[0001] Countersink Cutter and Screw End Trimmer

CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No.

62/623,023 filed January 29, 2018 entitled“Countersink Cutter and Screw End Trimmer”, which is incorporated by reference herein in its entirety.

FIELD OF THE INVENTION

[0003] The present invention generally relates to a countersink cutter and a screw end trimmer, and more particularly, to using a countersink cutter and a screw end trimmer to create a countersink, placing a screw within the countersink, and removing a remaining portion of the screw extending from the material.

BACKGROUND OF THE INVENTION

[0004] The use of screws in a variety of fields, such as carpentry and medicine, is important and necessary to secure two items together or to ensure that an item is secure. Further, in certain situations it is necessary for the top of the screw to be flush with the top surface of the material in which the screw is being inserted into. This may be difficult if the material that the screw is being inserted into is hard or if the material may fracture under pressure. To assist in creating a flush surface, countersinks are utilized so that the screw head or screw nut may be inserted into the countersink to ensure a flush surface is created. Further, any excess portion of the screw extending past the screw head or screw nut may be removed to ensure a flush surface. Moreover, a user may not determine that a countersink is necessary until after the screw has already been partially placed within the material.

[0005] Current methods of creating countersinks involve creating a countersink prior to insertion of the screw within the material. This requires knowing the precision location and placement of the screw. Further, these methods do not allow for the creation of a countersink after a screw has been partially inserted into a material. For example, a countersink may have been created prior to inserting the screw into the material, however it may be determined that the countersink is not deep enough to create a flush surface. In certain situations, it is detrimental to back out and remove the screw from the material once it has been partially inserted. Current methods also do not allow for easy removal of an excess screw shaft extending from the material.

[0006] Accordingly, there is a need for a more effective method of creating countersinks, preferably when a screw has already been partially inserted into a material. In addition, there is a need for easy and effective removal of a screw shaft extending from the surface of the material.

BRIEF SUMMARY OF THE INVENTION

[0007] Embodiments of the present invention are directed to a cutting tool for a cutting a countersink in a material, including a body having a slot extending along a longitudinal axis and configured to receive a proximal end of a screw shaft while a distal end of the screw shaft remains in the material, retaining arm removably coupled to the body and disposed within the slot and configured to retain the screw shaft within the slot in a cutting position, the body and retaining arm configured to rotate around the screw shaft in the cutting position, and at least one cutting edge extending from a distal end of the body and configured to cut a countersink bore into the material by rotating the cutting tool around the screw shaft in the cutting position.

[0008] In some embodiments, the body may include a first recess and the retaining arm may include a second recess, the first recess and the second recess each having a width larger than a width of the slot and forming an opening configured to receive a screw head or nut in the cutting position.

[0009] In some embodiments, the opening may be open to each lateral side of the cutting tool.

[0010] In some embodiments, the retaining arm may include a hook and placing the retaining arm into the slot and sliding the retaining arm distal relative to the body may engage the hook around a portion of the body. The retaining arm may be pivotably coupled to the body

[0011] In some embodiments, the at least one cutting edge may be at an oblique angle relative to the longitudinal axis.

[0012] In some embodiments, a closed bottom of the slot may be rounded and an open top of the slot may be rectangular.

[0013] Another embodiment of the present invention may provide a trimming tool configured to remove a proximal end of a screw, including an outer shaft extending along a longitudinal axis, the outer shaft having an internal bore, a distal end of the outer shaft having two or more keyed projections configured to engage a nut coupled to a screw, and an inner shaft rotatably and axially slidably positioned within the internal bore of the outer shaft, the inner shaft having a female thread configured to engage a male thread of the screw proximate a distal end of the outer shaft, and a distal end of the inner shaft disposed within the internal bore of the outer shaft proximate the one or more keyed projections.

[0014] In some embodiments, each of the outer shaft and the inner shaft may include a keyed feature configured to engage a tool configured to rotate the inner shaft relative to the outer shaft.

[0015] In some embodiments, in a disengaged position, the inner shaft may be axially slidable relative to the screw without rotation of the inner shaft relative to the outer shaft and, in an engaged position, the female thread of the inner shaft may engage with the male thread of the screw. The inner shaft may include two or more segments axially movable relative to one another.

[0016] In some embodiments, the outer shaft may be configured to prevent movement of the nut and the screw, and the inner shaft may rotate the proximal end of the screw relative to the nut.

[0017] In some embodiments, the inner shaft may include a securing element having a female thread, the securing element may be rotatable relative to the inner shaft in an initial disengaged position and may be rotatably fixed to the remainder of the inner shaft in an engaged position, wherein in the engaged position the female thread of the securing element engages the male thread of the screw.

[0018] In some embodiments, the outer shaft may include an aperture configured to receive a pin, the pin configured to prevent axially movement of inner shaft within the outer shaft.

[0019] In some embodiments, the inner shaft may include one or more slots open towards the distal end of the inner shaft, the one or more slots may be configured to allow the distal end of the inner shaft to reduce in width as the distal end of the inner shaft is proximate the distal end of the outer shaft until the distal end of the inner shaft engages the male thread of the screw.

[0020] Another embodiment of the present invention may provide a method of trimming a proximal end of a screw extending from a bone, the method including the steps of inserting a screw into the bone having a surface, placing an outer shaft having an internal bore over a proximal end of the screw until a distal end of the shaft having two or more keyed projections engages a nut coupled to the screw such that the outer shaft is rotationally fixed relative to the nut, sliding an inner shaft within the internal bore of the outer shaft until a female thread of the inner shaft engages a male thread of the screw, screwing the inner shaft over the proximal end of the screw until a distal end of the inner shaft contacts a top of the nut, and twisting the inner shaft relative to the outer shaft until the proximal end of the screw shears across a plane approximately flush with the top of the nut and a surface of the bone. [0021] In some embodiments, in a disengaged position, the inner shaft may be axially slidable relative to the screw without rotation of the inner shaft relative to the outer shaft and, in an engaged position, the female thread of the inner shaft may engage with the male thread of the screw.

[0022] In some embodiments, the inner shaft may include a securing element having a female thread, the securing element may be rotatable relative to the inner shaft in an initial disengaged position and may be rotatably fixed to the remainder of the inner shaft in an engaged position, wherein in the engaged position the female thread of the securing element engages the male thread of the screw.

[0023] In some embodiments, the inner shaft may include one or more slots open towards the distal end of the inner shaft, the one or more slots may be configured to allow the distal end of the inner shaft to reduce in width as the distal end of the inner shaft is proximate the distal end of the outer shaft until the distal end of the inner shaft engages the male thread of the screw.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0024] The following detailed description of embodiments of the countersink cutter and a screw end trimmer will be better understood when read in conjunction with the appended drawings of an exemplary embodiment. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.

[0025] Fig. l is a perspective view of a countersink cutter in accordance with an exemplary embodiment of the present invention;

[0026] Fig. 2A is a perspective view of the body of the countersink cutter shown in Fig. 1;

[0027] Fig. 2B are top and side views of the body of the countersink cutter shown in Fig. 1;

[0028] Fig. 3 is a side view of the retaining arm of the countersink cutter shown in Fig. 1;

[0029] Fig. 4A is a perspective view of the countersink cutter shown in Fig. 1 shown in use with a wire screw and nut;

[0030] Fig. 4B is a side view of the countersink cutter shown in Fig. 4A;

[0031] Fig. 5 is a side view of the countersink cutter shown in Fig. 1 shown in use with a screw;

[0032] Fig. 6 is an exploded perspective view of a screw end trimmer in accordance with an exemplary embodiment of the present invention;

[0033] Fig. 7 is a perspective view of the inner insert of the screw end trimmer shown in Fig. 6;

[0034] Fig. 8A is a side view of the screw end trimmer shown in Fig. 6; [0035] Fig. 8B is a cross sectional side view of the screw end trimmer of Fig. 6 shown taken about a plane as indicated by line B-B in Fig. 8A;

[0036] Fig. 8C is a zoomed in cross sectional side view of the screw end trimmer of Fig. 6 shown taken about a plane as indicated by line B-B in Fig. 8B;

[0037] Fig. 8D is a zoomed in cross sectional side view of a screw end trimmer in accordance with an exemplary embodiment of the present invention.

[0038] Fig. 9 is a side view of a screw end trimmer in accordance with another exemplary embodiment of the present invention;

[0039] Fig. 10A is a cross sectional view of a screw end trimmer in accordance with another exemplary embodiment of the present invention;

[0040] Fig. 10B is a zoomed in cross sectional view of the screw end trimmer of Fig. 10A in accordance with an exemplary embodiment of the present invention;

[0041] Fig. 10C is a zoomed in cross sectional view of the screw end trimmer of Fig. 10A;

[0042] Fig. 10D is a zoomed in cross sectional view of the screw end trimmer of Fig. 10A;

[0043] Fig. 10E is a zoomed in cross sectional view of the screw end trimmer of Fig. 10A;

[0044] Fig. 11 A is a zoomed in cross sectional view of a screw end trimmer in accordance with another exemplary embodiment of the present invention; and

[0045] Fig. 11B is a zoomed in cross sectional view of the screw end trimmer of Fig. 11 A.

DETAILED DESCRIPTION OF THE INVENTION

[0046] Exemplary embodiments of the present invention provide an improved countersink cutting tool. An embodiment is shown in Figs. 1-5. In use, countersink cutting tool 110 may be used to create a countersink in a surface of a material for a nut or screw head coupled to a screw or wire such that the top surface of the nut or screw head is generally flush with the surrounding surface of the material. Countersink cutting tool 110 may be configured to be used with a variety of materials such as bone, wood, metal and plastic. In certain situations, it may be desirable to create a countersink after the screw has already been at least partially driven into the material. For example, the original countersink that was previously created may not be deep enough or the material is too thick to drive a drill bit far enough to engage the countersink feature. Particularly in certain surgical applications, it may be undesirable to remove the screw entirely by backing the screw out, forming or reforming the countersink and then reinserting the screw. Countersink cutting tool 110 may be cannulated and slotted such that the screw may remain in the material while the countersink is fitted around the portion of the screw extending from the material.

[0047] Referring to Fig. 1, countersink cutting tool 110 may include body 112 and retaining arm 116. Body 112 may include slot 114, recess 123, cutting edge 115, pin 128, proximal end 1 l2b, and distal end 1 l2a. Body 112 may extend along longitudinal axis A of countersink cutting tool 110, between proximal end 1 l2b and distal end 1 l2a. Retaining arm 116 be coupled to body 112 at recess 123 and may include indent 125. Retaining arm 116 may be coupled and secured to body 112 via pin 128. Cutting edge 115 may be disposed at distal end 1 l2a of body 112. Slot 114 may be disposed within body 112 and aligned along longitudinal axis A of body 112. Slot 114 may be configured to receive a screw or threaded wire. For example, slot 114 may be configured to receive a proximal end of a screw shaft, while a distal end of the screw remains in material M.

[0048] Referring to Figs. 2A and 2B, countersink cutting tool 110 may include body 112. Body 112 may be a single piece and may be comprised out of an alloy, such as stainless steel. In one embodiment, body 112 is comprised of alloy 17-4PH (H900) or an equivalent. Body 112 may have a length between approximately 80 millimeters and approximately 200 millimeters, between approximately 100 millimeters and approximately 180 millimeters, or between approximately 120 millimeters and approximately 160 millimeters. For example, body 112 may have a length of approximately 100 millimeters, 125 millimeters, 150 millimeters, 175 millimeters, or 200 millimeters. In a preferred embodiment, body 112 has a length of 175 millimeters. In one embodiment, body 112 is shaped to be easily held by the hand of user. For example, body 112 may be shaped similar to a writing instrument such that body 112 of countersink cutting tool 110 is easily held during operation, such as during an orthopedic surgery for inserting a screw into bone. Body 112 may include slot 114 which may extend along longitudinal axis A and may further extend radially into a portion of body 112. In one embodiment, slot 114 may have a depth sized to fit a proximal end of screw or wire to be inserted into material M. For example, the depth of slot 114 may be sized to fit a proximal end of a bone screw while a distal end of the bone screw is inserted into bone. In one embodiment, slot 114 may be configured to receive a proximal end of a screw shaft while a distal end of the screw shaft remains in a material. Referring to Fig. 2A, slot 114 may include closed bottom 1 l4b and open top 1 l4a. Closed bottom 1 l4b of slot 114 may be rounded to receive a screw and open top 114a of slot 1 l4a may be rectangular or square for receiving retaining arm 116. [0049] In one embodiment, body 112 may include cutting edge 115. Cutting edge 115 may be located at distal end 1 l2a of body 112 and may extend distally from the body 112. Cutting edge 115 may be configured to cut a countersink or counterbore into a material by rotating countersink cutting tool 110 around a screw shaft. In one embodiment, cutting edge 115 is at an oblique angle relative to longitudinal axis A of body 112 to create a frustoconical cut having a diameter larger than the diameter of the screw within a material. The frustoconical cut may taper down to the diameter of the screw. However, in other embodiments, cutting edge 115 may be shaped to create other types of cuts. For example, cutting edge 115 may create cylindrical cuts, tubular cuts, rectangular cuts, or triangular cuts. In one embodiment, cutting edge 115 is approximately perpendicular to longitudinal axis A to create a tubular cut having a diameter larger than the diameter of the screw. Cutting edge 115 may include one, two, three four or more cutting edges. Cutting edge 115 may be comprised of a material capable of cutting into a hard material such as bone or wood. For example, cutting edge 115 may be comprised of metal, or glass, or an alloy, such as stainless steel. In one embodiment, cutting edge 115 is comprised of alloy 17-4PH (H900) or an equivalent, such as an alloy of cobalt chrome or titanium. In one embodiment, cutting edge 115 may include slot 114, which may extend through cutting edge 115. Slot 114 may be configured to hold a screw in place while cutting edge

115 cuts a countersink around the screw for placement into a material, such as bone.

[0050] Referring to Figs. 1-3, countersink cutting tool 110 may include retaining arm 116.

Retaining arm 116 may be removably coupled to body 112 within recess 123. In one embodiment, retaining arm 116 is pivotably coupled to body 112. Further, retaining arm 116 may be configured to be removably disposed within slot 114 and configured to retain a screw shaft within slot 116. Retaining arm 116 may include hook 120, which may include indent l20a. Hook 120 may be configured to engage a portion of body 112. Hook 120 may be inserted into recess 123 of body 112 and may be configured to removably couple a proximal end of retaining arm 116 to body 112. In practice, retaining arm 116 may be slid distally relative to body 112 such that hook 120 engages a portion of body 112 securing retaining arm 116 to body 112 and preventing retaining arm 116 from pivoting out of slot 114. Retaining arm 116 may also include a hole or slot 122. Retaining arm 116 may include one or more grip features such as indent 125. Retaining arm 116 may be configured to rotatably couple to body 112 by a fastener extending through hole 130 such as pin 128. In practice, hook 120 of retaining arm 116 may be inserted into recess 123 of body 112 to allow retaining arm

116 to be rotatably coupled to body 112. [0051] Referring to Figs. 2A and 2B, retaining arm 116 rotatably coupled to body 112 may form recess 118. Recess 118 may be offset and may be formed by first recess 1 l8a extending through body 112 and second recess 118b extending through retaining arm 116. First recess 1 l8a of body 112 and second recess 118b of retaining arm 116 may each have a width larger than slot 114. As a result, recess 118 may have a diameter larger than the diameter of slot 114. Recess 118 may be sized and configured to receive a nut or screw head. In one embodiment, recess 118 is open on both sides to form a window. In other embodiments, recess 118 may be closed on one or both sides.

[0052] Referring to Figs. 4A-5, body 112 and retaining arm 116 may be used with screw 124 extending from a surface of material M to cut a countersink around the screw. For example, body 112, with retaining arm 116 pivoted outwardly out of slot 114 about pin 128, may be coupled with a screw such that the screw sits in closed bottom 1 l4b of slot 114. Screw 124 may be a wire or threaded wire. Screw 124 may be a wire or threaded wire having a diameter between approximately 0.02 inches and approximately 0.07 inches. In one embodiment, screw 124 has a diameter less than approximately 0.07 inches. For example, screw 124 may be a threaded wire having a diameter of approximately 0.028 inches, approximately 0.045 inches, approximately, 0.054 inches,

approximately 0.057 inches, or approximately 0.062 inches. Nut l24a of screw 124 or screw head l26a of screw 126 may be positioned within recess 118. Retaining arm 116 may be pivoted about pin 128 to move retaining arm 116 inward toward body 112 and into slot 114, placing countersink cutting tool 110 from an open position into a cutting position. In the cutting position, retaining arm 116 may be removably coupled to body 112 and disposed within slot 114. Retaining arm 116 may be further configured to retain screw 124 within slot 114 to allow retaining arm 116 to rotate relative to screw 124. In one embodiment, retaining arm 116 is slid distally relative to body 112 to engage hook 120 with body 112 to secure retaining arm 116 to body 112. Countersink cutting tool 110 being in the cutting position may then be rotated relative to screw 124 to cut the countersink around screw 124, into material M with cutting edge 116. Once the countersink is cut around screw 124, retaining arm 116 may be slid proximally to release hook 120 from body 112, no longer securing retaining arm 116 to body 112. Retaining arm 116 may be pivoted about pin 128 to remove retaining arm 116 from slot 114, thereby opening slot 114 and placing countersink cutting tool 110 into the open position. Body 112 may then be pulled radially off of screw 124, removing screw 124 from slot 114. Nut l24a of screw 124 or screw head l26a of screw 126 may then be driven into the countersink created by countersink cutting tool 110 thereby resulting in nut l24a or screw head l26a being flush with the top surface of material M. In one embodiment, countersink cutting tool 110 may have keyed feature 132 such as diametrically opposed indents to receive a tool (not shown) for rotating countersink cutting tool 110. For example, proximal end 1 l2b of body may include keyed feature 132 to receive a tool for rotating body 112.

[0053] Exemplary embodiments of the present invention also provide an improved screw end trimmer. An embodiment is shown in Figs. 6-8D. In use, screw end trimmer 210 may be used to remove the remaining portion of a screw extending from a material. Particularly in surgical applications, it may be desirable to have the proximal end of a screw be generally flush with the top surface of a material and free from burrs or sharp edges. Using a tool to clip the end of the screw may leave a raised sharp edge. Screw end trimmer 210 may help remove the excess portion of the screw and leave a generally flush and smooth end.

[0054] Referring to Figs. 6-8D, screw end trimmer 210 may include outer shaft 212 and inner shaft 226. Outer shaft 212 may include distal end 2l2b, proximal end 212a, internal bore 214, and grip 218. Outer shaft 212 may extend from proximal end 2l2a to distal end 2l2b along a longitudinal axis B. Inner shaft 226 may be disposed within internal bore 214 of outer shaft 212. Inner shaft 226 may include proximal end 226a, distal end 226b, internal bore 228, and notch 230. Tool 222 may be used with outer shaft 212 and may be configured to couple to proximal end 2l2a of outer shaft 212. For example, tool 222 may include keyed feature 222a configured to couple with proximal end 212a of outer shaft 212. In one embodiment, proximal end 212a of outer shaft 212 includes keyed feature 220 for coupling to tool 222 for controlling the rotation of outer shaft 212 about axis B having a corresponding keyed feature 222a. In one embodiment, tool 222 may be used to allow a user to generate increased torque to rotate outer shaft 212.

[0055] Referring to Figs. 6-8D, outer shaft 212 may be comprised of an alloy, such as stainless steel. For example, outer shaft 212 may be comprised of alloy 17-4PH (H900), Custom 465 (H90) or an equivalent. Outer shaft 212 may have a length between approximately 75 millimeters and 120 millimeters, approximately 85 millimeters and approximately 110 millimeters, or approximately 95 millimeters and 105 approximately millimeters. For example, shaft 212 may be approximately 75 millimeters, approximately 80 millimeters, approximately 100 millimeters, or approximately 120 millimeters. In a preferred embodiment, outer shaft 212 is approximately 80 millimeters. As shown in Figs. 6 and 8A-8D, a diameter of outer shaft 212 proximate to proximal end 2l2a may be greater than a diameter of outer shaft 212 proximate to distal end 2l2b. The diameter of outer shaft 212 being greater proximate to proximal end 2l2a allows for a user to easily grip outer shaft 212. In addition, the outer surface of outer shaft 212 proximate to proximal end 212a may include grip 218. Grip 218 may be a plurality of axially extending grooves and ridges to provide grip to a user’s hand. Grip 218 may also be a tight elastic sleeve disposed over a portion of outer shaft 212 proximate to proximal end 2l2a. In one embodiment, grip 218 of outer shaft 212 is comprised of a different material than outer shaft 212. For example, grip 218 may be comprised of a rubber material with a high coefficient of friction to allow a user to grip and rotate outer shaft 212 without slipping. In another embodiment, grip 218 may be comprised as the same material of outer shaft 226. Grip 218 may be disposed on the portion of outer shaft 212 proximate to proximal end 2l2a having a larger diameter.

[0056] In one embodiment, internal bore 214 of outer shaft 212 is sized to receive inner shaft 226. For example, inner shaft 226 may be inserted into internal bore 214 of outer shaft 212 during use. Further, distal end 2l2b of outer shaft 212 may be configured to engage with screw 224, such as nut 224a or screw head 224. For example, distal end 2l2b of the outer shaft 212 may have one or more keyed projections 216 configured to engage nut 224a coupled to screw 224. Outer shaft 212 may have one, two, three, or four keyed projections 216. For example, outer shaft 212 may have four equally spaced keyed projections 216, three equally spaced keyed projections, or two diametrically opposed keyed projections 216. Nut 224a may include slots or grooves configured to receive key projections 216. For example, nut 224a may have a number of slots or groves corresponding to the size, shape, and number of key projections 216 such that keyed projections 216 engage with the slots or grooves and prevent movement of nut 224 relative to outer shaft 212.

Internal bore 214 may have a length between approximately 64 millimeters and 109 millimeters, approximately 75 millimeters and approximately 100 millimeters, or approximately 85 millimeters and approximately 95 millimeters. For example, internal bore 214 may have a length of

approximately 69 millimeters, approximately 75 millimeters, approximately 85 millimeters, or approximately 105 millimeters. In a preferred embodiment, internal bore 214 has a length of approximately 69 millimeters. Internal bore 214 may have a diameter between approximately 5 millimeters and 8 millimeters or approximately 6 millimeters and approximately 7 millimeters. For example, internal bore 214 may have a diameter of approximately 5 millimeters, approximately 6 millimeters, approximately 7 millimeters, or approximately 8 millimeters. In a preferred

embodiment, internal bore 214 has a diameter of approximately 6.35 millimeters.

[0057] Referring to Figs. 6-7 and 8B, screw end trimmer 210 may include inner shaft 226 that is configured to be disposed within outer shaft 212. Inner shaft 226 may extend from proximal end 226a to distal end 226b along longitudinal axis B. Inner shaft 226 may be rotatably and axially slidably positioned within internal bore 214 of outer shaft 212. In one embodiment, inner shaft 226 includes internal bore 228. Internal bore 228 may include distal end 229 which may have a female thread configured to engage a male thread of screw 224. Distal end 226b of inner shaft 226 may be extendable within internal bore 214 of outer shaft 212 to be proximate to keyed projections 216. Inner shaft 226 may include window or notch 230 that exposes a portion of internal bore 228 of inner shaft 226. Notch 230 may be exposed when inner shaft 226 is removed from outer shaft 212. Notch 230 may be configured to allow a user to access proximal end 224b of screw 224 through inner shaft 226. In one embodiment, notch 230 is disposed proximate to distal end 226b of inner shaft 226. Further, inner shaft 226 may include keyed feature 232. Keyed feature 232 may be configured to engage a tool configured to rotate inner shaft 226 relative to outer shaft 212. For example, a tool may be provided to couple to keyed feature 232 to allow for a user to provide increased torque for rotating inner shaft 226. In one embodiment, each of outer shaft 212 and inner shaft 226 includes keyed features configured to engage a tool configured to rotate inner shaft 212 relative to outer shaft 212.

[0058] Referring to Figs. 8A-8D, in use, outer shaft 212 may be placed over proximal end 224b of screw 224 until keyed projections 216 engage nut 224a coupled to screw 224 such that outer shaft 212 is rotationally fixed relative to nut 224a. Screw 224 may have been inserted into material M through bore 225 and nut 224a may be disposed within bore 225. Nut 224a may be threaded or include slots or grooves to allow keyed projections 216 to engage nut 224a. Inner shaft 226 may then be inserted into internal bore 214 of outer shaft 212 and slid axially until the female thread of inner bore 228 engages the male thread of screw 224. Inner shaft 226 may be initially inserted into outer shaft 212 such that proximal end 224b of screw 224 contacts inner shaft 226 and pushes inner shaft 226 proximally relative to outer shaft 212. Inner shaft 226 may then be rotated to engage the threads of proximal end 224b and may be further rotated and screwed down proximal end 224b of screw 224 until distal end 226b of inner shaft 226 and distal end 229 of internal bore 228 contact the top surface of nut 224a. In one embodiment, inner shaft 226 includes a quick connect feature for a handle enabling inner shaft 226 to be easily threaded down screw 224. Inner shaft 226 may be threaded down screw 224 by hand or via a power tool.

[0059] Once inner shaft 226 has been screwed down proximal end 224b such that distal ends 226b and distal end 229 contact the top surface of nut 224a, inner shaft 226 may then be twisted relative to outer shaft 212 to remove proximal end 224b of screw 224. For example, inner shaft 226 may be rotated relative to outer shaft 212 until inner shaft 226 pulls proximal end 224b of screw 224 away from nut 224a due to inner shaft 226 engaging with proximal end 224b and outer shaft 212 being rotationally fixed relative to nut 224a. The rotating and pulling of proximal end 224b results in proximal end 224b shearing across a plane approximately flush with the top of nut 224a, allowing proximal end 224b of screw 224 to be removed from screw 224. Rotation of inner shaft 226 relative to rotationally fixed outer shaft 212 results in both a pulling force and a shearing force being placed on proximal end 224b of screw 224 due to inner shaft 226 being engaged with proximal end 224b of screw 224 right above nut 224a. The pulling force and shearing force placed on proximal end 224b of screw 224 causes proximal end 224b to cleanly break off from screw 224 above nut 224a, leaving the top of nut 224a of screw 224 flush with the surrounding surface. Thereafter, inner shaft 226, which contains proximal end 224b of screw 224, may be removed from internal bore 214 of outer shaft 212, and proximal end 224b of screw 224 may then be removed from inner shaft 226 through notch 230. In one embodiment, the top surface of nut 224a may be recessed and inner shaft 226 may be rotated until distal end 226b of inner shaft 226 and distal end 229 of internal bore 228 are disposed within the recess of nut 224a and engaged with proximal end 224b of screw 224 within the recess. This ensures that no part of screw 224 is protruding from the top of nut 224a and surface M when proximal end 224b of screw 224 is cleanly broken off from screw 224 above nut 224a.

[0060] A secondary embodiment of a screw end trimmer is shown in Fig. 9. Screw end trimmer 310 is similar to screw end trimmer 210 except outer shaft 312 of screw end trimmer 310 may not include grip 218 resulting in the outer surface of outer shaft 312 being generally smooth. A majority of screw end trimmer 310 may have the same diameter. For example, outer shaft 312 may be a cylinder having a constant diameter. In one embodiment, outer shaft 312 is comprised of a single piece of material.

[0061] In exemplary embodiments shown in Figs. 10A-11B, the inner shaft of the screw end trimmer may include a distal end configured to reduce its width as the inner shaft moves axially down the internal bore of the outer shaft towards the distal end of the outer shaft. This allows the inner shaft to slid over the screw without engaging the male thread of the screw, saving time and effort from having to screw and rotate the inner shaft down the entire length of the screw.

[0062] A third embodiment of a screw end trimmer is shown in Figs. 10A - 10E. Screw end trimmer 410 may include outer shaft 412, inner shaft 426, and pin 430. Inner shaft 426 may include one or more segments. For example, inner shaft 426 may include securing element 436. Securing element 436 may be located at a distal end of inner shaft 426. Outer shaft may include hole 429 configured to received pin 430. Hole 429 may be an aperture, a through-hole, or an opening. Pin 430 may be secured in hole 429 and may prevent inner shaft 426 from disengaging from outer shaft 412. In one embodiment, inner shaft 426 includes recessed portion 428. Recessed portion 428 may be circumferentially disposed around the exterior surface of inner shaft 426. Recessed portion 428 may be configured to engage with pin 430 when pin 430 is inserted in hole 429 and when inner shaft 426 is disposed within distal end 4l2b of outer shaft 412. Recessed portion 428 engaging with pin 430 may prevent axially movement of inner shaft 426 in and out of outer shaft 412, but may allow for rotation of inner shaft 426 relative to outer shaft 412. For example, when inner shaft 426 is inserted within outer shaft 412, recessed portion 428 may align with hole 429, and pin 430 may be inserted through hole 429 to engage with recessed portion 428 preventing inner shaft 426 from being removed from outer shaft 412. In one embodiment, recessed portion 428 is sized to be larger than hole 429 and pin 430 to allow for minor axial movement of inner shaft 426 in and out of outer shaft 412 and rotation of inner shaft 426 relative to outer shaft 412 when pin 430 is engaged with recessed portion 429 of inner shaft 426.

[0063] In one embodiment, inner shaft 426 includes an internal bore configured to receive screw 424. Inner shaft 426 may be configured to axially slide down screw 424 without engaging screw 424 until a distal end of inner shaft 426 reaches proximal end 424b of screw 424. Inner shaft 426 may include securing element 436 at a distal end of inner shaft 426 which engages with proximal end 424b of screw 424 at distal end 4l2b. For example, inner shaft 426 may be slidable relative to screw 424 without rotation of inner shaft 426 and the distal end of inner shaft 426 reduces in width as the distal end of inner shaft 426 is proximate distal end 4l2b of outer shaft 412 until the distal end of inner shaft 412 engages the male thread of screw 424. Distal end 4l2b of outer shaft 412 may include keyed projections 416 configured to engage and secure nut 424a. For example, outer shaft 412 may have keyed projections 416 configured to correspond to slots 425 of nut 424a. Nut 424a may be coupled to proximal end 424b of screw 424 and may be threaded or include slots 425 to allow keyed projections 416 to engage nut 424a. In use, outer shaft 412 may be placed over screw 424 and slid axially down screw 424 until keyed projections 416 engage nut 424a coupled to proximal end 424b of screw 424 such that outer shaft 412 is rotationally fixed relative to nut 424a.

In one embodiment, securing element 436 is a part of inner shaft 426 and both are inserted into outer shaft 412. In another embodiment, securing element 436 is separate from inner shaft 426 and is already disposed within outer shaft 412 at distal end 212b when outer shaft 412 engages nut 424a via keyed projections 416. [0064] Referring to Figs. 10B - 10D, inner shaft 426 may be coupled to securing element 436 via protrusions 427 located at a distal end of inner shaft 426. Inner shaft 426 may include one protrusion, two protrusions, three protrusions, or four protrusions. In a preferred embodiment, inner shaft 426 includes two protrusions 427. Protrusions 427 may be configured to engage with securing element 436 within outer shaft 412. In one embodiment, securing element 436 may include distal ends 442. Distal ends 442 of securing element 436 may be configured to allow securing element 436 to sit within distal end 412b of outer shaft 412 and may prevent securing element 436 from exiting distal end 412b of outer shaft 412.

[0065] Securing element 436 of inner shaft 426 may include a female thread disposed on an interior surface allowing inner shaft 426 to slide axially down screw 424 when securing element 436 is in an initial disengaged position. In an engaged position, the radial width of securing element 436 may be reduced causing securing element 436 to be secured around proximal end 424b of screw 424 preventing movement and rotation of screw 424. In an engaged position, the female thread of securing element 436 may engage with the male thread of screw 424 allowing inner shaft 426 to engage with screw 424. Inner shaft 426 may be configured to couple to securing element 436 causing the radial width of securing element 436 to decrease thereby securing the female thread of securing element 436 to the male thread of screw 424. For example, securing element 436 may be rotatable relative to inner shaft 426 in a disengaged position and rotatably fixed to inner shaft 426 in an engaged position. Securing element 436 of inner shaft 426 may be comprised of halves 436a, 436b. Halves 436a, 436b may be mirror images of each other and may be semi-circular halves that are disposed within outer shaft 412. Each half 436a, 436b of securing element 436 may include engaging area 438 and chamfered area 440 located on an exterior surface. Engaging areas 438 of securing element 436 may be configured to receive protrusions 427 of inner shaft 426. For example, inner shaft 426 may be axially slid down the internal bore of outer shaft 412 along with securing element 436. Inner shaft 426 may be rotated relative to securing element 436 at distal end 5l2b such that protrusions 427 align with chamfered areas 440 and engaging area 438 of securing element 436. Chamfered areas 440 of securing element 436 may allow protrusion 427 to easily engage with engaging area 438 of securing element 436 when securing element 436 is in the disengaged position.

[0066] In use, inner shaft 426 and securing element 436 are axially slid down screw 424 within outer shaft 412. Inner shaft 426 may be rotated relative to outer shaft 412 and securing element 436 until protrusions 427 of inner shaft 426 engage with chamfered areas 440 of securing element 436. This allows protrusions 427 to easily slide down chamfered areas 440 into engaging areas 438, thereby coupling inner shaft 426 to securing element 436. When protrusions 427 slide down chamfered areas 440 thereby engaging with engaging areas 438, the radial width of securing element 436 is reduced and halves 436a, 436b of securing element 436 move closer together and around proximal end 424b of screw 424. Halves 436a, 436b moving closer together and around proximal end 424b results in inner shaft 426 and securing element 436 being secured to proximal end 424b preventing movement of proximal end 424b and screw 424.

[0067] Referring to Fig. 10E, when protrusions 427 are fully disposed within engaging area 438, inner shaft 426 may be fully coupled to securing element 436 causing securing element 436 of inner shaft 426 to be in the engaged position. In the engaged position, inner shaft 426 and securing element 436 grip and secure proximal end 424b of screw 424, preventing rotation of screw 424.

Once securing element 436 is in the engaged position, inner shaft 426 may be rotated relative to outer shaft 412 until proximal end 424b is pulled and sheared from screw 424. For example, inner shaft 226 may be rotated relative to outer shaft 412 until securing element 436 of inner shaft 416 pulls proximal end 424b of screw 424 away from nut 424a due to securing element 436 of inner shaft 426 engaging with proximal end 424b and outer shaft 412 being rotationally fixed relative to nut 424a. The rotating and pulling of proximal end 424b results in proximal end 424b shearing across a plane approximately flush with top 423 of nut 424a, allowing proximal end 424b of screw 424 to be removed from screw 424. Rotation of inner shaft 426 relative to rotationally fixed outer shaft 412 results in both a pulling force and a shearing force being placed on proximal end 424b of screw 424 due to inner shaft 426 being engaged with proximal end 424b of screw 424 right above nut 424a. The pulling force and shearing force placed on proximal end 424b of screw 424 causes proximal end 424b to cleanly break off from screw 424 above nut 424a, leaving top 423 of nut 424a of screw 424 flush with the surrounding surface.

[0068] A fourth embodiment of a screw end trimmer is shown in Figs. 11 A - 11B. Screw end trimmer 510 may include outer shaft 512 and inner shaft 526. Inner shaft 526 may be disposed within outer shaft 512 and may include securing portion 536 located at a distal end of inner shaft 526. Securing portion 536 may include protrusions 538 extending from inner shaft 526 and may include slot 540. Securing portion 536 of inner shaft 526 may include one or more slots 540. Slot 540 may open towards the distal end of inner shaft 526 and may also open towards distal end 5l2b of outer shaft 512. The distal ends of protrusions 538 may include a female thread configured to mate with a male thread of screw 524. Protrusions 538 may be configured to radially flex inwards or outwards due to slot 540. Slot 540 may expand as securing portion 536 and protrusions 538 of inner shaft 526 pass over screw 524 resulting in protrusions 538 radially flexing outwards.

Protrusions 538 may flex inwards when securing portion 536 is inserted into distal end 5l2b. For example, slot 540 may allow protrusions 538 to be flexed radially inwards when inward pressure is applied to protrusions 538, such as when protrusions 538 are inserted into distal end 5l2b. Slot 540 of inner shaft 526 may allow the distal end of inner shaft 526 to increase in width to be slidable relative to screw 524 without rotation of inner shaft 526 and to reduce in width as the distal end of inner shaft 526 is proximate distal end 5l2b of outer shaft 512 until the distal end of inner shaft 526 engages the male thread of screw 524.

[0069] In practice, outer shaft 512 may be slid axially down screw 524 until keyed projections 516 engage with nut 524a. Nut 524a may be threaded or include slots to allow keyed projections 516 to engage nut 524a such that outer shaft 512 is rotationally fixed relative to nut 524a. Inner shaft 526 may then be inserted into outer shaft 512 and slid axially down until securing portion 536 of inner shaft 526 engages with distal end 5 l2b. Inner shaft 526 may be further inserted into outer shaft 512 such that protrusions 538 are disposed within distal end 5l2b. When protrusions 538 are disposed within distal end 5l2b, they are flexed radially inwards due to pressure applied by the walls of outer shaft 512 at distal end 5l2b. Protrusions 538 being flexed radially inwards may reduce the radial width of securing portion 536 which may cause the distal end of protrusions 538 to engage with proximal end 524a of screw 524. While protrusions 538 are engaged with proximal end 524a, inner shaft 526 may be rotated relative to rotationally fixed outer shaft 512 causing proximal end 524b to be pulled and sheared from screw 524. For example, inner shaft 526 may be rotated relative to outer shaft 512 until protrusions 538 of securing portion 536 pull proximal end 524b of screw 524 away from nut 524a due to securing portion 536 of inner shaft 526 engaging with proximal end 524b and outer shaft 512 being rotationally fixed relative to nut 524a. The rotating and pulling of proximal end 524b results in proximal end 524b shearing across a plane

approximately flush with the top of nut 524a, allowing proximal end 524b of screw 524 to be removed from screw 524. Rotation of inner shaft 526 and securing portion 536 relative to rotationally fixed outer shaft 512 results in both a pulling force and a shearing force being placed on proximal end 524b of screw 524 due to inner shaft 226 and securing portion 536 being engaged with proximal end 524b of screw 524 right above nut 524a. The pulling force and shearing force placed on proximal end 524b of screw 524 causes proximal end 524b to cleanly break off from screw 524 above nut 524a, leaving the top of nut 524a of screw 524 flush with the surrounding surface. [0070] It will be appreciated by those skilled in the art that changes could be made to the exemplary embodiments shown and described above without departing from the broad inventive concepts thereof. It is understood, therefore, that this invention is not limited to the exemplary embodiments shown and described, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the claims. For example, specific features of the exemplary embodiments may or may not be part of the claimed invention and various features of the disclosed embodiments may be combined. The words“proximal”,“distal”,“upper” and“lower” designate directions in the drawings to which reference is made. Unless specifically set forth herein, the terms“a”,“an” and“the” are not limited to one element but instead should be read as meaning “at least one”.

[0071] It is to be understood that at least some of the figures and descriptions of the invention have been simplified to focus on elements that are relevant for a clear understanding of the invention, while eliminating, for purposes of clarity, other elements that those of ordinary skill in the art will appreciate may also comprise a portion of the invention. However, because such elements are well known in the art, and because they do not necessarily facilitate a better understanding of the invention, a description of such elements is not provided herein.

[0072] Further, to the extent that the methods of the present invention do not rely on the particular order of steps set forth herein, the particular order of the steps should not be construed as limitation on the claims. Any claims directed to the methods of the present invention should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the steps may be varied and still remain within the spirit and scope of the present invention.