TECHNICAL FIELD
The present invention relates to positioner devices and, more specifically, to a separable base plate configured to hold, move, and maintain a body part in a specific position as needed in orthopedic surgery; the separable base plate is further configured to decouple into separate parts to facilitate sterilization of said parts, after an orthopedic surgery is performed.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 5,462,551 entitled “Knee Positioner” describes limb surgery on the human body including knees, knee replacement, fracture repair, as well as similar hand, foot, and ankle surgery such that the join or limb to be operated on is precisely and predictably position during such surgery. U.S. Pat. No. 7,380,299 entitled “Operating Table Support Clamp” describes a support platform and operating table clamp that connects to an operating table.
A problem exists with conventional surgery systems in that the hardware and associated components are not easily sterilizable, e.g. the base plate can be 28-42 inches. Typically, sterilizer systems consist of a cabinet with a series of trays or slots in which such hardware and associated components can be placed to be sterilized; these sterilizer systems are commonly limited to accept items that fit within trays 24″×11.5″×8″ (depth, width, and height, respectively). Conventional base plates with a length of plus 24 inches occupy multiple trays when inserted into the sterilization cabinet, e.g. 6 tray bays. The sterilization cabinets are also used for storage of sterilized systems. Consequently, there is a long-felt need to overcome these space and sterilization disadvantages of conventional positioner systems. Conventional surgery systems, typically, either require a multitude of sterilization trays (making the sterilization process unnecessarily cumbersome), or that consist of certain components that do not fit within the sterilization trays altogether (further complicating the sterilization process).
It would therefore be functionally and economically advantageous to provide a knee positioner system that overcomes these challenges.
SUMMARY OF THE INVENTION
A functionally and economically advantageous knee positioner system that can be efficiently sterilized and stored is described. The knee positioner invention has a separable base plate, which can operatively connect for use during surgery, and which can decouple into separate parts to facilitate sterilization.
BRIEF DESCRIPTION OF THE DRAWINGS
Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following drawings. In the drawings, like reference numerals refer to like parts throughout the various figures unless otherwise specified.
For a better understanding of the present invention, reference will be made to the following Description of the Embodiments, which is to be read in association with the accompanying drawings, which are incorporated in and constitute a part of this specification, show certain aspects of the subject matter disclosed herein and, together with the description, help explain some of the principles associated with the disclosed implementations, wherein:
FIG. 1 illustrates an environment of operation of the limb/knee positioner having a solid and/or a separable base plate in accordance with an embodiment of the apparatus, system and method present invention operation.
FIG. 2 illustrates a perspective view of a separable base plate apparatus, system and method in accordance with an embodiment of the present invention.
FIG. 3 illustrates a top view of a separable base plate apparatus, system and method in accordance with an embodiment of the present invention;
FIG. 4 illustrates a side view of a separable base plate apparatus, system and method in accordance with an embodiment of the present invention;
FIG. 5 illustrates a bottom view of a separable base plate apparatus, system and method in accordance with an embodiment of the present invention;
FIG. 6 illustrates another side view of a separable base plate apparatus, system and method in accordance with an embodiment of the present invention;
FIG. 7A illustrates a perspective view of a base plate connector, in accordance with an embodiment of the present invention;
FIG. 7B illustrates a side view of a base plate connector, in accordance with an embodiment of the present invention;
FIG. 8A illustrates an exploded perspective view of a drop pin assembly, in accordance with an embodiment of the present invention;
FIG. 8B illustrates a perspective view of a drop pin assembly, in accordance with an embodiment of the present invention;
FIG. 8C illustrates a side view of a drop pin assembly, in accordance with an embodiment of the present invention;
FIG. 9A illustrates a perspective view of a stop head, in accordance with an embodiment of the present invention;
FIG. 9B illustrates a top view of a stop head, in accordance with an embodiment of the present invention;
FIG. 9C illustrates a side view of a stop head, in accordance with an embodiment of the present invention;
FIG. 9D illustrates a section view of a stop head, taken along the section A′-A′ shown in FIG. 9B, in accordance with an embodiment of the present invention;
FIG. 10A illustrates a top view of a slide lock, in accordance with an embodiment of the present invention;
FIG. 10B illustrates a side view of a slide lock, in accordance with an embodiment of the present invention;
FIG. 11 illustrates a first step showing the alignment of certain components, according to a method of assembling an embodiment of the invention;
FIGS. 12 and 13 illustrate a second step showing coupling of certain components, according to a method of assembling an embodiment of the invention;
FIGS. 14-16 illustrate a third step showing coupling of a slide lock to certain components, according to a method of assembling an embodiment of the invention;
FIGS. 17-19 illustrate a fourth step showing coupling of drop pin assemblies to certain components, according to a method of assembling an embodiment of the invention;
FIG. 20 illustrates a fifth step showing coupling of a slide lock to certain components, according to a method of assembling an embodiment of the invention;
FIGS. 21A and 21B illustrate certain coupling features of a slide lock and associated components, according to a method of assembling an embodiment of the invention;
FIG. 22 illustrates a side view of a separable base plate apparatus, system and method in accordance with an alternative embodiment of the present invention;
FIG. 23 illustrates a top view of a latch, according to an alternative embodiment of the invention;
FIG. 24 illustrates a perspective view of a latch, according to an alternative embodiment of the invention;
FIG. 25 illustrates a partial sectional, top view of a spring-loaded lock assembly, taken along section B′-B′ of FIG. 22, according to an alternative embodiment of the invention;
FIG. 26 illustrates a third step showing coupling of a spring-loaded lock assembly, according to an alternative embodiment of the invention;
FIG. 27 illustrates a fourth step showing coupling of a spring-loaded lock assembly, according to an alternative embodiment of the invention;
FIG. 28 illustrates a side view of a separable base plate apparatus, system and method in accordance with an alternative embodiment of the present invention;
FIG. 29 illustrates a top view of first and second base portions, according to an alternative embodiment of the invention;
FIG. 30A illustrates an exploded, perspective view of a turn pin lock assembly, according to an alternative embodiment of the invention;
FIG. 30B illustrates a perspective view of a turn pin lock assembly, according to an alternative embodiment of the invention;
FIG. 30C illustrates a side view of a turn pin lock assembly, according to an alternative embodiment of the invention;
FIGS. 31 and 32 illustrate a third step showing coupling of turn pin lock assemblies to associated components, according to an alternative embodiment of the invention; and
FIG. 33 illustrates a fourth step showing coupling of turn pin lock assemblies to associated components, according to an alternative embodiment of the invention.
DESCRIPTION OF THE EMBODIMENTS
Non-limiting embodiments of the present invention will be described below with reference to the accompanying drawings, wherein like reference numerals represent like elements throughout. While the invention has been described in detail with respect to the preferred embodiments thereof, it will be appreciated that upon reading and understanding of the foregoing, certain variations to the preferred embodiments will become apparent, which variations are nonetheless within the spirit and scope of the invention.
The terms “a” or “an”, as used herein, are defined as one or as more than one. The term “plurality”, as used herein, is defined as two or as more than two. The term “another”, as used herein, is defined as at least a second or more. The terms “including” and/or “having”, as used herein, are defined as comprising (i.e., open language). The term “coupled”, as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically.
Reference throughout this document to “some embodiments”, “one embodiment”, “certain embodiments”, and “an embodiment” or similar terms means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of such phrases or in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments without limitation.
The term “or” as used herein is to be interpreted as an inclusive or meaning any one or any combination. Therefore, “A, B or C” means any of the following: “A; B; C; A and B; A and C; B and C; A, B and C”. An exception to this definition will occur only when a combination of elements, functions, steps or acts are in some way inherently mutually exclusive.
The drawings featured in the figures are provided for the purposes of illustrating some embodiments of the present invention, and are not to be considered as limitation thereto. The term “means” preceding a present participle of an operation indicates a desired function for which there is one or more embodiments, i.e., one or more methods, devices, or apparatuses for achieving the desired function and that one skilled in the art could select from these or their equivalent in view of the disclosure herein and use of the term “means” is not intended to be limiting.
As is illustrated in FIGS. 1 through 21B, a separable base plate for a positioner apparatus, system and method is generally shown as element 100. A separable base plate 100 may be used as illustrated in the schematic view in FIG. 1. The separable base plate 100 is configured to be set atop a support table or operating room table (OR table) 101 and attached to a side rail 102 using a clamp assembly 150, which works in conjunction with first and second drop pin assemblies, 104a and 104b, respectively. Clamp assembly 150 may be operably connected to the OR table 101 at side rail 102 by a suitable design such as a 713 Series clamp manufactured by Innovative Medical Products, Inc., a spring-loaded lever clamp (shown schematically, in FIG. 1), or by another suitable clamp adapted with a pin-locking mechanism such as an equalizer clamp described in U.S. patent application Ser. No. 17/073,334, filed Oct. 17, 2020, which claims benefit to U.S. Prov. App. No. 62/916,674, filed Oct. 17, 2019.
Referring to FIGS. 2 through 6, the separable base plate 100 is shown in a fully assembled configuration. Referring to FIG. 3, separable base plate 100 may include first and second base portions 110a, 110b, which each may include first and second track portions, 140a and 140b, disposed above and rigidly connected to first and second base portions 110a, 110b. First and second track portions 140a and 140b, may be configured to receive a carriage unit 170 (not shown) and facilitate knee replacement surgeries.
Referring to FIG. 3, each of the first and second base portions 110a and 110b may include first and second flat upper base surfaces, 111a and 111b. Similarly, each of the first and second track portions, 140a and 140b, may include first and second flat upper track surfaces 141a and 141b, respectively. A parallel vertical end edge 112 may be common to both 110a and 140a, while an opposite parallel vertical end edge 114 may be common to both 110b and 140b. A slide lock 130 may be used to operatively connect first and second base portions 110a and 110b. Referring to FIG. 4, the first and second drop pin assemblies, 104a and 104b, may be seen in an assembled configuration, which is configured to drop substantially below first and second base portions 110a and 110b. Each of the first and second base portions 110a and 110b may include first and second opposite vertical base edges, 118a and 118b. Furthermore, each of the first and second track portions, 140a and 140b, may include first and second opposite vertical lateral edges, 148a and 148b, respectively.
Referring to FIG. 4, each of the first and second base portions 110a and 110b may include first and second flat bottom surfaces, 115a and 115b. A first protrusion portion 125 is configured with a pin opening 127 on the first flat vertical lateral edge 118a and a second protrusion portion 126 is located on the second flat vertical lateral edge 118b also having a pin opening 128. A base plate connector 120 may be included, and in an assembled configuration, base plate connector 120 may operatively connect the first and second base portions 110a and 110b, in conjunction with the slide lock 130. First and second flat vertical lateral edges 116a and 116b may define an end along first and second base portions 110a and 110b. Similarly, another set of first and second flat vertical lateral edges 146a and 146b may define an end along first and second track portions 140a and 140b. As shown in FIG. 5, first and second inner vertical lateral edges 142a and 142b (disposed near one side of track portions 140a and 140b), and first and second inner vertical lateral edges 144a and 144b (disposed near the other side of track portions 140a and 140b) may be utilized to offset the base portions, 110a and 110b, from the track portions, 140a and 140b, so that carriage unit 170 may operably connect to the separable base plate assembly 100, and change its position along the track formed therein.
Referring to FIG. 6, the portions comprising first and second base portions 110a and 110b and first and second track portions 140a and 140b may include a cavity assembly 190, within which base plate connector 120 may be inserted. Generally, cavity assembly 190 forms an opening that may extend entirely through separable base plate assembly 100, from parallel vertical end edge 112 through to opposite parallel vertical end edge 114. Alternatively, cavity assembly 190 may extend through a center portion of separable base plate assembly 100, formed within the material offset between parallel vertical end edge 112 and opposite parallel vertical end edge 114, or in any manner suitable to achieve rigid connection of the associated components and overall assembly. Cavity assembly 190 may include inner-cavity surfaces comprising a profile that is substantially configured to receive the complementary shape formed by base plate connector 120, as detailed above. Therefore, cavity assembly 190 may comprise: first and second cavity tops 191a and 191b; first and second upper vertical cavity surfaces 193a and 193b; first and second opposite upper vertical cavity surfaces 193c and 193d; lateral and opposite lateral cavity surfaces 194a and 194b; first and second opposite lateral cavity surfaces 194c and 194d; first and second lower vertical cavity surfaces 195a and 195b; and, first and second opposite lower vertical cavity surfaces 195c and 195d.
Referring to FIGS. 7A and 7B, in one embodiment, the base plate connector 120 may include an upper connector surface 121, a lower connector surface 122, an upper vertical connector surface 123a, and an opposite upper vertical connector surface 123c. Base place connector 120 may further include a lateral connector surface 124a, an opposite lateral connector surface 124c, and may also include a lower vertical connector surface 125a and an opposite lower vertical connector surface 125c. In operation, the base plate connector 120 forms a linearly-extruded shape formed from a T-shaped cross-section, which facilitates the joining of respective first and second base portions, 110a and 110b, within a bottom-facing track (as substantially represented in FIG. 5). Base plate connector 120 may be operably connected within the bottom-facing track formed within first and second flat lower base surfaces 115a and 115b by use of a stop, or a protrusion, or by any other means that stops travel of the base plate connector 120 within the track to allow for continued coupling of the device. Importantly, the base plate connector 120 may take the form of any cross-sectional shape, adapted for the purpose of joining and/or rigidly coupling respective first and second base portions 110a and 110b. For example, base plate connector 120 may have a cross-sectional shape in the form of a dovetail joint, a cylindrical extrusion, or one or more L-shaped extrusions. Similarly, the receiving portion of the baseplate connector 120—the bottom-facing track formed within first and second flat lower base surfaces 115a and 115b—may be formed in a complementary fashion to receive these alternative cross-sectional shapes.
FIGS. 8A-8C detail an embodiment of the first and second drop pin assemblies, 104a and 104b, respectively, each of which may include a bolt 105 (designated as first and second bolts 105a, 105b), a stop head 160, and a drop pin 107, comprising an upper drop pin portion 108 and a lower drop pin portion 109. Lower drop pin portion 109 may be configured with a bullet-point end 106, to facilitate assembly of the first and second drop pin assemblies, 104a and 104b, in relation to separable base plate assembly 100.
FIGS. 9A-9D detail an embodiment of the stop head 160, which may include a top 164, a bottom 165, and a cylindrical outer surface 161. Stop head 160 may further include a tapered inner surface 162 disposed adjacent to a cylindrical inner surface 163, both of which form the opening extending from the top 164 through to the bottom 165. In operation, the tapered inner surface 162 may be configured to receive the head of the bolt 105, in which the bolt 105 then threads into the body of drop pin 107. The gap substantially formed by upper drop pin portion 108 becomes apparent by affixing the upper and lower drop pin portions 108 and 109 to stop head 160, as shown in FIGS. 8A to 8C.
Turning now to FIGS. 10A and 10B, the slide lock 130 may include a body portion 131 that may further include a pin receiver assembly 132a and an opposite pin receiver assembly 132b, and an L-shaped nut receiver assembly 136a and an opposite L-shaped nut receiver assembly 136b. Pin and opposite pin receiver assembly 132a and 132b may include a first and second opening 133a and 133b, and may also include a first and second opposite opening 134a and 134b, also as shown in FIG. 10A. L-shaped and opposite L-shaped nut receiver assemblies 136a and 136b may further include a first and second mid-portion 138a and 138b. First and second openings, 133a and 133b, may be configured to receive a diameter substantially equivalent to that of the lower drop pin portion 109, while the first and second opposite openings 134a and 134b may be configured to receive another diameter substantially equivalent to that of the upper drop pin portion 108. In a side view represented in FIG. 10B, slide lock 130 may have a height, represented by element H.
Lastly, in a side view represented in FIG. 10B, slide lock 130 may include a uniform height, represented element H, which may be configured to allow for portions of the body 131 surrounding pin receivers 132a and 132b to fit within the vertical gap formed by upper drop pin portion 108 as shown in FIG. 8C. Similarly, H allows nut receivers 136a and 136b to receive bolts 105a and 105b, as will be described in reference to FIG. 13.
Referring to FIG. 13, a projection assembly 180 may be included, which may be disposed on first and second flat upper surfaces 111a and 111b of first and second base portions 110a and 110b, which may further form openings extending fully through to first and second flat lower base surfaces 115a and 115b. The portion of projection assembly 180 that extends over the first base portion 110a may include a first pin flange 182a and a first bolt flange 184a. Similarly, the portion of projection assembly 180 that extends over the second base portion, 110b, may include a second pin flange 182b and a second bolt flange 184b. With reference to FIGS. 1-2, 4, 6, and 13, each of the first and second pin flanges 182a and 182b form openings that extends through bottom surfaces 115a and 115b of first and second base portions 110a and 110b, which allows first and second drop pin assemblies, 104a and 104b, to extend below the bottom surfaces 115a and 115b for further assembly separable base plate assembly 100, and for further coupling to clamp assembly 150.
Referring to FIGS. 11 through 20, a method of assembling the separable base plate assembly 100 is described. At a first step 400, as shown in FIG. 11, the components comprising first and second base portions 110a and 110b and first and second track portions 140a and 140b, may be provided, along with the base plate connector 120. The portion comprising first base portion 110a is shown to have first middle vertical surface 117; the portion comprising second base portion 110b is shown to have second middle vertical surface 119. Step 400 may include aligning the portions comprising first and second base portions, 110a and 110b, so that first and second middle vertical surfaces 117 and 119 face each other, and so that base plate connector 120 substantially aligns with the bottom-facing track formed within first and second flat bottom surface 115a and 115b, represented as the cavity assembly 190 as shown in FIG. 6.
At a second step 401, and as shown in FIGS. 12 and 13, the portions forming first and second base portions 110a and 110b are urged together, with the base plate connector 120 operatively connecting the same. Step 401 may further include stopping the base plate connector 120 from movement within the bottom-facing track, represented as cavity assembly 190, formed within first and second flat bottom surfaces 115a and 115b by any means that stops travel of the base plate connector 120 within the track which allows for continued coupling of the device, such as first and second set screws 196a and 196b, as shown in FIG. 5.
Referring to FIG. 14-16, in a third step 402, slide lock 130 may be provided, and first and second bolts 105a and 105b may be partially installed within threaded openings formed at first and second bolt flanges, 184a and 184b, respectively. As further shown in FIG. 16, and with reference to FIGS. 10A-10B, 21A, and 21B, slide lock 130 may be positioned as shown, so that bolts 105a and 105b are positioned at mid-portions of the L-shaped and opposite L-shaped nut receivers 136a and 136b, designated as first and second mid-portions 138a and 138b.
Referring now to FIG. 17-19, first and second drop pin assemblies 104a and 104b may be provided, in a fourth step, 403. In specific reference to FIGS. 17-19, and 21A, the first and second openings, 133a and 133b, allow for sufficient space such that lower drop pin portion 109 may fit through the opening, so that the bottom 165 of stop head 160 may rest on body portion 131 of slide lock 130. FIG. 19 specifically shows how first and second drop pin assemblies 104a and 104b are to be configured in a dropped position.
Referring to FIG. 20 (also substantially represented in FIG. 1), and 21B, the slide lock may be translated in a fifth step, 404, which engages first and second opposite openings, 134a and 134b, to operatively couple to the upper pin portion(s) 108 of first and second drop pin assemblies 104a, 104b. In this way, the drop pin assemblies 104a, 104b, are operably coupled within their respective openings, 134a and 134b, ensuring that first and second base portions 110a and 110b remain coupled.
Referring to FIGS. 22-27, in an alternative embodiment, first and second spring-loaded lock assemblies, 200a and 200b respectively, are described. First spring-loaded lock assembly 200a comprises a first latch 201a and spring 208, while second spring-loaded lock assembly 200b comprises a second latch 201b and spring 208. As best seen in FIGS. 23 and 24, first latch 201a may include a pivot portion 202, an engagement portion 203, a latch portion 204 having an arcuate surface 205, and a spring receiver portion 206. Second spring-loaded lock assembly 200b may include a similar arrangement of components, albeit in a mirrored fashion to that of first spring-loaded assembly 201a shown in FIGS. 23 and 24. In operation, first spring-loaded lock assembly 200a is configured to couple to a spring-loaded projection assembly 180b at a first recessed portion 207a, such that first latch 201a may be pivoted about pivot portion 202. The location and general shape of the first recessed portion 207a is evidenced from Section B′-B′ taken in FIG. 22 through the first base portion 110a. Section B′-B′ is shown in FIGS. 25 and 26. Spring 208 couples to a first spring abutment 209a of first recessed portion 207a. As shown in FIG. 26, when acted upon by force F1, first latch 201a pivots about pivot portion 202, compressing spring 208 and exposing a first bolt opening 186a in its entirety, such that first drop pin assembly 104a may pass through during the assembly of separable base plate assembly 100. Second drop pin assembly 104b may be installed in a similar manner (not shown). This results in the positioning of second drop pin assembly 104b as substantially shown in FIGS. 25 and 26, achieved by exerting a force F2 on the engagement portion 203 of second latch 201b, such that second latch 201b coupled to a second recessed portion 207b pivots about pivot portion 202 while compressing spring 208 contained within a second spring abutment 209b (not shown). This exposes a second bolt opening 186b in its entirety, such that second drop pin assembly 104b may pass through during the assembly of separable base plate assembly 100, as shown in FIGS. 25 and 26. Once fully inserted, upper drop pin portion 108 of each of the first and second drop pin assemblies 104a and 104b engages with the arcuate surface 205 of each of the first and second latches 201a and 201b, respectively, due to the reactionary forces of each spring 208. In this manner, first and second drop pin assemblies 104a and 104b may be rigidly connected to the separable base plate assembly 100, as shown in FIG. 27.
The method of assembling the separable base plate assembly 100 may be conducted substantially similar to the previously described first and second steps 400 and 401 as shown in FIGS. 11-13. However, in this alternative embodiment in a third step 402b, first and second latches are pushed in the direction represented as F1 of FIG. 26 and F2 (not shown), to an extent which allows first and second drop pin assemblies 104a and 104b to pass through first and second bolt openings 186a and 186b, respectively. In the third step 402b, first and second drop pin assemblies 104a and 104b are fully inserted. Then, in a fourth step 403b, first and second latches are released, as shown in FIG. 27. In the fourth step 403b, the upper drop pin portion 108 of each of the first and second drop pin assemblies 104a and 104b engages with the arcuate surface 205 of each of the first and second latches 201a and 201b, respectively, due to the reactionary forces of each spring 208. In this way, the method of assembly with respect to this alternative embodiment similarly results in first and second drop pin assemblies 104a and 104b being rigidly connected to the separable base plate assembly 100 (as shown in FIG. 27).
Referring to FIGS. 28-33, according to an alternative embodiment, first and second turn pin lock assemblies, 210a and 210b, are described. In this embodiment, with reference to FIG. 29, first and second base portions comprise a turn pin assembly 180c. The portion of the turn pin assembly 180c that extends over the first base portion 110a, may include a first turn pin opening 216a and a first slotted spring pin opening 218a. Similarly, the portion of the turn pin assembly 180c that extends over the second base portion 110b, may include a second turn pin opening 216b and a second slotted spring pin opening 218b. First and second turn pin openings 216a and 216b, and first and second slotted spring pin openings 218a and 218b extend through turn pin projection assemblies 180c, as well as through first and second base portions 110a and 110b so that first and second turn pin lock assemblies 210a and 210b may pass therethrough.
As illustrated in FIGS. 30A-30C, first and second turn pin lock assemblies 210a and 210b each comprise: bolt 105, stop head 160, a slotted spring pin 211, and a turn pin 212. Slotted spring pin 211 may comprise a loaded spring portion that permits slotted spring pin 211 to shorten with respect to its axial length when acted upon by an axial force, and return to initial elongated position upon removal of the same axial force. Turn pin 212 may include a turn pin body 213 and bullet end 106. Turn pin body 213 may be distinguished in that it forms a substantially uniform diameter throughout the entirety of the pin's length (compare to drop pin 107 of FIGS. 8A-8C).
The method of assembling the separable base plate assembly 100 may be conducted substantially similar to the previously described first and second steps 400 and 401 as shown in FIGS. 11-13. However, in this alternative embodiment in a third step 402c, first and second slotted spring pin assemblies, 210a and 210b, are fully inserted. During insertion defined by third step 402c, the slotted spring pin 211 of the first slotted spring pin assembly 210a is aligned with the first slotted spring pin opening 218a. By the same token, the slotted spring pin 211 of the second slotted spring pin assembly 210b is aligned with the second slotted spring pin opening 218b. The first and second slotted spring pin openings, 218a and 218b, are shown in FIG. 29. Also during insertion as defined by third step 402c, slotted spring pins 211 are sized to come in contact with turn pin projection assembly 180c, such that the slotted spring pins 211 provide resistance along the axial direction (relative to the turn pin 212) as the slotted spring pins 211 reach the first and second slotted spring pin openings, 218a and 218b, akin to a clicking motion, in the initial elongated position. The slotted spring pins then retract, allowing first and second turn pin assemblies, 210a and 210b, to be fully inserted. In one aspect, the intent of this design is to provide the person assembling separable base plate assembly 100 with a tactile response, indicating to the person that the first and second turn pin assemblies, 210a and 210b, have been properly inserted. Then, in a fourth step 403c, first and second turn pin lock assemblies, 210a and 210b, are respectively turned in the radial direction (again, relative to the turn pin 212) so that the slotted spring pins 211 become radially offset from first and second slotted spring pin openings, 218a and 218b. By this method, first and second base portions, 110a and 110b, are rigidly coupled via first and second turn pin lock assemblies, 210a and 210b, clamp assembly 150, and associated components, as shown in, for example, FIGS. 28 and 33.
While certain configurations of structures have been illustrated for the purposes of presenting the basic structures of the present invention, one of ordinary skill in the art will appreciate that other variations are possible which would still fall within the scope of the appended claims. Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.