Patent Publication Number: US-11654534-B2

Title: Locking mechanism and clocking cylinder

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/943,909, filed Dec. 5, 2019, which application is hereby incorporated herein by reference, in its entirety. 
    
    
     TECHNICAL FIELD 
     The invention relates generally to a multi-bit screwdriver, and more particularly, to a multi-bit screwdriver having a clocking cylinder to align a bit in a screwdriver shaft, and a locking mechanism for locking the bit in a shaft for use. 
     BACKGROUND 
     A screwdriver represents a particular case in point wherein a person may need a number of different types of screwdrivers to perform a task. This is particularly problematic, time consuming, and even dangerous, when such person is working on a ladder and must continually go up and down the ladder to fetch different screwdrivers. For such cases, screwdrivers are available which hold a number of different bits selectable by a user; such screwdrivers are referred to as multi-bit screwdrivers. There are, however, a number of drawbacks associated with “multi-bit” screwdrivers. The most common drawback is that such screwdrivers typically require two hands to change a bit, which can be dangerous when, for example, a user is standing atop a high ladder. Another common drawback is that the number of bits is very limited, such as six or even fewer bits. A still further drawback is that bits can be dropped or lost during handling. 
     These drawbacks have been largely overcome with multi-bit screwdrivers as depicted by U.S. Pat. No. 10,442,074 B2 issued on Oct. 15, 2019 (the &#39;074 patent), and US Pat. Publ. No. 2019/0047134 published on Feb. 14, 2019 (the &#39;134 publication), which patent and patent publication are incorporated herein by reference in their entirety. A drawback with the screwdrivers disclosed in the &#39;074 patent and the &#39;134 publication is that the shaft and locking mechanism are difficult to manufacture and therefore expensive to manufacture. 
     In view of the foregoing, there is a need for a multi-bit screwdriver that incorporates a shaft and locking mechanism that is simple and relatively inexpensive to manufacture. 
     SUMMARY 
     The present invention, accordingly, provides a multi-bit screwdriver that incorporates a shaft assembly with a clocking cylinder and a locking mechanism that is relatively simple and inexpensive to manufacture. Specifically, a multi-bit screwdriver is disclosed that includes a locking mechanism formed from a tubular shaft having a passageway for facilitating travel of a selected bit through the passageway. A locking finger is formed longitudinally in the tubular shaft and cantilevered from the shaft at a rearward end of the locking finger for facilitating radial spring action at a forward end of the locking finger. A locked detent and an unlocked detent are formed in the locking finger and are longitudinally spaced from each other, the locked detent being rearward of the unlocked detent. A track extends from the locked detent to the unlocked detent. A locking sleeve is slidably positioned on the tubular shaft proximate the locking finger. A roller ball is mounted in the locking sleeve portion for engaging one of the locked detent and the unlocked detent, the roller ball being rollable along the track between the locked detent and the unlocked detent. When the roller ball is in the locked detent, the locked finger is depressed into the passageway and urges against a bit to lock it in place. When the roller ball is moved to the unlocked detent, the locking finger is released from the passageway and the bit is allowed to travel back in the passageway to the handle where it is stored. 
     A clocking cylinder is disclosed which is preferably sized to fit between a tubular shaft and an opening in a storage device for receiving a bit. The clocking cylinder comprises a cylinder. Each of preferably six lands are formed in the shape of a triangle on an interior surface of the cylinder. Each of preferably six grooves are formed in the shape of a triangle on the interior surface of the cylinder. The lands and grooves alternate in a complementary fashion so that a six-sided bit passing from the handle will be turned as needed to pass through a hexagonal passageway of the tube. 
     The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
         FIG.  1    is a perspective view of a multi-bit screwdriver embodying features of the present invention; 
         FIG.  2    is a perspective view of a shaft assembly of the screwdriver of  FIG.  1   ; 
         FIG.  3 A  is a cross-section of the tubular shaft of the screwdriver of  FIG.  1   , taken along line  3 A- 3 A of  FIG.  2   ; 
         FIG.  3 B  is a cross-section of the tubular shaft of the screwdriver of  FIG.  1   , taken along line  3 B- 3 B of  FIGS.  1 ,  6 , and  7   ; 
         FIGS.  4  and  5    are perspective views of a clocking cylinder utilized in the screwdriver of  FIG.  1   ; 
         FIG.  6    is a cross-section of the screwdriver shaft assembly taken along line  6 - 6  of  FIG.  1    in an unlocked configuration; and 
         FIG.  7    is a cross-section of the screwdriver shaft assembly taken along line  6 - 6  of  FIG.  1    in a locked configuration; 
     
    
    
     DETAILED DESCRIPTION 
     The following description is presented to enable any person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein. Additionally, as used herein, the term “substantially” is to be construed as a term of approximation. Refer now to the drawings wherein like or similar elements are designated by the same reference numeral through the several views. 
     For purposes of definition, the term “bit” is used herein to signify any items desirable for storage, such as, by way of example, but not limitation, artist charcoal/pencils, children&#39;s crayons, drill bits, taps (for cutting threads), bobbins for sewing, spices, gauge pins, bits for a screwdriver, fishing weights, and the like. For purposes of illustration, bits will be depicted herein, by way of example, but not limitation, as a Phillips head bit in  FIGS.  1 ,  6  and  7   , representative of any of the foregoing items desirable for storage. Terms such as “forward” and “rearward” are relative terms as will be defined below with respect to respective drawings. 
     Referring to  FIG.  1    of the drawings, the reference numeral  100  generally designates a multi-bit screwdriver embodying features of the invention for storing bits, as defined above. Screwdriver  100  includes a handle  102 , a clocking cylinder  104 , and a shaft assembly  106 , at the end of which a bit  116  is secured. Handle  102  defines an opening (not shown) that opens into clocking cylinder  104  for communicating a bit between handle  102  and the clocking cylinder. Such a handle is exemplified as a storage device in the &#39;074 patent and the &#39;134 patent publication, and will not be described in further detail herein except insofar as necessary to describe the present invention. Shaft assembly  106  further includes locking mechanism  108 , described in further detail below. 
     As shown in  FIGS.  2 ,  4  and  5   , clocking cylinder  104  is a cylinder preferably having a straight end  128  and a swaged end  130 . Straight end  128  is configured to be securely joined within handle  102 , and swaged end  130  is configured to be securely joined (e.g., press-fitted, tack-welded) to tubular shaft  110 , so that a bit  116  may be communicated between handle  102  and tubular shaft  110 , wherein tubular shaft  110  preferably defines an interior hexagonal passageway  140 , as shown in  FIG.  3 A . Straight end  128  further includes an interior surface with substantially triangular-shaped grooves  120  and complementary substantially triangular-shaped lands  122  formed so that the base of each groove is interposed between the apex of two adjacent lands, and similarly, so that the base of each land is interposed between the apex of two adjacent grooves. The grooves  120  and lands  122  thus alternate in a complementary manner so that a six-sided bit  116  passing from the handle  102  to tubular shaft  110  will be turned as needed to align with and pass through hexagonal passageway  140  of shaft  110 . 
       FIG.  2    depicts portions of locking mechanism  108 . Accordingly, locking mechanism  108  preferably includes two locking fingers  150  (only one of which is shown in  FIG.  2   ), spaced about 180° apart. Each locking finger  150  is configured as a cantilever extending longitudinally along shaft  110  from a rearward end (proximate cylinder  102 ) toward a forward end (distal from handle  102 ). Each of the two locking fingers  150  preferably defines an unlocked detent  162 , a locked detent  164 , and a track  160  extending from unlocked detent  162  to locked detent  164 . Unlocked detent  162  is formed forward of locked detent  164 , and runs deeper into a respective locking finger  150  than does locked detent  164 . 
       FIGS.  6  and  7    depict locking mechanism  108  in greater detail. As discussed above, each locking finger  150  preferably includes an unlocked detent  162 , a locked detent  164 , and a track  160 , the locking fingers being spaced about 180° apart. Locking sleeve  112  is preferably split longitudinally into two portions, each portion being configured to wrap over a respective locking finger  150 . It can be appreciated that the two portions of locking sleeve  112  together form a cylinder that wraps around tubular shaft  110  proximate locking fingers  150 , and are preferably secured in place via a retaining ring  156  positioned at each end of locking sleeve  112 . Each portion of locking sleeve  112  preferably includes a protrusion  166  configured with a seat  158  into which a roller ball  152  is seated. 
     A stop  114  is positioned at the tip of tubular shaft  110  for preventing bit  116  from falling out of tubular shaft  110 . Stop  114  comprises an element, such as a snap ring, a pin, a swage, or the like, effective for preventing bit  116  from falling out of tubular shaft  110 . 
     In operation, a bit  116  is selected from handle  102  in a manner such as described in the &#39;074 patent and/or the &#39;134 patent publication. With reference to  FIG.  4   , bit  116  enters clocking cylinder  104  in the direction shown by arrow  124 . As bit  116  passes through clocking cylinder  104 , each of the hexagonal corners  116   a  ( FIG.  3 B ) enters a groove  120  and engages a wall  121  which causes the bit to turn as necessary to enable the bit to pass through hexagonal passageway  140  as shown in  FIG.  3 B . 
     With locking sleeve  112  in a forward position as shown in  FIG.  6   , bit  116  then travels through locking mechanism  108 . Locking sleeve  112  is then pulled rearward to cause roller ball  152  to roll along track  160  from unlocked detent  162  to locked detent  164 , as shown in  FIG.  7   . As roller ball  152  seats in locked detent  164 , each locking finger  150  is depressed into tubular shaft  110  passageway  140  as shown in  FIG.  7    to cause forward edge  154  of locking finger  150  to urge against bit base  118  to thereby preclude bit  116  from traveling rearward toward handle  102 . Multi-bit screwdriver  100  may then be used as a conventional screwdriver. 
     When it is desired to return bit  116  back to handle  102 , locking sleeve  112  is moved forward to cause roller ball  152  to roll along track  160  from locked detent  164  ( FIG.  7   ) to unlocked detent  162  ( FIG.  6   ). As roller ball  152  seats in unlocked detent  162 , each locking finger  150  is released from shaft passageway  140  as shown in  FIG.  6   , causing forward edge  154  of locking finger  150  to disengage from bit base  118  and allow bit  116  to travel rearward through clocking cylinder  104  in the direction of arrow  126  (see  FIG.  5   ) toward handle  102  for storage therein. 
     It is understood that the present invention may take many forms and embodiments. Accordingly, several variations may be made in the foregoing without departing from the spirit or the scope of the invention. For example, the clocking cylinder may be positioned at the tip of the screwdriver, or the tip of the tubular shaft could have the requisite lands and grooves formed directly in it so a separate clocking cylinder would not be needed. In a further variation, the roller ball may be replaced with an extended protrusion  166  that is integral with the locking sleeve and simulates the shape and function of ball  152 . Still further, there may be more or less than two locking fingers  150 . The cross-sectional shape of bit  116  and passageway  140  as depicted in  FIGS.  3 A and  3 B  may be more or less than six-sided (hexagonal); e.g., it could have four or eight sides. 
     Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present invention may be employed without a corresponding use of the other features. Many such variations and modifications may be considered obvious and desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.