Roller Shutter for Opening and Closing a Doorway

20170101818 ยท 2017-04-13

Assignee

Inventors

Cpc classification

International classification

Abstract

The invention relates to a roller shutter for opening and closing a doorway (12) having a door blade (11), the door blade (11) comprises several rigid shutter elements (13) which are hinged with each other, the shutter elements (13) are guided by side rails (18) at opposed sides of the doorway (12), wherein each shutter element (13) provides an end piece (19) at each horizontally spaced end of the shutter element (13) for spacing layers of rolled up shutter elements (13) apart from each other, each end piece (19) has at least one concave section (27) for coiling the end pieces (19) on a coiling device (14) and/or in layers on top of each other. For reducing the risk of weakening a connection between the end piece (19) and the shutter element (13), for reducing noise and/or vibrations during the opening and/or closing of the door way and/or to increase the stability of the roller shutter the roller shutter (10) is characterized in that at least some of the end pieces (19) having at least one plane gliding section (28), the plane gliding section (28) is arranged for interacting with a slide guide (36) of the side rail (18) for leading the end pieces (19) into and/or out of the side rails (18).

Claims

1. Roller shutter for opening and closing a doorway (12) having a door blade (11), the door blade (11) comprises several rigid shutter elements (13) which are hinged with each other, the shutter elements (13) are guided by side rails (18) at opposed sides of the doorway (12), wherein each shutter element (13) provides an end piece (19) at each horizontally spaced end of the shutter element (13) for spacing layers of rolled up shutter elements (13) apart from each other, each end piece (19) has at least one concave section (27) for coiling the end pieces (19) on a coiling device (14) and/or in layers on top of each other, characterized in that at least some of the end pieces (19) have at least one plane gliding section (28), the plane gliding section (28) is arranged for interacting with a slide guide (36) of the side rail (18) for leading the end pieces (19) into and/or out of the side rails (18), wherein a lifting device (21) is connected with the end pieces (19) to roll up and roll down the shutter elements (13), wherein each side rail has a slit (34) extending substantially vertically and the shutter elements (13) are guided within the slit (34).

2. Roller shutter according to claim 1, wherein the thickness of the plane gliding section (28) exceeds the thickness of the concave section (27) for avoiding any abutment of the concave section (27) with the slide guide (36), preferably the thickness of the gliding section (28) exceeds the thickness of the concave section (27) by at least 2 mm, especially preferred by at least 4 mm, particularly by at least 5 mm.

3. Roller shutter according to claim 1, wherein the gliding section (28) extends over the whole height of the end piece (19) and/or edges of the gliding section (28) are rounded, preferably the gliding section (28) is made of a low friction and/or wear-resistant material and/or plastic.

4. Roller shutter according to claim 1, wherein the gliding section (28) is arranged, preferably in the middle, between a first concave section (27) and a second concave section (27), especially preferred the gliding section (28) is integrally formed with the, preferably first and second, concave section (27).

5. Roller shutter according to claim 1, wherein the shutter elements (13) are guided within a slit (34) of the side rails (18) and the end pieces (19) are arranged inside the hollow side rails (18) for opening and closing the doorway (12), preferably a carrying strap (21) is connected with the end pieces (19) and/or the coiling device (14) to roll up and roll down the shutter elements (13).

6. Roller shutter according to claim 1, wherein the slide guide (36) is arranged in the area of an upper end of the side rail (18), preferably a first section (39) of the slide guide (36) is arranged within the hollow side rail (18) and a second section (40) of the slide guide (36) extends out of the side rail (18) towards the coiling device (14).

7. Roller shutter according to claim 1, wherein the slide guide (36) is arranged at an inner side of the side rail (18) and/or at least the upper end of the slide guide (36) has a ramp-like design, preferably the ramp-like upper end of the slide guide (36) is substantially directed and or curved towards an rotation axis (16) of the coiling device (14).

8. Roller shutter according to claim 1, wherein the slide guide (36) has a sliding face (37) for contacting the plane gliding section (28) of the end pieces (19), the sliding face (37) is directed towards an inner side of the end pieces (19) and the gliding section (28) of the end pieces (19), preferably the sliding face (37) is curved, especially preferred the radius of the curved sliding face (37) is bigger than the smallest radius of the coiling device (14) without a partly and/or fully up rolled door blade (11).

9. Roller shutter according to claim 1, wherein the slide guide (36) has a length for guiding at least two end pieces (19) and their plane gliding sections (28) at the same time, preferably the slide guide (36) has a length for guiding not more than three or four end pieces (19) and their plane gliding sections (28) at the same time.

10. Roller shutter according to claim 1, wherein the coiling device (14) comprises two pairs of spiral discs (17), whereby a pair of spiral discs (17) is arranged at each end of a rotatable shaft (16) facing away from each other, preferably a pair of spiral discs (17) is arranged for receiving the concave sections (27) of end pieces (19) rolled up on the coiling device (14), especially preferred the spiral discs (17) of each pair have a distance to each other for receiving the plane gliding section (28) of the end piece (19) between the spiral discs (17).

11. Roller shutter according to claim 1, wherein the end pieces (19) of the upper shutter elements (13) have the plane gliding section (28), preferably only or not more than the end pieces (19) of the shutter elements (13) have the plane gliding section (28) which are rolled up on the coiling device (14) to form a first layer of rolled up end pieces (19).

12. Roller shutter according to claim 1, wherein the end pieces (19) are fixed to a carrying strap (21) and only those end pieces (19) have the plane gliding section (28) whose assigned carrying strip (21) section is deflected and/or displaced out of a vertical alignment by an angle greater than zero, preferably the deflection of the carrying strip (21) section is assigned to a transition area between the upper end of the side rail (18) or slide guide (36) and the coiling device (14), especially preferred only those end pieces (19) have a gliding section (28) which are assigned to a deflection and/or a displacement of the carrying strap (21) section out of the vertical towards the coiling device (14).

13. Roller shutter according to claim 1, wherein the shutter elements (13) are formed as lamellae and/or panels which are connected with each other by a flexible joint and/or a flexible carrying strap (21) for rolling up and unrolling the door blade (11) on and off a coiling device (14), preferably the shutter elements (13) are foamed lamellae.

14. Roller shutter according to claim 1, wherein the roller shutter (10) is a high speed roller door, preferably the door blade (11) of the high speed roller door is moved in normal operation with a speed in the range of 0.5 m/s to 5 m/s, especially preferred is a speed in normal operation in the range of 1 m/s to 3 m/s, particularly a speed of 2 m/s.

Description

[0030] The following detailed description, given by way of example and not intended to limit the present invention solely thereto, will best be appreciated in conjunction with the accompanying figures, wherein like reference numerals denote like elements and parts, in which:

[0031] FIG. 1 is a schematic front view of a roller shutter according to the present invention,

[0032] FIG. 2 is a schematic perspective view of an end piece fixed to an end of a shutter element for a roller shutter according to the present invention,

[0033] FIG. 3 is a schematic cross section sectional top view of an end piece for a shutter element in a side rail of a roller shutter according to the invention,

[0034] FIG. 4 is a schematic cross sectional side view of a detail and with partially removed elements of a roller shutter according to the invention,

[0035] FIG. 5 is a further schematic cross sectional side view of a detail of a roller shutter according to the invention,

[0036] FIG. 6 is a schematic perspective view of a detail of a coiling device for a roller shutter according to the invention, and

[0037] FIG. 7 is a schematic cross sectional view of a detail of a coiling device for a roller shutter according to the invention.

[0038] The present invention will now be described more fully hereinafter with reference to the accompanying figures in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the illustrated embodiments set forth herein. Rather, these illustrated embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0039] The roller shutter will be described as a high speed roller door selectively blocking or opening a doorway. This recitation is for convenience only. It would be understood by one skilled in the art that such a roller door or rollup door is suitable for many embodiments and/or applications, including but not limited to industrial high speed rollup doors, interior doorway covering, exterior doorway covering, etc.

[0040] FIG. 1 is a schematic front view of a roller shutter 10 according to the present invention with partly removed elements. The roller shutter 10 has a door leaf or door blade 11. According to this figure the door blade 11 is shown in a fully unrolled position for closing a doorway 12. The door blade 11 comprises several shutter elements 13. For greater clarity not all shutter elements 13 provide a reference numeral. In this embodiment the shutter elements 13 are rigid and foamed lamellae 13. Thus, the lamellae 13 comprise a foamed core. The lamellae 13 are at least partly rotatable coupled to each other allowing up and unrolling of the lamellae 13 around a coiling device 14.

[0041] A drive system 15 provides a rotational force or torque to a rotatable shaft 16 of the coiling device 14 to raise or up roll the door blade 11 by rotating the coiling device 14 in a first direction and to lower or unroll the door blade 13 by rotating the coiling device 14 in a second direction opposite to the first direction.

[0042] The rotatable shaft 16 is part of a coiling device 14. According to this embodiment the coiling device 14 comprises four spiral discs 17. A pair of two spiral discs 17 is fixed to each end of the rotatable shaft 16. The rotatable shaft 16 is aligned in a horizontal direction.

[0043] The roller shutter 10 further comprises two side rails 18. The side rails 18 elongate or extends in a vertical direction and are designed to receive end pieces 19 of the lamellae 13 within the hollow side rails 18. In this figure only some end pieces 19 can be seen as a part of the right side rail 18 is removed.

[0044] The side rails 18, provided on both sides of the doorway 12, define the width of the passable doorway 12 and are configured to accept and guide the lamellae 13 within a slot or slit. Each lamella 13 provides two end pieces 19, one end piece 19 at each lamella end. The lamellae 13 elongate in a horizontal direction.

[0045] The lamellae 13 are connected pivotable with each other by a flexible carrying strap 21 connected to the end pieces 19. Between adjacent pivotable connected lamellae 13 a horizontal sealing 20 is provided avoiding the entry of moisture and/or dirt. The sealing 20 is flexible and in this embodiment the sealing 20 is made of an elastomer, preferably EPDM (Ethylene Eropylene Diene Monomer) or TPE (Thermo Plastic Elastomer). For greater clarity not all sealings 20 provide a reference numeral.

[0046] A carrying strap 21 is affixed at each side of the coiling device 14. In this embodiment the upper ends of both carrying straps 21 are fixed between the spiral discs 17 of a pair at each side of the coiling device 14 respectively. The carrying strap 21 is connected with the end pieces 19 to roll up and roll down the lamellae 13. The flexible carrying strap 21 realizes a flexible and/or hinged connection. The end pieces 19 are fixed to the carrying strap 21. One carrying strap 21 is provided on each side of the doorway 12 in conjunction with the end pieces 19 assigned to the side rails 18 at each side of the roller shutter 10. In one rotating direction of the coiling device 14 the carrying strap 21 with end pieces 19 will be hoisted and rolled up, causing the lamellae 13 to be wound up around the coiling device 14, opening the doorway 12. In second rotating direction of the coiling device 14 turned away from the first direction the carrying strap 21 with the end pieces 19 will unwind from its rolled up position, releasing the lamellae 13 to cover the doorway 12. The sections of the carrying straps 21 connected with up rolled end pieces 19 are arranged within or inside the hollow side rails 18.

[0047] Each spiral disc 17 comprises a damping profile 22 on its outer circumference leading to a reduction of noise when end pieces 19 are rolled on or rolled up the spiral discs 17. In this embodiment the damping profiles 22 are made of rubber leading to an anti-slip function which avoids movements of up rolled end pieces 19. Furthermore, the wear of a contacting face of end piece 19 is reduced.

[0048] FIG. 2 is a schematic perspective view of an end piece 19 fixed to an end of a shutter element 13 for a roller shutter 10 according to the present invention. The lamella 13 and the end piece 19 have an outer side 23 and an inner side 24. In a closed position of the door blade 11 the outer side 23 is directed outwards and the inner side 24 is directed inwards.

[0049] The end piece 19 has a substantially U-shaped recess 25. The recess 25 fits around an end of the lamella 13. The end piece 19 is connected to the lamella 13 by the recess 25 and fastening components 26, like bolts, rivets or screws. Additionally or in an alternative the end piece 19 and/or the recess may be glued to the lamella 13. At the inner side 24 the end piece 19 has according to this embodiment two concave sections 27. Upper and lower edges of the concave sections 27 protrude at the inner side 24 over the recess 25 and the lamella 13.

[0050] The end piece 19 has a plane and even gliding section 28 arranged at its inner side 24. According to this embodiment the plane gliding section 28 is arranged between the two concave sections 27. The gliding section 28 protrudes inwards and/or beyond the concave sections 27. The thickness of the gliding section 28 exceeds the thickness of the concave sections 27. Thus, the gliding section 28 is arranged as a protrusion at the inner side 24 projecting beyond all other parts of the end piece 19 and the lamella 13.

[0051] The concave sections 27 and the gliding section 28 have an elongated design, oriented perpendicular to the elongated design of the lamella 13 and in a plane parallel to the plane of the lamella 13.

[0052] Edges 29 of the gliding section 28 arranged at an upper and lower end in the longitudinal direction of the gliding section 28 are rounded. The gliding section 28 is made of a low friction, wear-resistant plastic material. In this embodiment the concave sections 27 and the gliding section 28 are made as separate elements mounted with each other. In an alternative the gliding section 28 may be integrally formed with the concave sections 27.

[0053] The end piece 19 comprises an outer convex section 30 at its outer side 23. The end piece 19 has a spacer 31. Each end piece 19 has a pair of spacer bars 32 connected with the spacer 31. The spacer bars 32 have a convex design, namely the outer faces of the spacer bars 32 form convex faces of the convex section 30. The spacer bars 32 are elongated perpendicular to the elongated design of the lamella 13 and in a plane parallel to the plane of the lamella 13. For spacing the spacer bars 32 from each other the spacer 31 is arranged between both spacer bars 32.

[0054] In an up rolled position of several end pieces 19 the convex section 30 provides convex contact faces on which subsequent end pieces 19, namely the concave sections 27, can rest.

[0055] The gliding section 28 is fixed to the carrying strap 21.

[0056] FIG. 3 is a schematic cross section sectional top view of an end piece 19 for a shutter element 13 in a side rail 18 of a roller shutter 10 according to the invention. As far as identical elements are concerned reference is made to the above mentioned description.

[0057] In this embodiment the spacer 31 is integrally formed with the spacer bars 32 in a U-shaped form. Furthermore according to this embodiment the convex face of the spacer bars 32 comprise a damping material 33 to reduce noise and/or wear when end pieces 19 are rolled onto or rolled up from each other.

[0058] The side rail 18 has a slit 34 for guiding an end of the lamella 13. The end of lamella 13 with the recess 25 of the end piece 19 extends through the slit 34 for arranging the end piece 19 substantially inside the hollow side rail 18. The outer face of the recess 25 serves as an abutment face for guiding the lamella 13 within the slit 34. To avoid noise and wear the edges of the side rail 18 forming the slit 34 comprises plastic bars 35A, 35B. Only in the area of a slide guide 36 the width of slit 34 is slightly bigger than the thickness of the lamella 13 with recess 25.

[0059] The slide guide 36 is partly arranged inside the hollow side rail 18 and connected with an inner side of the side rail 18. The slide guide 36 is positioned in the area of an upper opening of the side rail 18. A sliding face 37 of the slide guide 36 is facing and contacting the gliding section 28 of the end piece 19. By the slide guide 36 the end piece 19 contacting the slide guide 36 and the assigned lamella 13 are pushed outwards such that the outer side of the recess 25 is slightly pushed off the inner plastic bar 35A and towards the outer plastic bar 35B.

[0060] FIG. 4 is a schematic cross sectional side view of a detail and with partially removed elements of a roller shutter 10 according to the invention. As far as identical elements are concerned reference is made to the above mentioned description. The coiling device 14 is assigned to the inner side 24. Thus, the inner side 24 of the roller shutter 10 is at least partly directed or faced towards the coiling device 14. The outer side 23 of the roller shutter 10 is facing away from the inner side 24 and the coiling device 14.

[0061] This cross sectional side view shows only one spiral disc 17 of a pair of spiral discs 17. It is shown that the upper end of the carrying strap 21 is mounted to the spiral discs 17. The spiral discs 17 have a continuously increasing radius such that an outer circumference 38 of the spiral discs 17 comprises a mismatch. The smallest radius merges smoothly to the greatest radius over a rotation of approximately 360 degrees. Furthermore, the two spiral discs 17 of each pair are arranged as mirror images of each other.

[0062] According to this embodiment the greatest radius of the spiral discs 17 exceeds the smallest radius of the spiral discs 17 by a dimension at least substantially equal to the thickness of the end pieces 19.

[0063] The spacer bars 32 of adjacent end pieces 19 are overlapping each other. The spacer bars 32 of each end piece 19 extend over the concave section 27 to the concave section 27 of a preceding end piece 19 and a following end piece 19. Thus, the spacer bars 32 of two adjacent end pieces 19 overlap, thereby bridging a gap between adjacent end pieces 19 in a row connected to the carrying strap 21. In this embodiment the spacer bars 32 of each pair are inclined to each other. In an alternative embodiment the spacer bars 32 of each pair may be aligned parallel and/or shifted to each other. According to this figure an upper end piece 19 is rolled up on the spiral disc 17.

[0064] The slide guide 36 is assigned to an area of an upper end or upper opening of the side rail 18. For a better understanding parts of the side rail 18 have been removed which is indicated by the dashed line if the side rail 18. The upper opening of the side rail 18 serves as an inlet and outlet for the end pieces 19 into and out of the interior space of the hollow side rail 18. A first section 39 of the slide glide 36 is mounted inside the hollow side rail 18. A second section 40 of the slide guide 36 facing away from an end of the first section 39 extends out of the interior space of the side rail and substantially towards the coiling device 14. The slide guide 36 has a substantially vertical elongated design.

[0065] The slide face 37 of the slide guide 36 is facing the gliding section 28 of the end pieces 19. In this embodiment the slide face 37 has a plane middle section oriented vertically which is substantially arranged between the first section 39 and the second section 40 of the slide guide 36. The slide face 37 in the area of the first and second sections 39, 40 is curved away from the end pieces 19. Thus, the slide face 37 forms in the area of the first and second sections 39, 40 a ramp-like inlet or outlet for the gliding section 28 of the end pieces 19. This allows a tangential transition of the plane gliding section 28 onto the slide face 37. According to this embodiment the slide guide 36 has a length for guiding not more than three end pieces 19 at the same time.

[0066] FIG. 5 is a further schematic cross sectional side view of a detail of a roller shutter 10 according to the invention. This figure shows a partially rolled up door blade 11 with end pieces 19 establishing a first layer of end pieces 19 on the outer circumference 38 of the coiling device 14. According to this embodiment the carrying strap 21 extends in this partially up or unrolled position of the door blade 11 vertically from the coiling device 14 into the side rail 18. The doorway 12 is partly closed or opened and the shutter elements 13, guided by the slit 34 in the side rail 18, run straight or substantially vertically into or out of the side rail 18.

[0067] In case the door blade 11 would be rolled up the outer radius of the coiling device 14 with the layers of end pieces 19 would increase. Thus, the shutter elements 13 run over and/or along an outer radius 41 of an opening at an upper end of the side rail 18. The face of the outer radius 41 is substantially directed towards the coiling device 14. The outer radius 41 is assigned to the outer side 23 of the side rail 18. Furthermore, the upper end of the side rail 18 is in the area of the outer radius 41 higher than the upper end of the side rail 18 in the area of the slide guide 36. In this embodiment the upper end of the side rail 18 in the area of the outer radius 41 is higher than the upper end of the slide guide 36.

[0068] In case the door blade 11 would be unrolled the outer radius of the coiling device 14 with the layers of end pieces 19 would decrease. Thus, the gliding sections 28 would run over and/or along the slide face 37 of the slide guide 36 according to FIG. 4.

[0069] According to FIG. 5 a first layer of end pieces 19 on a pair of spiral discs 17 follows a smooth curve or radius as preset by the outer circumference 38 of the spiral discs 17. If the door blade 11 is further rolled up on the coiling device 14, each successive layer of end pieces 19 will lay smoothly on top the convex section 30, namely the outer convex surface of spacer bars 32, of the preceding layer of end pieces 19. The outer convex surface of spacer bars 32 may build an approximately continued outer spiral circumference 38 or provide a convex surface on the preceding layer of end pieces 19 and/or in continuation of the outer circumference 38 of the spiral discs 17.

[0070] The cross sections of end pieces 19 are chosen to substantially correspond to the outer circumference 38 of the spiral discs 17 and/or of the layers of up rolled end pieces 19 respectively. This allows successive layers of end pieces 19 wound onto or around the spiral discs 17 and onto preceding layers of end pieces 19 to present a smooth wound outer surface and a compact rolled up door blade 11. In this regard a geometric relationship has to be considered which combines the height of the doorway, the configuration of the spiral discs 17 and the height as well as the cross section of the end pieces 19. Each layer of rolled up end pieces 19 creates a greater diameter or radius of the coiling device 14 for successive layers to wind up onto. This may result in deviating cross sections, convex sections 30 and concave section 27 for each end piece 19 in a row as fixed to the carrying strap 21. Preferably a fully wound up door will require partial and/or full 360 degree revolutions, especially preferred one, two, three or more 360 degrees turns, of the shaft 16 depending on the height of the door blade 11 and/or doorway 12.

[0071] The upper free end of the second section 40 of the slide guide 36 is arranged between the upper end of the side rail 18 at the inner side 24 and the coiling device 14 such that the slide guide will not touch the outer layer of up rolled end pieces 19 for a fully up rolled door blade 11. At the same time the slide guide 36 extends out of the side rail 18 towards the coiling device 14 as much as possible for providing a guide for at least some of the end pieces 19 in a transition area between the upper end of the side rail 18 and the coiling device 14. A distance X between the outer circumference of the coiling device 14 and the upper end of the slide guide 36 depends on how many layers of end pieces 19 are rolled up on the coiling device 14. The distance X is greatest when no layer of end pieces 19 is rolled up the outer circumference 38 of the spiral discs 17. The distance X is smallest when the door blade 11 is fully rolled up on the coiling device 14. In the latter case the distance X should be as small as possible. Just a direct contact of the slide guide 36 with the outer circumference of the outer rolled up layer of end pieces 19 has to be avoided.

[0072] FIG. 6 is a schematic perspective view of a detail of a coiling device 14 for a roller shutter 10 according to the invention. For greater clarity only one end piece 19 with its assigned shutter element 13 is shown. The shutter element 13 is the top lamella of the door blade 11 according to FIG. 1. The end piece 19 is resting with its concave sections 27 on the outer circumference 38 of the spiral discs 17. The gliding section 28 is placed and extends between the spirals discs 17 of a pair at one end of the coiling device 14. Thus, the gliding section 28 is accommodated in a spacing within a pair of spiral discs 17.

[0073] FIG. 7 is a schematic cross sectional view of a detail of a coiling device 14 for a roller shutter 10 according to the invention. The spacer bars 32 are formed such that the total thickness of the end piece 19 exceeds the thickness of the lamella 13. The end piece 19 is arranged to the lamella 13 such that the end piece 19 protrudes the lamella 13 at its inner and its outer side. This avoids any contact of up rolled lamellae 13 with each other.

[0074] According to this embodiment the spacer bars 32 are spaced from each other for allowing a gliding section 28 of a subsequent layer of up rolled end pieces 19 (not shown) to be placed or received between the spacer bars 32 of the underlying end piece 19. Thus, the distance between two adjacent spacer bars 32 of the same end piece 19 is at least slightly greater than the width of the gliding section 28.

[0075] Although preferred embodiments of the present invention and modifications thereof have been described in detail herein, it is to be understood that this invention is not limited to these precise embodiments and variations and may be affected by one skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.

[0076] The use of expressions like: particularly, preferably or especially preferred etc. is not intended to limit the invention. Features which are not specifically or explicitly described or claimed may be additionally included in the structure or method according to the present invention without deviating from its scope.

REFERENCE NUMERALS

[0077] 10 roller shutter [0078] 11 doorblade [0079] 12 doorway [0080] 13 shutter element [0081] 14 coiling device [0082] 15 drive system [0083] 16 shaft [0084] 17 spiral disc [0085] 18 side rail [0086] 19 end piece [0087] 20 sealing [0088] 21 carrying strap [0089] 22 damping profile [0090] 23 outer side [0091] 24 inner side [0092] 25 recess [0093] 26 fastening component [0094] 27 concave section [0095] 28 gliding section [0096] 29 edge [0097] 30 convex section [0098] 31 spacer [0099] 32 spacer bar [0100] 33 dumping material [0101] 34 slit [0102] 35 plastic bar [0103] 36 slide guide [0104] 37 sliding face [0105] 38 outer circumference [0106] 39 first section [0107] 40 second section [0108] 41 outer radius