Asymmetrical-force connector system

An asymmetrical-force connector system includes a socket having a longitudinally-oriented shaft bore defining a bore axis. A spring-receiving cavity is coaxial with the bore axis and extends laterally around the shaft bore. The spring-receiving cavity has an inner circumference that is open to the shaft bore. A toroidal canted coil spring is located at least partially within the spring-receiving cavity. The toroidal canted coil spring has an inner spring circumference. A connector pin including a maximum shaft circumference is configured for selective sliding insertion into the shaft bore longitudinally from the front housing face. A v-groove extends laterally inward from the maximum shaft circumference toward the pin axis and defines a minimum shaft circumference. The connector pin is located in a maintenance position within the shaft bore when at least a portion of the toroidal canted coil spring laterally extends into the v-groove beyond the maximum shaft circumference.

TECHNICAL FIELD

The present invention relates to an apparatus and method for use of an asymmetrical-force connector system and, more particularly, to an asymmetrical-force connector system for use in a medical device.

BACKGROUND OF THE INVENTION

In the medical field, it is becoming increasingly common for small electrical devices to be implanted into a patient's body and dwell within to provide some therapeutic effect on an ongoing basis. For example, implanted neuroprosthetic devices may include a stimulating electrode, a computing or instruction-providing block connected to the electrode, and a power source (e.g., a battery) connected to the computing block and/or the electrode.

In some use environments, the electrode, computing block, and/or power source may be located some distance from each other because of, for example, space constraints in the area of the body being treated. Accordingly, medical providers often will provide these components in a modular format, with connecting wires of any desired length(s) linking the components into a complete system. In this manner, the components can each be located within the patient's body as desired, relatively unconstrained by available space at/near the therapeutic site.

During implantation surgery for a modular device, the surgeon places each component (electrode, computing block, power source, wire(s)) of the device into its desired position and, shortly before or after the placement, connects the components together by plugging a male connecting tip on one component into a female connecting socket on another component. This modular construction, having reversible connections, allows for custom-combined groups of components to be used for a particular patient (e.g., customized connecting wire lengths) as well as leaving open the potential of easy maintenance, upgrades, and/or replacement of components as opposed to a hard-wired, non-modular device.

Due to saline, blood, or other operating-room fluids and/or patient tissues, the components are often rather slippery and may be difficult to grasp firmly due to these extra substances and/or the position/location of the component within the body. Therefore, the surgeon wants the plug-in portion of the operation (insertion of the male connecting tip into the female connecting socket) to occur reliably with relatively low insertion force, to avoid damaging nearby body tissues or other components of the device.

However, a certain amount of retention force is needed to insure that the connection has been made firmly enough to resist inadvertent post-operative pull-out or retraction forces, such as those generated on the body tissues surrounding the components by normal movement of the patient. Accordingly, it can be difficult to balance the concurrent desires for relatively small insertion forces and relatively large retraction forces in connected-component medical devices. Currently, set screws are used to help maintain the connection. However, in the operative environment, the small size of the set screws and “envelope” of space needed to manipulate the installation tools adds unwanted complexity and inconvenience to an already difficult task.

SUMMARY OF THE INVENTION

In an embodiment of the present invention, an asymmetrical-force connector system is described. A socket includes a housing shell, having oppositely disposed front and rear housing faces and a longitudinally-oriented shaft bore extending longitudinally through the housing shell and linking the front and rear housing faces. The shaft bore defines a bore axis. A spring-receiving cavity is coaxial with the bore axis and extends laterally around an entirety of the shaft bore. The spring-receiving cavity has an inner circumference that is open to the shaft bore. A toroidal canted coil spring is located at least partially within the spring-receiving cavity. The toroidal canted coil spring has a laterally-oriented inner spring circumference coaxial with the bore axis and extending laterally around an entirety of the shaft bore. A connector pin is configured for selective sliding insertion into the shaft bore longitudinally from the front housing face. The connector pin includes an elongate shaft having proximal and distal shaft ends and defining a pin axis. The shaft has a laterally-oriented maximum shaft circumference that is larger than the inner spring circumference. A v-groove extends laterally inward from the maximum shaft circumference toward the pin axis. The v-groove is located longitudinally between the proximal and distal shaft ends and extends circumferentially around the entirety of the shaft to define a minimum shaft circumference as the apex of an included angle, as viewed perpendicular to the pin axis. The v-groove has a proximal groove face extending laterally and proximally outward from the minimum shaft circumference of the shaft at an acute angle with respect to the pin axis and a distal groove face extending laterally and distally outward from the minimum shaft circumference of the shaft at an obtuse angle with respect to the pin axis. The connector pin is located in a maintenance position within the shaft bore when at least a portion of the connector pin is located longitudinally between the front and rear housing faces with at least a portion of the toroidal canted coil spring laterally extending into the v-groove beyond the maximum shaft circumference.

In an embodiment of the present invention, a method of use of an asymmetrical-force connector system is described. A socket is provided. The socket includes a longitudinally-oriented shaft bore extending thereinto to define a longitudinal bore axis. The socket includes a toroidal canted coil spring having an inner spring circumference extending laterally around the shaft bore. An elongate connector pin having a longitudinally asymmetrical v-groove extending laterally around a circumference of the connector pin is provided. At least a portion of the connector pin is inserted longitudinally into the shaft bore. At least a portion of the connector pin is passed through the inner spring circumference in a longitudinally-oriented insertion direction. The toroidal canted coil spring is compressed laterally outward from the bore axis by exertion of an insertion force against the toroidal canted coil spring with the portion of the connector pin passing therethrough. The toroidal canted coil spring is allowed to at least partially rebound from the insertion force by aligning the toroidal canted coil spring and the v-groove in the same longitudinal location relative to each other, such that at least a portion of the toroidal canted coil spring laterally enters the v-groove and a maintenance force develops laterally between the toroidal canted coil spring and the connector pin at the v-groove. The maintenance force is overcome with a retraction force to pass at least a portion of the connector pin through the inner spring circumference in a longitudinally-oriented retraction direction, longitudinally opposite the insertion direction. The toroidal canted coil spring is compressed laterally outward from the bore axis by exerting the retraction force against the toroidal canted coil spring with the portion of the connector pin passing therethrough. The connector pin is removed from the socket. The retraction force, to overcome the maintenance force and allow the connector pin to move in the retraction direction, is substantially greater than the insertion force to move the connector pin in the insertion direction due to the relative designs of the v-groove and the toroidal canted coil spring.

DESCRIPTION OF EMBODIMENTS

FIG. 1depicts a cross-sectional view of a prior art socket100which can be used with an asymmetrical-force connector system102according to the present invention. The socket100includes a housing shell104including oppositely disposed front and rear housing faces106and108, respectively. In the orientation ofFIG. 1, the front housing face106is toward the right side of the page and the rear housing face108is toward the left side of the page. However, one of ordinary skill in the art will understand that the directional conventions used herein for ease of description are not absolute, and that “front” and “rear” could be differently defined/used for various use environments of the present invention.

A longitudinally-oriented shaft bore110extends longitudinally through the housing shell104and links the front and rear housing faces106and108. The shaft bore110defines a bore axis112, which is collinear with a longitudinal axis of the depicted socket100.

The socket100also includes a spring-receiving cavity114which is coaxial with the bore axis112and extends laterally around an entirety of the shaft bore110. The term “lateral” herein is used to indicate a direction that is perpendicular to the bore/longitudinal axis112—i.e., a “lateral” direction extends into and out of the plane of the page inFIG. 1. The spring-receiving cavity114includes an inner circumference116that is open to the shaft bore110. As shown inFIG. 1, the inner circumference116is located at an apex of the v-shaped cross-section of the spring-receiving cavity114, for reasons which will be discussed below. However, the inner circumference116could be defined elsewhere on a spring-receiving cavity, particularly one having a cross-section that is not v-shaped. Optionally, a plurality of spring-receiving cavities114may be provided to a single socket100, with each of the spring-receiving cavities being longitudinally spaced from one another along the shaft bore110.

A toroidal canted coil spring118may be located at least partially within the spring-receiving cavity114. The toroidal canted coil spring118may have a laterally-oriented inner spring circumference120that is coaxial with the bore axis112and extends laterally around an entirety of the shaft bore110. The toroidal canted coil spring118may be, for example, similar to that shown in U.S. Pat. No. 4,893,795, issued 16 Jan. 1990 to Peter J. Balsells. A socket100, such as an example type which may be suitable for use with the present invention, is commercially available as the Bal Conn product line from Bal Seal Engineering, Inc. of Foothill Ranch, Calif.

The construction and orientation of the toroidal canted coil spring118, and related physical responses/properties of the socket100, may be of interest in particular use environments of the present invention.FIGS. 2A-2Dschematically depict various physical properties of example springs known in the art. Springs may be wound in either a right-hand or left-hand direction, and may also be canted, or skewed, in either direction.FIG. 2Adepicts an uncanted right-hand wound spring222.FIG. 2Bdepicts an uncanted left-hand wound spring224.FIG. 2Cdepicts a canted right-hand wound spring222C.FIG. 2Ddepicts a canted left-hand wound spring224C. The handedness of the spring windings is defined similarly to the way that right-hand or left-hand screw threads are defined.

To create a toroidal canted coil spring118, the two ends of a straight/linear canted spring222C or224C are connected together to form the donut- or circular-shaped toroidal canted coil spring118. Toroidal canted coil springs118can be inserted into the spring receiving cavity114in a clockwise or counterclockwise orientation and may be made from right-hand or left-hand wound springs. Accordingly, four different types of toroidal canted coil springs are available for use in the present invention:

It should be noted that that the spring of configuration #3 above is substantially the same spring as in configuration #1 except that the spring of configuration #3 is “upside down” as compared to that of #1. Similarly, the spring of configuration #4 is an inverted version of the spring of configuration #2. Because the apparent orientation and winding/canting directions of the springs are dependent upon the point of view of the observer (analogous to the hands of a clock seeming to move counterclockwise if viewed from a rear surface of the clock face), one of ordinary skill in the art will understand that the “upside down” characterizations above are, similarly, relative to the observer's position. Stated differently, if a clockwise-canted toroidal spring is viewed along the axis112in a first direction, that same spring would be identified as a counterclockwise-canted spring when viewed along axis112in a second direction that is opposite to the first direction. However, the spring configurations #1 through #4 can be used with the present invention as described herein, regardless of the perspective of the observer.

Each of these configurations of toroidal canted coil springs118may have different effects upon the socket100and other components of the asymmetrical-force connector system102described herein, due to the differing resistances and other physical responses of the four types of toroidal canted coil springs to applied forces. One of ordinary skill in the art will be able to select, optionally with the aid of experimentation, the type of toroidal canted coil spring118and other spring variables (material, processing [e.g., heat-treatment], dimensions, and the like) which result in a spring of the desired physical properties in a particular use environment of the present invention.

With reference back toFIG. 1, a laterally-oriented counterbore126may be provided. The counterbore126shown here is longitudinally interposed between the spring-receiving cavity114and the front housing face106, but may be located in any desired position with respect to other structures of the housing shell104, such as longitudinally interposed between the spring-receiving cavity114and the rear housing face108. Optionally, at least one washer128may be located in the counterbore126. When present, the washer128may have a longitudinally-oriented washer bore130extending therethrough, the washer bore130laterally surrounding the shaft bore110and being coaxial with the bore axis112. The washer(s)128may be provided for any suitable purpose. For example, when the spring-receiving cavity114is relatively “open” to the front and/or rear housing faces106and/or108(e.g., so that the toroidal canted coil spring118can be placed within the spring-receiving cavity114during assembly), a washer128may be placed/retained within an appropriately located counterbore126(e.g., as a later step in assembly) to prevent the toroidal canted coil spring from being able to exit the housing shell104by passing longitudinally out through the counterbore126. Particularly if the washer128is at least partially resilient, it may also or instead serve a sealing function by pressing laterally inward toward the bore axis112against a structure (not shown inFIG. 1) which is being inserted into the shaft bore110.

With reference now toFIG. 3, an intermediate member332may be provided to assist with formation of a multi-shell socket100′, shown inFIGS. 4-6. When present, the intermediate member332may include oppositely facing front and rear protrusions334and336, located longitudinally apart from one another along a seal axis338, along with a sealing disc340located longitudinally interposed between the front and rear protrusions.

Optionally, the socket100′ may include multiple housing shells104and their related components (toroidal canted coil springs118, washers128, or any other components), as shown in exploded view inFIG. 4, in assembled perspective view inFIG. 5, and in cross-sectional view inFIG. 6. In the multi-shell socket100′ shown in the Figures, first and second housing shells104A and104B are shown. However, any suitable number of housing shells104, oriented in any suitable direction(s) relative to one another, may be included in a socket100without harm to the present invention, optionally with appropriately designed intermediate members332interposed longitudinally between any or all adjacent housing shells to achieve a desired effect.

The intermediate member332may be longitudinally interposed between the first and second housing shells104A and104B, as shown inFIGS. 4-6. In this description, it is presumed that the first and second housing shells104A and104B are substantially the same, other than as noted in the below description. However, one of ordinary skill in the art could provide differently configured housing shells104collectively forming a socket100for a particular use environment of the present invention. In the below description, and as is shown in detail inFIG. 6, the first housing shell104A has oppositely disposed front and rear first housing faces106A and108A and a first shaft bore110A. The multi-shell socket100′ includes a second housing shell104B having oppositely disposed front and second rear housing faces106B and108B and a longitudinally-oriented second shaft bore110B extending longitudinally through the second housing shell104B and linking the front and second rear housing faces. The second shaft bore110B is located collinearly with, and is longitudinally adjacent to, the first shaft bore110A. A second spring-receiving cavity114B is coaxial with the bore axis112and extends laterally around an entirety of the second shaft bore110B. The second spring-receiving cavity114B has a second inner spring circumference120B that is open to the second shaft bore110B. A second toroidal canted coil spring118B is located at least partially within the second spring-receiving cavity114B, the second toroidal canted coil spring having a laterally-oriented second inner spring circumference120B coaxial with the bore axis112and extending laterally around an entirety of the second shaft bore110B.

As described herein, the first and second housing shells104A and104B are oriented in opposite longitudinal directions, as seen inFIG. 6. That is, the second front housing face106B is located longitudinally interposed between the rear first housing face108A and the second rear housing face108B. Stated differently, the first and second housing shells104A and104B are in “mirror image” orientations relative to each other across the intermediate member332. This may be helpful, for example, if the washers128A and128B are cooperatively acting to seal the toroidal canted coil springs118A and118B from each other. As another example of a situation in which the first and second housing shells104A and104B may be desired to be oriented in opposite longitudinal directions as shown, the properties of the particular types (handedness and cant direction) of toroidal canted coil springs118A and118B present may be different depending upon the longitudinal direction along which force is applied, and reversing these toroidal canted coil springs relative to each other may provide some desired force exertion characteristics to the socket100′.

In order to connect the first and second housing shells104A and104B together into the arrangement shown inFIGS. 5-6, both the front and rear protrusions334and336should be configured for insertion into corresponding structures of the first and second housing shells104A and104B. For example, and as shown in the cross-sectional view ofFIG. 6, the front protrusion334could be inserted in a counterbore126A in the first front housing face106A, while the second protrusion336could be inserted in a counterbore126B in the second front housing face106B. If these protrusion/counterbore components are sized appropriately, friction between the intermediate member332and the first and second front housing faces106A and106B may be sufficient to hold the intermediate member and first and second housing shells104A and104B together in a male/female mating arrangement to form a multi-shell socket100′. Alternatively or additionally, another structure or substance such as, but not limited to, a snap ring, a set screw, an adhesive, a weld, a housing/enclosure, or the like, may be provided to assist with maintaining the desired connections. Optionally, a resilient intermediate member332could provide some compressibility of the multi-shell socket100′ in the longitudinal direction, if desired.

When the intermediate member332is interposed longitudinally between the second front housing face106B and the rear first housing face106A as shown inFIGS. 4-6, the intermediate member332and first and second housings104A and104B cooperatively defining the shaft bore110therethrough. The intermediate member332, when present, may be provided for any desired purpose, including, but not limited to, providing connection of the first and second housing shells104A and104B to one another; providing electrical, mechanical, or any other type of insulation to (i.e., resistance to flow between) the bodies of the first and second housing shells; and/or providing sealing to an inserted structure in a similar manner to that of the aforementioned washer(s)128.

The sealing disc340may have a laterally-oriented inner intermediate circumference342, as shown inFIG. 3, that is longitudinally coaxial (i.e., located longitudinally spaced along the same bore axis112) with both of the first and second inner spring circumferences120A and120B. When present, the inner intermediate circumference342may be laterally smaller than both of the first and second inner spring circumferences120A and120B. Particularly if the intermediate member332is at least partially made of a resilient material, the intermediate member may provide a sealing function longitudinally between the first and second toroidal canted coil springs118A and118B and laterally against any structure located at least partially within the shaft bore110and at least partially laterally surrounded by the first and second housing shells104A and104B and/or any components thereof, as described below.

Incidentally, the uppermost housing shell104B, in the orientation ofFIG. 5, includes a groove544which may assist with identification/positioning by providing the user with a directional reference, or may be provided, in any desired location and having any desired configuration, to the socket100for any reason, such as to help the socket100engage with an installation tool (not shown) and/or engage with nearby structures, for example, when the socket forms a part of an asymmetrical-force connector system. This groove544, which may be present on any structure of the socket100, will not be further discussed herein.

FIG. 7depicts a portion of an optional use environment for the present invention. InFIG. 7, an interconnect device746includes a socket manifold748. Here, the term “manifold” is used to reference a device or structure which includes a plurality of multi-shell sockets100′, each of which is held substantially stationary relative to one another and each of which has a shaft bore110exposed to the ambient environment and available to help form an electrical connection. The multi-shell sockets100′ of the socket manifold748shown inFIG. 7are substantially identical to one another and are similar to the multi-shell socket100′ ofFIGS. 4-6, but it is contemplated that a variety of different types of sockets—multi-shell or otherwise—could be provided by one of ordinary skill in the art for a particular use application of the present invention.

The socket manifold748shown inFIG. 7includes a manifold housing750(shown as translucent inFIG. 7) laterally enclosing the plurality of multi-shell sockets100′. A manifold cap752engages with the manifold housing750to “cap” the manifold housing and enclose the multi-shell sockets100′ within the body of the socket manifold748. The manifold cap752includes at least one socket interface754, which usually will be equal in number to the number of sockets100′ in the socket manifold748. Each socket interface754holds a corresponding multi-shell socket100′ substantially in position within the socket manifold748—for example a protrusion (not shown) could extend longitudinally (i.e., substantially parallel to arrow “L” inFIG. 7) into the shaft bore110from the second rear housing face108B of the multi-shell sockets. This protrusion could be held therein using any desired means (e.g., adhesion, friction, mechanical [set screw, snap-fit, etc.] or the like) to prevent the multi-shell socket100′ from shifting within the manifold housing.

A plurality of manifold apertures756—one per socket100′, in most use environments of the present invention—are each longitudinally aligned with a shaft bore110from a “leading” end (here, first rear housing faces108A) of the multi-shell sockets100′. The manifold apertures756place the shaft bores110of their respective multi-shell sockets100′ into fluid communication with an ambient atmosphere. It is contemplated that, for most use environments of the present invention, the manifold apertures756will have a cross-sectional (i.e., perpendicular to longitudinal direction L) shape and size commensurate with those of the shaft bore110at the “leading” end (here, first rear housing faces108A) of the respective multi-shell sockets100′. The manifold apertures756could, instead, differ from the cross-sectional shape and/or size of the shaft bores110at the interface therebetween, for any desired reason.

To form the socket manifold748, the manifold housing750and manifold cap752could be provided separately and then assembled with the sockets100located within the enclosure cooperatively provided by the manifold housing and cap. Alternatively, at least a portion of the socket manifold748could be molded around the sockets100—for example, the sockets could be sub-assembled to a freestanding manifold cap752and the resulting sub-assembly potted or otherwise molded into a substantially solid manifold housing750that directly contacts and surrounds the sockets.

Turning toFIG. 8, an exploded view of the interconnect device746is shown schematically, though the socket manifold748(already shown in detail inFIG. 7) is left largely unnumbered, for clarity. At least one multi-shell socket100′ is in electrical contact with a first component858, via the socket manifold748or portions thereof. A plurality of connector pins860are in electrical contact, via a pin header862, with a second component864. The first and second components858and864may be of any type between which an electrical connection is desired to be made, such that the asymmetrical force connector system102is configured to pass electrical signals to and/or from the first component858and the second component864, via the interface between the socket100and the connector pin860. For most use environments of the present invention, there will be at least as many sockets100in the socket manifold748as there are connector pins860in the pin header862, with either a 1:1 correspondence in number and relative spacing/location/orientation between connector pins and sockets, or optionally instead a few “extra” sockets that do not have a corresponding connector pin. There could be fewer sockets100than connector pins860if, for example, “dummy pins” were used as locators or to “key” or otherwise align/orient a particular connector for a particular application.

Each connector pin860is inserted into its corresponding socket100(here, multi-shell sockets100′) via relative movement of those structures in a substantially longitudinal direction to place the first and second components858and864into electrical contact with each other via an electrically-connective interface formed between the sockets and their respective connector pins, as will be described below with reference to a single connector pin860and corresponding multi-shell socket100′. One of ordinary skill in the art will be able to provide an interconnect device746having any suitable number of sockets100, any suitable number of connector pins860(whether or not there are the same number of sockets and connector pins), and any desired physical arrangement of the connector pins on the pin header862and the sockets on the socket manifold748, for a desired use environment of the present invention. For example, and as shown by communication wires758inFIGS. 7 and 8, the interconnect device746could include any suitable number, type, and configuration of interconnect wires758to place the connector pins860into electrical, mechanical, or any other desired type of connection or communication with a first component858in any suitable manner. ThoughFIG. 8shows all of the multi-shell sockets100′ on a single socket manifold748and all of the connector pins860on a single pin header862, it is contemplated that multiple socket manifolds and/or pin headers, each of which would carry any desired number and type of sockets100or connector pins, respectively, could be used as/at a single interconnect device746site—for example, connector pins could be each electrically connected to a different component (third, fourth, and so on), with no common structure linking all of the connector pins together into the interconnect device.

FIG. 9is a side view of a single connector pin860of an asymmetrical-force connector system102. The connector pin860an elongate shaft966having proximal and distal shaft ends968and970, respectively, and defining a pin axis972. The shaft966has a laterally-oriented maximum shaft circumference974that is larger than the inner spring circumference120of the socket100. A v-groove976extends laterally inward from the maximum shaft circumference974toward the pin axis972. The v-groove976is located longitudinally between the proximal and distal shaft ends968and970and extends circumferentially around at least a portion of, and optionally the entirety of, the shaft to define a minimum shaft circumference978as the apex of an included angle α, as viewed perpendicular to the pin axis—that is, when the included angle α is viewed from a lateral direction as inFIG. 9. The included angle α may be in the range of 0-180 degrees.

The v-groove976is shown in the embodiment of the Figs. as having an angular, “pointed” apex at the intersection of proximal and distal groove faces980and982(e.g., the smallest-diameter portion along the pin shaft966, as shown inFIG. 9). Although, for ease of description, the v-groove976is shown and discussed as having this abrupt transition, it is also contemplated that the apex of the “v” groove may, for some embodiments of the present invention, have a more gradual, radiused transition between the proximal and distal groove faces980and982. In other words, the apex of the v-groove may be rounded in some embodiments, rather than the angular apex shown, for any desired reason, including, but not limited to, allowing for wider mechanical tolerances to ease manufacturing precision, avoiding a stress concentrator point, and affecting a mating function of the v-groove with another structure of the device. The below description is agnostic and apathetic as to the radiused/angular nature of the apex. Instead, the depicted embodiment is described herein with reference to the proximal and distal groove faces980and982. For this embodiment, it is merely contemplated that the apex is either angular (as shown) or has a rounded radius that is smaller than the corresponding radius of the canted coil spring118to facilitate the described interactions between these components.

Optionally, the distal shaft end970may have a terminal diameter TD (i.e. the diameter of the distal face of the shaft966), that is smaller than the maximum shaft circumference974. When this is the case, the distal shaft end970may “taper down” as shown inFIG. 9, or even to a relatively sharp point (e.g., an extremely small value for TD), to help locate and center the connector pin860with respect to the shaft bore110of a socket100. It is contemplated that the proximal shaft end968may be in electrical communication with a component (e.g., first or second component858or864) of an apparatus such as an implanted electrical medical device (not shown).

InFIG. 9, there are two v-grooves976A and976B, spaced longitudinally apart along the pin axis972and located between the proximal and distal shaft ends968and970. As both of the v-grooves976A and976B shown inFIG. 9are substantially identical, for the purposes of this description, they will be referenced interchangeably herein as “v-groove976”, with the description being common to both, except when some distinction is being drawn between the proximal-most v-groove976A and the distal-most v-groove976B. For clarity, each of the v-grooves976shown in the Figures include element numbers and callout lines which are not repeated for both v-grooves, but which should be presumed to reference corresponding structures in both v-grooves unless otherwise stated.

The v-groove976has a proximal groove face980extending laterally and proximally outward from the minimum shaft circumference978of the shaft966at an acute angle β to the pin axis972and a distal groove face982extending laterally and distally outward from the minimum shaft circumference of the shaft at an obtuse angle γ. The acute and obtuse angles β and γ may be chosen by one of ordinary skill in the art, using the teachings of the present invention, to provoke desired force responses in the toroidal canted coil spring(s)118of the socket100, as described below. Some example values that might be used for acute angle β are in the range of 0-90 degrees, for example, 2-10 degrees, or, as a more particular example, 5 degrees. Some example values that might be used for obtuse angle γ are in the range of 90-180 degrees, for example, 100-150 degrees. Since the difference between the acute and obtuse angles β and γ is equal to the included angle α, then, an example range of suitable values for the included angle α in some embodiments of the present inventions is 90-148 degrees.

In use, the connector pin860is configured for selective sliding insertion longitudinally into the shaft bore110, as will now be shown inFIGS. 10A-10Iand discussed with reference to these Figures. When one housing shell104is provided to an asymmetrical-force connector system102, the connector pin860will often be inserted longitudinally into the shaft bore110from the front housing face106, as shown in the arrangement ofFIG. 1. However, since a multi-shell socket100′ is shown inFIGS. 10A-10I, the “front housing face” in these Figures (i.e., the face into which the connector pin860is initially inserted) is actually the rear first housing face108A. To avoid confusion, the below description will maintain the front/rear and first/second housing appellations and orientations introduced inFIGS. 6-7and repeated inFIG. 10A, with the exception that a front socket face1084, encompassing the rear first housing face108A, is considered to be the “front” of the multi-shell socket100′, and a rear socket face1086, encompassing the rear second housing face108B, is considered to be the “rear” of the multi-shell socket. Under this convention, and with reference to longitudinal arrow L inFIG. 10A, the connector pin860enters the multi-shell socket100′ by longitudinal “insertion” movement from the right to the left, in the orientation ofFIGS. 10A-10I, and the connector pin exits the multi-shell socket by longitudinal “retraction” movement from the left to the right, in the orientation ofFIGS. 10A-10I.

In addition, the second housing shell104B and associated structures are similar to the first housing shell104A and therefore, structures of the second shell that are the same as or similar to those described with reference to the first housing shell have the same reference numbers with the addition of the suffix “B”—the suffix “A” is used herein to indicate a structure of, or related to, the first housing shell in a multi-shell socket100′. Description of common elements and operation similar to those related to the first housing shell104A will not be repeated with respect to the second housing shell104B.

One of ordinary skill in the art will realize that the front/rear and first/second housing appellations and static/dynamic directional indications used in the below description of the operation of the asymmetrical-force connector system102are somewhat arbitrary and depend heavily on the frame of reference of the observer and the number and orientations of housing shells104included in the socket100or100′. Accordingly, a system or device including similar structures and functions to those described with reference toFIGS. 10A-10Imay be described differently (e.g., front/rear faces could be thought of as being leading/trailing faces) while still, in practice, falling under the description and claims herein.

In order to insert the connector pin860into the multi-shell socket100′ via the sequence ofFIGS. 10A-10I, the user longitudinally and laterally aligns these two structures, as shown inFIG. 10A, with the connector pin prepared to enter the shaft bore110. Since the connector pin860and the multi-shell socket100′ remain laterally aligned throughout the depicted sequence, the pin axis972is presumed to be coaxial with the bore axis112throughoutFIGS. 10A-10I.

Continuing toFIG. 10B, at least a portion of the connector pin860(here, the distal shaft end970) is inserted longitudinally into the shaft bore110, optionally with centering and/or penetration assistance provided by the tapered feature near the distal shaft end of the pin shaft966. Particularly if the inner spring circumference120A is smaller than the maximum shaft circumference974, the distal shaft end970may exert a laterally-oriented insertion force upon the first canted coil spring118A while passing there through, to compress the first canted coil spring outward from the bore axis112. Even if no compressive force is exerted on the first canted coil spring118A, the connector pin860is subject to a longitudinally-oriented component of the insertion force that continues to slide the connector pin further into the shaft bore110in the insertion direction.

As shown inFIG. 10C, the tapered portion of the pin shaft966has passed beyond the first canted coil spring118A under the insertion force. When the inner spring circumference120A is sized for an “interference fit” with the connector pin860, a lateral component of the insertion force is present and is pushing the first inner spring circumference outward from the bore axis112. The first canted coil spring118A may resist this lateral “spreading” through the “compression” or “deflection” forces developed within the first canted coil spring. Optionally, this resistance developed in the first canted coil spring118A will help assist with laterally centering the pin shaft966within the bore axis112.

Because the first canted coil spring118A is configured with a first inner spring circumference120A which is smaller than the (at least local) maximum shaft circumference974, the connector pin860slides longitudinally past the first canted coil spring in contact therewith. Alternately, when the first canted coil spring118A is configured with a first inner spring circumference120A which is larger than the (at least local) maximum shaft circumference974, it is contemplated that the connector pin860could move longitudinally past the first canted coil spring without contact there between. This latter situation may occur, for example, if the first and second housing shells104A and104B, and/or components thereof, are differently dimensioned to achieve desired electrical and/or mechanical connections between the connector pin860and the multi-shell socket100′ in a nonuniform manner.

Once the connector pin860has been inserted sufficiently into the bore axis112, the first canted coil spring118A is allowed to at least partially rebound from the laterally-oriented component of the insertion force, as shown inFIG. 10D, through alignment of the first canted coil spring and the second v-groove976B in the same longitudinal location relative to each other—that is, both of these structures are located in substantially the same location along the bore axis112. The relatively sudden decrease in circumference of the pin shaft966caused by the obtuse angle α of the second v-groove976B allows the first canted coil spring118A to “snap” into the v-groove. In other words, at least a portion of the first canted coil spring118A laterally enters the second v-groove976B under influence of the spring force developed within the first canted coil spring to bias the inner spring circumference120A into its resting state. A maintenance force, therefore, develops laterally between the first canted coil spring118A and the connector pin860at the second v-groove976B. Optionally, the “snapping” action of the asymmetrical-force connector system102provides the user with a tactile and/or aural indication that the first stage of engagement between the connector pin860and the multi-shell socket100′ has occurred.

In addition, for many use environments of the present invention, the asymmetrical-force connector system102will complete an electrical circuit by virtue of the first canted coil spring118A coming into electrical contact with at least a portion of the second v-groove976B. In other words, the first canted coil spring118A may create an electrical circuit/connection by coming into concurrent electrically conductive contact with both the second v-groove976B and the first spring-receiving cavity114A. In this manner, electrical signals can be passed between the connector pin860and the socket100.

Also optionally, when the components of the asymmetrical-force connector system102have reached the arrangement shown inFIG. 10D, the inner intermediate circumference342could exert a force laterally against the pin shaft966when the connector pin860is located in a maintenance position, with a canted coil spring of the socket100“snapped” into a corresponding v-groove of the connector pin. Particularly if the intermediate member332is made of a relatively resilient material, the inner intermediate circumference342could thus perform a “sealing” function against the pin shaft966to prevent fluid (e.g., blood) from flowing between the first and second canted coil springs118A and118B, and perhaps shorting out the electrical connections desired by the user of the asymmetrical-force connector system102.

As the connector pin860continues to move in the insertion direction (toward the left, in the orientation ofFIGS. 10A-10I), the pin shaft966enters further into the shaft bore110. As shown inFIG. 10E, the laterally oriented maintenance force existing between the first canted coil spring118A and the second v-groove976B in theFIG. 10Dview has been overcome via force exerted to move the connector pin860in the insertion direction. While the asymmetrical-force connector system102continues along the insertion sequence ofFIGS. 10A-10I, the relatively gradual slope of the proximal groove face980A (a product of the acute angle β) pushes laterally outward from the bore axis112against the first inner spring circumference120A to overcome the maintenance force and thus “ramp” the first canted coil spring118A out of the second v-groove976B and into the arrangement ofFIG. 10F.

InFIG. 10F, the first inner spring circumference120A of the first canted coil spring118A is once again held “open” by a non-v-grooved portion of the pin shaft966—here, a portion of the pin shaft having the maximum shaft circumference974is located longitudinally aligned (i.e., within the same cross-section taken perpendicular to the bore axis112) with the first canted coil spring118A. Also inFIG. 10F, the distal shaft end970has passed through the second canted coil spring118B and the tapered area of the pin shaft966is pushing the second inner spring circumference120B laterally outward from the bore axis112in much the same way that the pin shaft dilated the first inner spring circumference120A inFIG. 10B.

Proceeding in the insertion sequence fromFIG. 10FtoFIG. 10G, both the first and second canted coil springs118A and118B are being held “open” by a laterally-oriented component of the insertion force which is driving the connector pin860to slide past the first and second canted coil springs. As the push-type insertion motion continues, under the influence of at least the longitudinal component of the insertion force, the components of the asymmetrical-force connector system102enter the relative positioning/arrangement shown inFIG. 10H.

InFIG. 10H, the first and second canted coil springs118A and118B have both “snapped” into the first and second v-grooves976A and976B, respectively, similar to the “snapping” action described above with reference to the initial groove/spring engagement shown inFIG. 10D. In the arrangement ofFIG. 10H, the first and second canted coil springs118A and118B have both been subjected to a relatively abrupt reduction in the circumference of the pin shaft966, from the (at least locally) maximum shaft circumference974to the (at least locally) minimum shaft circumference978at the apex of the first and second v-grooves976A and976B, due to the obtuse angles α of these two v-grooves. This “snapping” action could provide the user with a tactile and/or aural indication that the connector pin860has become fully engaged with the multi-shell socket100′. The connector pin860and multi-shell socket100′ may remain in theFIG. 10Harrangement (A.K.A., a “maintenance position”) to achieve a relatively long-term indwelling mechanical and/or electrical connection via the asymmetrical-force connector system102. Stated differently, the connector pin860is located in a “maintenance position” within the shaft bore110when at least a portion of the connector pin is located longitudinally between the front and rear socket faces1084and1086(which could be front or rear housing faces, as discussed above), with at least a portion of at least one of the first and/or second canted coil springs118A and118B laterally extending into at least one of the first and second v-grooves976A and976B, the canted coil spring extending “beyond” (i.e., further laterally inward from) the maximum shaft circumference974. Optionally, the first and/or second v-groove976A and976B may be held in mechanical and/or electrical contact with a respected first and/or second canted coil spring118A and118B via a maintenance force when the connector pin860is located in the maintenance position within the shaft bore110.

Also optionally, and as shown in the Figures, the connector pin860could include an insulator band1088. Particularly when the first and second canted coil springs118A and118B are used to create an electrical connection between the first and second v-grooves976A and976B and the respective spring-receiving cavities114A and114B, the insulator band1088could be configured to contact, or even “seal” against via lateral force, the inner intermediate circumference342of the sealing disc340of the intermediate member332. As shown inFIG. 10H, this “sealing” function between the insulator band1088and the intermediate member332may help to electrically and/or physically isolate the first and second housing shells104A and104B from each other.

In addition, some component of the asymmetrical-force connector system102or a related structure could be used to provide a “stop” function and avoid unwanted over-insertion of the connector pin860into the shaft bore110. For example, as the connector pin860is inserted into the multi-shell socket100′, a shoulder1090(here, an increased-diameter structure that is too large to fit into the shaft bore110) or other “stop” feature could be provided. When present, the shoulder1090or other “stop” feature could have a predetermined longitudinal positioning with respect to at least one of the first and second v-grooves976A and976B to physically interfere with insertion of the connector pin860into the multi-shell socket100′. Using the depicted shoulder1090as an example, the shoulder could impinge upon the front socket face1084to halt longitudinal movement of the connector pin860in the insertion direction.

From the maintenance position inFIG. 10H, the connector pin860may be at least partially retracted from the shaft bore110under the influence of a retraction force, oppositely directed from the insertion force (i.e., exerted from the left toward the right side ofFIGS. 10A-10I), into the retraction position ofFIG. 10I. As the connector pin860is pulled in the retraction direction, the first and second canted coil springs118A and118B come into contact with the distal groove faces982A and982B. Because of the relatively large obtuse angles α of the first and second v-grooves976A and976B, the first and second canted coil springs118A and118B must be relatively suddenly compressed laterally outward to permit passage there through of the pin shaft966. The retraction force must therefore be sufficient to overcome the maintenance force and “jump” the first and second inner spring circumferences120A and120B laterally outward to permit passage of the maximum shaft circumference974there through as the connector pin860is retracted or withdrawn from the multi-shell socket100′.

As previously mentioned, an insertion force, which may be primarily longitudinally-oriented, is exerted upon the connector pin860to advance the first and second distal groove faces982A and982B of the first and second v-grooves976A and976B past the first and second canted coil springs118A and118B. This total insertion force may include needed force to advance the second proximal groove face984B past the first canted coil spring118A, as shown inFIG. 10E, as well. A maintenance force, which may be primarily laterally-oriented, may then be developed between the first and second v-grooves976A and976B and the first and second canted coil springs118A and118B to hold the connector pin860and the multi-shell socket100′ in the maintenance position. A retraction force, which may be primarily longitudinally-oriented, is then exerted upon the connector pin860to retract the first and second proximal groove faces984A and984B of the first and second v-grooves976A and976B past the first and second canted coil springs118A and118B. This total retraction force may include needed force to retract the second distal groove face982B past the first canted coil spring118A, as well.

In many use environments of the present invention, an “easy-in, tough-out” relationship between the connector pin860and the multi-shell socket100′ may be desired. For example, and as discussed in the background section of this application, a user may wish to connect implanted medical devices using a relatively low insertion force, but the indwelling asymmetrical-force connector system102may desirably have a relatively high retraction force to resist pullout or disconnection during a maintenance phase of ordinary use of the medical devices. This asymmetry may be achieved in some embodiments of the present invention by coordinating orientation of one or more of the canted coil springs118of the system. For example, and with reference to the previously discussed spring configurations #1 through #4, both the first and second canted coil springs118A and118B in a completed multi-shell socket100may be oriented in the same direction within their respective spring-receiving cavities114A and114B, as viewed by an outside observer (e.g., inFIGS. 10A-10I), even though other components of the first and second housing shells104A and104B may be mirror images of each other. The described asymmetry may be increased through design of the v-grooves976, and particularly the obtuse and acute angles α and β. The asymmetrical-force connector system102of the present invention can be configured to require a retraction force that is substantially greater than the insertion force. In other words, while the acute angle β helps support electrical and/or mechanical contact between the connector pin860and the multi-shell socket100′ when these components are in the maintenance position, the obtuse angle α contributes to a relatively steep distal groove face982which affects the retraction force needed to remove the connector pin from the multi-shell socket.

The term “substantially greater” is used herein to indicate that the retraction force is at least measurably larger than the insertion force—for example, for some embodiments of the present invention, the (larger) retraction force could be in the range of 1.50-10.00 Newtons, as opposed to a (smaller) insertion force in the range of 0.25-5.00 Newtons. The retraction and insertion forces for a particular use environment of the present invention could be “tuned” or controlled by the choice of obtuse, acute, and/or included angles α, β, and γ for the v-groove(s)976and/or by choice of handedness, installation orientation, and/or canting direction for at least one canted coil spring118. Optionally, the retraction and insertion forces may bear a predictable relationship to each other (e.g., proportional), which could arise from particular configurations of the first and second canted coil springs118A and118B.

The dimensions and configurations of the first and second canted coil springs118A and118B, as well as other components of the asymmetrical-force connector system102, may also be provided by one of ordinary skill in the art to achieve desired insertion and retraction resistances in a single assembly. For example, for certain use environments of the present invention, 32-36 rotations (coils) of the canted coil springs118A and118B may provide desired insertion and retraction resistances. The inner spring circumferences120A and120B may be, for example, in the range of 0.034-0.040 inches. As another example, and particularly in medical device use environments, the socket100itself could have fairly small dimensions, such as a lateral outer diameter in the range of 0.104-0.112 inches and a longitudinal height in the range of 0.165-0.170 inches. It has been found that, particularly for diminutively-sized sockets100, currently commercially available canted coil springs118having the same nominal physical properties may vary widely in actual dimensions and spring forces. Accordingly, the dimensions and interactions of the components of the asymmetrical-force connector system102which collectively provide the different retraction and insertion forces may be designed and/or adjusted to account for the variances in commercially available canted coil springs118.

From the arrangement shown inFIG. 10I, the retraction force may be maintained to reverse the sequence of operation shown inFIGS. 10A-10Hand remove the connector pin860from the multi-shell socket100′. The asymmetrical-force connector system102then is in a disassembled state. Depending upon the use environment of the present invention, the asymmetrical-force connector system102may then be reconnected, possibly with differently configured structures (e.g., a connector pin860electrically connected to a different device component) through repetition of the insertion sequence ofFIGS. 10A-10I.

Optionally, and with reference toFIGS. 11-12, a port-plug1192could be provided to fill an unused shaft bore110(e.g., of the socket manifold748) to prevent entry of undesired substances (e.g., blood) from an ambient environment. The port-plug1192and associated structures are similar to the connector pin860and therefore, structures of the port-plug that are the same as or similar to those described with reference to the connector pin have the same reference numbers with the addition of the suffix “C”. Description of common elements and operation similar to those related to the connector pin860will not be repeated with respect to the port-plug1192.

The port-plug1192includes a shaft966C which is sized to extend into/through the shaft bore110of both the first and second housing shells104A and104B of the multi-shell socket100′, but only a single v-groove976C is provided on the port-plug. A stub end1194is located on the proximal shaft end968C. The port-plug1192is inserted into the shaft bore110substantially similarly to the insertion of the connector pin860shown inFIGS. 10A-10Iand described above. However, since the port-plug only has a single v-groove976C, the second inner spring circumference120B of the second canted coil spring118B will remain laterally forced/“stretched” outward from the bore axis112when the first inner spring circumference120A of the first canted coil spring118A has “snapped” into the v-groove976C of the port-plug. Optionally, the shaft966C or other components of the port-plug1192may include insulator bands or other insulating or conducting features (not shown) to achieve long-term electrical and/or mechanical isolations or connections when the port-plug is used to block an unused socket100of an asymmetrical-force connector system102. In other words, the port-plug1192could act as a “blind” connector pin860and cap off a proximal end of the shaft bore110to provide a plug function to the asymmetrical-force connector system102when the port-plug1192type connector pin860is located in a maintenance position within the shaft bore.

The purpose of the single v-groove976C configuration of the port-plug1192is at least in part to avoid wear on the first canted coil spring118A of a multi-shell socket100′ such as that ofFIGS. 10A-10I. The steeper the obtuse angle α of a particular v-groove976, the higher retraction force will be needed to remove a connector pin860or a port-plug1192from a socket100and therefore the more stress will be seen by a canted coil spring118interacting with that v-groove.

“Deflection cycling” of the canted coil springs118(i.e., the compression/release cycle caused by interaction with a v-groove976) during connector pin860insertion and retraction is a significant contributor to wear or even failure of the canted coil springs. The diminutive canted coil springs118used in miniature use applications such as medical device connections may fail after fewer, possibly far fewer, than one hundred of these deflection cycles. The first canted coil spring118A of a multi-shell socket100′ will see twice as many deflection cycles in use than the second canted coil spring118B of the same socket, because the first canted coil spring interacts with both the first and second v-grooves976A and976B during insertion/retraction of the connector pin860, while the second canted coil spring118B only interacts with the second v-groove976B. However, mere compression (i.e., being pressed outward by the shaft) does not have as much of a deleterious effect on the canted coil springs118as does deflection cycling.

Moreover, the port-plug1192has a relatively short stub end1194that is not subject to the pullout forces that may be developed in a connecting wire or device component extending a significant distance away from a connecting pin860in maintenance position in a socket100. Accordingly, the port-plug1192does not need to be held as firmly within the shaft bore110as would an “active” (i.e., non-plug-type) connector pin860. Since a reduced magnitude retraction force is acceptable for a port-plug1192and reduced deflection cycling may be desirable to support later usage of the port-plug-blocked socket100with an active connector pin860, a port-plug having a single v-groove976C, longitudinally aligned with the first canted coil spring118A in the maintenance position, may be an acceptable compromise to save wear on the first and second canted coil springs118A and118B during the lifetime of the socket100.

While the above description uses an electrical connection between first and second components858and864as an example, the interconnect device746, or subassemblies/elements thereof, could also or instead be used to make a mechanical connection between the first and second components, even if no electrical connection exists at the time of connection formation or at any other time. The first and second components858and864, along with any additional components (not shown) which are also electrically connected using the interconnect device746, may be components of any type of apparatus/device, such as, but not limited to, an implanted medical device (not shown).

It should also be understood that the number and type of canted coil springs118in the multi-shell socket100may provide a multiplier value to the quantitative insertion and retraction forces. For example, with all other factors being equal, providing a second canted coil spring118B arrangement which is substantially similar to a first canted coil spring118A which is already present would effectively double the forces developed during operation of the asymmetrical-force connector system102. Similarly, providing a third canted coil spring arrangement (not shown) would effectively triple those forces. One of ordinary skill in the art will be able to specify types and numbers of canted coil springs118to achieve desired forces for a particular use environment of the present invention.

While aspects of the present invention have been particularly shown and described with reference to the preferred embodiment above, it will be understood by those of ordinary skill in the art that various additional embodiments may be contemplated without departing from the spirit and scope of the present invention. For example, the specific methods described above for using the asymmetrical force connector system102and/or interconnect device746are merely illustrative; one of ordinary skill in the art could readily determine any number of tools, sequences of steps, or other means/options for placing the above-described apparatus, or components thereof, into positions substantively similar to those shown and described herein. Any of the described structures and components could be integrally formed as a single unitary or monolithic piece or made up of separate sub-components, with either of these formations involving any suitable stock or bespoke components and/or any suitable material or combinations of materials such as, but not limited to, stainless steel, titanium, platinum, nickel-cobalt alloy MP35N, Nitinol, Polyether ether ketone, epoxies, urethanes, metals, polymers, ceramics, and the like; however, the chosen material(s) should be biocompatible for many applications of the present invention. While the above depiction presumes that the connector pin860is removed from the socket100by reversal of the insertion motion (in other words, by movement in the retraction direction) to remove the connector pin from the front of the socket, it is also contemplated that, in some use environments, the connector pin860could pass entirely longitudinally through the shaft bore110and exit through the rear of the socket. Though certain components described herein are shown as having specific geometric shapes, all structures of the present invention may have any suitable shapes, sizes, configurations, relative relationships, cross-sectional areas, or any other physical characteristics as desirable for a particular application of the present invention. The above description references “maximum” and “minimum” dimensions, but these could be local maximums/minimums—it is contemplated that some other areas of the described structures, spaced apart from the interfacing structures of the asymmetrical-force connector system102, could have dimensions larger than the aforementioned “maximum” or smaller than the aforementioned “minimum”. Any structures or features described with reference to one embodiment or configuration of the present invention could be provided, singly or in combination with other structures or features, to any other embodiment or configuration, as it would be impractical to describe each of the embodiments and configurations discussed herein as having all of the options discussed with respect to all of the other embodiments and configurations. More than two housing shells104, linked by multiple intermediate members332or in any other way, may be connected together into a longitudinally-oriented “stack” of any suitable length. A device or method incorporating any of these features should be understood to fall under the scope of the present invention as determined based upon the claims below and any equivalents thereof.