This invention relates to adhesive tape dispensers made of molded plastic from which tape may be dispensed and severed from a roll of tape supported on the dispenser.
Adhesive tape is used in great quantities by consumers and by businesses. Adhesive tape is used in packaging, mailing, gift wrapping, and numerous other applications in factories, and businesses and by the consumers at home. One widely used type of adhesive tape is transparent adhesive tape which is used by businesses and consumers in stationery applications, gift wrapping, craft projects and the like. Transparent adhesive tape is often supplied in rolls having a width of one-half or three-quarters of an inch and a length of several yards. The tape comprises a flexible film strip with adhesive on one side. Acetate and oriented polypropylene are frequently used in making the film strip. The tape is wound upon a core which is often a cardboard cylinder or a plastic cylinder. The core normally has a hollow center of uniform diameter. Rolls of transparent adhesive tape are sold to businesses and consumers as is for mounting on reusable tape dispensers. Such tape dispensers are common in office environments in which a heavy tape dispenser is a frequent desk accessory and is also frequently available at mailing stations. Rolls of transparent adhesive tape are also frequently sold on dispensers. Many rolls of transparent adhesive tape are sold on single use dispensers having a single side wall, a flat base, a cutter support extending from the base, a hub extending from the side wall, and a merchandising card on the side of the hub opposite the side wall. Such single use tape dispensers are often seen on pegs in drug stores and general merchandise stores. The consumer purchases the tape dispenser, removes a portion of the merchandising card, and is left with a tape dispenser suitable for sitting a flat surface such as a table. The consumer can remove a length of tape and apply it to a substrate with the consumer's fingers. Thus, the dispenser is a dispenser, not an applicator.
Other tape dispensers, particularly those used with two inch wide packaging tape, also function as applicators. These dispensers often comprise two generally flat side walls each of which has a hub projecting inwardly from the side wall. The side walls extend away from the hub in one direction and are interconnected by a cross piece. The end of the flat piece away from the hubs often bears a cutter for severing a piece of tape. A roll of tape is supported on the hubs on the side walls. The end of the length of tape on the roll is fed along the cross piece and can be applied to a substrate, such as a package, by pulling the dispenser along the substrate. When sufficient tape has been applied, the cutter at the end of the cross piece is used to sever the dispensed length of tape. Such dispenser/applicators often include various additional pieces addressing problems with dispensing tape. Such dispensers in various configurations have been available for several years, especially in the two inch packaging tape width.
Consumers do not always use tape on a daily basis. Therefore, consumers often do not have heavy reusable tape dispensers as a desk accessory. Consumers often prefer to keep a roll of transparent adhesive tape on a dispenser in a drawer or the like. Transparent adhesive tape on a dispenser is a popular consumer product.
Many consumer products are price sensitive. An inexpensive product which provides good functionality has an advantage when compared to a product providing the same functionality at a higher cost. The cost of manufacturing is therefore an important characteristic of a product such as a roll of tape on a tape dispenser. Part count, method of manufacture, and choice of materials can have a significant impact on the cost of a consumer product. Providing a tape dispenser and tape of high quality, with good features and at a low price is a challenge.
The present invention contemplates a new and improved tape dispenser which overcomes the above problems and others. The present invention provides a tape dispenser for adhesive which also acts as an applicator and which is inexpensive to manufacture.
In accordance with the invention there is provided a tape dispenser for tape carried upon a hollow cylindrical tape core, the tape dispenser having a first side wall having inwardly facing hub elements, a second side wall having inwardly facing hub elements, an interconnecting top wall generally perpendicular to the first and second side walls and extending between the two side walls with a cutter supported on the top wall remote from the hub portions, the portions of the side walls adjacent the cutter extending beyond the cutter and being provided with thickened portions such that the width of the side walls is greater at the edges adjacent the cutter and an enlarged pressing element near the cutter adapted to press dispensed tape against a substrate.
Further in accordance with the invention, a pressing bar generally parallel to the cutter extends between the cutter support portions of the first side wall and the second side wall parallel to, below, and behind the cutter, the pressing bar or element having a smooth surface facing downwardly and forwardly and being adapted to press tape downwardly upon a substrate and apply tape to that substrate.
Still further in accordance with the invention, the pressing element is a resilient element adapted to apply pressure to an adhesive tape on a substrate over an enlarged area.
Yet further in accordance with the present invention, the resilient pressing element is a polymeric resilient pressing element.
Still further in accordance with the invention, the resilient pressing element is held in place by at least one barb on the dispenser.
Still further in accordance with the invention a central button projects downwardly from the pressing bar or adjacently the pressing element toward the roll of tape and into the gap between the two tape retaining tabs, said tabs and button adapted to urge a length of tape into a downwardly bulging arch in the area adjacent the pressing bar or pressing element.
Still further in accordance with the invention, ridges are provided on the upper surfaces of the tabs limiting the area of adhesive contacted by the tabs.
Further in accordance with the invention, a friction bar is provided between the roll of tape and the tabs adapted to engage a length of tape and prevent tape rollback.
Yet further in accordance with the invention, a tab extension extends downwardly and laterally from one of the tape retaining tabs below the gap between the two tape retaining tabs but maintaining a space between the tab extension and the other of the tabs wherein the length of tape can be threaded into position above the tabs and securely maintained in that position by the tabs and the tab extension.
Still further in accordance with the invention, the tape dispenser, with the possible exceptions of a metallic cutting bar and the pressing element, is a unitary plastic molded structure.
Still further in accordance with the present invention, a tape dispenser is provided having two side walls and a top interconnecting wall, the top interconnecting wall bearing a cutter on its distal end, the two side walls also interconnected by a bottom interconnecting wall generally perpendicular to the side walls and extending between them, the top interconnecting wall, the bottom interconnecting wall, and the two side walls forming a roll of tape containing volume opening to the front and adapted to permit the insertion of a roll tape into the dispenser from the front.
Further in accordance with the invention, the bottom interconnecting wall comprises two bottom interconnecting wall halves separably interconnected to one another and fixed to the side walls.
Still further in accordance with the invention, the two bottom interconnecting wall halves may be moved away from one another facilitating the loading of a roll of tape.
Still further in accordance with the present invention, the bottom interconnecting wall has a generally planar lower surface and adapted to form a base allowing the tape dispenser to stand upon the bottom interconnecting wall stably.
Still further in accordance with the present invention, the top interconnecting wall and the bottom interconnecting wall diverge from one another from back to front and, when pressed together, are adapted to cause the side walls to bulge away from one another facilitating the loading of a roll of tape.
Yet, further in accordance with the present invention, the two side walls are provided with slots facilitating the bulging apart and loading of a roll of tape.
It is a principal object of the present invention to provide a tape dispenser for adhesive tape which also acts as an applicator and is usable with a single hand.
It is yet another object of the present invention to provide a tape applicator which is adapted to hold an end of the roll of tape extending from the front of the tape applicator in a ready to use position.
It is still another object of the present invention to provide a tape dispenser which can be used with one hand by grasping the tape applicator, applying the end of the supported tape to a substrate, pressing the tape into position with a pressing bar or pressing element, applying a selected amount of tape, and rotating the tape dispenser to cut off the applied tape and at the same time present a leading end for further applications of length of tape.
It is yet another object of the present invention to provide a tape dispenser which supports the end of a roll of tape to be dispensed with the end arched and projecting straight away from the front of the dispenser.
It is still another object of the present invention to provide a tape dispenser which has an enlarged forward area allowing one to dispense and cut off tape while holding down delicate substrates, such as wrapping paper, without ripping them.
It is still another object of the present invention to provide a tape dispenser which can be easily reloaded with a roll of tape and is reusable.
It is yet another object of the present invention to provide a tape dispenser, roll of tape combination, which is inexpensive to manufacture, has superior operational characteristics which are readily visible to the consumer, and which is easy to merchandise.
Further objects and advantages of the invention will be apparent from the following detailed description of the preferred embodiments thereof and from the accompanying drawings.
The invention may take physical form in certain parts and arrangements of parts, a preferred embodiment of which will be describe in detail and illustrated in the accompanying drawings which form a part hereof and wherein:
Referring now to the drawings wherein the showings are for the purposes of illustrating a detailed description only and not for the purposes of limiting the claims, the figures show a tape dispenser 10 for a roll of tape 12. The tape dispenser 10 has a right side wall 16, a left side wall 18, a top interconnecting wall 20, rear wall segments 22, 72 and a bottom interconnecting wall 24. The right side wall 16 has an inwardly facing surface and an outwardly facing surface. The right side wall 16 includes a tape core support portion 30 and a cutter support portion 32 extending from the tape core support portion 30. The inwardly facing surface of the right side wall 16 supports three inwardly extending tape core support elements 34, 36, 38. (See
With respect to the elements thus far described, and most elements of the side walls, the left side wall 18 is the mirror image of the right side wall 16. Thus, the left side wall 18 comprises a left side wall tape core support portion 50, a left side wall cutter support portion 52, and three inwardly extending tape core support elements 54, 56, 58.
For purposes of this description, the tape dispense orientation will be presumed to be with the bottom interconnecting wall 24 on the bottom, the top interconnecting wall 20 on the top, the portion of the top interconnecting wall 20 most remote from the roll of tape 12 being the front, the portion of the dispenser most remote from the cutter being the back. The inside surfaces of the right side wall 16 and the left side wall 18 face toward one another and “inwardly” means facing toward the mid plane between the planes of the two side walls 16 and 18. The axis of the tape dispenser is coincident with the axis of the roll of tape 12 and is thus perpendicular to the side wall 16 and 18 and the mid plane of the dispenser. A line perpendicular to the mid plane of the dispenser will be described as parallel to the axis of the dispenser and thus parallel to the axis of the tape roll 12.
The two side walls are generally planar and the planes of the two side walls are generally parallel to one another. A slight amount of “draft” from back to front may be provided to ease manufacturing.
The top interconnecting wall 20 is gently curved from back to front but flat from side to side.
The tape roll 12 is conventional. It comprises a core, either cardboard or plastic, having a hollow cylindrical interior; and, a long length of tape wound upon the core in many turns. In the preferred embodiment the tape is ¾ inch wide plastic transparent adhesive tape. Adhesive is carried on one side of the tape, the inside as rolled upon the core. The roll of tape and the tape core are generally symmetrical about a central axis. When the roll of tape 12 is mounted in the tape dispenser 10, the inside surface of the tape core rides upon the axially outwardly facing curved surfaces of the tape core support elements 34, 36, 38, 54, 56, 58. The axially outwardly facing surfaces of the tape core support elements form small segments of a circle slightly smaller than the inside of the tape core having an axis 60 generally coaxial with the axis of the roll of tape 12. Of course, the roll of tape has some slight play with respect to the tape core support elements. The axis of the roll of tape will sometimes be only generally coaxial with the axis 60 of the tape dispenser 10.
The bottom interconnecting wall 24 is continuous over a portion of its length from the right side wall 16 to the left side wall 18. Likewise, the top interconnecting wall 20 is continuous over at least a portion of its length from the right side wall 16 to the left side wall 18. Thus, the right side wall 16 and the left side wall 18 are held a predetermined distance apart. In the preferred embodiment, the inside surfaces of the right side wall and the left side wall are spaced slightly greater than ¾ inch apart. This allows a ¾ inch width roll of tape to be carried upon the tape for support elements 34, 36, 38, 54, 56, 58 and freely rotate while still being supported closely enough so as not to escape from the dispenser 10.
Looking in more detail at the tape core support elements, (
The upper forward tape core support elements 36, 56 also have a forward edges 67 generally perpendicular to the side wall adjacent to the side wall but curving to the rear remote from the side wall. The rearward tape core support elements 38, 58 have curved exterior surfaces facing the rear of the dispenser. A tapered ramp 68 extends from the forward side of the rearward tape core support elements and tapers to the inside surface of the side walls. The curved forward edges 66 and tapered ramp 68 facilitate the loading of a roll of tape into the tape dispenser 10.
Rear wall segments 22, 72 extend from the rear of the right side wall tape core support portion 30 and left side wall tape core support portion 50 respectively. The rear wall segments 22, 72 extend inwardly toward the central plane of the tape dispenser. The rear wall segments 22, 72 stop just short of the central plane of the dispenser. Thus, the real wall segments 22, 72 are not continuous but are distinct one from the other. A long narrow slot or gap 76 is present along the central plane of the dispenser between the two rear wall segments 22, 72. The rear wall segments 22, 72 are curved with a radius of curvature about the axis of the tape dispenser 60 slightly larger than the radius of the largest roll of tape expected to be used with the tape dispenser 10. The bottom edges of the rear wall segments 22, 72 join the bottom interconnecting wall 24. The bottom interconnecting wall 24 is provided with a central, trapezoidal opening 78 (
The rear wall segments 22, 72 end at a large opening 80 extending from the right side wall 16 to the left side wall 18 at the top rear of the side wall tape core support portions 32, 34.
The forward edge of the side wall tape core support portions 30, 32 are gently curved in their lower portions leading to forward opening U-shaped recesses 82, 84 in the right side wall tape core support portion 30 and the left side wall tape core support portion 50. The side wall cutter support portions 32, 52 extend from the tape core support portions 30, 50 above these U-shaped recesses 82, 84.
Additionally, a pair of rear slots 86, 88 extend rearwardly across the rear ⅓ of the right side wall tape core support portion 30 to and into the right rear wall segment 72. A parallel pair of rear slots 92, 94 extend through the rear portions of the left side wall tape core support portion 52 into the left rear wall segment 74.
As can be seen in
The bottom interconnecting wall 24, the side wall tape core support portions 30, 50, the rear wall segments 72, 74 and a portion of the top interconnecting wall 20 define a tape roll containing volume 100.
A roll of tape can be inserted into the tape roll containing volume 100 by pressing the bottom interconnecting wall 24 toward the top interconnecting wall 20. This is conveniently done with the thumb and forefinger of one hand. This pressing causes the side wall, particularly the tape core support portions 30, 50 of the side walls to bulge outwardly from one another moving the tape core support elements 34, 36, 38 on the one side wall away from the tape core support elements 54, 56, 58 on the other side wall, as seen in
With reference to
Referring now to
With respect to the cutter support portions 32, 52 and the elements associated with the cutter support portions 32, 52 the terms proximal and distal will be used. Proximal refers to that portion of an element closer to the axis of the tape dispenser 60 and the roll of tape 12. Distal means that portion of an element more distant from the axis of the tape dispenser 60 and the roll of tape 12.
The tape retaining tabs 112, 114 have curved proximal ends 116, 118 and straight distal ends 120, 122. The tabs extend inwardly to inward edges 124, 126. The inward edges have a distal portion which is generally parallel to the side walls and a proximal portion which curves to merge with the tab proximal ends 116, 118. The tabs extend inwardly from the side walls toward the central plane of the dispenser but do not meet. Rather a substantial gap is left between the two tabs 112, 114. The tabs each extend toward the other side wall a distance between one quarter of the spacing between the two side walls and one third the spacing between the two side walls. Thus, a gap between the two tabs 112 and 114 of one third the distance between the interior surfaces of the two side walls or slightly greater is created.
A pressing bar 134 extends from the right side wall cutter support portion 32 to the left side wall cutter support portion 52 parallel to the axis of the tape dispenser 60. The pressing bar 134 is positioned somewhat forward of the tabs 112, 113 and slightly above the top surface of the tabs 130,132. The pressing bar 134 serves two functions. The forward lower surface 136 of the pressing bar is smooth, gently curved and has a uniform profile across its entire width from the right side wall to the left side wall. The forward lower surface 136 of the pressing bar 134 extends a slight distance below the lower edges of the rights side wall cutter support portion 32 and the left side wall cutter support portion 52. This allows the pressing bar to be used to press a length of tape against a substrate as will be hereinafter described.
The pressing bar 134 also supports a button 140 which extends downwardly and rearwardly from the center of the pressing bar 134. The button 140 has a smooth rounded lower surface which extends downwardly into the gap between the tabs 112 and 114. The pressing bar 140 has a width less than one third the distance between the two side walls 16, 18.
A tab extension extends downwardly from the proximal portion of one of the tabs 112, 114. In the illustrated dispenser, the tab extension 142 extends from the left tape retaining tab. However, the tab extension could just as effectively extend from the right tape retaining tab. The tab extension 142 extends below the plane of the tabs 112, 114 and substantially below the button 140. The tab extension 142 does not contact the other of the tape retaining tabs 112, 114. Thus, as seen in
As can be seen in
The right side wall cutter support portion 32 and the left side wall cutter support portion extend forwardly of the forward edge of the cutter 156. The forward edges 162, 164 of the side wall cutter support portions 32, 52 extend beyond the forward edge 156 of the cutter 154. The cutter support forward edges, 162, 164 are curved with their most forward points being close to the cutter 154. Moreover, the forward edges 162, 164 are widened when compared to the thickness of the rest of the side walls 16, 18. Thus, in the preferred embodiment, the forward edges 162, 164 have a maximum width, that is the dimension measured parallel to the axis of the dispenser 60 and the cutter 154, which is generally at least twice the thickness of the side walls elsewhere in the dispenser. This width varies and tapers over the forward edges of the side walls 162, 164. Thus, at the bottom of the forward edges 162, 164 adjacent the forward lower surface 136 of the pressing bar 134, the width of the forward edge is only slightly greater than the adjacent thickness of the side walls. The width of the forward edge gradually increases to its maximum adjacent the cutter 154 and forward of the cutter 154 and then tapers back to a smaller value as the forward edges reach the top edge of connecting wall 20. The forward edges 162, 164 are generally transversely flat and smooth. The widened forward edges protect delicate substrates from being torn in operation of the tape dispenser as will be hereinafter described.
The above-described structures support operation of the dispenser as follows. A roll of tape 12 may be inserted into the dispenser 10 by pressing the top interconnecting wall 20 and the bottom interconnecting wall 24 toward one another. As previously described, this causes the side walls 16, 18 to bulge away from one another increasing the distance between the tape core support portions 30, 32, 34, 50, 52, 54. The roll of tape 12 is inserted into the tape roll containing volume 100 and pressure on the top wall 20 and bottom wall 24 released allowing the dispenser to engage the roll of tape 12. The end of the tape 170 is separated from the roll of tape 12 and the leading length of tape 172 is pulled from its adhered position on the tape roll 12. This leading length of tape is threaded over the tab extension 142 and tabs 112, 114 (
To dispense tape, a user grasps the tape dispenser 10 with a thumb on one of the tape core support portions 30, 50, an index finger on the top interconnecting wall 20 and some or all of remaining fingers on the other of the side wall tape core support portions 30, 50 (
The tab extension 142 acts as a tape lock. Should the leading length of tape 172 shift laterally toward one side wall or the other, it may become disengaged from one or the other of the tabs 112, 114. The adhesive side of the length of tape 172 is then likely to engage the tab extension 142 rather than completely leaving the threaded state. The user may then easily rethread the length of tape 172 and continue use.
Additionally, if a user lays the dispenser down with the cutter support portions 32, 52 lowermost, as in
Additionally, because the top surface of the tabs 112, 114 are engaged to the bottom (adhesive) surface of the length of tape 172, the tape 172 is restrained from rolling back onto the roll of tape 12.
The elements of the tape dispenser described above consist of two parts: A molded plastic part comprising all of the elements except the cutter 154, and, the cutter 154. The molded plastic part is molded from any appropriate polymer material resulting in a reasonably rigid yet somewhat flexible frame. Moreover, for certain kinds of tapes and plastics, the metallic cutter 154 may be deleted and the bar 150 provided with a serrated forward edge replacing the cutter 154. This results in a single piece dispenser which is less expensive to manufacture.
In the preferred embodiment, the tape dispenser is provided preloaded with a roll of tape. Because the dispenser is inexpensive to manufacture, some users may treat the dispenser as a single use dispenser and discard it with the core from an exhausted roll of tape. However, the tape dispenser is reusable. A consumer may buy an additional roll of tape 12 and reload the dispenser as described above. Forward opening U-shaped recesses 82, 84 and rear slots 86, 88, 92, 94 as well as slot 76, bottom wall opening 78 and a gap to the rear of the top wall 20 have been described. These features aid in providing appropriate flexibility allowing one to reload the tape dispenser. However, these configurations are not the only way to achieve this flexibility and resiliency. Different side wall configurations can be easily implemented to achieve the same functionality. Thus, the U-shaped recesses can be of a different shape or dispensed with altogether as can be the rear slots. One may select a different plastic to achieve the flexibility necessary or one may use different slots, wall thicknesses or the like.
A second tape dispenser in accordance with the invention is illustrated in
Rather than having a one piece bottom interconnecting wall as in the first embodiment, this tape dispenser 200 has a right bottom interconnecting wall half 226 and a left bottom interconnecting wall half 228. A linear prong 202 with an enlarged head 204 extends axially from the right bottom interconnecting wall half 226. A linear recess 206 having a restricted slot opening 208 is integral to the left bottom interconnecting wall half 228. The ends of the recess 206 and slot opening 208 are open. Thus, the prong 202 can be engaged in the recess 206 by moving it beyond the ends of the recess, aligning the enlarged head 204 with the recess 206 and sliding the prong into engagement in the recess 206. This arrangement holds the right bottom interconnecting wall half 226 in locked engagement with the left bottom interconnecting wall half 228 creating a smooth bottom surface for the tape dispenser 200. In the locked configuration, the two side walls, 216, 218 are held a fixed distance apart and a roll of tape (not shown) to be dispensed can be securely mounted within the dispenser 200.
With further reference to
The above described structures allow a user to disengage the right bottom interconnecting wall half 226 from the left bottom interconnecting wall half 228 and move the wall halves away from one another. This opens the tape dispenser and allows the removal of an empty tape core and the insertion of a new loaded tape core. With a new loaded tape core in place, the linear prong 202 is engaged in the linear recess 206 locking the tape dispenser bottom interconnecting wall halves 226, 288 together so that the tape core supporting the new tape roll is securely held in place. As can be seen in
With reference again to
Adjacent the button support cross bar 333 is a tape pressing element 335. In
As can be seen in
As can be seen best in
The right side wall cutter support portion and the left side wall cutter support portion terminate at their forward ends in a right cutter support portion forward edge 262 and a left cutter support portion forward edge 264. The two forward edges 262, 264 are considerably widened with respect to the width of the side walls 216, 218. The two forward edges 262, 264 have smooth curved widened forward facing surfaces. When compared to the forward edges of the first embodiment illustrated in
The elements described above modify the tape dispensing tape path seen in the first embodiment in the following ways. A tape end is fed from a roll of tape within the dispenser with its adhesive coated side facing in the “down” direction. The tape passes under the friction bar 262 such that its non-adhesive face may rub against the friction bar 262. The tape then passes under the button 340 and over the tape retaining tabs 312, 314 and tab extension 342. A fin 344 aids in threading the tape between the button and tabs. As with the embodiment seen in
Tape is dispensed from the dispenser of
As with the embodiment of
The enlarged forward edges 262, 264 hold the substrate, such as wrapping paper, down and away from the cutter 354. The large width of the forward edges 262, 264 and their smooth, gently curved shape, assures that the substrate is held down over a relatively large area. This protects delicate substrates such as wrapping paper from tearing when the dispenser s rotated and tape cut off.
It is not necessary that the tape pressing surface 336 be entirely planar. A curve over its length may be appropriate for some dispensers.
Should the roll of tape in the dispenser start to rotate in the direction opposite dispensing, the length of tape between the roll of tape and the friction bar 262 will move toward the top of the tape dispenser 200. This pulls the length of tape against the friction bar 262, increasing friction over the length of tape which is engaging the friction bar 262, the tabs 312, 314 and the button 340. Reverse rotation is thereby stopped. Tape “roll back” in which the end of the tape slides back onto the roll of tape and must be rethreaded is prevented.
Switching the tab extension 342 to the right tab 312 has been found to prevent tape disengagement when tape is applied in a curved line as favored by right handed dispensing as opposed to left handed dispensing.
A compressible or resilient pressing element 384 is also seen in
The octagonal shape described with respect to preferred resilient pressing element 384 allows assembly of the resilient pressing element 384 into the tape dispenser 210 without needing to align in a particular direction. There is no reverse or inverted orientation in which the pressing element 384 can be misinstalled. However, different shapes giving up this advantage or answering this advantage in a different way, such as a cylindrical pressing element are also considered to be within the scope of this invention.
The material of the pressing element is preferably a resilient material such as foam elastomer. The foam elastomer can be open celled or closed celled. The foam elastomer can have a “skinned” exterior or an open cell exterior. Any material providing appropriate resiliency is an appropriate material.
Two pressing elements, 335 and 384 are described because different pressing elements interact advantageously with different tapes. Some tapes, such as exceptionally clear tapes using an orientated polypropylene film, are applied more advantageously with the rigid pressing element 335 while other tapes, such as acetate film based tapes, are applied more advantageously with the resilient foam based pressing element 384. This appears to be particularly the case when the resilient foam based pressing element is a polyethylene foam.
The invention has been described with reference to preferred embodiments. It will be appreciated that modifications or alterations can be made without deviating from the present invention. Such modifications and alterations will occur to others upon the reading and understanding of this specification. It is intended that all such modifications and alterations be included insofar as they come within the scope of the appended claims or the equivalents thereof.