portion 1 of the container main body A. Accordingly, the screw cap B is prevented from being placed obliquely with respect to the mouth tubular portion 1, and capping is proceeded with reliably.
(38) In the present embodiment, the slope screw portions 2 are disposed protrudingly in the form of the four ridges at an equal interval. However, to maintain the cap B horizontally with respect to the container main body A at the time of the beginning of capping, the slope screw portions 2 only need to be disposed protrudingly in the form of three or more ridges at an equal interval.
(39) Subsequently, suppose that the screw cap B is rotated clockwise through 30 or more from the position in which the screw cap B is placed on the container main body A. Then, the cap screw protrusions 15a, 15b, 15c, and 15d are displaced off from the upper surfaces of the upper screw protrusions 4a, 4b, 4c, and 4d. As illustrated in
(40) Suppose also that the screw cap B is rotated through 60 or more from the position in which the screw cap B is placed on the container main body A. In this case, as illustrated in
(41) Even when the length in the circumferential direction of the cap screw protrusions 15a, 15b, 15c, and 15d is little greater than the right half of each of the lower long screw protrusions 5d, 5a, 5b, and 5c, left end portions of the cap screw protrusions 15a, 15b, 15c, and 15d are displaced downward without abutting against right end portions of the upper screw protrusions 4d, 4a, 4b, and 4c during the downward displacement in accordance with the obliquity of the oblique screw protrusions 6d, 6a, 6b, and 6c. The reason is that the cap screw protrusions 15a, 15b, 15c, and 15d each have a width reduced toward the rotational direction. Thus, the rotation and the downward displacement are not interfered with.
(42) When the screw cap B is further rotated, the cap screw protrusions 15a, 15b, 15c, and 15d are guided between the upper screw protrusions 4d, 4a, 4b, and 4c and left halves of the lower long screw protrusions 5d, 5a, 5b, and 5c.
(43) Finally, as illustrated in
(44) At this time, the inner ring 16, which is provided in the sealing tubular portion 13 of the screw cap B, is inserted in the inner circumference of the mouth tubular portion 1 of the container main body A. Furthermore, the contact ring 17, which is also provided in the sealing tubular portion 13 of the screw cap B, tightly contacts the upper surface of the mouth tubular portion 1. Thus, the inside of the container main body A is surely sealed.
(45) Upon capping, the cap screw protrusions 15a, 15b, 15c, and 15d are fitted between the upper screw protrusions 4d, 4a, 4b, and 4c and the left halves of the lower long screw protrusions 5d, 5a, 5b, and 5c. Accordingly, the screw cap B is prevented from being displaced upward or downward with respect to the container main body A, thus maintaining sealing performance.
(46) Additionally, the screw cap B might be placed on the container main body A, with the cap screw protrusion 15b being located at a position corresponding to an angle of greater than 30 and less than 90 in the section a with respected to the container main body A. Even in this case, as illustrated in
(47) To open the screw cap B, the screw cap B needs to be rotated anticlockwise through approximately 30. Then, as illustrated in
(48) In the present embodiment, uncapping is achieved easily by unscrewing the screw cap B from the container main body A by rotating the screw cap B through approximately 35 from the capped state.
(49) In the present embodiment, the inner ring 16 is suspended on the inner side of the lower end of the sealing tubular portion 13 of the screw cap B, and the contact ring 17, which is formed as the deformable and thin ring, is suspended on the outer side of the lower end of the sealing tubular portion 13 of the screw cap B. However, as illustrated in
(50) The inside of the container main body A may also be sealed simply by inserting the outer circumference of the inner ring 16 in the inner circumference of the mouth tubular portion 1 of the container main body A.
Embodiment 2
(51) Next, a description is given of Embodiment 2, in which the slope screw portions of Embodiment 1 are modified.
(52) In the following, the same components as those in Embodiment 1 are denoted by the same reference numerals, and the description focuses on differences.
(53) As illustrated in
(54) In the top view, the slope screw portions 2 are configured by the upper screw protrusions 4a, 4b, 4c, and 4d, the lower long screw protrusions 5a and 5c, lower short screw protrusions 7b and 7d, and the oblique screw protrusions 6a and 6c. In the top view, the upper screw protrusions 4a, 4b, 4c, and 4d are disposed at four different positions at an interval of 90. In the front view, the upper screw protrusions 4a, 4b, 4c, and 4d extend horizontally or gently obliquely in the lower left direction and, as illustrated in
(55) Furthermore, in the outer circumference of the mouth tubular portion 1, a gap 8b is defined between the upper screw protrusion 4b, along with the lower short screw protrusion 7b, and the upper screw protrusion 4c, along with the lower long screw protrusion 5c, and a gap 8d is defined between the upper screw protrusion 4d, along with the lower short screw protrusion 7d, and the upper screw protrusion 4a, along with the lower long screw protrusion 5a. The gaps 8b and 8d each have a length in the circumferential direction of approximately 60, and no screw protrusions are present there.
(56) In the present embodiment, the upper screw protrusions 4a etc. of the slope screw portions 2 are disposed at the four positions at an equal interval. However, the upper screw protrusions 4a etc. only need to be disposed at four or more even number of positions at an equal interval. The gaps 8b and 8d only need to be defined at two positions at an interval of 180 in the top view.
(57) Next, a description is given of modes of use and advantageous effects of the present embodiment.
(58) Similarly to Embodiment 1, suppose that the screw cap B is placed from above on the mouth tubular portion 1 of the container main body A, with the lower surfaces of the cap screw protrusions 15a, 15b, 15c, and 15d abutting against the upper surfaces of the upper screw protrusions 4a, 4b, 4c, and 4d of the container main body A as illustrated in
(59) Subsequently, suppose that the screw cap B is rotated through 30 or more from the position in which the screw cap B is placed on the container main body A. Then, the cap screw protrusions 15a, 15b, 15c, and 15d are displaced off from the upper surfaces of the upper screw protrusions 4a, 4b, 4c, and 4d. As illustrated in
(60) At this time, the cap screw protrusions 15a and 15c are located in the gaps 8d and 8b. Accordingly, the screw cap B is rotated and displaced downward without any resistance.
(61) Suppose also that the screw cap B is rotated through 60 or more from the position in which the screw cap B is placed on the container main body A. In this case, as illustrated in
(62) At this time, the cap screw protrusions 15a and 15c are still located in the gaps 8d and 8b and accordingly, guided in the circumferential direction without any resistance.
(63) When the screw cap B is further rotated, the cap screw protrusion 15b is guided between the upper screw protrusion 4a and the left half of the lower long screw protrusion 5a, and the cap screw protrusion 15d is guided between the upper screw protrusion 4c and the left half of the lower long screw protrusion 5c. Furthermore, the cap screw protrusion 15a is guided between the upper screw protrusion 4d and the lower short screw protrusion 7d, and the cap screw protrusion 15c is guided between the upper screw protrusion 4b and the lower short screw protrusion 7b.
(64) Finally, as illustrated in
(65) In the present embodiment, the gaps 8b and 8d are present on a parting line, where no screw protrusions are present. This permits smooth mold opening and closing at the time of molding and also prevents, even when a burr is generated on the parting line, the problem of hooking at the time of opening and closing the cap.
(66) Furthermore, the presence of the gaps 8b and 8d helps reduce the amount of resin used in molding.
(67) Additionally, when the above problem is unlikely to occur, the slope screw portions may be formed contiguously from the lower short screw protrusions 7b and 7d.
(68) Other advantageous effects are substantially the same as those in Embodiment 1 and the modification thereof.
Embodiment 3
(69) Next, a description is given of Embodiment 3, in which the shape of the screw cap in Embodiment 1 is modified.
(70) In the following, the same components as those in Embodiment 1 are denoted by the same reference numerals, and the description focuses on differences.
(71) As illustrated in
(72) The top wall 10 is provided, in an outer edge end portion of the back surface thereof, with the contact ring 17 in a suspended manner. The contact ring 17 is formed as a deformable and thin ring having the tip portion configured to tightly contact the upper surface of the mouth tubular portion 1 of the container main body A at the time of capping. The top wall 10 is also provided, in a predetermined position on the back surface that is located on the inner side of the contact ring 17, with the inner ring 16 in a suspended manner. The inner ring 16 is configured to be inserted in the inner circumference of the mouth tubular portion 1 of the container main body A and has the outer circumference that seals the inside of the container main body A at the time of capping.
(73) The outer circumferential wall 20 is provided, in an upper end portion of an inner circumference thereof, with an annular protrusion 21. The outer circumferential wall 20 is also provided, in portions thereof that are located below the annular protrusion 21, with the cap screw protrusions 15a, 15b, 15c, and 15d. The cap screw protrusions 15a, 15b, 15c, and 15d are disposed at an interval of 90 at four different positions that are located above the middle of the outer circumferential wall 20, that is to say, at a height from a lower end of the outer circumferential wall 20.
(74) Additionally, a portion of the inner circumference of the outer circumferential wall 20 that is located below the cap screw protrusions 15a, 15b, 15c, and 15d forms an engagement surface 20a, which has the height from the lower end of the outer circumferential wall 20.
(75) Next, a description is given of modes of use and advantageous effects of the present embodiment.
(76) When the screw cap B is placed from above on the mouth tubular portion 1 of the container main body A, the screw cap C is displaced downward, with the engagement surface 20a on the inner circumference of the outer circumferential wall 20 being in sliding contact with the outer circumferences of the slope screw portions 2 of the container main body A.
(77) As illustrated in
(78) Furthermore, in the present embodiment, the screw cap C does not include the sealing tubular portion. Since the screw cap C includes the inner ring 16 and the contact ring 17, which are suspended directly from the back surface of the top wall 10, the amount of resin used in molding is reduced.
(79) Other advantageous effects are substantially the same as those in Embodiment 1 and the modification thereof.
Embodiment 4
(80) Next, a description is given of Embodiment 4, in which the slope screw portions of the container main body and the cap screw protrusions of the screw cap in Embodiment 1 are modified.
(81) In the following, the same components as those in Embodiment 1 are denoted by the same reference numerals, and the description focuses on differences.
(82) As illustrated in
(83) The slope screw portions 25 are configured by the upper screw protrusions 4a, 4b, 4c, and 4d, the lower long screw protrusions 5a, 5b, 5c, and 5d, the oblique screw protrusions 6a, 6b, 6c, and 6d, and engagement protrusions 26. In the top view, the upper screw protrusions 4a, 4b, 4c, and 4d are disposed at four different positions at an (equal) interval of 90. The engagement protrusions 26 are disposed between the left sides of the middles of the upper screw protrusions 4a, 4b, 4c, and 4d and the lower long screw protrusions 5a, 5b, 5c, and 5d in the front view thereof.
(84) As illustrated in
(85) Next, a description is given of modes of use and advantageous effects of the present embodiment.
(86) Similarly to Embodiment 1, for capping, the screw cap D is placed from above on the mouth tubular portion 1 of the container main body A, displaced downward, and rotated.
(87) In the present embodiment, at the time just before the end of capping with the screw cap D, as illustrated in
(88) At the time of the end of rotation, as illustrated in
(89) With the engagement protrusions 26 entering the engagement recesses 30, the climbing of the cap screw protrusions 15a, 15b, 15c, and 15d is resolved, and the force expanding the outer circumferential wall 12 to the outer side is cancelled. Accordingly, the outer circumferential wall 12 is returned to the original state.
(90) The outer circumferential wall 12, which is expanded at the time just before the end of capping and which returns to the original state at the time of the end of rotation, provides a click sensation to a user.
(91) To open the screw cap D, the screw cap D needs to be rotated in an uncapping direction. Then, the engagement recesses 30 of the cap screw protrusions 15a, 15b, 15c, and 15d of the screw cap D are released from the state where they are fitted with the engagement protrusions 26 of the container main body A. The cap screw protrusions 15a, 15b, 15c, and 15d abut against and climb on the engagement protrusions 26. Consequently, the outer circumferential wall 12 of the screw cap D is expanded to the outer side and deformed. As the screw cap D is rotated further, the engagement recesses 30 of the cap screw protrusions 15a, 15b, 15c, and 15d are released from the state where they abut against the engagement protrusions 26 of the container main body A, and the outer circumferential wall 12 is returned to the original state. Thus, a click sensation is provided to a user.
(92) The container of the present embodiment provides a click sensation to a user at the time of the end of capping and the beginning of uncapping. Furthermore, since the engagement protrusions 26 of the slope screw portions 25 of the container main body A are fitted into the engagement recesses 30 of the cap screw protrusions 15a, 15b, 15c, and 15d of the screw cap D at the time of capping, this provides resistance that prevents the screw cap D from being rotated spontaneously and opened due to an external impact outside the container.
(93) Other advantageous effects are substantially the same as those in Embodiment 1 and the modification thereof.
(94) Needless to say, the configurations of the cap screw protrusions of the screw cap and the engagement protrusions of the slope screw portions of the container main body according to the present embodiment may be applied to the configurations of Embodiments 2 and 3.
(95) In the present embodiment, the engagement protrusions 26 of the slope screw portions 25 are disposed in total at the four positions between the upper screw protrusions 4a, 4b, 4c, and 4d and the lower long screw protrusions 5a, 5b, 5c, and 5d. However, the engagement protrusion(s) 26 may also be disposed at one or more of the four positions.
Embodiment 5
(96) Next, a description is given of Embodiment 5, in which the neck ring of the container main body and the outer circumferential wall of the screw cap in Embodiment 1 are modified.
(97) In the following, the same components as those in Embodiment 1 are denoted by the same reference numerals, and the description focuses on differences.
(98) As illustrated in
(99) The neck ring 35 is provided around an outer circumference thereof with an outward engagement ridge 36.
(100) The screw cap E includes the outer circumferential wall 12. The outer circumferential wall 12 is provided, in a lower portion of the inner circumference thereof, with an inward engagement ridge 40, which has an upper portion configured to abut against a lower portion of the outward engagement ridge 36 of the neck ring 35 of the container main body A at the time of capping.
(101) Next, a description is given of modes of use and advantageous effects of the present embodiment.
(102) Similarly to Embodiment 1, for capping, the screw cap E is placed from above on the mouth tubular portion 1 of the container main body A, displaced downward, and rotated.
(103) In the present embodiment, when the screw cap E is displaced downward until the time just before the end of capping, a lower surface of the inner engagement ridge 40 of the screw cap E abuts against and climbs on an upper surface of the outward engagement ridge 36 of the neck ring 35 of the container main body A. Consequently, a portion of the outer circumferential wall 12 of the screw cap E is expanded to the outer side and deformed.
(104) Then, at the time of the end of capping, as illustrated in
(105) The outer circumferential wall 12, which is expanded at the time just before the end of capping and which returns to the original state due to the inward engagement ridge 40 climbing over the outward engagement ridge 36 at the time of the end of capping, provides a click sensation to a user.
(106) To open the screw cap E, the screw cap E needs to be rotated in an uncapping direction. Then, the screw cap E is displaced upward, and the inward engagement ridge 40 climbs over the outward engagement ridge 36 of the container main body A. Consequently, the outer circumferential wall 12 is expanded and subsequently returned to the original state. Thus, a click sensation is provided to a user.
(107) The container of the present embodiment provides a click sensation to a user at the time of the end of capping and the beginning of uncapping. Furthermore, since the upper surface of the inward engagement ridge 40 of the screw cap E abuts against the lower surface of the outward engagement ridge 36 of the container main body A at the time of capping, this provides resistance that prevents the screw cap E from being rotated spontaneously and opened due to an external impact outside the container.
(108) Other advantageous effects are substantially the same as those in Embodiment 1 and the modification thereof.
(109) Needless to say, the configurations of the engagement ridges of the screw cap and the container main body according to the present embodiment may be applied to the configurations of Embodiments 2 and 3.
(110) Additionally, although in the above embodiments the screw cap is rotated clockwise for capping, the screw cap may also be configured to be rotated reversely, namely, anticlockwise for capping. In this case also, the same advantageous effects are obtained. That is to say, even when the slope screw portions of the container main body and the cap screw protrusions of the screw cap are reversed right-side left, the same advantageous effects as in the above embodiments are obtained.
INDUSTRIAL APPLICABILITY
(111) The screw cap container according to the present disclosure prevents the cap from being placed obliquely with respect to the container main body at the time of capping, permits easy sealing of the container, is configured to be uncapped by unscrewing the cap easily with a little rotational angle at the time of uncapping, and provides a click sensation to a user at the time of uncapping and capping, and as such, may be widely used.
REFERENCE SIGNS LIST
(112) A Container main body B, C, D, E Screw cap a, b, c, d Section , Height Width Length in circumferential direction of upper screw protrusion Length in circumferential direction of oblique screw protrusion Length in circumferential direction of lower long screw protrusion 1 Mouth tubular portion 2, 25 Slope screw portion 3, 35 Neck ring 4a, 4b, 4c, 4d Upper screw protrusion 5a, 5b, 5c, 5d Lower long screw protrusion 6a, 6b, 6c, 6d Oblique screw protrusion 7b, 7d Lower short screw protrusion 8b, 8d Gap 10 Top wall 11 Inclined wall 12, 20 Outer circumferential wall 12a, 20a Engagement surface 13 Sealing tubular portion 14, 21 Annular protrusion 15a, 15b, 15c, 15d Cap screw protrusion 16 Inner ring 17 Contact ring 26 Engagement protrusion 30 Engagement recess 36 Outward engagement ridge 40 Inward engagement ridge