Protecting and Sealing Cap

This invention relates to a self-contained protecting and sealing cap for covering the open end of a tubular body and particularly, to a protecting and sealing cap for making secure the lock receiving end of security hardware, and for also preventing access to the key receiving end of a lock unless a portion of the cap is broken or destroyed in a manner which will prevent reuse thereof.

Although the cap of the invention has other uses, such as for protecting and sealing other tubular and non-tubular bodies of devices, access to the interior of which is to be indicated, the cap of the invention will be described in connection with the protection and sealing of a ferrule at its open end for preventing unauthorized access to equipment which is secured by a lock, but it is to be understood that the cap of the invention can be used for protecting and sealing a ferrule with opposed openings in its wall and associated with other devices.

Locks are commonly used to prevent unauthorized access to various types of equipment. In particular, utility companies use such locks in large numbers to prevent unauthorized access to current transformer cabinets, meter enclosures, solid state metering devices, gas cocks, etc. See, for example, U.S. Pat. Nos. 4,313,319 and 4,024,740.

The lock itself may be of any desired type and the key receiving end may have a ferrule with holes or slots in the portion thereof which extends outwardly from the key receiving end, as illustrated in said Patents, or may be provided with such a ferrule as a separate component for use with security hardware. See, for example, U.S. Pat. Nos. 4,391,110 and 4,519,225. Normally, the wire of a wire seal is threaded through said holes after the lock is installed, and the free ends of the wire are sealed together by a lead disk so that access to the lock cannot be had without breaking the wire or the seal. Such sealing of the access end of the lock is not entirely satisfactory not only because unauthorized persons are quite ingenius in duplicating the seal or concealing the break in the seal, and thereby use the same seal, but also because the locks are often installed where they are subject to contamination by dirt, moisture, insect nesting, etc. In addition, the wire seal leaves large openings in the ferrule which permit insects and contaminants to enter the key receiving opening of the lock. The protecting and lockable sealing cap of the invention overcomes the disadvantages of the prior art wire seals and may be used with the already installed, prior art lock ferrules or with such a ferrule which may be added to lock installations which do not have such a ferrule therewith.

One object of the invention is to provide a self-contained, lockable sealing cap for the open end of a tubular member which both prevents access to the interior of the tubular member unless a portion of the cap is ruptured and prevents the ingress of contaminants into the interior of the tubular member.

A second object of the invention is to provide a self-contained, lockable sealing cap for securing the entrance of a ferrule for use with locks or other type fasteners.

A third object of the invention is to provide a self-contained, lockable sealing cap that requires no tools or instruments for its installation or more importantly for its removal.

Another object of the invention is to provide a cap which is lockable and to which there is no access for unlocking it without destroying the cap and thereby making it non-reusable.

Other objects and advantages of the present invention will be apparent from the following detailed description of the presently preferred embodiments thereof, which description should be considered in conjunction with the accompanying drawings in which:

FIG. 1 is a side elevation view partly broken away, of one manner of mounting a ferrule with a housing extending over the key receiving end of a lock;

FIG. 2 is a side elevation view of an alternative embodiment for the mounting of a ferrule with a housing extending over the key receiving end of a lock;

FIG. 3 is an exploded, perspective view, partly in cross-section, of an embodiment of the security cap of the invention with the ferrule's housing omitted;

FIGS. 4 and 5 are respectively, side elevation and end views, partly in cross-section, of the security cap and ferrule shown in FIG. 3;

FIG. 6 is an axial cross-section of a cap of the invention;

FIG. 7 is an exploded, perspective view of a modified form of the cap of the invention;

FIG. 8 is an axial cross-section of the embodiment o cap shown in FIG. 7;

FIG. 9 is an axial cross-section of a modification of the embodiment illustrated in FIG. 8;

FIG. 10 is an axial cross-section of a modified embodiment of the invention;

FIG. 11 is a perspective view of the retainers employed in the embodiment illustrated in FIG. 9;

FIG. 12 is an axial cross-section of a modified embodiment of the invention;

FIG. 13 is a perspective view of the retainer employed in the embodiment illustrated in FIG. 12;

FIG. 14 is an axial cross-section of a further modified embodiment of the invention;

FIG. 15 is a side-elevation view of the retainer and clip shown in FIG. 14 connected together by a flexible cord;

FIG. 16 is an axial cross-section of a further modified embodiment of the invention;

FIG. 17 is a side-elevation view of the retainer and clip shown in FIG. 16 connected together by a flexible cord;

FIGS. 18-22 are axial cross-sections of further modified embodiments of the invention;

FIG. 23 is a fragmentary cross-section of a modification of the embodiment illustrated in FIG. 12;

FIG. 24 is an axial cross-section of a modification of the embodiment shown in FIGS. 3-5;

FIG. 25 is an axial cross-section of a modified embodiment of the sealing cap of the invention covering an end of a ferrule;

FIG. 26 is an end view of the sealing cap shown in FIG. 25;

FIG. 27 is an enlarged perspective view of the retainer shown in FIG. 25; and

FIGS. 28 and 29 are fragmentary views of modified forms of the retainer shown FIG. 27.

If the lock to be protected already has a ferrule around the key receiving end, as illustrated in said U.S. Pat Nos. 4,024,740 and 4,313,319, the protecting and sealing cap of the invention may be applied to such ferrule in the manner hereinafter described. However, if the lock does not have such a ferrule therewith, a ferrule may be provided at the key receiving end of the lock as illustrated in FIGS. 1 and 2. Although the invention will be described in connection with the use of a ferrule with a "barrel" type lock, it will be apparent that the invention is applicable for the protection and sealing of other types of locks, such a cylinder type which are used in doorways, gates, etc.

FIG. 1 illustrates a barrel type lock with as body 1 having a head 2 which fits within a ferrule 3 having a press fit or permanent fit within a housing 4. A reduced size end portion 5 of the housing 4 passes through an opening in a panel 6 of the equipment to be protected, and the housing 4 is retained on the panel 6 by a hair-pin type retainer clip 7 which fits into a groove 8 on the housing 4. Of course, other known types of retainers may be substituted for the retainer clip 7.

The ferrule 3 has a pair of opposed slots 9 and 10 in the wall thereof (FIGS. 1 and 3) and a pair of opposed holes 11 and 12 disposed 90 degrees from the centers of the slots 9 and 10. With the cap of the invention, the holes 11 and 12 in the ferrule 3 may be omitted.

FIG. 2 illustrates a modified form of the ferrule and housing which may be installed in a panel 6. The housing 4a is integral with a ferrule portion 3a and has a threaded portion 13 which fits through an opening in the panel 6. The housing 4a is retained on the panel 6 by a nut 14 having peripheral teeth 15 which "bite" into the panel 6 when the nut 14 is tightened so as to resist loosening of the nut 14.

In the description given hereinafter, the ferrule 3 or 3a will be shown without a housing 4 or 4a because, as pointed out hereinbefore, the sealing cap of the invention is applicable to a ferrule protruding in front of and over a lock head 2, or other security device or fastener, whether the ferrule is separably mounted as illustrated in FIGS. 1 and 2, is secured to the lock itself or is otherwise mounted and captured by the lock head 2.

The ferrule 3 illustrated in FIG. 3 and in later figures is intended to represent the ferrule 3 of FIG. 1, the ferrule portion 3a of FIG. 2 or any ferrule associated with the key receiving end of a lock or a pipe end or other tubular or non-tubular device which has slots or other openings to secure the lockable sealing cap.

In the embodiment illustrated in FIGS. 3-5, the protecting and sealing cap 16 of the invention comprises a cup-shaped portion 17 with an integral stem or prong 18 disposed centrally of the inside of the portion 17. The portion 17 has a circular, tubular wall 19 and a frangible end wall 20. For corrosion prevention and ease of manufacture, the cup 16 preferably is made of a plastic material which will rupture with bending of the wall 20 when the latter is pushed or pulled for removal.

The stem 18 has a cylindrical portion 21 with an end slot 22 which permits the portions at the opposite sides of the slot 22 to move toward each other when the head portion 25 of the stem 18 is inserted through an opening 23 in a retainer 24 as described hereinafter. The head portion 25 has a lip 26 and is sufficiently compressible and elastic to permit it to pass through the opening 23 and thereafter, to return to its normal size.

Although the inner diameter of the wall 19 of the cap 16 may be only large enough to permit the cap 16 to fit over the ferrule 3, the exterior diameters of ferrules are of various sizes, and therefore, it is desirable to make the inner diameter of the wall 19 large enough to permit the cap 16 to fit over ferrules of several sizes. In the embodiments illustrated in FIGS. 3-12, it will be assumed that the cap 16 fits over a ferrule 3 of a smaller exterior diameter so that after the cap 16 is placed over a ferrule 3, as illustrated in FIG. 4, there is a space 27 of small radial dimension between the inner surface of the wall 19 and the outer surface of the ferrule 3.

To install the cap 16 on a ferrule 3, the retainer 24 is inserted in the slots 9 and 10 so that the opening 23 is concentric with the axis of the ferrule 3. In this position of the retainer 24, the opposite ends thereof are a distance apart which is smaller than the inner diameter of the cap 16 and greater than the outer diameter of the ferrule 3. The cap 16 is then placed over the end of the ferrule 3 with insertion of the head portion 25 through the opening 23. The length of the stem 18 is selected so that the head portion 25 passes through the opening 23 of the retainer 24 and the lip 26 is engageable with the side of the retainer 24 remote from the end wall 20 before the end wall 20 engages the end of the ferrule 3 as illustrated in FIG. 4. As the head portion 25 passes through the opening 23, the head portion 25 is compressed, and after the head portion passes through the opening 23, it "snaps" back to its uncompressed size.

After the cap 16 is installed, the caps tubular wall 19 covers the retainer 24 and the slot openings 9 and 10 and it can be rotated about the ferrule's axis. The protecting and sealing cap's locking mechanism is thereby concealed and unobvious after installation of the cap 16.

Once the cap 16 is installed, it is rotatable and locked in place, but as described, it cannot be removed without breaking either the retainer 24 or some portion of the cap 16. Preferably, the strength of the retainer 24 is selected so that the retainer 24 will not break before a portion of the cap 16 breaks. Thus, if someone attempts to remove the cap 16 by pulling or prying it, a portion of the cap 16 will fracture. Preferably, the strength and dimensions of the end wall 20 are selected so that it will break first when an attempt to pull or pry the cap 16 off the ferrule 3 is made or when the end wall 20 is pushed toward the lock body 1 with a force in excess of the force required to install the cap 16 initially. Thus, when an attempt is made to remove the cap 16, the cap will be damaged beyond repair and will be rendered non-reusable.

If it is desired to have the stem 18 separate from the end wall 20 when an attempt is made to remove the cap 16 from the ferrule 3, the stem may be tapered, as illustrated in FIG. 6, so as to weaken it where it joins the end wall 20a and/or at the slot 22. The cap 16a shown in FIG. 6 is like the cap 16 shown in FIGS. 3-5 except for the tapered stem 18a.

The connection of the stem to the cap may be further weakened as illustrated in FIGS. 7 and 8. In FIGS. 7 and 8 the cap 16b has a pair of slots 28 and 29 in its end wall 20b and the stem or prong 18b is connected to the cap 16b by relatively thin arcuate sections 30 and 31. Preferably, the slots 28 and 29 and the space between the arcuate sections 30 and 31 and the outer surface of the end wall 20b are filled by a clip 32 having teeth 33 and 34 on resilient fingers 35 and 36 which engage an enlarged portion 37 at the base of the stem 18b so as to prevent removal of the clip 32. Preferably, the clip 32 is made of a material stronger than the material of the cap 16b, e.g. of a stronger plastic material or of metal, so that the clip 32 will not be destroyed when a part of the cap 16b, e.g., the arcuate sections 30 and 31 are fractured. The clip 32 may have a color different from the color of the cap 16b for identification purposes and/or may have identification marks, e.g. numbers or letters, on its end face 38 or elsewhere thereon.

Instead of enlarging the base portion of the stem for the purpose of securing the clip, the stem may have the configuration shown in FIG. 9, and the teeth on the clip may extend outwardly, rather than inwardly, so as to engage the inner surface of the end wall of the cap. As illustrated in FIG. 9, the stem 18c has a cylindrical portion 39 which is secured to the cap 16c by arcuate sections, not visible in FIG. 9 but like the sections 30 and 31 shown in FIG. 7, and the clip 32a has outwardly extending teeth 40 and 41 which engage the inner surface of the end wall 20c.

In the embodiments described, the retainer 24 is inserted in the slots 9 and 10 and the cap 16, 16a, 16b or 16c is applied to the ferrule 3. After application of the cap to the ferrule, the cap is rotatable and locked in place. There are no external wires to cut, or manipulate. If desired, the cap and retainer may be constructed as illustrated in FIGS. 10 and 11 so that the retainer may be inserted after the cap is applied to the ferrule and so that the cap is not rotatable after application to the ferrule.

FIGS. 10 and 11 illustrate a cap 16d which is the same as the cap 16 (FIGS. 3-5) except for the inclusion of a pair of slots in the wall 19a thereof for receiving a retainer 42 having two parts 43 and 44. The parts 43 and 44 have slots 45 and 46 for receiving the cylindrical portion 21 of the stem 18 and are provided with interlocking teeth 47 and 48.

To install the cap 16d, it is applied over the ferrule 3 with its slots aligned with the slots 9 and 10 in the ferrule 3. The retainer parts 43 and 44 are then inserted through the slots in the cap 16d and in the ferrule 3, with the teeth 47 facing the teeth 48. When inserted and disposed as shown in FIG. 10, the parts 43 and 44 cannot be removed because of the interengagement of the teeth 47 and 48, and the cap 16d cannot be removed without fracturing a part. The cap 16d also cannot be rotated because of the presence of the parts 43 and 44 in the slots in the wall 19a.

Although FIGS. 10 and 11 illustrate relatively long retainer parts 43 and 44 and relatively long slots 45 and 46 and show such parts 43 and 44 extending outwardly of the wall 19a, the parts 43 and 44 may be shorter and of a length such that their outer ends 49 and 50 are substantially flush with the outer surface of the wall 19a so as to make it difficult to grasp the parts 43 and 44 after they have been installed. Also, the length of the slots 45 and 46 may be selected so that when the parts 43 and 44 are fully inserted, parts 43 and 44 abut the portion 21 of the stem 18 at the ends of the slots 45 and 46.

A further embodiment of the invention is illustrated in FIGS. 12 and 13. The cap 16e illustrated in FIG. 12 is essentially the same as the cap 16b (FIGS. 7 and 8) except for the addition of a slot 51 and a groove 52 in the wall 19b to receive a further embodiment of a retainer 53. The retainer 53 has teeth 54 on opposite sides thereof and a pair of teeth 55 and 56 at the ends of a pair of resilient fingers 57 and 58 separated by a slot 59.

The spacing between outer surfaces of the fingers 57 and 58 is substantially equal to the length of the slot 51, and the lengths of the slots 9 and 10 in the ferrule 3 so that the fingers 57 and 58 move toward each other as the teeth 55 and 56 move through the slots. However, when the retainer 53 is fully in place, the fingers 57 and 58 resume their normal positions, and the teeth 55 and 56 engage the outer surface of the ferrule 3. At the same time, the portion of the retainer at the end of the slot 59 engages the cylindrical portion of the stem 18b, and the lower end of the retainer 53 is in the groove 52 of the cap 16e.

Although the teeth 55 and 56 may provide sufficient resistance to the removal of the retainer 53, the resistance to removal may be increased by the use of the saw-tooth shaped teeth or barbs 54 which, when the retainer 53 is in place, are engageable with the inner surface of the ferrule 3 and also resist removal of the retainer 53. It is not necessary that teeth 54 be provided at both sides of the retainer 53, and therefore, teeth 54 at one side of the retainer 53 may be omitted. Furthermore, as described hereinafter, the teeth or barbs 54 may be formed in a different manner.

The cap 16e and the retainer 53 may be installed on the ferrule 3 in the manner described in connection with the embodiment described in connection with FIGS. 10 and 11. It will be apparent that in both embodiments, removal ofthe cap, 16d or 16e, is resisted not only by the engagement of the stem, 18 or 18b, engaging the retainer, 42 or 53, but also by entry of the retainers into the slots and groove of the cap. Similarly, as with the embodiments described in connection with FIGS. 3-9, a part, such as a part of the cap, must be fractured and destroyed in order to remove the cap from the ferrule 3.

A slightly modified form of the embodiment illustrated in FIGS. 12 and 13 is shown in FIG. 23. The embodiment shown in FIG. 23 differs from the embodiment shown in FIGS. 12-13 in that the groove 52 is replaced by a slot 60 in the wall 19cof the cap 16f and the retainer 53a is made longer so as to extend through the slot 60.

FIG. 14 illustrates a further modification of the embodiment shown in FIGS. 12 and 13. FIG. 14 shows a larger diameter ferrule 3 which has a sliding fit with the cap 16e, a thinner end wall 20d and a domed clip 32b which extends outwardly of the outer surface of the end wall 20d. Although clips 32 and 32a have been illustrated with their outer surfaces flush with the outer surface of the cap end wall, such clips 32 and 32a may also protrude from the outer surface of the cap end wall.

For ease of manufacture and to eliminate the need for, and loss of, individual retainers and clips, the retainers and clips may be secured together by a flexible cord which may be made of the same plastic material as the retainer and clip. FIG. 15 illustrates a clip 32 secured to a retainer 53 by a flexible umbilical cord 61. The umbilical cord 61 may be circular, noncircular, rectangular or polygonal in cross-section. The cord 61 may be provided with a plurality of perforations or indentations extending transversely to the length thereof and/or a plurality of indentations or grooves extending longitudinally of the cord 61 to provide a pattern which will aid in recognition of a cutting and reconstruction of the cord 61. It will be apparent that in the various embodiments employing a clip and a retainer which extends to an exterior surface of a cap, the clip and the retainer may be similarly secured together.

FIG. 16 illustrates an embodiment of the invention which is similar to the embodiments illustrated in FIGS. 12-14 and 23. In the embodiment shown in FIG. 16, the retainer 53b has a pair of grooves 62 and 63 for reducing the ability of the retainer 53b to resist fracture. The cap 16g may also have one or more weakening grooves, such as the peripheral groove 64 and the circular groove 65 to reduce the force required to fracture the cap 16g.

FIG. 16 also illustrates a modified clip 32c having a handle 66 for ease in removal of the cap 16g (with fracture) and for rotating the stem 18a-18c in those embodiments in which the cap is rotatable.

FIG. 17 illustrates the retainer 53b secured to the clip 32c by a cord 61a.

FIG. 18 illustrates a further embodiment of the invention in which the retainer 67 is circular or rectangular in cross-section and has a pair of compressible and resilient, peripheral barbs 68 and 69 which are oppositely directed to permit the retainer 67 to be pushed upwardly into the position shown in FIG. 18 but which resist removal of the retainer 67. The retainer 67 has an end slot 70 which aids in compressing the barb 69 during insertion of the retainer 67.

The cap 16h and the stem 18d have holes therein shaped to receive the retainer 67.

A further modified embodiment of the invention is illustrated in FIG. 19. FIG. 19 shows a rod or bar type retainer 72 with an enlarged end 73 which will not pass through the hole in the tubular wall 19d of the cap 16i. The retainer has three barbs 74, 75 and 76, although one of the barbs 74 or 75 may be omitted, which permit the retainer 72 to be inserted downwardly into the position shown in FIG. 19 but which resist removal of the retainer 72. The cap 16i has a modified stem 18e for receiving the barbs 74 and 75.

The barb 76 may be arranged to break off the retainer 72 easily if an attempt is made to remove the latter. The retainer 72 may have grooves or necked-down portions, as illustrated in FIG. 20, to cause it to break more readily if an attempt is made to remove the cap 16i.

In some cases, the lock may have a head with a hole therethrough for receiving a conventional seal. Insofar as the invention is concerned, such head is the equivalent of a ferrule 3 and may receive a cap and retainer of the invention. FIG. 20 illustrates a lock body 1 with a head 77 having a hole therethrough into which a retainer 72a, similar to the retainer 72, is inserted. The retainer 72a has weakening grooves 78 and 79 and the barb 74 is received in the tubular bore 80 of the stem 18f of the cap 16j.

FIG. 21 illustrates the use of the cap 16h (FIG. 18), with a retainer 81, similar to the retainer 67 (FIG. 18), secured to the handle 71 by a cord 61b.

It may be desired, in some cases, to make the stem or prong on the cap separately from the cap, particularly if it is desired to make the prong or stem of a material different from the material of the cap or if it is desired to simplify the molds used to make the cap. FIG. 22 illustrates an embodiment of a cap 16k formed in two parts and used with a retainer 82 of the type described in connection with FIGS. 12-14.

The cap 16k (FIG. 22) has a cup-shaped portion 83 which may be made of a plastic materials which is relatively easily frangible. If desired, the end wall 84 may have a circular weakening groove 85.

A one piece stem 18g and handle 86 is received in an opening in the end wall 84 and is held on the end wall 84 by a conventional retaining ring 87 which provides as relatively large area of contact with the end wall 87 and accordingly, would remove a relatively large area of the end wall 87 when the end wall 87 is fractured by pulling of the handle 86. Of course, the stem 18g and the handle 86 may be secured to the cap 16k other than by means of the retaining ring 87.

It will be observed that the stem 18g shown in FIG. 22 has an enlarged portion 18h which is larger than the opening in the retainer 82 and which is spaced from the lip 18i by an amount greater, and preferably, substantially equal to, the thickness of the retainer 82. Such enlarged portion 18h will engage the retainer 82 when the handle 86 is pushed inwardly of the ferrule 3 and will fracture the retainer 82. A similar enlargement, or an enlarged lip, may be included on the stems illustrated in FIGS. 3-14, 23 and 24 for the same purpose.

As in the embodiment of the retainer illustrated in FIGS. 12-14, the retainer 82 has teeth or barbs 88 and a pair of teeth, tooth 89 being shown in FIG. 22 to resist removal of the retainer 82. The retainer 82 also has a slot, like the slot 59 of the retainer 53 (FIG. 13), for receiving the stem 18g. The retainer 82 may be connected to the handle 86 by a cord as illustrated in FIG. 21.

As previously mentioned, one of the objects of the invention is to provide a cap which prevents contaminants from entering the key hole of the lock. With the embodiments described, the entry of contaminants into the key hole will be reduced, as compared to a wire seal, even if there is a small space between the inner surface of the tubular wall of the cap and the exterior surface of the ferrule. However, if desired, a resilient ring shaped member may be inserted between the tubular wall of the cap and the ferrule.

FIG. 24 illustrates the use of a sealing ring 90 with a cap 161 similar to the cap 16 (FIGS. 3-5) but it will be apparent to those skilled in the art that such a ring 90 may be used with the other embodiments of the cap. The ring 90, commonly known as an "O-ring" and made of rubber or other similar compressible and resilient material, is received and retained in a circumferential groove 91 in the tubular wall of the cap 161 and is compressed between the wall of the groove 91 and the outer surface of the ferrule 3 to provide a seal between the cap 161 and the ferrule 3.

Alternatively, the cap may be made without the groove 91, and the ring 90, or a similar sealing member of compressible and resilient material, may be bonded to the inner surface of the exterior wall of the cap to provide the desired seal, such ring 90 or similar sealing member acting in the manner of a gasket.

FIGS. 25 and 26 illustrate a further embodiment of a cap 16m. The cap 16m has a pair of concentric tubular walls 92 and 93, the wall 92 extending around the periphery of the ferrule 3, either close or in slightly spaced relation thereto, and the wall 93 being in slightly spaced relation to the interior surface of the ferrule 3. The inner tubular wall 93 acts as a stem and may have a circular section as shown in FIG. 26 or it may comprise a pair of arcuate sections. The tubular walls 92 and 93 have slots 94, 95 and 96 for the passage of a retainer 97 which has a pair of teeth or barbs 98 and 99. The cap 16m has a handle 92a which is integral with the end wall 92b and which is used for purposes described hereinbefore.

The retainer 97 is shown in enlarged perspective view in FIG. 27, and it will be observed that the teeth or barbs 98 and 99 have cavities 100 and 101 between them and the main body of the retainer 97 into which they fit when they are pressed toward the retainer body during insertion of the retainer 97. Of course, previously described similar retainers may have such cavities for such purpose.

In the various embodiments described hereinbefore, the teeth or barbs for preventing removal of a retainer have been illustrated as integral with the retainer. If it is desired to make a tooth or barb of a material different from the material of the body of the retainer, such as of a spring metal, the barb may be struck out from a metal strip which is secured to the retainer. FIGS. 28 and 29 illustrate a metal strip 102 having a resilient barb or tooth 103. In FIG. 28, the strip 102 is secured to the retainer 97a by flush rivets 104 and 105 and is on the surface of the retainer 97a. In FIG. 29, the retainer 97b has a groove or channel 106 which receives the strip 102 so that its surface 107 is flush with the surface 108 of the retainer 97b.

Although preferred embodiments of the present invention have been described and illustrated, it will be apparent to those skilled in the art that various modifications may be made without departing from the principles of the invention.