Patent Publication Number: US-7895920-B2

Title: Open end ratchet wrench

Description:
I. BACKGROUND/FIELD OF THE INVENTION 
     The present invention is used by plumbers and mechanics continuously engaged in assembling and removing hydraulic lines which require the handling of axially placed fasteners which can only be torqued with open-ended wrenches. Such tasks involve the frequent placement and removal of the wrench from the nut for the completion of a single operation. Such tasks, which are time wasting and exasperating, can be greatly facilitated if an efficient and practicable ratcheting wrench can be devised to deal with them. 
     The present invention is designed to provide such a ratcheting wrench with a practicably sized head which makes it usable under most confined space conditions; which can be simply and smoothly opened and closed to fit perfectly around a nut fastener perpendicular to its axis, and functions as a standard ratching wrench without subjecting the fastener to damaging wear that may be caused by repeatedly clamping mechanism. (U.S. Pat. No. 5,960,679; U.S. Patent Application Publication Nos. US2004/0194589 and U.S. 2005/0044999). 
     II. PRIOR ART 
     U.S. Patent Application Publication No. 2006/0137492 and U.S. Pat. No. 5,501,124 present solutions whereby the hexagonal notch for engaging a bolt is open at one side to allow for the positioning of the notch around the nut. For the system to operate property, the ratcheting head required would be of an exaggerated size that will be awkward to handle in confined spaces. Further, upon removal of the wrench from the tightened nut, the wrench has to be rotated by up to 180 degrees in the neutral mode should the slot in the rotating jaw be aligned opposite to the opening in the head member. In confined spaces, this can be highly problematic, and therefore place limits on the usefulness of the wrench. 
     U.S. Patent Application Publication No. 2006/0230882 which employs C-shaped collars hingedly connected to a head member would be more practicable in relation to the wrench&#39;s head size. The mechanism through which the two C-shaped collars containing the ratcheting inserts swing into position circumscribing the fastener from hinges attached to the C-shaped open head will fail to provide a perfect ratcheting wheel or a perfectly closed hexagonal socket, as this will be hindered by the thickness of the head member or the C-shaped collars as these swing around their hinges. The disengagement of the wrench from the fastener will be problematic in confined spaces as the ratcheting wheel may have to be turned by up to 90 degrees to align the two parts of the ratcheting inserts to the open position for the swinging collars to open up. 
     III. OBJECTS AND SUMMARY OF THE NEW INVENTION 
     The invention illustrated herein comprises a ratcheting wrench of a practicable size whereby the head member and the ratcheting wheel with its hexagonal socket can optionally be opened (split up) and closed to perfectly circumscribe a hexagonal nut fastener on a hydraulic (or other similar) line, and henceforth be used as a normal ratcheting wrench. 
     According to one embodiment of the invention, there is provided a semicircular metal collar head member opening to one side, attached radially to an elongated handle the axis of which is co-linear with its diametrical chord. Below the collar element and at right angles to the handle&#39;s axis is a rectangular slot with a circular middle part which runs across the width of the head member from one side up to 2 mm short of the opposite side. Three identical metal inserts which are 60 degree segments of a circular metal disc, ratcheted on the outside perimeter and straight on the inside fit into the metal collar forming one half of a peripherally ratcheted wheel with half a concentric hexagonal socket. The designed rotational movement of the inserts within the head collar and the transfer of forces thereto from the ratchet wheel are provided by a thickening of the inserts on both sides between the inner edge of the circular metal collar and the hexagonal socket, thus forming a bearing rotational shoulder with the adjacent collar. A rectangular groove on one face of the metal inserts coaxial with the perimeter, with three control pin rivets dipped therein from the head member&#39;s circular collar stop any inward radial movement of the assembled inserts. Relative movement between adjoining faces of the insert elements is restricted to tangential movement only by vertical pins and corresponding perfectly aligned facing bores on any two adjoining sides of the insert elements. Completing the head member is a second mirror image semicircular metal collar component coplanar with the first one with an elongated tangential metal pin of a cross section which slides into and fits perfectly in the slot in the first collar head component to form a complete circle from the two identical and opposing collars. Disposed within the second semi-circular collar are three additional metal disc inserts identical to the ones in the first member and similarly installed. The circular part of the tangential pin is tubular. Disposed within the tubular pin is a compression spring cartridge biased to push the two semi-circular frame members apart when the pin is inserted into the slot of the first head component. A notch in the rectangular side of the pin and a corresponding spring-biased unidirectional pawl in the first component are provided to prevent the separation of the two components while they are in the open mode. 
     The wrench is engaged to the hexagonal tie member to be tightened with the two components in the “open” mode. The second component is then pushed towards the first component along the axis of the notch in the first component until the two semi-circular frame components touch to form a complete circle. In this “closed” mode the six metal insert components circumscribe the hexagonal tie in a perfectly fitting hexagonal socket. A notch deployed in the rectangular side of the tangential pin in the second component and a corresponding spring-biased locking tab in the first component maintain the two collar frames in the closed position during the tightening operation. 
     Upon turning the ratchet handle around the nut&#39;s axis, a ratchet pawl disposed inside the first component adjacent to the ratchet wheel&#39;s perimeter engages the ratchet wheel thus providing the required torquing mechanism. The ratchet pawl can be disengaged (placed into a neutral mode) through a switch handle disposed on the outer face of the first component, and connected to the pawl&#39;s pivot pin inside the head member. 
     Upon completion of the operation, the ratchet pawl is disengaged to allow neutral bidirectional rotational movement of the wrench around the nut&#39;s axis. A spring controlled button disposed on the first component is pushed by the operator thus applying constant pressure on a pin which is connected to the spring biased mechanism which locks the two components together. Movement of the subject pin and the connected locking mechanism remain restricted by the rotating ratchet wheel components until the pin is perfectly aligned with any of matching holes disposed axially in each of the insert components. This is designed to occur only when radial edges of the insert components are in line with the common radial axis of the two semi-circular frames, and the pins and facing bores on the adjoining faces of the insert elements are at right angles thereto. When the pin sinks into the facing hole, the locking tab is disengaged, thus allowing the compressed spring cartridge inside the tubular pin to push the two semi-circular collar members apart releasing the tightened nut. The sunken pin in the insert elements remains in position preventing their rotational movement in the first component while the wrench head is in the open mode. A spring biased latch with a wedged head and an inward projecting tooth sized to fit radially into the wheel&#39;s peripheral ratchet teeth is disposed in the second head component tangentially with the ratcheting wheel. The latch is disengaged when the two head components are in the closed mode through pressure against the wedged head provided by a pin disposed in the first component. Upon separation of the two head parts, the latch&#39;s head is released sinking its projecting tooth into the wheel&#39;s peripheral ratchet teeth thus preventing any rotational movement of the inserts in the second component while the ratchet head is in the open mode. The matching pins and corresponding holes in the adjoining sides of the metal inserts prevent their separation one from the adjacent other during this stage. 
     When the two adjacent semicircular collars are pushed together into the closed mode, the wedged head of the latch on the second component is pushed out by the pin in the first component thus releasing the three (connected) insert elements in the second component for rotational movement. As the semicircular collars close together, the notch in the elongated pin in the second component is aligned with the spring biased locking tab in the first component, which moves up into the notch thus locking the two components together. The pin attached to the locking tab moves simultaneously out of the bore in the insert elements in the first component thus releasing them for rotational movement. 
     When the two adjacent semicircular collars are pushed together into the closed mode, the wedged head of the latch on the second component is pushed out by the pin in the first component thus releasing the three (connected) insert elements in the second component for rotational movement. As the semicircular collars close together, the notch in the elongated pin in the second component is aligned with the spring biased locking tab in the first component, which moves up into the notch thus locking the two components together. The pin attached to the locking tab moves simultaneously out of the bore in the insert elements in the first component thus releasing them for rotational movement. 
     According to a second embodiment of the invention, the elongated pin protruding tangentially from the second semi-circular collar component has a solid cross-section. The lower rectangular part of the pin has a plurality of notches on one side only along its entire length. A wheel with compatible notches (pinion) with a biased torsion spring engages the pin (rack) from below. The pinion winds up when the pin member is pushed into the slot, and tends to push it in an outward direction when the locking mechanism of the two semi-circular collars is released, thus separating the two semi-circular collar heads and releasing the tie nut. 
     According to a third embodiment of the invention designed for economic mass production; both two components of the wrench are made up of three flat metal plates riveted together (two casing parts and one core part). The three parts can be stamped out by dies and require no machining, thus reducing the production cost thereof. A semicircular tongue is stamped out into the inner face of one of the casing parts of the wrench to accommodate the groove in the rotating ratcheting inserts thus preventing their inward radial movement when the two head parts are in the open mode. The elongated tangentially protruding pin which is part of the second head frame component is rectangular with a plurality of notches and with a disengaging mechanism as described in the second embodiment of the invention. Two rectangular grooves disposed on the sides of the elongated pin with corresponding compatible tongues stamped out in the opposing inner faces of the casing plates control lateral movement of the pin as it slides into and out of the cavity in the second component. Two spring biased latches with wedged heads and teeth sized to fit into the peripheral ratchet teeth are disposed tangentially on the perimeters of the two head components. In the locked head condition, the latches are kept unengaged through outward pressure exerted against their heads by suitably shaped indentations deployed in the opposing semicircular frames, thus allowing free rotational movement of the ratchet wheel. 
     To disengage the wrench from the tightened nut, the locking mechanism of the two ratchet head components is released, and the ratchet pawl is disengaged to allow neutral bidirectional rotation of the of the wrench around the nut. The wrench is turned (by no more than 30 degrees) in either direction to align any adjoining line of adjacent inserts with the axis of the wrench, whereat the matching pins and corresponding holes in the adjoining sides of the insert elements are at right angles to the axis, thus allowing the separation of the semicircular head components each with a set of three inserts. When the two head components separate, the spring biased tangential latches are released to sink their teeth into the peripheral ratcheted teeth of the insert components thus preventing their rotational movement while the wrench head is in the open mode. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention described herein is best described in conjunction with the following attached drawings and illustrations: 
         FIG. 1  is a schematic perspective view from both sides of the open end ratchet wrench in the closed mode. Shown are the elongated wrench handle; the assembled ratchet head with its segmented ratchet wheel and axial hexagonal slot; the switch handle for disengaging the pawl and setting it into the neutral mode; the release button for separating the two wrench&#39;s head segments, and the six rivets which stop the ratchet wheel inserts from inward axial movement when the two head components are in the open mode, 
         FIG. 1A  is a face and right side schematic perspective view of the wrench of  FIG. 1 , constructed according to the present invention, 
         FIG. 2  is a face view of the ratchet wrench with the two head components in the closed and open modes, showing the main internal parts of the head component, and the biased spring mechanism which separates the two head components, 
         FIG. 3  is a face view of the second embodiment of the open end ratchet wrench with a biased torque spring acting on a rack and pinion mechanism for separating the two head components, 
         FIG. 4  is a face view of the segmented ratchet wheel from both sides, 
         FIG. 5  is a diagrammatic illustration of the wrench&#39;s head member showing its interior components, 
         FIG. 6  is a diagrammatic illustration of the locking mechanism of the two head components, 
         FIG. 7  is a cross-sectional view of the locking mechanism of the two head components (cross-section A-A from  FIG. 2 ), 
         FIG. 8  is a diagrammatic illustration of the ratchet pawl and its switch handle on the face of the wrench&#39;s head, 
         FIG. 9  is a diagrammatic perspective view from both sides of the third embodiment of the open end ratchet wrench in the closed mode. Shown are the elongated wrench handle; the assembled ratchet head with its segmented ratchet wheel and axial hexagonal slot; the switch handle for disengaging the pawl and setting it into the neutral mode; the switch handle for unlocking the two head segments, the rivets which hold together the three flat metal plate wrench components, and the spring biased latches which stop the rotational movement of the ratchet wheel segments when the wrench head is in the open mode, 
         FIGS. 10 and 11  are diagrammatic views of the third embodiment of the ratchet wrench showing the interior components, and 
         FIG. 12  is a cross-sectional view of the spring-biased side latches in the third embodiment of the ratchet wrench which stop the ratchet wheel segments from rotational movement while the wrench&#39;s head is in the open mode. 
     
    
    
     V. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     For convenience and clarity in describing these embodiments, similar elements or components appearing in different figures will have the same reference numbers. 
     The invention illustrated herein discloses a ratcheting wrench with a practicably sized head that is suitable for use in most confined spaces; can be simply and smoothly opened and closed to fit closely around a nut fastener perpendicular to its axis, and functions as a standard ratcheting wrench without subjecting the fastener to damaging wear that may be caused by repeatedly clamping mechanisms. 
     In the following preferred embodiments of the invention as shown in  FIGS. 1-12 , identical part components with identical functions in the different embodiments of the invention have been marked with the same reference numbers. 
       FIGS. 1-2  are schematic diagrammatical illustrations of the wrench  100  with an elongated handle  101 , and a semicircular channeled collar head member  102  opening to one side. Below collar member  102 , in coplanarity therewith, and at right angles to the handle&#39;s axis is a rectangular slot with a circular middle part  103 . The slot runs across head member  102  up to 2 mm short of the opposite side. Three identical metal inserts  104  which are 60 degree segments of a circular metal disc, ratcheted on the outside arcuate perimeter and straight on the inside fit into semicircular collar  102  forming one half of a peripherally ratcheted wheel  105  with half a concentric hexagonal socket  140 . The designed rotational movement of inserts  104  within head collar  102  and the transfer of forces thereto from the ratchet wheel is provided by a thickening (flanging) of inserts  104  on both sides between the circular metal collar inner edge  102 A and the hexagonal socket  140 , thus forming a bearing rotational shoulder with adjacent collar  102 . A rectangular arcuate groove  107  on one face of metal inserts  104  concentric with collar  102 , with three control pin rivets  108  dipped therein from the head member&#39;s circular collar  102  stop any inward radial movement of the assembled inserts. Relative movement between adjoining faces of the insert elements is restricted to tangential movement only by vertical pins  109  and corresponding aligned facing bores  110  on any two adjoining sides of the insert elements. 
     Completing the head member is a second mirror image semicircular metal collar component  202  coplanar with  102  with an elongated tangential metal pin  203  of a cross section which slides into and fits perfectly in slot  103  to form a complete circular collar from the two opposing components. Disposed within the second semi-circular collar  202  are three additional metal disc inserts  104  identical to the ones in  102  and similarly installed. The circular part of metal pin  203  is tubular. Disposed therein is a compression spring cartridge  301  biased to push pin  203  out of slot  103 . A notch  204  in the lower rectangular side of pin  203  and a spring biased unidirectional pawl  110  in the first component are provided to prevent the separation of components  102  and  202  when the ratchet head is in the open mode. 
     The wrench is engaged to the hexagonal tie member to be tightened with the wrench head in the “open” mode (members  102  and  202  separated). Component  202  is pushed towards component  102  along the axis of notch  103  in the first component until the two semi-circular frame components touch to form a complete circle. In this “closed” mode the six metal insert components  104  form a ratcheting wheel  105  circumscribing the hexagonal tie in a perfectly fitting hexagonal socket  140 . A rectangular notch  205  in the upper rectangular side of tubular pin  203  and a corresponding spring biased locking tab  111  in the first component maintain collar frames  102  and  202  in the closed mode during the tightening operation. 
     Upon turning ratchet handle  101  around the nut&#39;s axis, a spring biased ratchet pawl  112  pivoted to pin  113  and disposed inside the first component adjacent to the ratchet wheel&#39;s perimeter engages the ratchet wheel thus providing the required torquing mechanism. 
     The ratchet pawl can be disengaged (placed into a neutral mode) through a switch handle  114  disposed on the outer face of the first component and attached to pin  113 . Pin  113  is attached inside the first component to cam  179 , which upon turning switch handle  114  in a clockwise direction, pushes pawl  112  out of the ratchet wheel&#39;s teeth range, and locks it into that position through detent head  180  and arch spring  181  until switch handle  114  is turned back anticlockwise to its original engaged position. 
     Upon completion of the tightening operation, ratchet pawl  112  is disengaged to allow neutral bidirectional rotational movement of the wrench around the nut. A button  115  disposed on the first component and controlled by a compression spring  118  is pushed by the operator thus applying constant pressure on a pin  116 . Pin  116  is connected to locking tab  111  which is constantly biased to fit into notch  205  by compression spring  119 . The rigidity of spring  118  is greater than that of spring  119 , such that the resultant force from button  115 , unrestricted, would tend to push locking tab  111  out of notch  205 . Movement of pin  116  and the connected locking mechanism remain restricted by rotating ratchet wheel  105  until the pin is perfectly aligned with any of matching bores  106  disposed axially in each of the insert components. This is designed to occur only when radial edges of the insert components  104  are in line with the common radial axis of the two semi-circular frames  102  and  202 , and the pins  109  and facing bores  110  on the adjoining faces of insert elements  104  are at right angles thereto. When pin  116  sinks into facing bore  106 , locking tab  111  is pushed out of slot  205 , thus allowing compressed spring cartridge  301  inside tubular pin  203  to push semi-circular collar members  102  and  202  apart releasing the tightened nut. Pin  116  further prevents any rotational movement of inserts  104  inside semicircular frame  102  while the wrench head is in the open mode. A spring biased latch  206  with a wedged head and an inward projecting tooth sized to bite radially into the peripheral ratchet teeth is disposed in the second head component tangentially with the ratcheting wheel. The latch is disengaged when the two head components  102  and  202  are in the closed mode through pressure against the wedged head provided by pin  118  disposed in the first component. Upon the separation of frames  202  and  102 , the latch&#39;s wedged head is released thus allowing the projecting tooth to bite into the peripheral ratchet teeth and prevent any rotational movement of inserts  104  in component  202  while in the ratchet head is in the open mode. Pins  109  and corresponding bores  110  in adjoining sides of metal inserts  104  prevent their separation one from the adjacent other during this stage. 
     When the two adjacent semicircular collars  102  and  202  are pushed together into the closed mode, the wedged head of latch  206  is pushed out by pin  118  thus releasing the three (connected) insert elements  104  in frame  202  for rotational movement. As semicircular collars  102  and  202  close together, notch  205  in the elongated joining pin  203  is aligned with tab  111 , which is biased to move into notch  205  by compression spring  119 , thus locking the two components together. Pin  116  is simultaneously pushed out of bore  106  thus releasing insert elements  104  therein for rotational movement in collar head  102 . 
     According to a second embodiment of the invention as illustrated in  FIG. 3 , the elongated pin  203 A protruding tangentially from the second semi-circular collar  202  has a solid cross-section (including the circular middle part). One side of the lower rectangular part of pin  203 A has a plurality of notches along its entire length. Wheel (pinion)  302  with compatible notches and a biased torsion spring  303  engages the pin rack from below. Pinion  302  winds up its torsion spring when pin member  203 A is pushed into slot  103 A, and when the locking mechanism of the two semi-circular collars  102  and  202  is released, tends to push pin  203 A in an outward direction, thus separating the two semi-circular collar head components and releasing the tie nut. 
     According to a third embodiment of the invention designed for economic mass production as illustrated in  FIGS. 9-12 ; both two components of the wrench are made up of three flat metal plates riveted together (two casing parts  410  and  430 , and one core part  420 ). The three parts can be stamped out by dies and require no machining, thus reducing the production cost thereof. A semicircular tongue  408  is stamped out into the inner face of casing part  430  of the wrench head component to accommodate groove  107  in rotating ratcheting inserts  104  thus preventing their inward radial movement when the two head parts are in the open mode. Two rectangular grooves  409  disposed on the sides of the elongated rectangular pin  403  with corresponding compatible tongues  407  stamped out on the opposing inner faces of casing plates  410  and  430  control lateral movement of the pin as it slides into and out of the second component. Pin  403  is provided with a plurality of notches along the lower part of one side. A wheel (pinion)  402  with compatible notches and a biased torsion spring attached thereto engages the (rack) pin from below. 
     The pinion winds up its torsion spring when pin  403  is pushed into place, and tends to separate the two head parts apart when the locking mechanism is released. A triangular notch  404  in the plain lower side of pin  403  and a spring biased unidirectional pawl  419  in the first component are provided to prevent the separation of the two components while they are in the open mode. In the closed head mode, the same notch  104  is engaged by a second spring biased pawl  429  which can be disengaged through a switch handle  415  disposed on the outer face of the first component. Two spring biased latches  406  with wedged heads  408  and teeth  407  sized to bite into the peripheral ratchet teeth are disposed on the perimeters of the two head components. In the locked head condition, latches  406  are kept unengaged through outward pressure exerted against their heads by suitably shaped indentations  418  deployed in the opposing semi-circular frames, thus allowing free rotational movement of ratchet wheel  105 . To remove the wrench head from the tightened nut, pawl  112  is disengaged through switch handle  114  to allow free bidirectional rotation of ratchet wheel  105 . Locking pawl  429  is disengaged by turning switch handle  415  clockwise, while the wrench is being rotated around the nut either clockwise or anti-clockwise (as is more convenient) by a maximum of 30 degrees. When any two adjacent radial edges of insert components  104  are in line with the common radial axis of the two semi-circular frames  102  and  202 , and the pins  109  and facing bores  110  on the adjoining faces of insert elements  104  are at right angles thereto, spring biased pinion  402  pushes racked pin  403  outwards until pawl  419  engages notch  404  thus preventing any further outward movement. When the two head components separate, spring biased latches  406  are simultaneously released to sink their teeth  407  into the wheel&#39;s peripheral ratchet teeth thus preventing any rotational movement of inserts  104  while the ratchet head components are in the open mode. 
     According to a fourth embodiment of the invention, (not shown in the attached drawings and illustrations), the ratchet teeth are rectangular in shape engaged by a bi-directional pawl which can be set into active rotation clockwise or anti-clockwise, or into the neutral mode, through a switch handle connected thereto from the face of the wrench head. 
     The above illustrations and descriptions are not to be construed as limiting to the scope, spirit or details of the invention. Variations thereof, omissions therefrom or additions thereto can be made without departing from the spirit and scope of the invention. 
     While the invention has been described in conjunction with several embodiments, it is to be understood that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, this invention is intended to embrace all such alternatives, modifications, and variations which fall within the spirit and scope of the appended claims.