Improved ratcheting mechanism for tool

Abstract

To provide a ratcheting mechanism for a tool that allows for the attachment to the tool and release from the tool, and control of the direction of rotation of the shafts of a variety of implements.SOLUTION: A ratcheting mechanism for a tool of the present disclosure eliminates exterior securing or engaging elements to hold a reverse or end cap in engagement on a housing for ratcheting mechanism. In a construction of the present disclosure, the reverse cap can be held on the housing for use in controlling operation of the ratcheting mechanism using only components internal to the ratcheting mechanism, limiting exposure to exterior element and simplifying the construction of the ratcheting mechanism.SELECTED DRAWING: Figure 15

Description

Technical Field

[0001] The present invention relates to hand tools, and more particularly to a ratchet mechanism for controlling the movement of various tools and shafts releasably fixed to the hand tools.

Background Art

[0002] Hand tools are designed for a variety of uses that enable an individual to perform various tasks. These tools include a handle that an individual can grip to more securely operate the tool.

[0003] Many tools of this type include various mechanisms that enable the tool to have a number of different tools with an attachment shaft removably attached to the tool. These mechanisms enable a single tool with multiple removable attachments to provide various functions for the tool by allowing the shaft of the tool to be attached to the tool and utilized with the tool in a replaceable manner.

[0004] However, one of the drawbacks commonly seen in this type of mechanism is that the mechanism cannot attach the tool shaft to the tool in such a way as to prevent the tool from shifting or becoming prone to shifting relative to the tool during use of the tool and the attachment, and as a result, it is often necessary to remove and reattach the attachment from the tool in order to properly align and relocate the attachment with the tool.

[0005] In addition, another drawback commonly seen in this type of mechanism is that the connection between the shaft of the attachment and the tool is not completely tight, and the amount of movement, toggle, or play between the handle and the attachment is perceived by the user. This can lead to malfunctions during use or a decrease in the quality or reliability of the performance of the tool.

[0006] Improvements to this type of mechanism are found in Patent Document 1 entitled "Shaft Securing Mechanism For A Tool" and Patent Document 2 entitled "Improved Shaft Securing Mechanism For A Tool", the entire disclosures of which are hereby expressly incorporated by reference for all purposes. However, while addressing certain drawbacks of the prior art mechanisms, there is still room for improvement with respect to the shaft securing mechanisms and other mechanisms present in various types of tools.

[0007] In particular, with respect to the structure of the shaft securing mechanism and / or ratchet control mechanism for a tool, the mechanism includes a number of components within the structure of the shaft securing mechanism / ratchet control mechanism that enable proper operation of the mechanism. While each of the components enables the shaft securing mechanism and / or ratchet control mechanism to operate as desired, the number and type of components required for the assembly of one or more mechanisms each introduce the possibility of failure and result in the inoperability of one or more of the mechanisms.

[0008] Accordingly, it is desirable to develop a shaft securing mechanism and / or ratchet control mechanism for a tool that can be easily manipulated to secure, release, and / or control the rotation of various replaceable tools engaging the tool while maintaining alignment of the shaft of the tool with respect to the tool as the tool is secured to and used with the mechanism.

[0009] Furthermore, it is desirable to develop a securing mechanism and / or ratchet control mechanism for a tool that eliminates any actual or perceived toggle or play between the tool and the handle by having a perfectly tight connection between the shaft of the tool and the tool.

[0010] In addition, in order to limit potential failure points of the fixing mechanism and / or the ratchet mechanism, it is desirable to develop a fixing mechanism and / or a ratchet control mechanism having a simplified structure.

Prior Art Documents

Patent Documents

[0011]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

[0012] According to one aspect of the exemplary embodiments of the present disclosure, a ratchet mechanism for a tool is provided that enables attachment of the shafts of various instruments to the tool and detachment from the tool, as well as control of the rotational direction of the shafts. The ratchet mechanism is applicable to uses in "navigated surgical instruments" such as handheld and / or manually operated surgical instruments, and instruments that are attached to a surgical navigation system and require absolute accuracy for a computer to know where the tip of the instrument is during surgery. The ratchet mechanism for a tool of the present disclosure has several improvements over conventional ratchet mechanisms. One improvement is to eliminate external fixing elements or engaging elements for engaging the housing for the ratchet mechanism to hold a reverse cap or an end cap. In the structure of the present disclosure, the reverse cap can be held on the housing for use in controlling the operation of the ratchet mechanism using only the internal components of the ratchet mechanism, and the reverse cap restricts exposure to external elements of the ratchet mechanism and simplifies the structure of the ratchet mechanism.

[0013] Another improvement is the reduction and / or elimination of the left and right toggles present in all existing connectors. This mechanism has a structure that provides a secure engagement of the tool axis within the mechanism, substantially reducing any tilt, toggle, or play in the engagement between the tool and the instrument. The reduction of the toggle is achieved by increasing the two locking regions present in the mechanism and the spacing between them. Additionally, one of the locking regions presses the axis against the internal geometry of the mechanism by pinching the axis with a point-to-line contact.

[0014] According to another aspect of an exemplary embodiment of the present disclosure, the fixing mechanism has an alignment feature that maintains the alignment of the tool axis with respect to the mechanism and the tool, resulting in an increase in the concentricity between the tool and the instrument. In one exemplary embodiment, the fixing mechanism provides this property by utilizing two concentric locking tapers on the same component that engage the axis with respect to the fixing mechanism to hold it concentrically.

[0015] According to yet another aspect of an exemplary embodiment of the present disclosure, the instrument can self-load without the need to disengage the mechanism, such as by pressing down on a collar. This function is achieved by utilizing multiple sets of ball bearings present within the mechanism that move along the tapered surface when the axis is inserted into the fixing mechanism.

[0016] According to yet another aspect of an exemplary embodiment of the present disclosure, the axis used with the mechanism enables a secure and aligned universal engagement between the axis and the mechanism on existing axes and custom axis configurations by allowing contact at multiple points between the axis and the mechanism.

[0017] According to another aspect of an exemplary embodiment of the present disclosure, the mechanism has a relatively simple structure that allows the mechanism to be utilized with tools having various other mechanisms disposed therein without significantly affecting the operation or overall size of the tool.

[0018] Many other aspects, features, and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the drawings. The drawings illustrate the best mode presently contemplated for carrying out the invention.

Brief Description of the Drawings

[0019]

Figure 1

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Figure 19

Figure 20

Mode for Carrying Out the Invention

[0020] Here, referring to the drawings in which the same reference numerals indicate the same parts throughout the present disclosure, a tool handle configured according to the present invention is indicated generally at 100 in FIG. 1. The handle 100 can be formed in any shape so as to be utilized as a hand tool, and is preferably ergonomically shaped so as to have a tactile feature 102 that assists a person in continuously gripping the handle 100 firmly. In addition to the feature 102, the handle 100 may have other design elements 104 disposed thereon as desired. An example of such a handle is disclosed in Patent Document 1 of Gauthier et al. entitled "Shaft Securing Mechanism For A Tool", the entirety of which is hereby expressly incorporated by reference for all purposes.

[0021] Here, referring to FIGS. 1 to 11, the handle 100 is formed with a fixing mechanism 106 that can releasably fix the instrument shaft 108 to the handle 100. The shaft 108 may include any instrument or feature (not shown) at the end of the shaft 108 that is not fixed to the mechanism 106 in order to provide various functionalities to the handle 100.

[0022] In addition to the fixing mechanism 106, the handle 100 may also include, alone or in combination with each other, other mechanisms such as a torque limiting mechanism or a ratchet mechanism, such as those shown and described in Patent Document 3 titled "Ratcheting Mechanism", which is hereby expressly incorporated by reference in its entirety. Further, the handle 100 may incorporate a variable gear ratio mechanism as shown and described in Patent Document 4 titled "Variable Gear Ratio Ratchet", which is hereby expressly incorporated by reference in its entirety.

[0023] In one embodiment shown in the drawings, the fixing mechanism 106 is incorporated within the handle 100 which also includes a ratchet mechanism 110. Details of the mechanism 110 are disclosed in the aforementioned U.S. Patent No. 594 and will not be described in detail herein.

[0024] The fixing mechanism 106 includes, as components, an engagement socket 112, a bush 114, a plurality of ball bearings 116, a lock sleeve 118, a biasing spring 120, a corrugated spring 310, a positioning ring 312, and a release collar 122. The engagement socket 112 is disposed within a cavity 1000 formed in the handle 100 and is aligned and held with the cavity 1000 by a plurality of bearings 1100 engaged between the socket 112 and the handle 100, as best shown in FIGS. 2 and 3. The socket 112 has a generally cylindrical shape defining a central passage 129 therethrough, and includes an inner portion 124, a radial flange 126 at one end of the inner portion 124, and an outer portion 128 extending outwardly from the flange 126 on the opposite side of the inner portion 124. A number of axial grooves 130 extending in the length direction of the socket 112 through the passage 129 are provided on the inner surface of the socket 112. The grooves 130 may be present in any number and may have any suitable cross-sectional shape. The grooves 130 are configured to engage all of the corners of various geometric shapes existing on the shaft 108, such as triangular, square, or other polygonal shapes, and are oriented around the inside of the socket 112. In the illustrated exemplary embodiment, there are eight grooves 130 disposed inside the socket 112 to provide a plurality of four-point engagement configurations between the socket 112 and the shaft 108. Additionally, the grooves 130 may include tapered outer ends 132 to provide a self-aligning function to the grooves 130 to assist in achieving proper alignment of the shaft 108 with respect to the grooves 130. The tapered groove ends 132 engage the shaft 108 when the shaft 108 is fully inserted into the socket 112, so the grooves 130 may function as a stop for the insertion of the shaft 108 into the socket 112. Further, when the shaft 108 receives an external compressive force acting axially on the shaft 108, such as by striking the handle 100 to drive an element engaging the shaft 108 on the opposite side of the handle 100 to a desired depth, the tapered ends of each groove 130 prevent the shaft 108 from being constrained within the socket 112.The tapered end 132 is formed complementary to the facet surface 304 on the shaft 108 to facilitate face-to-face contact and minimize bearing stress when the shaft 108 is fully seated within the socket 112.

[0025] The socket 112 also includes a plurality of openings 134 that extend through the socket 112 and, more specifically, through the outer portion 128 between adjacent grooves 130. A ball bearing 116 is disposed within each opening 134, although the bearing 116 may also have alternative shapes such as, among other things, pins, cylindrical rollers, or wedges. The opening 134 has a narrow inner end 136 that prevents the bearing 116 from fully entering the interior of the socket 112. Any number of bearings 116 and openings 134 may be used, although in the exemplary embodiment best shown in FIGS. 11 and 12, there are four bearings 116 and openings 134 each to provide secure engagement of the shaft 108 with the bearings 116 and socket 112 for any configuration of the shaft 108 as a result of the multiple engagement points between the bearings 116 and the shaft 108. Further, in the illustrated embodiment, the bearings 116 and openings 134 are disposed within the socket 112 at a position between the grooves 130 so as to minimize interference between the bearings 116 and an instrument engaged within the grooves 130.

[0026] As best shown in FIG. 3, the bearing 116 is partially held in the opening 134 from the outside of the socket 112 by a bush 114 disposed around the outside of the socket 112. By forming the bush 114 as a cylindrical sleeve having a diameter slightly larger than the diameter of the socket 112, the bush 114 is enabled to slide relative to the socket 112. The bush 114 includes a radially extending flange 140 disposed spaced from the socket 112 and defines a through opening 142 aligned with the central passage 129 of the socket 112. The radially extending flange 140 is disposed at least partially over the opening 134 by contact with the outside of the socket 112 such that the bush 114 partially covers the opening 134 on the outer surface of the socket 112 and holds the bearing 116 therein. Alternatively, the bush 114 may be used in association with, or replaced by, other suitable actuating member(s) such as a push rod (not shown) that biases the bearing 116 into the opening 134.

[0027] The movement of the bushing 114 along the socket 112 is guided by a lock sleeve 118 which abuts against a flange 126 on the socket 112 and, in the illustrated embodiment, is connected thereto, as best shown in FIGS. 2 and 3. The lock sleeve 118 is generally cylindrical in shape and defines a central passage 144 which is aligned with an opening 142 in the bushing 114 and the central passage 129 of the socket 112. The passage 144 has an inwardly tapered outer end 146 which is adjacent to but spaced from a flange 140 of the bushing 114. In addition, while the lock sleeve 118 may be formed in any desired configuration, in one embodiment the sleeve 118 may include a plurality of teeth 148 on an outer surface 149 and thus the sleeve 118 can also function as a central gear in the ratchet mechanism 110 disclosed in the '594 patent. The sleeve 118 is secured to the flange 126 on the socket 112 by any suitable method, such as welding, for axially aligning and holding the socket 112, the bushing 114, and the sleeve 118 relative to one another.

[0028] A biasing member or spring 190 held at a predetermined position between the outer end of the socket 112 and the flange 140 of the bush 114 biases the bush 114 in a direction away from the socket 112. The spring 190 biases or pushes the bush 114 away from the socket 112 so that the bearing 116 can be placed in a defined engagement position within the socket 112. Additionally, the spring 190 also presses the release collar 122 outwardly from the lock sleeve 118. The collar 122 includes a cylindrical guide portion 150 and an outwardly extending engagement portion 152, as best shown in FIGS. 2 and 3. The guide portion 150 is disposed in direct contact with the flange 140 of the bush 114 and defines a central passage 151 that is aligned with the central passage 144 of the lock sleeve 118, the opening 142 of the bush 114, and the central passage 129 of the socket 112. By having the guide portion 150 with a diameter slightly smaller than the diameter of the passage 144, the guide portion 150 can be inserted into the passage 144. To hold the guide portion 150 within the passage 144, the guide portion 150 includes a peripheral notch 154 in which a retaining ring 156 is disposed. To hold the sleeve 118 and the socket 112 within the cavity 1000 in the handle 100, the ring 156 extends outwardly from the guide portion 150 into a corresponding recess 158 within the handle 100, such as within an end cap 160 that is fixed to the handle 100 covering the lock sleeve 118. The recess 158 has a width greater than the width of the ring 156 so that the ring 156 can move within the recess 158. The ring 156 is biased by the biasing member / spring 190 to engage the outer end of the recess 158.

[0029] Between the flange 140 and the ring 156, the guide portion 150 includes a plurality of openings 162 spaced around the circumference of the guide portion 150, in which a ball bearing 164 is disposed, although the bearing 164 may equally have alternative shapes such as pins, cylindrical rollers, or wedges. The openings 162 are formed similarly to the openings 134 of the socket 112 and receive and hold the bearing 164 therein. The dimensions of the bearing 164 are such that when the openings 162 and the bearing 164 are aligned with the larger diameter portion of the passage 144 of the lock sleeve 118, the bearing 164 extends outwardly from the guide portion 150 and contacts the surface of the passage 144. As the biasing member 120 biases the collar 122 and the guide portion 150 outwardly from the passage 144, the bearing 164 contacts the inwardly tapered section of the passage 144 and is biased inwardly through the opening 162 into the passage 151. In this position, the bearing 164 can engage a portion of the shaft 108 disposed within the passage 151.

[0030] As best shown in FIGS. 4-7, in the illustrated exemplary embodiment, the shaft 108 includes a first geometric portion 200 disposed at an end 202 of the shaft 108 and a second geometric portion 204 axially spaced from the first portion 200 on the opposite side of the end 202. The first portion 200 has an angled or curved corner 206 but a generally square cross-section such that the first portion 200 can be readily oriented, aligned, and engaged within a groove 130 formed within the socket 112 and associated bearing 116. The second portion 204 also has a generally square cross-section with an angled or curved corner 208, but is slightly larger than the first portion 200 and has a greater width or diameter. Each portion 200, 204 includes a plurality of flat surfaces or faces 304, 306 thereon that can have different sizes. However, in other embodiments, the second portion 204 may have other cross-sectional shapes such as circular or any other suitable outer shape that is insertable within the passage 151 of the collar 122. The first portion 200 is joined to the second portion 204 by a faceted surface 133 to provide a stop function for inserting the shaft 108 within the socket 112. Additionally, the configuration of the second portion 204 enables some of the bearings 164 within the guide portion 150 to engage the second portion 204 of the shaft 108 and fix it relative to the mechanism 110.

[0031] In the exemplary embodiment shown in FIG. 5, eleven bearings 164 are present within the guide portion 150. When the second portion 204 of the shaft 108 is disposed within the guide portion 150 and the bearings 164 are pushed through the openings 162 into the passage 151, a subset of the bearings 164 engage the second portion 204 and the remaining portion of the bearings 164 remain non-contact with the second portion 204. In this configuration, the bearings 164 can engage universally with both an existing shaft and a custom shaft having various configurations for the second portion 204 and surface 306. Some of the bearings 164 engage the second portion 204 of the shaft 108 and the other bearings remain non-contact to enable the second portion 204 to be securely engaged by the bearings 164.

[0032] Referring now to FIGS. 3, 8-10, and 14, the sleeve 118 includes a first or front taper 300 and a second or rear taper 302 to enable the fixing mechanism 106 to provide a substantial reduction and / or elimination of toggle or play between the shaft 108 and the mechanism 106. Each taper 300, 302 is concentric with the sleeve 118 and extends around the inner circumference of the sleeve 118 and is aligned with one of the sets of bearings 116, 164, respectively. The tapers 300 and 302 are spaced apart from each other on the sleeve 118 such that the sleeve 118 is a single component that enables a load applied to the shaft 108 to be transmitted to the sleeve 118 through both sets of bearings 116 and 164. When this load is transmitted to a single component, namely the sleeve 118, the alignment of the shaft 108 with respect to the sleeve 118, and thus with respect to the handle 100, is significantly improved, and the ability of the mechanism 106 to hold the shaft 108 concentric with respect to the handle 100 during use is enhanced.

[0033] In addition, since both sets of bearings 116 and 164 are engaged with their respective tapers 300, 302, when the shaft 108 is inserted into the collar 122, the shaft 108 can engage and bias the bearings 116 and 164 along the associated taper 300 or 302. Thus, the operation of the handle 100 is simplified because it is not necessary to further press the collar 122 inward to disengage the fixing mechanism 106.

[0034] Next, referring to FIGS. 11 - 13, when shaft 108 is inserted into mechanism 106, bearings 116 and 164 engage shaft 108 and, in the illustrated exemplary embodiment, engage a first portion 200 and a second portion 204 of shaft 108. By the engagement of bearing 116 with the first portion 200, the number of bearings 116 is selected to provide a desired number of contact points between bearing 116 and the first portion 200 of shaft 108. In the illustrated exemplary embodiment having eleven bearings 116, mechanism 106 provides sufficient contact points between mechanism 106 and the instrument / shaft 108 to hold the instrument 108 concentric with handle 100, which is also good for a shaft 108 having additional flats or interruptions on the circumference of shaft 108 such as the first portion 200 and the second portion 204.

[0035] Regarding bearing 164, the positions of these four bearings 116 in the illustrated exemplary embodiment are selected to contact the rear locking ball bearings 116 in a point - to - line manner and sandwich shaft 108. As best shown in FIGS. 11 - 13, bearings 116 engage each side surface 304 of the first portion 200 of shaft 108 at a position offset from the mid - point of side surface 304, and thus "sandwich" each corner 206 of shaft 108 between groove 130 and bearing 1116. This orientation presses shaft 108 against the internal geometry of sleeve 118 such that, as a result, during the use of handle 100 and shaft 108, this force causes shaft 108 to twist with respect to the internal square geometry of sleeve 118.

[0036] To assist in compressing mechanism 106 and bearing 116 against shaft 108, in the exemplary embodiments shown in FIGS. 3, 10, and 14, two different biasing members 190 and 310, compression springs 190 and wave springs 310, act to hold the instrument / shaft 108 in place by pushing the balls against respective tapered surfaces 300, 302 of sleeve 118 and toward the aligned instrument / shaft surface / portion 200, 204. When a tensile force is applied to attempt to remove shaft 108, both sets of balls 116 and 164 ride further up the associated tapers 300, 302, gripping the instrument / shaft 108 with increased radial force.

[0037] Release of each independent bearing set 116 and 164 is initially achieved by pushing on outer release collar 122 for bearing lock set 116. This causes collar 122 to be pushed inward against bushing 114 and compression spring 190 disposed within bushing 114, allowing bearing 116 to move outward from shaft 108 along taper portion 300. Bushing 114 also contacts bearing 164 on the opposite side of collar 122, pushing bearing 164 downward along taper 302 against the bias of wave spring 310, releasing the second set of bearings 164 from shaft 108. This release of bearings 116 and 164 is similarly achieved in another embodiment where bushing / release sleeve 114 is formed as an extension of collar 112, such that collar 112 and release sleeve / bushing 114 are a single piece. Positioning ring 312 is concentrically disposed within sleeve 118 and is positioned around socket 112 between wave spring 310 and bearing 164. Positioning ring 312 acts to engage and bias bearing 164 against socket 112 under the bias of wave spring 310 until it receives a reaction by pressing on collar 122 to engage bushing 114 as described above.

[0038] As best shown in FIGS. 4-5 and 11-13, when the shaft 108 of a suitable instrument engages the handle 100 using the mechanism 106, the first portion 200 of the shaft 108 is inserted into the socket 112 and received within the aligned groove 130 in the socket 112 to engage the shaft 108 with the handle 100. Insertion of the shaft 108 into the groove 130 is facilitated by the tapered end 132 of the groove 130. The end 202 of the shaft 108, when disposed within the groove 130, is aligned and maintained with the handle 100 by engagement of the groove 130 with the bearing 116 surrounding the first portion 200.

[0039] To lock the shaft 108 within the handle 100 during use, initially, the release collar 122 is biased inwardly into the passage 144 against the bias of the biasing member 190. In so doing, the ring 156 moves within the recess 158 until it reaches the inner end of the recess 158, thereby stopping further movement of the collar 122. In this position, when the end 202 of the shaft 108 is inserted into the passage 151 of the collar 122, the end 202 can contact the bearing 164 and push the bearing 164 out of the guide portion 150 of the collar 122, such that, as shown in FIG. 4, the end 202 can pass through the collar 122 and enter the lock sleeve 118, the bushing 114, and the socket 112. By rotating the shaft 108 as necessary, the end 202 can contact the tapered end 132 such that it is aligned with, seated within, and engaged with the groove 130 and the bearing 116 of the socket 112 as previously described.

[0040] After the end 202 and the first portion 200 are properly seated within the groove 130 of the socket 112, the release collar 122 is released, whereupon the biasing member 190 biases the collar 122 outwardly relative to the socket 112 from the lock sleeve 118 and the bushing 114. By doing so, the opening 162 and the bearing 164 on the guide portion 150 of the collar 118 are moved into the inwardly tapered section of the lock collar 122, and the bearing 164 is biased inwardly into the passage 151 defined within the lock collar 118 by the release collar 122. However, since the shaft 108 is disposed within the passage 151, a particular bearing 164 frictionally engages the face 306 of the second portion 204 of the shaft 108, thereby providing secure engagement of the shaft 108 within the mechanism 106. The particular bearing 164 that engages the second portion 204 depends on the orientation of the shaft 108 within the socket 112, the particular cross-sectional shape of the second portion 204, and the position of the associated face 306 on the second portion 204, but the number and position of the bearings 164 within the passage 151 provide a universal and secure engagement between the bearings 164 and the second portion 204 of various configurations and / or shapes, thereby preventing the shaft 108 from disengaging from within the collar 122, and as a result, enabling the shaft 108 to be utilized with the handle 100 as desired.

[0041] In addition, in this position, the shaft 108 engages with the bearings 164 within the collar 122 and the groove 130 and the bearing 116 within the socket 112 respectively, resulting in two separate and spaced axial alignment contacts between the shaft 108 and the handle 100. This structure of the mechanism 106 ensures that the force applied to the shaft 108 via the handle 100, due to the engagement of both the groove 130 and the bearing 116, as well as the bearing 164 with the shaft 108, does not change the alignment of the shaft 108 relative to the handle 100, i.e., significantly reduces the amount of shaft misalignment or "tilt", while significantly increasing the concentricity of the shaft 108 relative to the mechanism 106 and the handle 100, even after repeated use.

[0042] To remove the shaft 108, the collar 122 is pushed back into the lock collar 118 against the biasing of the biasing member 190. This allows the bearings 116 and 164 to disengage from the shaft 108. The shaft 108 can be removed from the collar 122, lock sleeve 118, and socket 112.

[0043] Thus, the mechanism 106 engages firmly with the shaft 108 having any configuration for the second portion 204 through the bearings 116 and 164 while simultaneously maintaining the alignment of the shaft 108 with respect to the mechanism 106 and the handle 100 through the bearing 164 and the bearings 116 and groove 130.

[0044] Certain improvements provided by the fixing mechanism 106 of the present disclosure include, but are not limited to, the following. Elimination of toggles by locking in two more spaced-apart tapered regions 300, 302, and an integral structure of the sleeve 118 that holds both sets of locking bearings 116, 164 spaced along the tapers 300, 302.

[0045] Since both locking tapers 300, 302 are present on the same part, i.e., the sleeve 118, the device / shaft / instrument 108 is held concentric with the handle 100. Concentric force by locking balls.

[0046] The grip strength is increased by point-to-line contact between the locking bearing 164 and the internal square of the driven shaft 108. The position of the bearing 164 on the double square points facilitates the attachment of a 0.635 cm (1 / 4 inch) drive square, and the shaft 108 can be rotated 45 degrees and reinserted. The bearing 164 locks in any position. The increased pull-out force screws the shaft with respect to the internal shape of the groove 130 and socket 112.

[0047] This fixation mechanism design can be used with other shaft shapes (AO, Tri-Flat, 1 / 4” Square, Hudson, Stryker, and many other standard shaft quick-connect shapes).

[0048] The design of bearing 116 allows for concentric contact on shaft 108 with flat surfaces 304, 306 on shaft portions 200, 204 that can be of different diameters. The design of bearing 116 always provides contact on the circumference.

[0049] Referring now to FIGS. 15 - 20, tool 100, which is used with or separately from fixation mechanism 106, also includes a ratchet mechanism 400. Ratchet mechanism 400 includes a reverse cap rotatably engaged with a housing, as shown and described in Patent Document 3 entitled "Ratcheting Mechanism", which is hereby expressly incorporated by reference in its entirety for all purposes. As shown in the exemplary embodiment of FIG. 15, housing 402 includes a central passage 405 within which a gear 407 adapted to engage shaft 108, e.g., by fixation mechanism 106 if present, is rotatably disposed. Housing 402 also includes at least one bore 408 spaced from central passage 405 within which a lock pin 410 is disposed. A biasing member 412, e.g., spring 414, is provided within bore 408 between the inner end 411 of bore 408 and pin 410, biasing pin 410 at least partially outwardly from bore 408. However, by pushing pin 410 against the bias of spring 414, pin 410 can be fully compressed into bore 408 such that the outer end 416 of pin 410 is disposed in the same plane as the outer end 413 of bore 408. Further, pin 410 may function to secure a pawl biasing spring 415 disposed within housing 404.

[0050] In an exemplary embodiment of the ratchet housing 404 shown in FIGS. 15 and 16, the housing 404 further includes an outer peripheral flange 418 along the periphery of which a plurality of recesses 420, 422, 424 are formed. The recesses 420, 422, 424 extend radially inwardly through at least a portion of the thickness of the flange 418, defining a plurality of locking portions 426, 428, 430 of the flange 418 between adjacent pairs of the recesses 420, 422, 424.

[0051] Referring now to FIGS. 17 and 18, the reverse cap 402 includes an upper wall 432 defining an opening 434 alignable with the gear 407, and has side walls 436 extending outwardly along the periphery of the upper wall 432. The side walls 436 having the upper wall 432 define the interior 438 of the reverse cap 402, and when the reverse cap 402 engages the housing 404, the peripheral flange 418 of the housing 404 can be disposed therein. The inner surface 440 of the upper wall 432 located within the interior 438 includes a pair of pockets 442 on both sides of the opening 434. These pockets are adapted to engage with one or more claw portions 452 (FIG. 20) movably disposed within the housing 404 adjacent to the central passage 405 to selectively move the claw portions 452, and by engaging or disengaging with the gear 407, control the rotation of the gear 407 and the shaft 108 engaged with the gear 407 during the operation of the ratchet mechanism 400 within the tool 100.

[0052] On the opposite side of the upper surface 432, the side walls 436 include a number of locking tabs 444, 446, 448 corresponding to the number of locking recesses 420, 422, 424 disposed on the housing 404. Each locking tab 444, 446, 448 extends radially inwardly from the side wall 436, thereby enabling the flange 418 or at least a portion thereof to be disposed within a space 450 defined between the locking tabs 444, 446, 448 and the upper wall 432a.

[0053] Referring now to FIGS. 19 and 20, in order to attach the reverse cap 402 to the housing 404, first, the lock tabs 444, 446, 448 on the reverse cap 402 are aligned with the lock recesses 420, 422, 424 in the orientation shown in FIG. 19. In this orientation, the lock tabs 444, 446, 448 can be moved through the recesses 420, 422, 424 to place the peripheral flange 418 within the interior 438 of the reverse cap 402. The flange 418 can be moved within the interior 438 of the reverse cap 402 until it contacts the inner surface 440 of the upper wall 432. In this position, the pin 410 is compressed into the bore 408 by contacting the inner surface 440 against the bias of the spring 414. The claw portions 452 are partially disposed within their respective pockets 442 in the reverse cap 402 for selectively engaging the respective pockets 442.

[0054] After contacting the inner surface 440, the peripheral flange 418 on the housing 404 is aligned with the space 450 within the interior 438 of the reverse cap 402. The flange 418 can rotate relative to the housing 404 and vice versa. Rotation of the flange 418 shifts the lock tabs 444, 446, 448 out of the recesses 420, 422, 424 such that the lock tabs 444, 446, 448 engage the flange 418 to hold the flange 418 within the interior 438 of the reverse cap 402. Further rotation of the reverse cap 402 and the housing 404 relative to each other aligns and positions one of the pockets 442 with the pin 410. As the pocket 442 moves over the pin 410, the spring 414 biases the pin 410 outwardly from the bore 408 and into the space defined within the pocket 442 until the pin 410 contacts the inner surface 440. In this engaged or locked position, a portion of the pin 410 extends into the pocket 442 and functions as a stop for rotation of the reverse cap 402 relative to the housing 404 by contacting the edge 454 of the pocket 442. Thus, the lock tabs 444, 446, 448 cannot be realigned with the recesses 420, 422, 424 and maintain the engagement of the reverse cap 402 on the housing 404. This structure allows the reverse cap 402 to be moved relative to the housing 404 such that one or more of the claw portions 452 engage or disengage from the gear 407 by contacting the surface of the pocket 442 with which the claw portions 452 are aligned, effectively controlling the rotation of the gear 210 in a ratchet manner. However, by using the pin 410 as both a movement stop for rotation of the reverse cap 402 and a lock for holding the reverse cap 402 on the housing 404, external engagement members or external lock members, such as retaining rings used on other tools, are not required.

[0055] Various other embodiments of the invention are contemplated as being within the scope of the following claims, which particularly claim and distinctly claim the subject matter regarded as the invention.

Claims

1. 1. A ratchet mechanism for a tool, comprising: a) a housing including a central passage, one or more pawls movably disposed within the housing adjacent the central passage, a plurality of locking recesses formed along a periphery of the housing, and a bore spaced from the central passage and including a biased locking pin disposed therein; b) a gear disposed within the central passageway and selectively engageable with the one or more pawls; c) a reverse cap for engaging with said housing on said gear, said reverse cap including a top wall including an inner surface having one or more pawl engagement pockets formed therein, a peripheral side wall extending outwardly from said top wall, and a plurality of locking tabs formed along a periphery of said side wall; the locking tabs are alignable with and insertable into the locking recesses and rotatable relative to the housing; The locking pin is positionable within one of the one or more pockets to act as a rotation stop for the reverse cap relative to the housing to prevent disengagement of the reverse cap from the housing, a ratchet mechanism.

2. The ratchet mechanism of claim 1 , wherein the biased locking pin includes a spring disposed within the bore between the bore and the locking pin.

3. The ratchet mechanism of claim 1 , wherein the one of the one or more pockets includes an edge engageable with the locking pin to act as a rotational stop for the reverse cap relative to the housing.

4. The ratchet mechanism of claim 1 , wherein the ratchet mechanism does not include an external retaining ring that engages the reverse cap with the housing.

5. The ratchet mechanism of claim 1 , further comprising a pawl bias secured within the housing by the locking pin and engaged with one of the one or more pawls.

6. The ratchet mechanism of claim 1 , further comprising at least two locking recesses formed along a periphery of the housing and at least two locking tabs formed along a periphery of the side wall.

7. 7. The ratchet mechanism of claim 6, wherein the at least two locking recesses and the at least two locking tabs are alignable when the locking pin is not disposed in the one of the one or more pockets.

8. 7. The ratchet mechanism of claim 6, wherein the at least two locking recesses and the at least two locking tabs are not alignable when the locking pin is not disposed in the one of the one or more pockets.

9. a) a handle; b) a ratchet mechanism as defined in claim 1 disposed within said handle.

10. The tool of claim 9 , further comprising a shaft locking mechanism disposed at least partially within the housing in alignment with the ratchet mechanism.

11. at least two locking recesses formed along a periphery of the housing and at least two locking tabs formed along a periphery of the sidewall; the at least two locking recesses and the at least two locking tabs are alignable when the locking pin is not disposed in the one of the one or more pockets; 10. The tool of claim 9, wherein the at least two locking recesses and the at least two locking tabs are not alignable when the locking pin is not disposed in the one of the one or more pockets.

12. 1. A method of assembling a ratchet mechanism for a tool, comprising the steps of: a) providing a housing including a central passage, one or more pawls movably disposed within the housing adjacent the central passage, a plurality of locking recesses formed along a periphery of the housing, and a bore spaced from the central passage and including a biased locking pin disposed therein; a gear disposed within the central passage and selectively engageable with the one or more pawls; and a reverse cap engaging the housing over the gear, the reverse cap including a top wall including an inner surface having one or more pawl engagement pockets formed therein, a peripheral side wall extending outwardly from the top wall, and a plurality of locking tabs formed along a periphery of the side wall; b) aligning said locking tabs on said reverse cap with said locking recesses on said housing; c) inserting said locking tabs into said locking recesses; d) rotating the reverse cap relative to the housing to position the locking pin in one of the one or more pockets.

13. The method of claim 12 , wherein the step of inserting the locking tabs into the locking recesses further comprises forcing the locking pin into the bore of the housing.

14. The method of claim 13 , wherein disposing the locking pin in the one of the one or more pockets prevents realignment of the locking tabs with the locking recesses.

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