Patent Publication Number: US-2021186583-A1

Title: Ratchet system for screwdrivers and its use

Description:
FIELD 
     The present invention relates to the field of tools. In particular, the present invention relates to a ratchet system applicable to a tool for screwing or unscrewing. 
     BACKGROUND 
     To be effective when screwing or unscrewing different parts of an assembly, it is necessary to be able to screw without the risk of unscrewing inadvertently. This is particularly true in the field of orthopedic surgery where it is essential to be able to be precise and efficient when screwing or unscrewing orthopedic elements. 
     It is known to those skilled in the art to use ratchet screwdrivers which make it possible to block the direction of rotation depending on whether the user seeks to screw or unscrew. EP 1617773 describes a ratchet screwdriver used in surgery comprising a handle, a drive mechanism, a ratchet mechanism and a locking mechanism. The ratchet mechanism is interposed between the handle and the drive mechanism, a locking mechanism holds the handle on the ratchet mechanism. However, this type of system involves systematically and completely disassembling the screwdriver in order to clean and sterilize it, a mandatory step for all medical use. Systematic and repeated dismantling of the ratchet mechanism makes the screwdriver fragile, causing it to lose its seal, thus creating risks of contamination. This type of screwdriver is also very expensive. 
     There is therefore a real demand for surgical screwdrivers making it possible to block a direction of rotation while being easily sterilizable and cleanable. 
     The object of the present invention is therefore to provide a snap-fastening system suitable for use in a surgical screwdriver making it possible to cause a rotation in the desired direction, and to prevent any contrary unwanted movement, by a simple mechanical principle and easily cleanable and sterilizable without risk of premature deterioration. This ratchet system does not include a complex mechanism to disassemble during sterilization, making it robust and easy to use. 
     SUMMARY 
     The present invention relates to a ratchet system comprising:
         at least one handle comprising a distal end and a connection surface;   at least one rod comprising a male distal end, a proximal end and a contact surface, said proximal end comprising a cavity;   cooperation means including:
           at least two lugs positioned on the distal end of the handle;   at least two grooves positioned on the internal wall of the cavity of the rod, each of the at least two grooves comprising a helical portion, one of the ends of which is a wall perpendicular to said internal wall;   
               

     the at least two lugs each cooperating in a predetermined rotation direction with one of the at least two grooves so as to be in contact with said perpendicular wall said contact allowing the driving, in said predetermined rotation direction, of the rod by the handle; 
     wherein the proximal end of the rod is adapted to cooperate with the distal end of the handle through the cooperating means until contact between the connection surface with the contact surface in order to drive the rod in the same rotation direction. 
     In one embodiment, the at least one rod is a screw rod. In one embodiment, the at least one rod is an unscrewing rod. In one embodiment, the proximal end of the at least one rod and the distal end of the at least one handle are cylindrical in shape. 
     The invention further to a ratchet system comprising:
         at least one handle comprising a distal end, said distal end comprising a cavity;   at least one rod comprising a male distal end and a proximal end;   means of cooperation including:
           at least two grooves positioned on the internal wall of the cavity of the handle, each of the at least two grooves comprising a helical portion, one of the ends of which is a wall perpendicular to said internal wall;   at least two lugs positioned on the proximal end of the rod;   
               

     the at least two lugs each cooperating in a predetermined rotation direction with one of the at least two grooves until coming into contact with said perpendicular wall, said contact allowing the driving, in the predetermined rotation direction, of the rod, by the handle; 
     wherein the proximal end of the rod is adapted to cooperate with the distal end of the handle through the cooperation means in order to drive the rod in the same rotation direction. 
     In one embodiment, the at least one handle is a screwing handle. In one embodiment, the at least one handle is an unscrewing handle. In one embodiment, the proximal end of the at least one rod and the distal end of the at least one handle are cylindrical in shape. The invention also relates to a screwdriver comprising a ratchet system according to the invention. 
     In the present invention, the terms below are defined as follows:
         “downward” relates to an orientation going from the proximal end to the distal end of an object.   “unscrewing” relates to an anti-clockwise direction of rotation.   “perpendicular wall” relates to a first wall describing an angle of approximately 90° with a second wall.   “groove” concerns a path carved into a wall. The terms groove, path, channel, notch, gutter, groove, slot, groove or slide can be used interchangeably.   “screwing” relates to a clockwise direction of rotation.       

    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following description will be better understood on reading the drawings. For the purpose of illustration, the device is shown in preferred embodiments. It should be understood, however, that the present application is not limited to the precise arrangements, structures, features, embodiments and appearance indicated on those drawings. The drawings are not drawn to scale and are not intended to limit the scope of the claims to the embodiments shown in these drawings. Therefore, it should be understood that when features mentioned in the claims are followed by references, said references are included only for the purpose of improving the understanding of the claims and in no way limit the scope of those claims. 
         FIG. 1  is a general perspective view of the handle according to a first embodiment of the invention. 
         FIG. 2A  is a three-dimensional view of distal end of the handle according to a first embodiment of the invention. 
         FIG. 2B  is a three-dimensional view of the distal end handle according to a first embodiment of the invention. 
         FIG. 3A  is a three-dimensional perspective view of a screw rod according to one embodiment of the invention. 
         FIG. 3B  is a three-dimensional perspective view of an unscrew rod according to one embodiment of the invention. 
         FIG. 4A  is a three-dimensional view of a proximal end of a screw rod according to one embodiment of the invention. 
         FIG. 4B  is a sectional view of a proximal end of a screw rod according to one embodiment of the invention. 
         FIG. 5  is a three-dimensional view of an unscrewing rod according to one embodiment of the invention. 
         FIG. 6  is a sectional view of an unscrewing rod according to one embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention relates to a ratchet system. 
     The ratchet system comprises:
         at least one handle comprising a distal end and a connection surface;   at least one rod comprising a male distal end, a proximal end and a contact surface, said proximal end comprising a cavity;   cooperation means including:
           at least two lugs positioned on the distal end of the handle;   at least two grooves positioned on the internal wall of the cavity of the rod, each of the at least two grooves comprising a helical portion, one of the ends of which is a wall perpendicular to said internal wall;   
               

     the at least two lugs each cooperating in a predetermined rotation direction with one of the at least two grooves so as to be in contact with said perpendicular wall, said contact allowing the driving, in the predetermined rotation direction, of the rod, by the handle; wherein the proximal end of the rod is adapted to cooperate with the distal end of the handle through the cooperating means until contact between the connection surface with the contact surface, in order to drive the rod in the same rotation direction. 
     The distal end of the handle is configured to fit into the cavity formed in the proximal end of the rod. During this operation, the lugs are supported and slide along the grooves dug in said cavity until they are each in contact with a perpendicular wall machined in the internal wall of the cavity, and that the connection surface of the handle is in contact with the contact surface of the rod. The walls perpendicular to the internal wall of the cavity of the proximal part of the rod are then rotated by the lugs in a predefined direction of rotation by the downward orientation (from the proximal end to the distal end) of the grooves: clockwise or anti-clockwise. As a result, a rotational movement is applied to the rod. 
     If, by an untimely gesture, the handle is actuated in a direction of rotation opposite to that predefined by the downward orientation of the grooves, the lugs separate from the perpendicular walls, their ends slide and go up on the grooves, thus preventing training of the rod rotating in the direction of rotation opposite to the predefined one. 
     The ratchet system of the invention therefore advantageously makes it possible to control a direction of rotation, clockwise or anti-clockwise, to transmit a movement in a determined direction and, above all, to prevent any untimely gesture from leading to the transmission of the movement. reverse. This is particularly useful for use of said system in a screwdriver since only one direction of rotation, corresponding to screwing or unscrewing, can be applied to the rod. 
     In the case of a screwdriver comprising the ratcheting system according to the invention, said system makes it possible to screw without the risk of inadvertently unscrewing and, conversely, of unscrewing without the risk of inadvertently screwing any object composed of one or more elements. 
     The handle is configured in a way that the lugs separate from the wall when the handle is moved in the opposite direction than the predetermined direction. 
     The rod is a drive mechanism, able to drive a screw for example in a chosen direction of rotation. 
     According to one embodiment, the at least one rod is a screw rod. 
     According to one embodiment, the at least one rod is an unscrewing rod. 
     According to one embodiment, the ratchet system comprises a screwing rod and an unscrewing rod. 
     According to one embodiment, the proximal end of the at least one rod and the distal end of the at least one handle displays a cylindrical shape. 
     According to one embodiment, the ratchet system is dismountable. In this embodiment, the elements of said ratchet system (handle, rod) are independent of each other and can be separated, advantageously for easy cleaning. 
     According to one embodiment, the ratchet system is sterilizable. 
     According to one embodiment, the various elements of the ratchet system can be sterilized. 
     According to one embodiment, the ratchet system further comprises a handle. In this embodiment, the handle is connected to the handle by a connection surface. 
     According to one embodiment, the handle comprises a shaft. In this embodiment, the handle and the shaft can be merged, i.e., be the same element of the ratchet system. 
     According to one embodiment, the distal end of the handle displays a cylindrical shape. This embodiment is particularly advantageous because the cylindrical shape facilitates the rotation of the distal end of the handle. Another shape could indeed hinder the rotation of the distal end of the handle. 
     According to one embodiment, the ratchet system includes the same number of lugs and grooves. 
     According to one embodiment, the ratchet system comprises at least 2, 3, 4, 5, 6, 7, 8, 9, or 10 lugs distributed over the distal end of the handle. The number of lugs determines the rotation of the wrist to screw or unscrew comfortably while being effective. The presence of 3 lugs is particularly advantageous in terms of efficiency, especially in the case of screwing. The presence of 6 pins is particularly advantageous in terms of precision. 
     According to one embodiment, the ratchet system comprises 2 lugs distributed over the distal end of the handle. 
     According to one embodiment, the ratchet system comprises 2 lugs distributed over the distal end of the handle and 2 grooves positioned on the internal wall of the cavity of the rod. 
     According to one embodiment, the ratchet system comprises 3 lugs distributed over the distal end of the handle. The presence of 3 lugs is particularly advantageous in terms of efficiency, especially in the case of screwing. The presence of 3 lugs equally distributed around the distal end of the handle offers a more comfortable and a more physiologically adapted handling. 
     According to one embodiment, the ratchet system comprises 3 lugs distributed over the distal end of the handle and 3 grooves positioned on the internal wall of the cavity of the rod. 
     According to one embodiment, the at least two lugs are evenly distributed over the distal end of the handle. 
     According to one embodiment, the at least two lugs have rounded ends. This embodiment is particularly advantageous because the rounded shape of the ends of the lugs allows the reversible movement consisting in being engaged and disengaged in the at least two grooves positioned on the internal wall of the cavity of the rod. 
     According to one embodiment, the at least one rod comprises a cylindrical body. This embodiment is particularly advantageous because the cylindrical shape makes it possible to limit the friction between the rod and another element of the screwing system. 
     According to one embodiment, at least one rod has a length of between 1 and 50 cm, preferably between 5 and 40 cm, more preferably between 5 and 20 cm. 
     According to one embodiment, the length of the at least one rod depends on the use made of the screwing system. For example, for applications in interventional radiology in particular, or in surgery in general, a short rod (that is to say having a length between 5 and 10 cm) will be used for screwing/unscrewing specific screws in small superficial bones such as vertebrae; a long rod (i.e. having a length greater than 20 cm) will be used for bones such as those of the pelvis (pelvis and sacrum). 
     According to one embodiment, the proximal end of the at least one rod is cylindrical in shape. 
     According to one embodiment, the proximal end of the at least one rod has a length of between 1 and 10 cm, preferably between 1 and 5 cm. 
     According to one embodiment, the length of the proximal end of the at least one rod depends on the use made of the screwing system. For example, for applications in interventional radiology in particular, or in surgery in general, a short rod (that is to say having a length between 5 and 10 cm) will be used for screwing/unscrewing specific screws in small superficial bones such as vertebrae; a long rod (i.e. having a length greater than 20 cm) will be used for bones such as those of the pelvis (pelvis and sacrum). 
     According to one embodiment, the proximal end of the at least one rod has a diameter of between 0.1 and 5 cm, preferably between 0.2 and 2 cm. 
     According to one embodiment, the diameter of the proximal end of the at least one rod depends on the use made of the screwing system. In particular, a short stem (length between 5-10 cm) will have a smaller diameter than a long stem (length greater than 20 cm). 
     According to one embodiment, the proximal end of the at least one rod is a bore. 
     According to one embodiment, the proximal end of the at least one rod is a bore comprising at least two threads. 
     According to one embodiment, the at least two grooves are also distributed over the inner wall of the proximal end of the at least one rod. 
     According to one embodiment, the at least two grooves are machined in the inner wall of the proximal end of the at least one rod. 
     According to one embodiment, the at least two grooves are obtained by turning the internal wall of the proximal end of the at least one rod. 
     According to one embodiment, the at least two grooves each describe a channel of helical or sinusoidal shape on the inner wall of the proximal end of the at least one rod. 
     According to one embodiment, the at least two grooves extend between the proximal end and the distal end of the at least one rod over a distance of between 0.5 and 5 cm, preferably between 0.5 and 3 cm. 
     According to one embodiment, the distance at which the at least two grooves extend between the proximal end and the distal end of the at least one rod depends on the use made of the screwing system. 
     According to one embodiment, the at least two grooves each comprise a helical portion descending from the proximal end of the rod towards the distal end of the rod. 
     According to one embodiment, the at least two grooves each comprise a helical portion descending from the proximal end of the rod towards the distal end of the rod in a clockwise direction. 
     According to one embodiment, the at least two grooves each comprise a helical portion descending from the proximal end of the rod towards the distal end of the rod in a counterclockwise direction. 
     According to one embodiment, the at least two grooves each describe a downward slope in a clockwise direction from the proximal end of the at least one rod towards the distal end of the at least one rod. 
     According to one embodiment, the at least two grooves each describe a downward slope in a counterclockwise direction from the proximal end of the at least one rod towards the distal end of the at least one rod. 
     According to one embodiment, the depth of the at least two grooves depends on the diameter of the rod and on the number of grooves. 
     According to one embodiment, the at least two grooves each have a length of between 0.5 and 5 cm, preferably between 0.5 and 3 cm. 
     According to one embodiment, the length of the at least two grooves depends on the use made of the screwing system. 
     According to one embodiment, the at least two grooves each have a helical radius of between 0.1 and 5 cm, preferably between 0.2 and 2 cm. 
     According to one embodiment, the helical radius of the at least two grooves depends on the use made of the screwing system, more precisely, it depends on the diameter of the rod. 
     According to one embodiment, the at least two grooves are internal threads. 
     According to one embodiment, the walls perpendicular to the internal wall of the cavity are machined in the internal wall of the proximal end of the at least one rod. 
     According to one embodiment, the proximal end of the at least one rod and the distal end of the at least one handle are cylindrical in shape. 
     According to one embodiment, the ratchet system is a screwing and/or unscrewing means. 
     According to one embodiment, the latching system is a screwdriver, a key, or any other screwing and/or unscrewing means known to those skilled in the art. 
     According to one embodiment, the ratchet system is a screwdriver suitable for use in surgery. 
     According to one embodiment, the ratchet system is a screwdriver suitable for use in orthopedic surgery. 
     According to one embodiment, the ratchet system is a surgical tool. 
     According to one embodiment, the ratchet system is a surgical screwdriver. 
     According to one embodiment, the latching system is suitable for screwing and/or unscrewing an object comprising one or more elements. In this embodiment, the elements are assembled or pre-assembled by threaded or tapped joints, with conventional or reverse pitches. 
     The present invention also relates to a ratchet system. 
     The invention relates to a ratchet system comprising:
         at least one handle comprising a distal end, said distal end comprising a cavity;   at least one rod comprising a male distal end and a proximal end;   means of cooperation including:
           at least two grooves positioned on the internal wall of the cavity of the handle, each of the at least two grooves comprising a helical portion, one of the ends of which is a wall perpendicular to said internal wall;   at least two lugs positioned on the proximal end of the rod;   
               

     the at least two lugs each cooperating with one of the at least two grooves until coming into contact with said perpendicular wall; 
     wherein the proximal end of the rod is adapted to cooperate with the distal end of the handle through the cooperation means. 
     In one embodiment, the at least one handle is a screw handle. 
     In one embodiment, the at least one handle is an unscrewing handle. 
     In one embodiment, the ratchet system includes a screwing handle and an unscrewing handle. 
     In one embodiment, the proximal end of the at least one rod and the distal end of the at least one handle are cylindrical in shape. 
     The handle and its distal end, the rod and its proximal end, the cooperation means, namely the lugs, grooves and perpendicular walls are as described above. 
     The present invention is about a ratchet system. 
     The ratchet system includes:
         at least one handle comprising a distal end and a connection surface;   at least one rod comprising a male distal end, a proximal end and a contact surface;   means of cooperation including:
           at least two lugs;   at least two grooves positioned on the internal wall of a cavity, each of the at least two grooves comprising a helical portion, one end of which is a wall perpendicular to said internal wall;   
               

     the at least two lugs each cooperating with one of the at least two grooves until they come into contact with said perpendicular wall; 
     wherein the proximal end of the rod is adapted to cooperate with the distal end of the handle through the cooperating means until contact between the connection surface with the contact surface. 
     In one embodiment, the at least two lugs are positioned on the distal end of the handle. 
     In one embodiment, the proximal end of the rod comprises a cavity, and the at least two grooves positioned on the inner wall of the cavity of the rod, each of the at least two grooves comprising a helical portion of which one end is a wall perpendicular to said internal wall. 
     In one embodiment, the at least two lugs are positioned on the proximal end of the rod. 
     In one embodiment, the distal end of the handle comprises a cavity, and the at least two grooves positioned on the internal wall of the handle cavity, each of the at least two grooves comprising a helical portion of which one end is a wall perpendicular to said internal wall. 
     The invention also relates to a screwdriver comprising a ratchet system according to the present invention. 
     In one embodiment, the screwdriver is a surgical screwdriver, or suitable for use in surgery, preferably in orthopedic surgery. 
     The invention also relates to the use of the ratchet system in a device requiring control of a direction of rotation of a rod. 
     The invention also relates to the use of the ratchet system in a screwing and/or unscrewing means. 
     The invention also relates to the use of the ratchet system in a screwdriver, a key, or any other screwing and/or unscrewing means known to those skilled in the art. 
     The invention also relates to the use of the ratchet system in a screwdriver suitable for use in surgery. 
     The invention also relates to the use of the ratchet system in a screwdriver suitable for use in orthopedic surgery. 
     The invention also relates to the use of the ratchet system in a screwdriver suitable for use in interventional radiology. 
     The invention also relates to the use of the ratchet system in a surgical tool, a surgical screwdriver. 
     The invention also relates to the use of the ratchet system in mechanics, carpentry or surgery. Although various embodiments have been described and illustrated, the detailed description should not be construed as being limited thereto. Various modifications can be made to the embodiments by those skilled in the art without departing from the true spirit and scope of the disclosure as defined by the claims. 
     Embodiments Illustrating the Invention 
     As illustrated in  FIGS. 1, 2A and 2B , the handle  1  includes:
         a handle  13 ;   a cylindrical distal end  11  linked to the handle  13  by a connection surface  131  extending preferably perpendicular to the axis of revolution of the cylindrical distal end  11 ;   two lugs  12  equally distributed around said distal end  11 , having rounded ends  121 . In the embodiments of  FIGS. 2A and 2B  said lugs  12  are two, and they are diametrically opposed. The lugs  12  extend parallel to the axis of revolution of the cylindrical distal end  11 .       

     As illustrated in  FIGS. 3A, 4A and 4B , the screw rod  2  comprises a cylindrical rod  22  comprising a male distal end  23  and a cylindrical proximal end  21 . The proximal end  21  comprises a cavity  215  displaying internal walls  212 . Two grooves  214  are machined in the internal wall  212  of the cavity  215 , the two grooves  214  comprising a helical portion descending from the proximal end of the rod  21  towards the distal end  23  of the rod  2  in a clockwise direction. The cavity  212  further comprises two walls  213  perpendicular to the internal wall  212  of the cavity  215 . The screw rod  2  displays a contact surface aimed at cooperating with the connection surface  131  of the handle  13 . 
     The distal end  11  of the handle  13  is configured to fit into the cavity  215  formed in the proximal end  21  of the screwing rod  2 . During this operation, the two lugs  12  are supported and slide along the two grooves.  214  carved into said cavity  215  until said lugs  12  are each in abutment contact with one perpendicular wall  213  machined in the internal wall  212  of the cavity  215  of the proximal end  21  of the rod  2 , and the connection surface  131  is in contact with the opposite contact surface  211  of the screw rod  2 . The walls  213  perpendicular to the internal wall  212  of the cavity  215  of the proximal part of the rod  21  are then rotated by said lugs  12  in the clockwise rotation direction f 1 , f 1 ′. It follows that a rotational movement, and more particularly, a screwing movement, is applied to the screwing rod  2 . 
     In this embodiment, when the shaft  13 , of the handle  1  is coupled with the screwing rod  2  and is actuated in the clockwise direction f 1 , meaning screwing, the lugs  12  of said handle  1  come to cooperate with the perpendicular walls  213 , so that the surface of the connection surface  131  is in abutment contact with the contact surface  211 , so as to drive the rod  2  in the same clockwise direction f 1 ′, meaning screwing it. 
     This embodiment is particularly advantageous because if, by an untimely gesture, said handle  1  is actuated in the counterclockwise direction f 2 , meaning unscrewing, the lugs  12  separate from the walls  213 , their ends  121  slide and go up on the grooves  214 , thus preventing the driving of the screw rod  2 . 
     This embodiment is also advantageous because the distal end  11  of the handle  1  remains trapped in the cavity  215 , so that said handle  1  is not separated from the screw rod  2 , to allow it to be actuated again clockwise f 1 , meaning screwing, to drive the screwing rod  2  in the clockwise direction f 1 ′, meaning screwing. 
     As illustrated in  FIGS. 3B, 5 and 6 , the unscrewing rod  3  comprises, similarly to the screwing rod  2 :
         a cylindrical rod  32  comprising a male distal end  33  and a cylindrical proximal end  31 , said proximal end  31  comprising a cavity  315 ;   two grooves  314  machined in the internal walls  312  of the cavity  315 , the two grooves  314  comprising a helical portion descending from the proximal end  31  of the unscrewing rod  3  towards the distal end  33  of the unscrewing rod  3  in a counterclockwise direction; and   two walls  313  perpendicular to the internal wall  312  of the cavity  315 .       

     In a similar way to the screwing rod  2 , the distal end  11  of the handle  13  is configured to fit into a cavity  315  formed in the proximal end  31  of the unscrewing rod  3 . During this operation, the two lugs  12  are supported and slide along two grooves.  314  carved out in said cavity  315  until said lugs  12  are each in contact with a perpendicular wall  313  machined in the internal wall  312  of the cavity  315  of the proximal part of the rod, and the surface of the connection surface  131  is in contact with a contact surface  311  of the rod  3 . The walls  313  perpendicular to the internal wall  312  of the cavity  315  of the proximal part  31  of the unscrewing rod  3  are then rotated by said lugs  12  in the direction of anti-clockwise rotation f 2 , f 2 ′. As a result, a rotational movement, and more particularly, an unscrewing movement, is applied to the unscrewing rod  3 . 
     In this embodiment, when the shaft  13 , of the handle  1  is coupled with the unscrewing rod  3  and is actuated in the counterclockwise direction of the arrow f 2 , meaning unscrewing, the lugs  12  of said handle  1  cooperate with the walls  313 , until the surface of the connection surface  131  is in contact with the contact surface  311 , so as to drive the unscrewing rod  3  in the same counterclockwise direction f 2 ′, meaning unscrewing. 
     This embodiment is particularly advantageous because if, by an inadvertent gesture, said handle  1  is actuated in the clockwise direction f 1 , meaning screwing, the lugs  12  separate from the walls  313 , their ends  121  slide and go up on the grooves  314 , thus preventing the driving of the unscrewing rod  3 . 
     This embodiment is also advantageous because the distal end  11  of the handle  1  remains trapped in the cavity  315 , so that said handle  1  is not separated from the unscrewing rod  3 , to allow it to be actuated by again in the counterclockwise direction f 2 , meaning unscrewing, to drive the unscrewing rod  3  in the counterclockwise direction f 2 ′, meaning unscrewing.