METHOD OF MANUFACTURING A PLASTIC COVERING PANEL AND THE PANEL OBTAINED

Abstract

Method for manufacturing a plastic panel having a first side (1) with a hook (11), a first assembly cavity (12) and a locking cavity (13) which is recessed and whose upper side forms a bearing surface and a protrusion (21) comprising a beak (24) in the junction plane, an inset recess (23) continuing by a bearing point (32) connecting with a groove (31), a flexible lock (3) which can retract by elastic deformation into the recess (23) during the assembly movement of the panel (100a) to be installed and extend inside the locking cavity (13).

According to the method, the first side (1) is machined (I) to its final section and with the blank of the second side (2) with a protruding tab (4) which is locally heated (II) after cooling (III) to bend it and form the lock (3).

Claims

1) Method for manufacturing a plastic covering panel comprising two pairs of parallel sides to be assembled by its pairs of sides with other panels of the same type the pairs of sides of which have matching assembly profiles, one top and one bottom, with the sides of the panels being assembled on the junction planes, with each panel; One pair of sides for the assembly, by the pivoting of the panel side into the matching side of another already laid panel and one pair of transverse sides for the assembly by the interleaving of the forms and their clipping by this movement in the corresponding transverse side of another already installed panel, A first transverse side having a junction plane at the edge of the tarp of the panel, continuing in a locking cavity opening to the top and in the form of a hook. The second transverse side matching the first side and having an upper edge in the junction plane terminating in a protrusion and separated from the panel body by the assembly cavity of a panel fitting over the hook of another panel and a protrusion housed in this cavity of the other panel, wherein we form a blank from the pair of transverse sides, giving the first side its final section and by forming on the second side, and assembly cavity opening into the bottom of the profile and a protrusion with a beak entering the junction plane and followed by an insert recess from the junction plane, the bottom of which extends in a tab and protrudes from the base of the protrusion. the area at the base of the tab is heated locally, Then when this area has softened, the tab is raised towards the recess to form the lock, and the form is stabilized by cooling it to obtain the panel whose two transverse sides have assumed their final shape.

2) Method of manufacturing a plastic covering panel according to claim 1, wherein the blank of the pair of transverse sides is formed by lathe milling the first side to its final section and by milling, forming on the second side an assembly cavity opening out into the bottom of the profile and a protrusion with a beak, followed by an inset recess from the junction plane and the bottom of which continues by a curved convex bearing point which connects to the beginning of a groove, extending by a protruding tab from the base of the protrusion.

3) Method of manufacturing a plastic covering panel according to claim 2, wherein at least one of the sides is machined by milling.

4) Method of manufacturing a plastic covering panel according to claim 1, wherein A rounded groove is formed connecting the curved bearing point and side of base of tab.

5) Method of manufacturing a plastic covering panel according to claim 1, wherein the tab is formed at an inclination angle with respect to the junction plane of the panel which is greater than 90.

6) Method of manufacturing a plastic covering panel comprising two pairs of parallel sides to be assembled with other panels of the same type the pairs of sides of which have matching assembly profiles. the panel having; one pair of sides for the assembly, by the pivoting of the panel side into the matching side of another already laid panel and one pair of transverse sides for the assembly by the interleaving of the forms and their clipping together by this pivoting movement in the corresponding transverse side of another already installed panel, The first side of this pair of sides has a hook and a first assembly cavity, opening into the top of the panel, through which the junction plane of the two sides and having a locking cavity inset from the junction plane and whose upper side forms a bearing surface, The second side of this pair of sides has a second assembly cavity opening into the bottom of the panel and receiving the first hook of the adjacent panel and an inverted hook forming a protrusion entering the first assembly cavity of the first side of this adjacent panel, The side of the protrusion has a beak the bearing surface of which is in the junction plane, to reach the top of the panel A recess inset from the junction plane continuing to the bottom by a flexible lock in the shape of an inclined tab, oriented towards the top and whose base derives from protrusion, wherein the blank of the pair of transverse sides is formed by lathe milling the first side to its final section and by lathe milling, forming on the second side, an assembly cavity opening out into the bottom of the profile and a protrusion with a beak and followed by a recess inset from the junction plane and the bottom of which connects to the beginning of a groove, extending by a protruding tab from the base of the protrusion. the area at the base of the tab is heated locally, then when this area has softened, the tab is raised towards the recess to form the lock, and the form is stabilized by cooling it to obtain the panel whose two transverse side shave assumed their final shape.

7) A plastic covering panel comprising two pairs of parallel sides to be assembled with other panels of the same type the pairs of sides of which have matching assembly profiles wherein the panel is made according to the process of claim 1:

8) Covering panel according to claim 7, wherein it includes one pair of sides for assembly, by the pivoting of the panel side into the matching side of another already laid panel and one pair of transverse sides for assembly by the interleaving of the forms and their clipping by this pivoting movement in the corresponding transverse side of another already installed panel, the first side of this pair of sides has a hook and a first assembly cavity, opening into the top of the panel, through which the junction plane of the two sides passes and having a locking cavity inset from the junction plane and whose upper side forms a bearing surface, the second side of this pair of sides has a second assembly cavity opening into the bottom of the panel and receiving the first hook of the adjacent panel and an inverted hook forming a protrusion entering the first assembly cavity of the first side of this adjacent panel, the side of the protrusion has a beak the bearing surface of which is in the junction plane, to reach the top of the panel a recess inset from the junction plane continuing to the bottom by a flexible lock in the shape of an inclined tab, oriented towards the top and whose base derives from protrusion,

9) Covering panel according to claim 8, wherein the inset recess of the junction plane has a base continuing in a curved and convex support connecting with the beginning of the groove and extending in the tab.

10) Covering panel according to claim 8, wherein it has a rounded groove connecting the curved bearing point and side of base of tab.

11) Covering panel according to claim 8, wherein the lock is formed from a strip chosen from a group comprising: A strip with local reduction of the thickness A strip with an enlarged base compared to the thickness of the strip which decreases towards its end, A strip with a reduced base compared to the thickness of the strip which increases towards its end, A strip with an increased bearing surface.

12) Covering panel according to claim 8, wherein the two transverse sides each end in a hook, preceded by a corresponding assembly cavity, The hook of the first transverse side of a panel being engaged in the cavity of the second transverse side of a preceding panel and reciprocally, the cavity of the second transverse side of the panel receiving the hook of the first transverse side of the following panel, The side forming a beak, of hook of a panel has a locking cavity of which the side forms a bearing surface for the lock of the previous panel and the side forming the nose above the assembly cavity of the previous panel is followed by a lock beneath the nose.

Description

ILLUSTRATIONS

[0060] The process according to the invention will be described in greater detail below by means of implementation examples represented in the attached illustrations in which:

[0061] FIG. 1 is a schematic section of a plastic covering material produced according to the method of the invention,

[0062] FIG. 2 is a partial sectional view of the assembly of two panels according to the invention,

[0063] FIG. 3, in its parts I-IV, represents the various manufacturing stages of a covering panel using the method of the invention,

[0064] FIG. 4 is an enlarged scale sectional view of the side of a profile with a locking tab, in its shape at the end of machining,

[0065] FIG. 5 is a sectional view of the profile according to the invention at the end of the manufacturing process,

[0066] FIG. 6, in its parts 6A, 6B, represents the assembly movement by the folding down of two panels according to the invention.

[0067] FIG. 7 in its parts 7a-7d shows the various machining shapes of the tab to obtain locks having different characteristics in particular according to the nature of the plastic materials of the panels,

[0068] FIG. 8 is a sectional view of another embodiment of the panel,

[0069] FIG. 9 shows the movement for the assembly of two panels according to the embodiment of FIG. 8.

[0070] FIG. 10 in its parts 10a-10c shows the various steps for the manufacturing of the two machined sides, one being thermoformed, of a panel according to the invention where part 10d shows the assembly of two panels at the end of the assembly movement schematized in FIG. 9.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0071] To understand the issue resolved by the methods of the invention, it is essential to describe in detail the structure of the covering panel whose two complementary sides are concerned directly by the manufacturing method.

[0072] FIG. 1 shows the section (profile) of a covering panel (100) on the floor, wall or partition, made of plastic. The top (101) of the panel comprises decoration and the bottom of 102) can be provided with an insulating layer; the decor and the insulating layer are both integrated into the panel but are not shown in the illustrations. The panel (100) is an elongated rectangular panel comprising a rectangular or square panel.

[0073] The panel (100) has a pair of parallel sides for the assembly of complementary shapes along an assembly line and a pair of parallel sides transversely turned towards the first pair of size ensuring the assembly by the interleaving of the complementary shapes by one side being clipped into the matching side of a panel, already installed in this positioning row. Clipping is obtained by the movement of the panel in the course of installation. This pair of parallel transverse slides (1, 2) has means of assembly by the shape, completed on one side by a tab (known as the lock) and on the other, by a locking cavity accommodating the tab by clicking into place, and locking the movements perpendicular to the plane of the panel, and therefore the positioning plane.

[0074] Accordingly, the two edges or transverse sides (1, 2) of the same panel have matching shapes, that is, shapes designed to be assembled with complementary shapes of a matching side on the other panel (100).

[0075] In greater detail, the first side 1 consists of relief forming a hook (11) preceded by an assembly cavity (12) (first cavity) ending toward the top by a locking cavity (13) and a nose (14) reaching the junction plane (JP).

[0076] Generally, the second side (2) has a shape matching that of the first side, also with a sort of hook forming a protrusion (21) fitted with a lock (3). More accurately, the top (101) of the panel near the second side (2) extends beyond the bottom (back of panel) (102) by an inverted hook forming a protrusion (21) beyond a second assembly cavity (22). The protrusion (21) generally has a section complementing that of the first assembly cavity (12); the hook (11) and the second assembly cavity (22) have the same complementary section.

[0077] The edge of the protrusion (21) forms the connecting surface with the nose (14) atop the locking cavity (13) of the other junction plane (JP) panel. The protrusion consists of a nose (24) in the junction plane above a recess (23) continuing towards the underside (102) by a locking tab referred to more simply as the block (3) connecting to the protrusion (21). The recess (23) has a bottom (231).

[0078] The unreferenced bearing surface of the nose (14) and the beak (24) enters the junction plane (JP). Their intersection with the top (101) can consist of a chamfer which is not shown.

[0079] FIG. 2 is a sectional view of two panels (100, 100a) built according to the procedure of the invention and connected by clips complementary sides. To simplify the description, the second panel and its parts have the same numerical references as the identical components of the first panel (100) completed by the suffix (a). The first panel (100), by convention, is the panel already installed and the other panel (100a) is installed subsequently in the chronological order of the steps to install panels in the same row of panels. The joining of the profiles of the sides (1, 2a) of the two panels (100, 100a) takes place at the point of passage of the nose (14) which ensures the elastic or crushing of the lock (3a) partly engaged in the recess (23); then, by elastic means, the lock (3a) returns to brace against the upper side (131) of the locking cavity (13), locking the panel (100a) and preventing it from lifting with respect to the panel 100 in the junction plane (JP).

[0080] An example of the embodiment of the procedure for manufacturing these panels will be described in the following. In the preliminary steps, a piece of plastic material is cut into panel blanks, generally rectangular, having two pairs of parallel sides. The first pair of sides is machined by milling. The other pair of sides, those of the transverse sides, will be produced according to the method of the invention described below in FIG. 3. Details about the shape of the transverse sides and their implementation will be described by means of FIGS. 4, 5 and 6.

[0081] According to FIG. 3, limiting the presentation of the panel (100) to the section of the second side (2) provided with a lock (3), the method for producing a panel (100) consists initially in (I) in machining by milling the blank of the panel (110) with the temporary section shown, for the second side (2) while the first side 1 machined by milling has a final section as shown in FIG. 1.

[0082] Depending on the section of the blank (110) machined by milling, the temporary shape of the second side (2) includes the protrusion (21) and the second assembly cavity (22). The face of the protrusion (21) consists of a protruding beak (24) in the junction plane (JP) followed by an inset recess (23), to a depth (in the direction of the drawing plane) at least equal to the thickness of the future lock (3) not yet put into form in this just-machined state of the profile. The recess (23) continues in a curved convex bearing (33) connecting a groove (32) with a rounded bottom (321) then a tab (4). Preferably, this tab is inclined downwards or as an extension of protrusion (21) to form the open groove (32) connected to the bottom (231) of the recess (23) by a curved and convex support (33) (see also FIG. 4). This open end formed by the tab (4) allows the bottom (321) to be milled and is a mechanical operating advantage for locking, as will be described at a later stage.

[0083] The following phase (II) consists in locally heating the blank (110) in area Z enclosed by a circle, to soften the material of this junction zone with the base (41) of the tab (4). Local heating can be obtained by various means to limit it to the area needed for shaping, for instance, by infrared radiation heating, contact heating with a heating plate, heating by a hot air jet, or by a laser beam. The temperature rise is that produced by the softening of the plastic (vitreous transitional temperature).

[0084] During this phase (II), heating is limited locally to the junction area (Z) by the ratio of the masses of material between the base mass (41) of the tab (4) and that of the protrusion (21). Local heating does not destabilize the shape of the protrusion (21) or that of the convex bearing (32) or that of the recess contour (23) or that of the tab beyond its base (41).

[0085] As soon as the base (41) is heated to the temperature at which softening begins, depending on the composition of the material in this area, the tab (4) is lifted mechanically in the direction of the arrow (A) to obtain the permanent deformation of its base (41), to incline the tab (4) upwards, that is towards the top (101) and form an elastic lock (3) while leaving the free end (34) to protrude from the junction plane (JP).

[0086] This lifting by the pivoting of the tab (4) about its base (41) and beyond base (32) of groove (32) can be carried out by various mechanical means, not detailed, such as: [0087] a blade pressing against the underside of the tab (4) causing it to pivot into the required position, [0088] a wheel gradually raising the tab (4) in the direction perpendicular to the plane of the section shown in figure (3). [0089] The passage of the profile (200) on a ramp or a wheel, fixed, to gradually swivel the tab (4) from its position in the phase II to that recorded in phase III which is the state of the tab then forming the lock (3).

[0090] Post-forming is followed by the cooling (III) of the junction zone (Z) to stabilize this form of the base (31) of the lock (3).

[0091] After this stabilization, we obtain the post-formed side whose section is that of FIG. 5 with the base (41) of post-formed tab (4) having become the lock (3) held by its base (31).

[0092] FIGS. 4 and 5 illustrated, at an enlarged scale, the shape of the section of the second side of the rough for panel (110) after machining and panel side after the stabilization of its post-forming.

[0093] The section of FIG. 4 shows the side machined by milling, indicating the convex bearing (33) at the end of bottom (231) of recess (23) and the Vee-section of the groove (32) separating the convex bearing (33) and the adjacent side (322) of groove (32) at base (41) of tab (4) and the rounded contour (321) of groove (32). In this example of its embodiment, the tab (4) forms with the junction plane (JP), an angle (b) of more than 900 advantageous both for machining by milling and in favoring the elastic return effect of the future base (31) of lock (3).

[0094] The net separation of the facing surfaces after machining, that of the convex bearing (33) and that of the base side of the tab (4), which becomes side (322) of the groove (32), appears clearly in FIG. 5.

[0095] FIG. 5 shows groove (32) and its rounded bottom (321) separately from the domed bearing point (33) so that the elastic deformation of the lock (3) to allow the block to be clipped, causes the lock (3) to bend in an elastic manner, while applying it locally against this bearing point (33).

[0096] This movement benefits from the elasticity to allow the lock to be clipped into cavity (13) and come to bear against its upper side (131) by the bearing face (341) of its end (34).

[0097] This elastic deformation movement of lock (3) does not fatigue the bottom (321) of groove (32) and has it benefit from a lever arm effect between the contact with bearing point (33) and bottom (321). Neither does the locked position cause any incipient cracking because the lock (3), bearing against side (131) of the other panel and affected by alternating thrusting/compression actions when laid panel 100 is walked on, does not risk any fatigue and breakage at its base (31).

[0098] This geometry of base (31) is an important characteristic regarding the function of the lock (3).

[0099] FIGS. 6A, 6B show the clipping movement of the lock (3) by the folding down of panel (100a) with respect to an already laid panel (100) indicative of the accuracy required of the stable shapes of the panel sides produced according to the method of the invention.

[0100] It can be assumed that the panels (100a, 100) are assembled by pivoting about their parallel side(s) (in the XX direction) as depicted in FIGS. 6A, 6B with known pivoting/engaging movements. For this assembly operation, a row of panels is already assembled in the XX direction (assembly-line) and the next row is started with panel (100) already positioned and assembled onto the panels of the previous line.

[0101] The installation of the new panel 100a consists in engaging its side (orientation of the XX direction parallel to the plane of the drawing sheet) on the assembly edge of the panels of the previous row (first row) then folding it down by pivoting, in doing so, engaging not only the sides already connected to the corresponding side of the panel or panels of the row of panels already installed (first row), but also engaging its side (2a) in the first side (1) of panel (100) already laid in the second row. This method of engagement by pivoting is shown in FIGS. 6A, 6B by the arrow B.

[0102] FIG. 6A shows the beginning of the pivoting movement when the lock (3a) on the side (2a) gradually comes up against the nose (14) of the first side (1) of the laid panel (100), by elastically retracting into the recess (23).

[0103] During the pivoting, the complementary shapes gradually engage, starting near the tilting axis (XX direction, behind the drawing sheet) and moving forwards so that, as soon as the pivoting movement begins, one part of the second cavity (22a) of panel (100a) is sufficiently held by the engaging of the hook (11) of panel (100) already laid in this second row, to prevent any sliding of the panel (100a) in the direction (XX). The lock (3a) is therefore obliged to curve gradually by flexing elastically against the curved bearing point (33a), recessed from the junction plane (JP) to move over the face of the beak (14) then leave the end (34a) of the lock (3a) to extend elastically into the locking cavity (13) until reaching the final locking position shown in the FIG. 6B. The lock (3a) is then braced against the upper side (131) locking cavity (13) of panel (100) by its bearing face (341a). The lock (3) then bears elastically against the curved bearing point (33a), guaranteeing attachment, even in the event of movements to insert the covering strip (100) with respect to the covering strip (100a) under the effect of the weight of a person standing on the covering strip (100) and not on the covering strip (100a).

[0104] In this position, the angle (al) of the lock (3a) is greater than the angle (a) before engagement, creating this thrust holding the lock (3a) against the locking support.

[0105] To summarize, the procedure of forming the assembly sides of the panel produces a panel having particular characteristics in terms of its shape for fast and accurate assembly of the panels.

[0106] FIG. 7 shows in its parts (7a-7d) various shapes of strips (4a, -4d) used to obtain a lock (3) which itself is not shown. The locks (3) not shown have different mechanical properties depending on the particular characteristics of the material used for the covering strip (100). This description uses the same numerical references as above with different alphabetical suffixes to designate components that are mostly identical to those already described.

[0107] All the figures are limited to representing the end of the second transverse side (2a, -d) in its machined form but not yet final, as it will be after localized thermoforming, consisting in raising the tab (4a-4d) and fixing this form by cooling it.

[0108] According to FIG. 7a, the machined blank (110a) consists of the protrusion (21a) and the second assembly cavity (22a) and are simply sketched.

[0109] The face of the protrusion (21a) consists of a protruding beak (24a) entering the junction plane (JP) then the inset recess (23a) the bottom (231a) of which continues in a curved, convex bearing point (33a) connecting with a groove (32a) with a rounded bottom and a tab (4a) forming an extension to the protrusion (21a).

[0110] On the two sides, beyond the base (41a), the (4a) is thinner (412a) to increase the flexibility of the future lock. This alternative is advantageous for blades made of very rigid materials.

[0111] FIG. 7b shows another alternative of a machined blank (110b) the representation of which is confined to a single protrusion (21b). It is limited to a single inverted hook (21b) consisting of the protrusion of the beak (24b) leading to the junction plane (JP) and continuing by the inset recess (23b) of the junction plane and by a curved, convex bearing point (33b) as far as groove (32b) at base (41b) of tab (4b). The base (41b) of tab (4b) is enlarged with respect to the remainder of the tab (4b) which decreases up to the tip.

[0112] This shape of the tab (4b) which will act as a lock is advantageous for planks made of low density or flexible materials.

[0113] FIG. 7c shows another alternative of a machined blank (110c) the representation of which is confined to the hook (21c) alone. This hook is limited to a single protrusion (24c) leading to the junction plane (JP) and continuing by the inset recess (23c) of the junction plane (JP) and by a curved, convex bearing point (33c) as far as groove (32c) at base (41c) of tab (4c). The base (41b) is reduced with respect to the remainder of the tab (4c) which increases up to the tip.

[0114] This shape of the tab (4c) which will act as a lock is advantageous for covering strips made of very rigid materials that are difficult to bend.

[0115] FIG. 4d shows another alternative of the machined blank (110d) the representation of which is limited to the inverted hook (21d) which consists of the protrusion (24d) leading to the junction plane (JP) and continuing by the inset recess (23d) in the junction plane.

[0116] The flat bottom (231d) reaches the groove (32d) at the base (41d) of the tab (4d).

[0117] The base (41d) has a bearing surface (42d) to increase resistance to vertical forces applied to the lock, made by the local thermoforming of the tab (4d).

[0118] FIGS. 8, 9, 10 show another embodiment of the panel (200) according to the invention, maintaining the basic structure of the transverse sides (1, 2) but reversing the locking system with the lock formed on the transverse side (a) and its housing, forming a sort of latch, made on the transverse side (2).

[0119] Accordingly, to designate the inverted male (M)/female (F) components of the sides, the references (1, 2) will be completed by the suffixes (M) and (F).

[0120] The side (1) which was previously a female side in the previous embodiment has a lock (3M) and a recess (23M) while the transverse side (2) which was the male side, has a locking cavity (13F) and its bearing side (131F).

[0121] It will be noted that the lock (3M) is obtained from a tab (4) which is the type of tab (4d) (FIG. 7d) designed to provide a strong seat. It consists of the nose (14M) (FIG. 8) which remains in the junction plane (JP) of this end (1M) and which is not rounded at the base, shaped as in the part (31a) of FIG. 6A because the nose (14m) extends as far as the top (201) of the panel (200). The bottom of the panel (200) bears reference (202).

[0122] The other parts are identical to those of the sides (1, 2) of the previous embodiments and have the same numerical references, completed simply by the suffix (M) or the suffix (F).

[0123] Accordingly, the side (1M) has a hook (11M) and a locking cavity (12M) whereas the side (2F) has an inverted hook (21F) and an assembly cavity (22F).

[0124] FIG. 9 is a schematic view of the clipping together of two panels by their transverse sides (smaller sides).

[0125] The panel (200-1) is the installed panel whose side (1M) receives the side (2F) of panel (200-2) which descends in the direction suggested by the arrow (FD).

[0126] The results of the clipping action are shown in FIG. 10d.

[0127] FIGS. 10a-10d illustrate the main phases for the production and assembly of the transverse sides (2F, 1M) of panel (200).

[0128] The transverse side (2F) is obtained by the machining of beak (24F) forming the junction plane (JP) and the locking cavity (13F) with its bearing side (131F) for the lock (3M). Then, there is the guiding surface (211F) of the inverted hook (21F).

[0129] Machining is carried out in addition to the machining of the cavity (22F) and the other sides of hook (21F).

[0130] The first transverse side (1M) is machined according to the profile shown in FIG. 10b. This shape is accessible to continuous/continuous feed machining tools, such as milling tools. Accordingly, tab (4M) is machined leaving an area (16M) above the one corresponding to the nose (14) of the embodiment shown on FIG. 1. Then by local thermoforming applied to the base of the tab (4M) the tab, whose base has softened, is folded down (231M) towards the recess (23M) and this folded state is fixed by cooling the thermoforming area. The lock (3M) is obtained in this way.

[0131] FIG. 10d shows the assembled/clicked in state of the two transverse sides (1M/2F).

LIST OF MAIN COMPONENTS

[0132] 100,200 Panels [0133] 110,210 Blank panel [0134] 100a Other panel [0135] 101,201 Top of panel [0136] 102,202 Bottom of panel/Back of panel [0137] 1, 1M First transverse side [0138] 11, 11M Hook [0139] 12, 12M Assembly cavity/first cavity [0140] 13, 13F Locking cavity [0141] 131F Top side [0142] 14 Nose [0143] 2, 2F Second transverse side [0144] 21, 21a-d, 21F Inverted/protruding hook [0145] 211F Guide surface [0146] 22, 22F Assembly cavity/second cavity [0147] 23, 23M Recess [0148] 231, 231M, 231a-d Bottom of recess [0149] 24, 24F Nose [0150] 3, 3M Lock [0151] 31 Shaping bar [0152] 32, 32a-d Groove [0153] 321 Rounded bottom of groove [0154] 322 Side of lock [0155] 33 Convex curved bearing [0156] 34 Free end [0157] 341 Bearing face [0158] 4, 4a-d, 4M Tab [0159] 41, 41a-d Base of tab [0160] 411 Side of tab [0161] 42d Seat [0162] JP Junction plane [0163] FD Clipping direction