Reverse taper mounting of separate components and coupling of devices with reverse taper fittings

A medical device has a base having an internally tapered wall mounted to a neck of a tube holder that has a reverse taper, so that rotation of the base relative to the neck may be effected with a controlled drag to provide a smooth and secure relative rotation. The base may be rotated relative to the holder by rotationally moving a needle protection housing hingedly attached to the base. The housing may be rotated to any orientation relative to the tube holder so long as a torsional force greater than the predetermined friction between the tapered surfaces is applied thereto. The base is designed to have a ring at its base that biases against the base of the neck in a self-adjustable manner. Other devices may also be fitted with reverse tapered complementary connection fittings to securely couple to each other.

FIELD OF THE INVENTION

The instant invention relates to the mounting of two plastic components together in such a way that there is controlled rotation between the components. The present invention more specifically relates to the mounting of a collar, to which a needle protection housing is hingedly attached, to the neck of a vacuum tube holder, so that controlled rotation of the collar relative to the neck of the tube holder is effected. The instant invention moreover relates to the way in which the collar and the neck are matingly coupled that provides the controlled rotation between the collar and the tube holder.

BACKGROUND OF THE INVENTION

A product under the trade name NEEDLE-PRO® has been sold by the assignee of the instant invention for a number of years. The NEEDLE-PRO® product is described in U.S. Pat. No. 5,154,285, among other patents assigned to the instant assignee. Briefly, NEEDLE-PRO® is a safety needle device that has a vacuum tube holder having a needle protection housing pivotable relative to the tube holder. In particular, the needle protection housing is hingedly attached to a collar or base, which is mounted about a neck or a receptacle end of the vacuum tube holder. As described in the '285 patent, the being sold NEEDLE-PRO® product has a circumferential protuberance, or boss, formed at the receptacle end, or neck, of the holder. A counterpart circumferential groove is formed about the inner wall of the base, so that when the base is fitted onto the receptacle end of the holder, the boss is mated to the groove so that the base is rotatable about the receptacle end. The neck, or receptacle end, of the holder has a channel or aperture that is internally threaded so that a conventional double-ended needle assembly is able to be threadedly mated thereto by means of its externally threaded needle hub. The disclosures of U.S. Pat. No. 5,154,285 and U.S. Pat. No. 5,277,311, a CIP of the '285 patent, are incorporated by reference to the disclosure of the instant application.

With the protuberance/groove configuration, the needle housing is able to be rotated about the receptacle end of the holder. So that the housing may be stopped at the desired orientation relative to the holder, the respective dimensions of the internal groove of the base and the circumferential boss at the neck are such that a given friction is provided, so that theoretically the rotation of the housing relative to the receptacle end of the holder may be controlled.

During the many years of use of the NEEDLE-PRO® product, there have been instances where the housing freely rotates about the receptacle end of the housing, and also where the friction between the base and the receptacle end is such that the base seizes to the neck when the housing is turned relative to the holder. These problems most likely result from the dimensional variances of the molded plastic base and receptacle end of the holder. In other words, if both the base and the receptacle end to which the base is to be mounted were manufactured to have the desired allowable dimensional tolerances, the assembled product would most likely have a base that may rotate in an acceptable fashion about the receptacle end. But if either or both of the base and the receptacle end to which the base is to be fitted was/were molded with their dimensions outside their respective allowable tolerances, then the base and the receptacle end may either lock up, when the housing is rotated relative to the holder, or rotate loosely.

SUMMARY OF THE PRESENT INVENTION

To eliminate the above potential problems of the NEEDLE-PRO® product, the present invention provides an improved self-adjusting mounting of the base of the housing to the neck of the holder so that a constant drag is provided between the base and the receptacle end when the housing is rotated relative to the holder, to thereby provide controlled rotation of the housing relative to the holder. At the same time, lock-up or seizure between the base of the housing and the receptacle end of the holder, when the base is rotated relative to the holder, is prevented.

To effect the controlled rotation, the present invention has the outer circumferential wall of the neck or receptacle end of the holder tapered at a given angle and the inner wall of the base or collar tapered at a reverse angle to that of the outer wall of the neck so that, when the base is press-fitted onto the neck, it is held thereat. To prevent lockup between the base and the neck, flat surfaces or equivalents such as extended ribs and protuberances are interspersely provided about the inner wall of the base. Moreover, the lower edge of the base is formed into a relatively thin walled ring, with sufficient flexibility to provide self-adjustment of the base relative to the neck by continually biasing the base to the neck even when there is flexure at or bending of the neck, relative to the body of the holder, when the base is rotated relative to the neck.

The instant invention is therefore a reverse taper design whereby the outer wall of the neck and the inner wall of the base have reverse tapers that substantially form fit to each other. To prevent lockup, flat surfaces extend longitudinally along and interspersed about the inner wall of the base break the tension between those two opposing walls that otherwise causes lockup were the inner wall of the base and the outer wall of the neck to be in intimate contact with each other. To enable the base and the neck to self-adjust when a torsional force is applied to rotate the base relative to the neck, a thin lower ring is provided at the lower edge of the base. In addition, an internal counter bore recess extends from the ring to the inner wall. When the neck flexes due to the rotation of the base thereagainst, appropriate portion(s) of the ring would bend or collapse against the cap portion of the holder due to its flexibility while the recess provides the space for the ring to bend or collapse, so that the base may continually be biased against the neck without being pushed upwards away from the neck. When the torsional force is removed, due to its elastic memory, the ring would return to its original shape while at the same time maintaining continual biasing of the base against the neck. Note that the flexure of the neck relative to the holder is relatively slight so as not to be observable by the casual observer.

The instant invention is moreover directed to an apparatus that comprises a holder that has a body including a cap having a neck projecting therefrom, the neck extending from the cap at a proximal end that is integral with the cap to a distal end, the neck having an outer circumferential wall defined by an outer diameter that increases in size from the proximal end to the distal end of the neck to form a tapered outer circumferential wall. The apparatus further comprises a base to which a needle housing is hingedly attached that has an aperture defined by a non-ending inner wall that extends between a proximal end and a distal end of the base, the inner wall having a diameter that increases in size from the proximal end to the distal end of the base to form a counterpart reverse tapered inner wall that enables the base to substantially form fit about the tapered outer circumferential wall of the neck. The respective dimensions of the tapered outer circumferential wall of the neck and the counterpart reverse tapered inner wall of the base are configured such that after the base is press-fitted onto the neck, the base is prevented form disengaging from the neck and a predetermined friction is established between the base and the neck to prevent the neck and the base from freely rotating relative to each other, and whereby the base and the neck are rotatable relative to each other when a force sufficient to overcome the predetermined friction is applied to rotate the housing with the holder relative to each other.

The present invention is also directed to a combination of a holder having a body and a neck extending from a cap portion of the holder and a base having an aperture defined by a non-ending inner wall. The neck of the holder has an outer circumferential wall defined by an outer diameter that increases in size from the proximal end of the neck to the distal end of the neck. A channel extends through the neck so that a passage into the holder is provided from the opening at the distal end of the neck through the channel into the holder. The outer circumferential wall of the neck tapers from the distal end to the proximal end at a given angle. The inner wall of the base has a diameter that tapers at an angle from the proximal end of the base to the distal end of the base that is in reverse to the given angle of the outer circumferential wall of the neck so that, when the base is press-fitted onto the neck with the proximal end of the base positioned about the proximal end of the neck, the tapered inner wall of the base substantially form fits about the tapered outer circumferential wall of the neck to prevent the base from separating from the neck and to establish a predetermined friction between the base and the neck to thereby prevent the neck and the base from rotating relative to each other absent a force sufficiently large to overcome the predetermined friction.

The present invention is further directed to a method of manufacturing a device that comprises the step of forming a holder to have a body having a cap portion, and a neck extending from the cap portion of the holder. The neck is formed to have an outer circumferential wall defined by an outer diameter that increases in size at the proximal end of the neck at the cap portion of the holder to a distal end of the neck so that the outer circumferential wall of the neck tapers from the distal end to the proximal end at a given angle. The neck has an opening at its distal end that extends into the holder. The method further comprises the step of forming a base that has a housing hingedly attached thereto. The base has an aperture defined by a non-ending inner wall that extends between a proximal end and a distal end of the base. The diameter of the inner wall of the proximal end of the base to the distal end of the base tapers at an angle that is the reverse of the given angle of the neck, so that when the base is press-fitted onto the neck with the proximal end of the base positioned about the proximal end of the neck, the tapered inner wall of the base substantially form fits about the tapered outer circumferential wall of the neck to prevent the base and the neck from disengaging from each other and to establish a predetermined friction between the base and neck to prevent the neck and the base from rotating relative to each other absent a force sufficiently large to overcome the predetermined friction.

The present invention also is directed to an apparatus, and method of manufacturing thereof, that has a first device having a neck that includes an outer circumferential wall having a first taper that extends from the base of the neck to the distal end of the neck at a first angle. The apparatus also has a second device having a collar that has an inner circumferential wall having a second taper that extends from the distal end of the collar to the base of the collar at a second angle in reverse to the first angle. The collar and the neck are mated to each other with the base of the collar passing the distal end of the neck to be in a resting position relative to the base of the neck so that the outer circumferential wall of the neck is in engagement with the inner circumferential wall of the collar. The engagement of the outer circumferential wall of the neck and the inner circumferential wall of the collar effects a friction to prevent relative rotation between the collar and the neck except when a torque that is greater than the friction is applied to rotate the collar relative to the neck.

The present invention is moreover directed to an apparatus that comprises a first device having a first connection fitting of a first configuration with an outer wall having a first taper at a first angle that extends from the base to the distal end of the first connection fitting, and a second device having a second connection fitting of a second configuration complementary to the first configuration with an inner wall having a second taper at a second angle in reverse to the first angle that extends from the distal end to the base of the second connection fitting. When the first connection fitting and the second connection fitting are mated to each other, the outer wall of the first fitting is in angled engagement with the inner wall of the second connection fitting to effect a secure connection between the first and second connection fittings.

The present invention is furthermore directed to a method of coupling two devices, comprising the steps of: forming a first device having a first connection fitting with a first configuration including an outer wall having a first taper at a first angle that extends from the base to the distal end of the first connection fitting; forming a second device having a second connection fitting with a second configuration complementary to the first configuration including an inner wall having a second taper at a second angle in reverse to the first angle that extends from the distal end to the base of the second connection fitting; and mating the first and second connection fittings to each other so that the outer wall of the first fitting is in engagement with the inner wall of the second fitting to effect a secure connection between the first and second connection fittings.

DETAILED DESCRIPTION OF THE INVENTION

With reference toFIG. 1, a vacuum tube holder2is shown to have a main body4that has a proximal end6whereat a rest or foot plate7is provided. As shown inFIG. 9, an opening8is provided at the proximal end of holder2whereinto a conventional vacuum tube, not shown, may be inserted as is well known in the art. Body4has at its distal end a cap, or cap portion,10whereat a receptacle end, or neck,12of holder2extends. As shown, neck12has a proximal end12athat is an integral continuation of cap10, by way of a chamfer14, to a distal end12b. As is conventionally known, neck12has a through bore or channel16that extends from its distal end12binto the interior of body4of holder2. As is further well known, channel16is threaded so as to be able to threadingly mate with a needle assembly, such as18shown inFIG. 9, by way of the latter's needle hub18b. Needle assembly18may be a conventional double-ended needle assembly having an outwardly extending end needle18cused to prick a patient, and another end needle inserted into the interior of holder body4used to pierce the rubber septum that seals the front end of the vacuum tube inserted into body4of tube2via its opening8. As shown inFIG. 9, the end needle to be inserted into the interior of body4is enclosed by an elastomeric boot18d.

Neck12has an outer circumferential wall20that extends from proximal end12ato distal end12bat an increasing incline amplified by the two dotted lines20aand22binFIG. 1. Thus, the outer wall of neck12has a taper due to the size or dimension of the diameter of the neck increasing from proximal end12ato distal end12bat a given angle (or the angle shown inFIG. 2with reference to the plane whereat the distal end12bof neck12lies along). Putting it differently, neck12slopes downward at an incline from its distal end12btowards its proximal end12a. From empirical studies, it was found that the angle, designated by θ, may be from approximately 2 degrees to 10 degrees, with an optimal incline being from approximately 3 degrees to 6 degrees, with reference to an imaginary circular plane represented by the dotted parallel lines24aand24b.

The taper of the outer wall20of neck12is further shown in the cross-section view ofFIG. 3, being represented by an angle θ with reference to the pair of parallel lines24aand24b. Also shown inFIG. 3is the internal screw thread12dof neck12which, as discussed above, is used to threadingly mate with a needle hub of a double-ended needle assembly, so that one end of the needle extends away from neck12while the other end of the needle extends into the interior4aof body4.

FIGS. 4-7are illustrations of the collar, or base22to which a needle protection housing24is hingedly connected by way of a living hinge26.FIG. 4is a top perspective view of base22and housing24. As shown, base22is in the shape of a collar or ring having an outer circumferential wall22aand a non-ending inner wall22b. Needle protection housing24is shown to have a longitudinal slot24aalong substantially its entire length whereby a needle such as needle18c(FIG. 9) passes when housing24is pivoted in the direction as indicated by directional arrow28(FIG. 9) to cover the needle, assuming that the needle assembly18has been matingly attached to neck12of holder4. Inside housing24a plurality of lock mechanisms in the form of hooks24bwould grasp the needle to fixedly retain housing24to the needle in the manner as disclosed in the aforenoted incorporated by reference '285 patent. Base22, with reference toFIGS. 4 and 7, has a proximal end22cand a distal end22d.

Base22has an aperture or opening22ethat is defined by the non-ending inner wall22b, which may be considered an inner circumferential wall that is divided into a number of sections with non-circumferential sections alternating with circumferential sections. As shown inFIGS. 4-6, a number of flat surfaces or flats28a,28band28cthat extend longitudinally between proximal end22cand distal end of22dof base22are interspersed about the inner wall22b. Alternating with and separating flats28a-28care circumferential surfaces30a,30band30c. Flats28a,28band28cwould be in contact with the outer wall of the neck, when base22is press-fitted onto the neck. Flats28a-28censure that the inner wall22bof base22does not lock up, or seized with the outer wall20of neck12, when base22is rotated relative to neck12by preventing continuous or non-ending intimate contact between the inner wall22band the outer wall20, as will be discussed further infra.

As best shown in the cross-sectional view of base22inFIG. 7, the non-ending inner wall, or simply the inner circumferential wall22b, of base22has a diameter that increases in size from its proximal end22cto its distal end22d. This increase in the dimension or size of the diameter of inner wall22b, or opening22e, of the base is amplified by the double dotted lines32aand32bto have an angle θ′ that is the reverse of the angle θ of the taper of outer wall20of neck12. In other words, the inner wall22b, or the opening22e, of base22has a reverse taper to that of the outer wall of neck12. The respective tapers of outer wall20of neck12and the inner wall22bof base22are configured such that opening22edefined by the inner wall22bsubstantially form fits about neck12, more specifically the outer wall20of neck12, per shown inFIGS. 8, 10 and 11.

With further reference to the enlarged view of base22per shown inFIG. 6and the cross-sectional view shown inFIG. 7, a ring34having a relatively thin wall is formed as part of the outer wall22aof base22at its proximal end22c. Ring34has a height34aso that an annular recess36is formed internal to ring34at proximal end22c. Recess36extends into a counterbore space, or simply counterbore36athat may be considered to be a continuation of recess36. Counterbore36ais configured as a counterpart to chamfer14, which may also be considered as a radius, of holder2(FIG. 1) that integrates cap10with the proximal end12aof neck12. Recess36, in combination with counterbore36a, ensure that base22substantially form fits about neck12with yet sufficient space separating inner wall22bof base22from the chamfered and cap portions14,10of holder2. With support contact from cap10of holder2, ring34biases base22upwardly against neck12, so that base22is self-adjustedly fitted to neck12even when neck12flexes, as will be discussed in further detail below.

With references toFIGS. 8-11, base22is shown to have been press-fitted onto neck12of holder2, with the top surface of the base, referenced by distal end22d, being slightly below the top, or the distal end12bof neck12. By having the distal end of the neck slightly above the distal end of the base prevents potential interference to the mating of the needle assembly18into the threaded channel16of neck12.

With reference to the enlarged view of base22fitted to neck12inFIG. 10, note that the outer wall20of neck12is in intimate contact only with flats28a,28band28cat the inner wall of base22. Thus, pockets of spaces are formed between circumferential surfaces30a,30band30cof the inner wall of base22and the outer wall20of neck12. This intermittent contact between the inner wall of base22and the outer wall of neck12breaks up any potential tension due to intimate contact between the respective tapered walls of the neck and base to thereby ensure that there is no lock up or seizure between inner wall22bof base22and the outer wall20of neck12, when base22and neck12are rotated relative to each other.

Although flat surfaces28a-28care shown, it should be appreciated that the inner circumferential wall of base22may instead be provided with other types of non-circumferential contact surfaces such as longitudinal ribs or protrusions interspersed thereabout so that only those non-circumferential surfaces would come into contact with the outer wall of the neck. Conversely, it is envisioned that the protrusions, ribs, flats and other equivalent means may be provided at the outer wall of the neck while the inner circumferential wall of the base is smooth to prevent the base and the neck from locking up, when the housing is moved to rotate the base relative to the neck.

When a rotational force is applied to move the base relative to the neck, due to the elasticity nature of the base and the holder since both components are made from plastics material such as polypropylene (PP), the neck of the holder tends to flex relative to the body of the holder. This flexure movement of the neck may cause a portion of the also being tilted base (since the base is mounted about the neck) to come into contact with the cap portion of the holder. As a result, if the circumferential wall of the base were to have the same thickness throughout, due to the abutment of the tilted bottom of the base with the cap of the holder, the base is forced upwards away from the neck, despite the reverse tapers of the neck and the base. To overcome this potential problem, as discussed above, ring34is formed at the lowermost portion of base22to have a wall that is substantially thinner than the rest of the base so that it is more flexible than the rest of the base. Given its flexibility, when there is flexure or tilting of the neck relative to the body of the holder due to rotational force applied thereagainst, the portion of ring34that is tilted downward would flex or collapse onto the cap of the holder2to absorb the downward movement of the base, instead of biasing base22upwards away from neck12. As a result, base22is continually and self adjustedly biased against neck12, while at the same time not forced by the flexure of the neck to eventually pop or push off from neck12. Ring34therefore acts as a mechanism to self-adjust the positioning of the base relative to the neck. As discussed above, the flexing of the neck relative to the holder body in most instances is quite slight and therefore may not be noticed by casual observation.

The contact between ring34of base22and cap10of holder4may best be seen inFIG. 11.FIG. 11also shows recess36and counterbore36a, and the space between the chamfered area of neck12relative to recess34. The counterbore recess36at the distal end22cof the base provides the space to allow the ring to flex without the proximal end of the base coming into contact with the chamfer12of neck12. Note that even though there is a frictional force between the bottom edge of the ring and the cap of the holder, the main frictional force that causes the friction force or drag between the base and the neck, when the base is rotated relative to the neck, results from flats28a-28cmaking contact with the outer wall20of neck12. Thus, with the reverse tapers for the neck and the base being configured such that inner wall22bof base22substantially form fits about outer wall20of neck12, and with ring34providing the force to bias the base to the neck and also to absorb flexure movements of the neck, base22is mounted about neck12in a self-adjusting manner.

The friction between the contacting surfaces of the inner wall of the base and the outer wall of the neck may be pre-determined by empirical trials or studies so that the base may be rotated relative to the neck smoothly with a proper drag in a controlled and smooth manner, when a force sufficiently larger than the predetermined friction is applied to the housing to rotate the base relative to the neck. Due to the predetermined friction, once the force is removed, the rotation of the base relative to the neck would stop to thereby position the needle protection housing at the appropriate orientation relative to the holder, for example enabling the user to readily observe the bevel of the needle as the needle is intravenously inserted into the patient. Thus, the inventive mounting of reverse tapered walls effects a controlled rotation of the components, i.e., the base of the needle protection housing and the neck of the tube holder as discussed above.

Even though the instant invention is discussed with reference to a medical device such as the Vacutainer Holder attached with a rotatable needle protection housing, it should be appreciated that the inventive reverse taper configuration may also be applicable for other plastic components that are mounted relative to each other to achieve controlled rotation of one component relative to the other at different orientations with a controlled drag.

The inventive reverse taper configuration concept may also be incorporated to connection or end fittings to connect or couple two components, parts or devices. In addition to using circular shaped connection fittings, to couple devices that do not require controlled rotation, configurations for the connection fittings may have complementary shapes that are other than circular or round. For this embodiment, the connection fittings (or simply fittings) of the components, parts or devices (may be referred to simply as devices) have coacting surfaces that are not rounded or circumferential. Some such non-circular exemplar reverse tapered coacting surfaces may include oval, square or rectangular, hexagonal. multi-sided, etc. The devices may include conduits, tubings and catheters that may be used, but not necessarily, in medical settings to convey fluid and/or materials along the coupled devices. The devices may also include fluid or material non-conveying components if the purpose of the fittings is simply to securely couple the two components. Of course, one of the to be coupled devices may be the vacuum tube holder and the other the needle protection housing as described above, with the connection fittings being the neck and the collar pivotally connected to the housing. As with the tube holder embodiment described above, the reverse tapered connection fittings of the devices are made of conventional medical plastics (and possibly a shape memory or retaining metal) that have the elasticity to enable those fittings to be press fitted together and then return to their original shapes to effect the coupling. With non-circular reverse tapered coacting coupling connection fittings, the devices that are connected with those fittings are not, and are not meant to be rotatable.FIGS. 12, 13 and 14hereinbelow illustrate examples of some non-circumferential reverse taper fittings.

With reference toFIG. 12, two to be coupled or connected devices38and40are shown. Devices38and40each have a conduit (or catheter or tubing)38aand40a, respectively, extending to corresponding complementary connection fittings38fand40f. Each of the connection fittings28fand40fis shown to have a distal square end designated38f1and40f1, respectively. The connection fittings each are formed by four sidewalls,38f3a-38f3dfor fitting38f(with only sidewalls38f3aand38f3blabeled), and sidewalls40f3a-40f3dfor fitting40f(with only sidewalls40f3aand40f3blabeled). As the exemplar devices38and40are conduits, respective openings38f5are formed by the respective four sidewalls of each of the fittings28and40.

For theFIG. 12embodiment, fittings38and40are shown to have complementary configurations that enable those fittings to mate to each other. Connection fitting38may be considered a male fitting while connection fitting40may be considered the female fitting. The distal end38f1of fitting38fhas a dimension slightly smaller than that of distal opening40f5of fitting40f. Given that the connection fittings38fand40fare molded or manufactured from plastics material and therefore each have the characteristic elasticity of plastics material, fitting38fmay be matingly inserted into fitting40f, when the two connection fittings are mated to each other, for example by press fitting. Once mated to and positioned within the interior cavity of fitting40f, the outer surfaces of the sidewalls38f3a-38f3dof fitting38fwould return to their memory positions to be in intimate contact with the corresponding inner surfaces of sidewalls40f3a-40f3dof fitting40f. For the sake of brevity, the outer surfaces of the sidewalls38f3a-38f3dof fitting38fmay simply be referred to as the outer sidewalls of fitting38f, while the inner surfaces of sidewalls40f3a-40f3dmay simply be referred to as the inner sidewalls of fitting40f.

As exaggeratedly shown inFIG. 12, each of the outer sidewalls of fitting38fis tapered from the distal end38f7of fitting38fto its proximal end38f9at an angle θ, which may be the same angle that was described above with respect to the tube holder embodiment. Connection fitting40fis also shown to have four sidewalls where there is a reverse taper provided at each of the inner sidewalls at an angle θ′ that extends from the distal opening40f7of fitting40fto its proximal end40f9. As described above with respect to the tube holding embodiment, angles θ and θ′ are the reverse of each other so that the outside sidewalls of connection fitting38fand the inside sidewalls of connection fitting40fhave reverse tapers. Accordingly, once connection fittings38fand40fare press fitted together, not only are the corresponding outer sidewalls of fitting38fand the inner sidewalls of devices38in intimate contact with each other, that the fittings are reverse tapered to each other means that fittings38fand40fare securely coupled together. As a result, devices38and40are securely coupled to each other. In the exemplar embodiment shown inFIG. 12, after coupling, given that devices38and40are conduits, a fluid, or other material, is passable or can be conveyed between the two devices.

Note that although the connection fittings are shown with respective openings to allow passing of fluid or other material between the devices, it should be appreciated that in the event that the devices to be coupled are devices that are not used to transfer fluid or other material therebetween, no opening may need to be formed for the male connection fitting of those devices. In other words, openings38f5for fitting38fis not needed for mating to opening40f5of fitting40f, which may have a closed proximal end40f9. It should be appreciated that those closed ended connection fittings nonetheless are reverse tapered to each other so that once press-fittedly connected or mated to each other, devices38and40are securely coupled together, and would ordinarily not be removable from each other unless a greater than normal force is applied to pull or remove the connection fittings away from each other. Such non-fluid or material transfer devices that are coupled by reverse tapered fittings may for example be rods or shafts.

FIG. 13is an illustration of another embodiment of to be connected fittings having complementary reverse tapered configurations that allow for easy engagement of two devices. In the embodiment shown inFIG. 13, to be connected or coupled devices42and44each have connection fittings42fand44f, respectively, extending from corresponding tubings42aand44a. The connection fittings42fand44feach have an oval shape with respective openings42f1and44f1. The outside wall of fitting42finclines from opening42f1to the junction where the tubing meets tubing42aat an angle θ. The wall, specifically the inside wall of fitting44fhas a reverse incline from opening44f1to tubing44aat an angle θ′. Thus, when connection fittings42fand44fare mated together by for example press-fitting, devices42and44are securely coupled together. As in the case of the connection fittings having the square configuration shown inFIG. 12, the oval shaped configuration of the connection fittings ofFIG. 13embodiment prevents devices42and44from rotating relative to each other once they are coupled by means of their respective connection fittings42fand44f. Also as described above, even though openings are shown in theFIG. 13oval shape configured connection fittings to enable fluid to pass between devices42and44once those connection fittings are matingly coupled to each other, in those cases where no fluid or material is to be transferred between the devices, opening42f1of connection fitting42is not needed, i.e., fitting42may be a solid fitting or its distal end is sealed or closed.

FIG. 14illustrates yet another embodiment of the instant invention in which the connection fittings for connecting two devices together have complementary reverse tapered configurations that are not circular or round. In the embodiment shown inFIG. 14, devices46and48have connection fittings46fand48f, respectively, that are multi-sided, in this instance in the shape of a hexagon or a hexagonal configuration. Fittings46fand48fextend respectively from tubings46aand48a, or some other conduits or shafts or members. As with the earlier embodiments, fitting46fhas a taper that extends from its distal end, represented by distal opening46f1, to its proximal end46f2along each of its sidewalls46f3at an angle θ. Connection fitting48ffor device48, on the other hand, is tapered from its distal end, represented by the open end of opening48f1to its proximal end48f2, along its sidewalls48f3(assuming the sidewalls do not vary in thickness along their respective lengths). The taper for the inner sidewalls of connection fitting48fis labeled θ′ which is reverse of the angle θ for the outer sidewalls of connection fitting46f. As a consequence, when connection fitting46fis matingly inserted into opening48f1of fitting48f, devices46and48are securely coupled together, due to the complementary reverse tapered configurations of their respective connection fitting46fand48f. As discussed above, opening46f1for fitting46fis necessary only if devices46and48are tubings or conduits or catheters, that are connected to enable fluid or other material to pass between those devices. But if no fluid or other material is to be conveyed between the devices, then fitting46fdoes not have to have an opening, and in fact may be a solid connection fitting with the same tapered outer sidewall configuration.

For the coupling of the devices with connection fittings that have complementary reverse tapered configurations, even though only three different embodiments are shown, it should be appreciated that other configurations for the connection fittings of to be coupled devices may also be used, so long as the outer sidewall(s) of one device and the inner sidewall(s) of the other device are reverse tapered and the connection fittings have complementary configurations that allow the fittings to be matingly connected to each other to thereby couple the devices together. it should further be appreciated that even though the exemplar embodiments ofFIGS. 12-14each show that the outer wall of the female fittings40f,44fand48fhave the same configured shapes as their respective inner walls, in practice, the outer walls of the female fittings may have shapes different form their respective openings (or bores) so long as the openings of those female fittings maintain the same complementary configurations as their respective male fittings that are to be mated to those openings. In other words, the sidewall(s) of the female fittings may have different thickness along different portions thereof. For example, the female fitting48fof theFIG. 14embodiment may have a circumferential outer wall while its inner wall would continue to have six sidewalls forming a hexagonal configuration that is complementary to the hexagonal configuration of the male fitting46f. Thus, the male and female fittings46fand48ffor the example continue to have configurations that are complementary to each other since the portions of those fittings that are to be fittingly connected to or matable with each other are in complement with each other.

It should be appreciated that the present invention is subject to many variations, modifications, and changes in detail. Thus, all matter described throughout this specification and shown in the accompanying drawings should be interpreted as illustrative only and not in a limiting sense. Accordingly, it is intended that this invention be limited only by the spirit and scope of the hereto appended claims.