Patent Publication Number: US-6990702-B2

Title: Multipurpose tool including folding scissors

Description:
This application is a continuation of U.S. patent application Ser. No. 10/123,948, filed Apr. 16, 2002, now U.S. Pat. No. 6,763,543, which is a continuation of U.S. patent application Ser. No. 09/632,630, filed Aug. 4, 2000, now U.S. Pat. No. 6,389,625, issued May 21, 2002, which is a continuation-in-part of U.S. patent application Ser. No. 09/479,411, filed Jan. 12, 2000, now U.S. Pat. No. 6,510,767, issued Jan. 28, 2003. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to a multipurpose folding tool, and particularly to such a tool including folding scissors, a blade latch release mechanism, and handles that provide comfort during use of pliers incorporated in such a tool. 
   As shown in Leatherman U.S. Pat. No. 4,238,862, Rivera U.S. Pat. No. 5,743,582 and Berg, et al., U.S. Pat. No. 5,745,997, multipurpose folding tools are well known and may contain folding pliers, various folding tool bits such as screwdrivers, files, and knife blades, and folding scissors that can be stored in cavities defined within handles configured as generally U-shaped channels. Tools of this type may include latches that hold a selected one of various screwdrivers or blades in an extended, operational position with respect to one of the handles, as shown in U.S. Pat. No. 5,979,059. Such tools may incorporate numerous types of handles, folding and latching arrangements, and folding scissors. 
   As useful as such folding multipurpose tools are, they still leave improvement desirable in certain details of their construction and operation. In particular, releasing certain latch mechanisms that hold selected blades in an extended position may require another blade or tool to be opened, or may entail use of a latch release lever that is located within a tool handle, occupying space that would better be occupied by a useful tool bit or blade. Accordingly, an improved latch release mechanism is desired. Preferably, such a latch release mechanism should be able to be operated easily, without the tool having to be held in a particular way in order to release a latched blade. 
   While functional blade latch mechanisms have previously been known in folding tools whose handles are of sheet metal construction, greater security for keeping a selected blade latch in an extended position is desired. 
   Most folding multipurpose tools having handles in the form of U-shaped channels have the open sides of the channels facing outwardly away from each other when the handles are unfolded to use a pair of pliers or similar tool jaws, in order to be able to receive the tool jaws within the channels when such a tool is folded. The channel sides, however, often have narrow edges that make use of such pliers uncomfortable. It is therefore desired to provide comfortable surfaces to be gripped when a multipurpose tool with handles in the form of channels is unfolded to permit use of the incorporated pliers or similar tools. 
   Construction of a folding multipurpose tool has previously required costly adherence to close manufacturing tolerances. Assembly of the pivot joint interconnecting a folding tool handle with a pliers jaw or the like has required adjustment by skilled personnel for the handles to be held securely in either an extended configuration or a folded condition with respect to a pair of tool jaws, yet also be folded and unfolded easily. It is therefore desired to provide a mechanism that permits smoothly folding and unfolding the handles, that operates reliably to hold the handles in a selected position with respect to such pliers jaws or the like, and that is less costly than the previously known corresponding mechanisms. 
   It is sometimes difficult to cut certain fibrous cords or bundles of strong fibers with scissors small enough for stowage in a folding multipurpose tool&#39;s handles. Small, tough fibers are sometimes squeezed out from between the scissors blades, and it is therefore desired to provide easily used folding scissors that overcome that problem. 
   Folding multipurpose tools have previously incorporated container openers intended to remove crown caps from bottles, to pierce the tops of beverage cans, and to remove the tops from cans used to preserve foods and the like. Such previously available openers have either been undesirably large, or if small enough to fit well within the space available in a folding multipurpose tool, such openers have tended not to function well in removing the tops from cans, often leaving rough or burred edges. It is therefore desired to provide a combination opener that performs well and reliably, without leaving excessively burred edges, yet is easily and inexpensively manufactured. 
   In using screwdrivers included in a folding multipurpose tool twisting forces may cause the handles of previously available tools to move undesirably with respect to each other. Also, where several blades may be stowed in a handle it is often difficult to open blades located between others. Tool construction that will keep a pair of handles securely located as they should be with respect to each other during use of such screwdriver blades, and that will also facilitate opening of a folded blade is therefore desired. 
   What is desired, then, is an improved multipurpose folding tool including improvements in some or all of the above-mentioned areas. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention provides answers to the needs mentioned above for improvements in various aspects of a folding multipurpose tool. In particular, in accordance with one aspect of the present invention, a blade latch release mechanism includes a latch release lever located within a channel-shaped handle for a multipurpose tool, adjacent one side of the handle. The latch release lever includes a protruding part which is moved to press against a latch spring and thus remove a catch from a notch defined in the base of a folding blade or tool bit. 
   In one preferred embodiment of a latch release mechanism according to the present invention a latch operating lever provides a force-multiplying mechanical advantage to move a cam arranged to move a latch release lever. 
   In one preferred embodiment of such a latch release mechanism an arcuate grip surface is located so as to provide an increasing lever arm length at the position where a person&#39;s thumb or finger is most likely to contact the grip surface during movement of the latch release operating lever, so that the mechanical advantage available to the user increases as the mechanism moves the latch spring further, and the force required to continue to move the latch release operating lever in releasing latch increases only slightly throughout the entire length through which the latch release operating lever has to be moved. 
   According to another aspect of the invention, the sides of the channel-shaped handle include rims merging with an outer surface of the handle in a smoothly arcuate surface. Such rims extend inwardly within the handle, defining a space for a portion of a latch release lever. 
   As another principal aspect of the present invention, the rim along the margin of each sidewall of the channel-shaped handle continues without interruption from one end of the handle to an opposite blade pivot end of the handle, providing a smooth, comfortable surface to be gripped, even in the areas where the margin of the sidewall is indented to give access to blades or tool bits stowed within cavities defined by the handles. 
   In one embodiment of this aspect of the invention the rim extends inwardly far enough to engage the back of a blade adjacent the sidewall of the handle to keep such a blade stowed within the handle while other blades located closer to the center of the handle are raised from their stowed positions. 
   According to another major aspect of the invention, a spring is attached to the handle and rides on a cam surface on a tang of a pliers jaw to control pivoting motion of each handle with respect to the tangs of a pair of pliers jaws and, by camming action, to urge the handles into the fully extended position or into a folded position with respect to the pliers jaws once the handles approach such a position with respect to the tangs of the pliers jaws. 
   In one embodiment of this aspect of the invention, a raised portion of the tang of a pliers jaw cooperates with a lateral surface on the spring to keep the spring aligned properly with the tang. 
   In such an embodiment of this aspect of the invention, the spring may have a forked outer end including a pair of prongs located on opposite sides of a centrally located raised portion of the tang of a pliers jaw. 
   In another embodiment of this aspect of the invention an interference bump is provided on the raised portion of the tang of a pliers jaw to engage an interior surface of the channel-shaped handle at the same time the spring acts in a cam-following manner on the cam surface of the pliers jaws to hold a handle securely in a fully extended position with respect to the tang of a pliers jaw. 
   Another aspect of the present invention is the provision of a folding scissors whose blades include edges that are straight except for a serrated portion on either or both of the blades near their outer tips. 
   In one preferred embodiment of the folding scissors aspect of the present invention, a spring extends alongside a base portion of one of the legs of the scissors and engages the other leg of the scissors to return the scissors blades to an open position after a cutting stroke of the scissors. In a preferred embodiment of this aspect of the invention, the spring extends from a base which is coupled to the first scissors leg with some freedom to pivot to provide clearance to permit the scissors to be folded and stowed within a cavity defined within one of the handles, with the spring relaxed when the scissors are stowed. In a preferred embodiment of the invention, the spring extends generally in the shape of a “U”, providing ample length to avoid excessive stress. 
   According to another aspect of the present invention a container opener includes a hook with a throat area behind the tip of the hook to provide clearance for a crimped rim of a container such as a “tin” can, and a sharp edge on the front part of the opener faces back toward the tip of the hook to cut free the top of such a container efficiently. 
   As yet another aspect of the present invention, interlocking portions of folded blades stowed within the cavities defined by the handles of the tool extend closely alongside each other, between such interlocks and other blades or tool bits stowed within the opposite handles, preventing the handles from moving laterally with respect to each other-when the handles are folded together about the associated pliers jaws or the like. 
   The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       FIG. 1  is a perspective view of a folding multipurpose tool embodying the present invention with a large screwdriver extended for use. 
       FIG. 1A  is a perspective view of the folding multipurpose tool shown in  FIG. 1 , with the handles unfolded to deploy a pair of pliers jaws for use, and showing how a person may use a thumb to operate a blade latch release mechanism. 
       FIG. 2  is an end view taken from the left end of the multipurpose tool shown in  FIG. 1 , in a folded configuration, with the screwdriver shown in  FIG. 1  folded. 
       FIG. 3  is a section view, taken generally along line  3 — 3  in  FIG. 1 , showing a portion of the blade latch release mechanism as well as the bases of exemplary tool blades. 
       FIG. 4  is an elevational view from the near side of the lower handle of the multipurpose tool as shown in  FIG. 1 , partially cut away to show clearly the blade latch release mechanism, with the blade latch fully engaged to hold a screwdriver blade in an extended position as shown in  FIG. 1 . 
       FIG. 5  is a view similar to  FIG. 4 , with the blade latch release operating lever moved a short distance in the direction required for releasing the latch catch from the screwdriver blade. 
       FIG. 6  is a view similar to that of  FIGS. 4 and 5  showing the latch release mechanism disengaging the catch fully from the extended screwdriver blade. 
       FIG. 7  is a view similar to that of  FIG. 4 , but with the screwdriver blade partly folded toward its stowage position so that a cam portion of the base of the screwdriver blade displaces the latch spring away from the latch release lever of the latch release mechanism. 
       FIG. 8  is a view similar to that of  FIG. 4 , but with the screwdriver blade folded into its position for stowage in the handle, and with the latch release mechanism in a relaxed state. 
       FIG. 9  is a top plan view of a portion of a handle and a portion of a blade for a multipurpose tool similar to that shown in  FIG. 1 , but including a different latch release mechanism associated therewith. 
       FIG. 10  is a partially cutaway side elevational view of the portions of a tool handle and extended blade shown in  FIG. 9 , with the latch release mechanism holding the catch disengaged from the base of the extended tool blade. 
       FIG. 11  is a top plan view of a portion of a handle and a portion of a blade for another multipurpose tool similar to that shown in  FIG. 1 , but including another different latch release mechanism. 
       FIG. 12  is a partially cutaway side elevational view of the portions of a tool handle and extended blade shown in  FIG. 11 , with the latch release mechanism holding the catch disengaged from the base of the extended tool blade. 
       FIG. 13  is a top plan view of a portion of a handle and a portion of a blade for yet a further multipurpose tool similar to that shown in  FIG. 1 , but including yet a different latch release mechanism associated therewith. 
       FIG. 14  is a partially cutaway side elevational view of the portions of a tool handle and extended blade shown in  FIG. 13  with the latch release mechanism holding the catch disengaged from the base of the extended tool blade. 
       FIG. 15  is a partially exploded isometric view from above one end of one of the handles of the tool shown in  FIG. 1 , showing a pair of jaws and a portion of the other handle. 
       FIG. 16  is a section view of a portion of the tool shown in  FIG. 1 , with the handles engaged with the tangs of the jaws of a pair of pliers which are included in the tool. 
       FIG. 17  is a section view taken along line  17 — 17  of  FIG. 1 , at an enlarged scale, omitting some tool blades for the sake of clarity. 
       FIG. 18  is a perspective view of a spring which forms a part of a jaw handle retention mechanism which is incorporated in the invention. 
       FIG. 19  is a view, taken in the direction of line  19 — 19  in  FIG. 16 , showing a portion of one of the handles of the multipurpose tool. 
       FIG. 20  is a section view taken along line  20 — 20  in  FIG. 16 , showing the relationship of a spring to the base of the pliers jaw and to the handle shown in  FIG. 19 . 
       FIG. 21  is a view of the multipurpose tool shown in  FIG. 1 , in a folded configuration, taken from the right end of the tool as shown in  FIGS. 1 and 17 . 
       FIG. 22  is an isometric view taken from the blade pivot end of the multipurpose tool shown in  FIG. 1 , but with the tool rotated 180° and thus showing the opposite side of the tool from that shown in  FIG. 1 , and showing a pair of folding scissors and a combination bottle opener and can opener both latched into their extended positions with respect to the handles. 
       FIG. 23  is a side elevational view of the folding scissors in its fully-extended operational position, together with a partially cutaway portion of a portion of the tool handle with which it is associated, with the latch release mechanism shown in  FIGS. 1–8  omitted for the sake of clarity. 
       FIG. 24  is a view of the folding scissors and somewhat larger partially cutaway portion of the handle shown in  FIG. 23 , with the scissors in a partially folded position approaching their stowage position within the tool handle. 
       FIG. 25  is a view similar to  FIG. 24 , but with the scissors blades and handle moved further toward their stowage position and in the position with respect to each other required for stowage of the folding scissors within the tool handle. 
       FIG. 26  is a view similar to  FIG. 25 , showing the folding scissors stowed within the tool handle. 
       FIG. 27  is an isometric view from the upper left front of a combined can opener and bottle opener included in the multipurpose folding tool shown in  FIGS. 1 and 22 . 
       FIG. 28  is a right side elevational view of the combined can and bottle opener shown in  FIG. 27 . 
       FIG. 29  is an isometric view, taken from the upper left front, of a combined bottle opener and can opener which is another embodiment of one aspect of the present invention. 
       FIG. 30  is an exploded isometric view taken from the upper left front of the opener shown in  FIG. 29 . 
       FIG. 31  is a right side elevational view of the opener shown in  FIGS. 29 and 30 . 
       FIG. 32  is a section view taken on line  32 — 32  of  FIG. 17 , showing an interlocking relationship between two of the folded tool blades contained within the handles of the tool. 
       FIG. 33  is a view similar to  FIG. 32  showing a tool including two pairs of interlocking blades. 
       FIG. 34  is an isometric view of a screwdriver which is one of the two interlocking tool blades shown in  FIGS. 17 and 32 . 
       FIG. 35  is a view similar to part of  FIG. 17 , showing a portion of a folding tool including two interlocked tool blades of a form somewhat different from that shown in  FIGS. 17 and 32 . 
       FIG. 36  is an isometric view of a screwdriver which is one of the two interlocking tool blades shown in  FIG. 35 . 
       FIG. 37  is a view similar to  FIG. 35  showing two interlocked tool blades of another form somewhat different from that shown in  FIGS. 35 and 36 . 
       FIG. 38  is an isometric view of a screwdriver which is one of the two interlocking tool blades shown in  FIG. 37 . 
       FIG. 39  is a side elevational view, at an enlarged scale, of a detail of the blade latch mechanism of the folding multipurpose tool shown in  FIG. 1 , showing the catch engaged in a notch to hold a folding blade in its extended position with respect to the tool handle including the latch mechanism. 
       FIG. 40  is a view similar to that of  FIG. 39 , showing a latch spring without a catch, holding a tool blade in an extended position with respect to the handle of a multipurpose tool similar to that shown in  FIG. 1 . 
       FIG. 41  is a right side elevational view of a handle for a folding multipurpose tool embodying the present invention and corresponding generally with one of the handles of the tool shown in  FIG. 1 . 
       FIG. 42  is an outside, or top plan view of the tool handle shown in  FIG. 41 . 
       FIG. 43  is an inside, or bottom plan view of the tool handle shown in  FIGS. 41 and 42 . 
       FIG. 44  is a left side elevational view of the tool handle shown in  FIGS. 41–43 . 
       FIG. 45  is an end elevational view taken from the blade pivot end of the handle shown in  FIG. 41 , in the direction indicated by line  45 — 45 . 
       FIG. 46  is an end elevational view taken from the tool jaw end of the tool handle shown in  FIG. 41 , in the direction indicated by line  46 — 46 . 
       FIG. 47  is a left side elevational view of the tool handle shown in  FIG. 44 , together with an outer blade stowed in the side trough. 
       FIG. 48  is a left side elevational view of the tool handle shown in  FIG. 47 , shown with the outer blade extended. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring now to the drawings which form a part of the disclosure herein, a multipurpose folding tool  40  has a pair of handles  42  and  44  shown in a folded configuration in  FIGS. 1 and 2 , and unfolded in  FIG. 1A . A straight screwdriver blade  46  is shown in an extended position in  FIGS. 1 and 1A , but is shown folded into a stowage position in  FIG. 2 . Each handle  42 ,  44  has a first, or blade pivot end  48 , at which various tool bits such as screwdriver blades, knife blades, files, and folding scissors are attached to the handle  42  or  44  by a respective pivot pin  50  extending through and between the opposite sidewalls  52 ,  54  of each handle  42 ,  44 . The handles  42 , and  44  are of sheet metal, blanked and pressed into the form of a generally U-shaped channel in which a channel base  56  is the back or outer side of each handle  42  or  44  when the multipurpose tool  40  is folded as shown in  FIG. 2 . The sidewalls  52 ,  54  join the channel base  56  along bends providing rounded corners for a comfortable grip. 
   Blade Latch Release 
   A latch spring  58  is an extension of the channel base  56 , and at an outer end of the latch spring  58  the sheet metal is bent downwardly, forming a catch  60  that extends generally perpendicular to the spring  58  over substantially the entire width, or combined thicknesses, of all of the folded tool bits and blades attached to the end  48  of the handle  42  or  44 . As will be explained in greater detail subsequently, the catch  60  is available to engage one or more extended tool bits or blades to keep each in its extended position. 
   An inwardly directed rim  62  extends along the margin of each sidewall  52 , and a similar inwardly directed rim  64  extends along the margin of each sidewall  54 . The rims  62 ,  64  merge smoothly with the sidewalls  52 ,  54  in a rounded surface along the margins of the sidewalls  52 ,  54 . The rims  62 ,  64  are directed inwardly toward each other, extending along a portion of the end  48  of each handle  42 ,  44  and thence continuously along the remainder of the margin of each sidewall  52 ,  54  toward the opposite second, or tool jaw, end  66  of each handle. The rims  62 ,  64  follow the contour of each of the sidewalls  52 ,  54 , also extending along indentations  68  ( FIG. 4 ) in the margins of the sidewalls. The indentations  68  provide access to nail nicks of blades stored adjacent the sidewalls in the cavities  70  in the handle  42  and a cavity  72  defined in the handle  44 . The rims  62  and  64 , together with the rounded surfaces where the rims  62 ,  64  merge with the sidewalls  52  and  54 , give a larger area to be gripped and squeezed, and thus provide for a more comfortable grip on the handles  42  and  44  when they are unfolded as shown in  FIG. 1A , with respect to a pair of pliers jaws  200 . 
   The latch spring  58  is separated from the adjacent sidewalls  52  and  54  along its length and is narrower, at least adjacent its outer end  74 , than the space between the opposed interior edges of the rims  62  and  64 , as may be seen in  FIG. 2 . As a result, the outer end  74  of the latch spring  58  is accessible between the sidewalls  52  and  54 , and may be trimmed to the appropriate length and be bent down to form the catch  60  after the sidewalls  52  and  54  and rims  62  and  64  have been formed, if desired, during manufacture of the handles  42  and  44 . 
   Additionally, space is provided as shown in  FIG. 2  for an axial spacer  77  fitted on the pivot pin  50  adjacent the sidewall  54  of the handle  44 , where the spacer  77  can be rotated alongside the margin  76  of the latch spring  58  to carry an attached lanyard eye  78  into the cavity  72  for stowage if desired. 
   The other side of each latch spring  58 , nearer to the sidewall  52  of each handle, extends closely alongside the margin of the sidewall  52  for a majority of its length and then is tapered inward, as shown at  80 . The portion of the latch spring  58  extending alongside the channel sidewall  52  is available to be contacted by a protruding shoulder  82  on a latch release lever  84  mounted on the pivot pin  50 . The latch release lever  84  preferably has a portion  85  which extends radially outward away from the pivot pin  50  to conform with the profile of the cam portions of the bases of the tool bits and blades, thus offering some lateral stabilizing support against the bases of those blades, and contributing to a neat appearance of the blade pivot end  48  of the handle. 
   A latch release operating lever  86  includes a knob or handle portion in the form of a rocker body  88  that extends outward from the cavity  70  or  72  within each handle through an opening  90  defined by both the sidewall  52  and the channel base  56  or back of each of the handles  42  and  44 . It will be understood that the openings  90  in the two handles are mirror images of each other, as are the latch release operating levers  86  located in the two handles  42  and  44 . While the latch release operating lever  86  may be manufactured by traditional machining processes, it may also be manufactured by powder metallurgy or metal injection molding methods. 
   Each latch operating lever  86  is attached to the adjacent sidewall  52  by a fastener such as a rivet  92 , defining a latch release operating lever pivot or fulcrum whose axis  94  extends normal to the sidewall  52 , so that the operating lever  86  can rotate about the fulcrum in a plane parallel with and adjacent to the sidewall  52 . Preferably, the rivet  92  is countersunk in the latch operating lever  86  to preserve clearance for folding tool blades to be stowed within the handles  42  and  44 . 
   Opposite ends  96  and  98  of the rocker body  88  include limit surfaces, and portions  100  and  102 , respectively, of the surfaces defining the opening  90  through the handles  42  and  44  are limit stops to be encountered by the limit surfaces of the ends  96  and  98  to limit the rotation of the latch release operating lever  86  about the fulcrum  94 . 
   An outer face or grip surface  104  of the rocker body  88  is arcuate, and has a shape approximating a sector of a short cylinder. Preferably, outer grip surface  104  is knurled or grooved to facilitate being gripped by a persons thumb or finger. The rocker body  88  extends laterally beyond an outer face  105  of the sidewall  52 , and also is exposed proud along the back  56  of the respective handle  42  or  44 , making it easy to pivot the latch release operating lever  86  about its fulcrum  94 , by moving either one&#39;s thumb or finger along the surface of the channel base  56  or along the sidewall  52 . The somewhat larger end  96  of the rocker body  88  contributes to comfort when pushing against that end of the rocker body  88  as shown in  FIG. 1A  rather than against the grip surface  104  to release the catch  60  from engagement with one of the folding blades or tool bits that has been latched into a position extending from one of the handles  42  or  44 . As may be seen in  FIG. 1A  it is practical to operate the latch release mechanism with respect to either of the handles  42  or  44  while holding the tool  40  with its handles  42  and  44  extended with respect to a pair of pliers jaws  200 . 
   As may be understood more clearly with reference to  FIGS. 4–8 , when a blade or tool bit attached to the handle  42  by the pivot pin  50 , such as the screwdriver blade  46 , is latched in its open, extended position as shown in  FIGS. 1 and 4 , the catch  60  extends into a notch  106  in the base  114  of the blade. A shoulder  108  is engaged by an outer face of the catch  60  to prevent the blade from rotating too far in the direction of extension, while an inner face of the catch  60  engages an inner face  110  of the notch  106  to prevent the latched, extended blade from rotating about a pivot axis  112  defined by the pivot pin  50  toward a stowed position within the cavity  70 . 
   A peripheral surface of the base  114  of the screwdriver  46  or other blade or tool bit acts as a cam, with a lobe  116  that presses against the latch spring  58 , deflecting it slightly outward from its relaxed position parallel with the channel base or back  56  of the handle  42 , when the catch  60  is engaged in the notch  106 . Pressure of the latch spring  58  against the cam lobe  116  urges the screwdriver blade  46  toward its extended position by creating a counterclockwise moment about the pivot axis  112 . 
   The elastic force of the latch spring  58  pressing against the lobe  116  must be overcome in moving the outer end  74  and the catch  60  far enough to disengage the catch  60  from the notch  106  in order to fold the screwdriver blade  46  into the cavity  70 . This is accomplished by rotating the latch release lever  84  far enough (in a clockwise direction as shown in  FIGS. 4–8 ) about its axis of rotation to move the shoulder  82  into contact with the latch spring  58  and by continuing movement of the latch release lever  84  in the same direction, to cause the shoulder  82  to deflect the latch spring  58  far enough to release the catch  60  from the notch  106 . 
   In the latch release mechanism depicted in  FIGS. 4–8 , the latch release lever  84  is moved when the latch release operating lever  86  is moved by a person engaging the rocker body  88  with a thumb or finger. 
   As may be seen best in  FIG. 3 , the pivot pin  50  is preferably a hollow-ended pin and a screw with mating threads extending through corresponding bores in the sidewalls  52  and  54 . Preferably, a shoulder  118  is provided on the pivot pin  50 , keeping the folding tool bits and blades including the screwdriver  46  away from the sidewall  52  to provide ample room axially along the pivot pin  50  for free rotation of the latch release lever  84  about the larger-diameter portion of the pivot pin  50 . 
   Using this construction the axis of rotation of the latch release lever  84  coincides with the pivot axis  112  about which the folding blades and tool bits rotate between their respective extended positions and their stowed positions within the cavities  70  and  72 . It will be understood, however, that it would be feasible to provide a separate axis of rotation for the latch release lever  84 , as by providing a rivet connecting the latch release lever  84  with the sidewall  52 . 
   It will be seen in  FIG. 4  that the latch release operating lever  86  includes two effective lever arms. A longer lever arm  120  is present between a fulcrum  94  and an effective point of contact  121  between a person&#39;s thumb or finger and the grip surface  104  of the rocker body  88 . A shorter lever arm  122  is present between the fulcrum  94  and a point of contact of an end  124  of the latch release lever  84 , following a cam surface  126  of a lever lifting cam portion of the latch release operating lever  86 . 
   It will be appreciated also that the grip surface  104  is not centered upon the pivot axis or fulcrum  94  of the latch release operating lever  86 , but is eccentrically located with respect to the fulcrum  94 . The grip surface  104  thus approximates a portion of a spiral expanding outward in a clockwise direction about the fulcrum  94 . The effective length of the longer lever arm  120  of the latch release operating lever  86  increases as the latch release operating lever  86  is moved, because the latch release operating lever  86  is moved by pressing one&#39;s thumb toward the back  56  of the handle  42  to engage the grip surface  104  and then moving the thumb longitudinally along the back  56  of the handle in the direction away from the blade pivot end  48 . Since the thumb&#39;s effective point of contact  121  moves along the grip surface  104 , the longer lever arm  120  increases in length as the latch release operating lever  86  is rotated counterclockwise, away from the blade pivot end  48 , to the position shown in  FIG. 5 . The lever arm  120  continues to increase in effective length as the latch release operating lever  86  is rotated further to the position in which the limit surface  98  encounters the stop  102 , as shown in  FIG. 6 . 
   Because of the shape of the cam surface  126 , however, the length of shorter lever arm  122  first increases and then decreases. Thus, for a force directed longitudinally along the back  56  of the handle  42  and applied at a point  121  where one&#39;s thumb or finger is tangent to the surface  104 , as the latch release operating lever  86  is rotated to approach the position shown in  FIG. 6  where the catch  60  is released from the notch  106 , the combined mechanical advantage provided by the changing lengths of the longer lever arm  120  and the shorter lever arm  122  first decreases and then increases to be greater than the initial mechanical advantage. This mechanical advantage, provided as the latch release lever is moved by the latch release operating lever  86 , compensates partially for the increasing force required at the end  124  to rotate the latch release lever  84  as the shoulder  82  deflects the latch spring  58  further from its relaxed position. As a result, the force that must be exerted on the grip surface  104  by one&#39;s thumb or finger, in a direction parallel with the back  56 , is much less than the force required at the end  124 , even as the spring  58  is deflected further and requires greater force. Also, the shoulder  82  moves slightly toward the outer end  74  of the spring  58  as the latch release lever  84  moves about its axis of rotation  112 , as shown by the arrow  125  in  FIG. 4  and the shorter arrow  127  in  FIG. 6 . This slightly lessens the increase in force required at the end  124  to move the latch release operating lever  86  further. 
   When the limit surface of the end  98  of the rocker body  88  encounters the stop  102 , the latch release lever  84  preferably does not protrude through the opening  90  more than a very small amount, as shown in  FIG. 6 , but the spring  58  is deflected sufficiently to raise the catch  60  and to release it from the notch  106 , as shown in  FIG. 6 , allowing the screwdriver blade  46  to be rotated clockwise toward its stowed position. The stop  102 , moreover, prevents the latch release lever  84  from flexing the latch spring  58  beyond its elastic limit. 
   As shown in  FIG. 7 , a peripheral surface of the base  114  of the screwdriver blade  46  acts as a cam followed by the catch  60  as the spring  58  moves back toward its substantially relaxed position shown in  FIG. 8 . Preferably, sufficient pressure is provided against the sides of the bases of the tool bits and blades, by the shoulder  118  and the head of the pivot pin  50  adjacent the outer side of the sidewall  54 , to keep the tool bits and blades from flopping too easily out from their respective stowed positions in the cavities  70  and  72 . Once a tool bit or blade has been moved a part of the way toward its respective extended position, the base  114  of each will act as a cam to lift the catch  60 , which can follow the cam surface until the catch  60  can engage itself into the respective notch  106 . 
   Preferably, the latch release lever  84  has a thickness  128  ( FIG. 3 ) which is greater than the thickness  129  ( FIG. 1 ) of the latch release operating lever  86 , assuring that the adjacent one of the blades stowed within the cavity  70  or  72  does not interfere with the latch release operating lever  86 . 
   When all of the tool bits or blades in one of the handles  42  and  44  are in their stowed positions, as shown in  FIG. 8 , the latch spring  58  preferably rests on the shoulder  82  of the latch release lever  84  with a small amount of pressure biasing the latch release lever  84  in a counterclockwise direction as shown in  FIG. 8 . This urges its outer end  124  against the cam portion, in turn urging the latch release operating lever  86  to rotate clockwise and thus bringing the limit surface of the end  96  of the rocker body  88  into engagement against the stop  100 . The latch release lever  84  includes a crook in its shape, fitting around the shape of the stop surface  100 , yet leaving a small amount of clearance, as shown in  FIG. 8 . Thus, when all of the tool bits and blades in the handle  42  or  44  are stowed within the respective cavity  70  or  72 , the rocker body  88  is held against the stop  100  with a small force originating from the latch spring  58 , and the latch release lever  84  and operating lever  86  are not free to rattle. 
   As shown in  FIGS. 9 ,  10 ,  11 ,  12 ,  13 , and  14  various other latch releasing mechanisms could also be used in conjunction with the configuration of the handles  42  and  44 . The rims  62  and  64  define a convenient space to receive a latch release lever without taking up space in which folding blades can be stowed within a handle and moved to an extended position with respect to the handle. 
   In particular, as shown in  FIG. 9 , a latch release lever  130  corresponds in function with the latch release lever  84  in the handle  42  or  44  and a main arm of the latch release lever  130  extends alongside an inner face of the sidewall  134 . Similar to the shoulder  82  on the latch release lever  84 , there is a shoulder  132  on the latch release lever  130  that presses against the latch spring  58  to deflect it and disengage the catch  60  from the notch  106  of an extended tool blade such as the screwdriver  46  when the latch release lever  130  is pushed to the position shown in  FIG. 10 . 
   A portion of the sidewall  134  of the tool handle  136  shown in  FIGS. 9 and 10  defines an opening  138  extending from the outer margin of the sidewall  134  toward the back  140 , or channel base portion of the handle  136 . The opening  138  thus interrupts the rim  142 , corresponding to the rim  62 , providing a space through which a U-shaped portion  144  of the latch release lever  130  can move as it is rotated about a pivot axis  146  defined in this embodiment of the invention by the pivot pin  50 . It will be understood that the pivot axis  146  could be located elsewhere, although it is convenient to allow the latch release lever arm  130  to rotate about the pivot pin  50  as shown. 
   On the outside of the tool handle  136  a flat handle or grip portion depends from the U-shaped portion  144  and includes an outwardly facing grip surface  148 . The flat grip portion extends closely alongside the outer face  150  of the sidewall  134 . The bottom of the opening  138  encounters the U-shaped portion  144  as a stop to prevent the shoulder  132  from flexing the latch spring  58  beyond its elastic limit. 
   When the latch release lever  130  is not being utilize to unlatch an extended blade, the U-shaped portion  144  is aligned with the rim  142 , and a lower margin  152  of the flat grip portion rests alongside the outer face  150 , as shown in broken line in  FIG. 10 . This keeps the latch release lever  130  mainly within space defined and protected by the rim  142 , so that contact of the upper side of the latch release lever arm  130  against the lower surface of the rim  142  keeps the U-shaped portion  144  from pivoting outward beyond a related position aligned with the margin of the sidewall  134 . 
   In another embodiment of the invention, as shown in  FIGS. 11 and 12 , a tool handle  156  includes a latch release lever  158 , with a shoulder  159  engaging the latch spring  58 , similar in its operation to the latch release lever  130 . In the handle  156 , however, a sidewall  160  defines a slot  162  through which extends a portion of the latch release lever  158  including a hook  164  that extends alongside and parallel with an outer face  166  of the sidewall  160 . When the latch release lever  158  is in its relaxed, or inoperative position, not being used to release the catch  60  from the notch  106  of the blade  46 , the outer end or hook  164  is located slightly below the indented portion  68  of the rim  168 , with an upper surface of the latch release lever  158  engaging an inner surface of the slot  162 . The latch release lever  158  is similarly prevented from moving too far toward the spring  58  by encountering a bottom surface of the slot  162 . 
   The rim  168  corresponds with the rim  62  described previously, and also extends along the indented portion  68  of the sidewall  160 , as in the handles of the tool  40  described above. As in the handles  42  and  136 , the latch release lever  158  is mounted to rotate about the pivot pin  50 , and thus its axis of rotation  170  coincides with the central axis of the pivot pin  50 , although the latch release lever  158  could be attached to the handle  156  to rotate about a different axis of rotation if desired. 
   As shown in  FIGS. 13 and 14 , in another embodiment of the invention, a handle  172  is also of generally channel-like form, and includes a sidewall  174  defining an opening  176  extending downward from its outer margin toward the back  178 . A rim  180 , similar to the rim  62 , extends along the outer margin of the sidewall  174  apart from the opening  176 . 
   A latch release lever  182  includes a shoulder  184  acting on the latch spring  58 , and is mounted for rotation about the pivot pin  50 , with an axis of rotation  186  of the latch release lever  182  coinciding with the central axis of the pivot pin  50 . The latch release lever  182  has a lower margin  188  that encounters the base or back  178  and prevents the latch release lever  182  from moving downward beyond the position shown in  FIG. 14  and from flexing the latch spring  58  beyond its elastic limit. 
   The upper margin  190  of the free end of the latch release lever  182  engages the rim  180  to limit upward movement of the latch release lever  182  from the position shown in  FIG. 14 , so that an outwardly directed rim  192  on the latch release lever  182  is aligned with the rim  180  of the sidewall  174  and provides a correspondingly rounded and comfortable shape to be encountered when the handle is gripped in using folding pliers or similar tools associated with a pair of handles such as the handle  172 . The rounded rim portion  192  also extends along an indentation  194  that provides convenient access to a nail nick in a folding tool bit or blade such as the screwdriver  46  located adjacent the sidewall  174  and the latch release lever  182 . 
   As may be seen best in  FIG. 15 , the rims  64  may extend inward to overlap a knife blade  196  or a file  198 , requiring the knife  196  or file  198  to be pushed into the respective cavity  70  or  72  before being extended so that removal of one of the other blades or tool bits does not carry the knife  196  or file  198  along unnecessarily. 
   Handle Folding 
   In a preferred embodiment of one aspect of the present invention, a pair of pliers jaws  200  shown in  FIGS. 15–17  include respective tangs  202 ,  204  of the jaws, and each tang is attached to a respective one of the handles  42  and  44  by a respective pivot pin  206 . The pivot pins  206  are preferably fasteners similar to the pivot pins  50 , such as matingly threaded screws and tubular pins, and extend through corresponding holes defined in a pair of opposite flanges  208 ,  210  in each of the handles  42 ,  44 , located at a second, or jaw pivot end  212  of the tool  40 . 
   The two parts of each pivot pin  206  are tightened together and fixed with a suitable adhesive to hold the flanges  208 ,  210  alongside each of the tangs  202 ,  204 , but the pivot pins  206  are long enough for the flanges  208 ,  210  to cause little or no frictional resistance to movement of each tang  202  or  204  with respect to the handle  42  or  44  to which it is attached. 
   In order to provide a controlled amount of friction resisting movement of the handles  42  and  44  with respect to the tangs  202  and  204 , a spring  216  is attached to the channel base  56  inside each of the handles  42 ,  44  at the jaw pivot end  212 . A fastener such as a rivet  218  extends through corresponding apertures in a rear end or inner end  220  of the spring  216  and in the channel base or back  56  of each handle  42  and  44 . 
   An outer end  222  of each spring  216  rests upon a cam  224 , which may have a raised arcuate middle portion  226  and a cam lobe  227  leading to an end portion  228 . As shown in  FIG. 16 , the end portions  228  are located at a smaller radial distance from the pivot pins  206  and are relatively flat. The outer ends  222  rest on the cam lobes  227  with a small clearance from the end portions  228  when the handles  42 ,  44  are extended with respect to the jaws  200 . The outer ends  222  of the springs  216  rest on cam lobes  229  adjacent relatively low flattened portions  230  when the handles  42 ,  44  are folded about the pair of jaws  200  as shown in  FIG. 17 . 
   As may be seen in  FIG. 18 , the spring  216  is a tapered, generally flat spring. Its outer end  222  is bent a few degrees away from the channel base  56  and out of alignment with the inner end  220 , and bears upon the tang  202  or  204 . The outer end  222  is forked, defining a pair of prongs that have lateral surfaces  232  that face toward each other and are located alongside radial surfaces  234  of a centrally located raised portion or land  236  located alongside the cam  224  on each tang  202  and  204 , as shown in  FIGS. 19–21 . The flat radial surfaces  234  cooperate with the lateral surfaces  232  to keep the outer end  222  of the spring  216  properly aligned with the tangs  202 ,  204 . 
   It would also be possible to provide the flat radial surfaces on raised portions on opposite sides of the cam  224  on each of the tangs  202 ,  204  and for the lateral surfaces  232  to be on opposite outer lateral sides of an outer end  222  of a spring  216 , which then need not be in the form of a fork. 
   When the handles  42 ,  44  are being folded or unfolded with respect to the tangs  202 ,  204  of the pliers jaws  200 , the outer end  222  of the spring  216  rides upon and is elastically biased toward the arcuate surface  226 , providing some friction to prevent the handles  42 ,  44  from moving too easily with respect to the jaws. As the handles  42 ,  44  approach the fully extended position shown in  FIG. 16 , the outer ends  222  ride onto the cam lobes  227  and extend toward the flat end portions  228  to urge the handles  42 ,  44  toward the fully extended position shown in  FIG. 16 . Similarly, the outer ends  222  ride onto cam lobes  229 , providing a small clearance from the flat portions  230  on the opposite side of each tang  202 ,  204  when the handles  42 ,  44  approach the fully folded position shown in  FIGS. 17 and 21 , and by spring force against the cam lobes  229 , the springs  216  then urge the handles  42 ,  44  toward the folded configuration with respect to the tangs  202  and  204  as shown in  FIGS. 1 and 17 . 
   When the tool is in the configuration shown in  FIG. 16 , for use of the pliers jaws  200 , an end stop or abutment surface  238  of the channel base  56  or back portion of each handle  42  or  44  rests against a shoulder  240  defined on the confronting side of each of the tangs  202 ,  204 . Consequently, squeezing forces exerted on the handles  42 ,  44  to close the pliers jaws  200  toward each other are carried through the end stop or abutment surfaces  238  and shoulders  240 , and not by the springs  216 , so that the rivet  218  needs only enough strength to retain the spring  216  attached to the channel base portion  56  against the elastic force of the spring  216 . 
   While the force of the outer end  222  of the spring  216  against the cam lobe  227  tends to keep the handles extended with respect to the tangs  202 ,  204 , a raised retention bump or interfering body  242  is also provided on the central land  236 , close to the shoulder  240 , to press against the inner surface of the channel base  56  when the handles  42 ,  44  are in or nearly in the fully opened configuration shown in  FIG. 16 . Pressure of the retention bumps  242  against the channel bases  56  provides additional frictional resistance against folding of the handles  42 ,  44  with respect to the pliers jaws  200 . Such resistance is useful, for example, when using wire-cutter portions of the pliers jaws. With the spring  216  acting on the spring cam  224 , it is unnecessary to provide interference between the central land  236  and the inner surface of the channel base  56 , except when the handles  42 ,  44  are intended to be more securely held in the open position shown in  FIGS. 1A and 16 . Nevertheless, there is ample friction provided by the spring  216  to prevent the handles from flopping freely about the tangs  202 ,  204  of the pliers jaws  200 . As a result, it is unnecessary to provide tension in the pivot pin  206  to hold the flanges  208 ,  210  tightly against the tangs  202 ,  204 , and it is unnecessary to manufacture the tangs  202 ,  204  with tolerances as demanding as is necessary when the central land  236  or a corresponding surface is required to provide friction against the inside surface of the channel base  56  throughout the entire range of motion of the handles  42 ,  44  with respect to the pliers jaws  200 . 
   Folding Scissors 
   As shown in  FIGS. 22 and 23 , a pair of folding scissors  250  included in the folding multipurpose tool  40  is latched in its operational configuration, extending from the tool blade end  48  of the handle  42 . The folding scissors  250  may be made of sheet steel and include a first scissors leg  252 , whose base portion  254  is mounted on the pivot pin  50  for rotation between the extended operational position shown in  FIG. 22  and a stowed position within the cavity  70  defined between the sidewalls  52  and  54  of the handle  42 . A fixed blade portion  256  extends outward from the base portion  254  beyond a blade pivot joint  258  preferably including a rivet extending through corresponding bores in the first scissors leg  252  and a second scissors leg  260  to interconnect the two scissors legs with each other. 
   The second scissors leg  260  includes a moving blade portion  262  and a handle  264  extending oppositely away from the blade pivot joint  258 . A thumb tab  266  extends laterally from an outer end of the handle portion  264  to contribute to comfortable operation of the scissors  250 . It may be formed by bending a sheet metal blank from which the second scissors leg  260  is made and, preferably, has an arcuately curved margin to be comfortably pressed. 
   Each of the blade portions  256  and  262  has a sharp, generally straight smooth edge portion  268 , which could be curved, if desired, and which can be used to cut easily through paper with a pushing movement and little movement of those edge portions  268  relative to each other. Additionally, sharpened serrations  270  are provided on each of the blades  256 ,  262  near the outer end or tip of each blade. The serrations  270  may be in the form of narrow, round-bottomed, grooves inclined with respect to the blades, or in the form of continuously wavy or sinuous curves, and may have a depth of 0.003 inch and a radius of curvature of 0.015 inch, for example. The serrations  270  may be spaced apart at a pitch of 0.023 inch, in a preferred embodiment, although variations of these dimensions on the order of a few thousandths of an inch will also be serviceable. Serrations  270  may be provided on either one or both of the blade portions  256  and  262 , and the serrations on each blade may be aligned with or staggered with respect to serrations on the opposite blade. Provision of the serrations  270  improves the ability to use the folding scissors  250  to cut materials including small strong fibers, as the serrations  270  can resist a tendency of materials being cut to be squeezed outward from between the tips of the blades  256  and  262 . 
   The first scissors leg  252  is held in its extended position with respect to the handle  42  by the engagement of the catch  60  in a notch  272 , corresponding with the notch  106  in the base of the folding screwdriver  46  described previously. Alternatively, an outer end of a flat spring (not shown), similar to the spring  58  without the catch  60 , could rest on a cam lobe  273  shown in  FIG. 26  to hold the first scissors leg  252  in the position shown in  FIG. 22 . 
   Pressure on the tab  266  toward the handle  42 , when the first scissors leg is in its extended position, pivots the moving blade portion  262  alongside the fixed blade portion  256  for a cutting stroke. In order to reopen the scissors blades from each other after each cutting stroke, a slender finger-like spring  274 , which may be of sheet steel cut to the appropriate shape, extends away from the handle  42  alongside the base portion  254 . The spring  274 , or at least its base  280 , is preferably slightly thicker than the second scissors leg  260  to give clearance for movement of the second scissors leg  260  between other blades or tool bits associated with the handle  42 . The spring  274  has a tip  276  or outer end that rests against a back surface  278  of the handle  264  when the scissors blades portions  256  and  262  are in a cutting relationship with each other, as with the pair of scissors  250  in the operational configuration shown in  FIG. 22 . 
   As shown more clearly in  FIG. 23 , the spring  274  has a base  280  located alongside the base portion  254  of the first scissors leg  252 . A spring pivot includes a protruding portion such as a spring pivot pin  283  fixed in the base  280  and extending rotatably into a hole of a corresponding size defined in the base  254  of the first scissors leg  252  a small distance form the notch  272  and spaced radially outward from the pivot pin  50  by a small distance  287 , such as about 0.07 inch. The base  280  includes a notch  282  that is aligned with but wider than the notch  272  in the base portion  254  of the first scissors leg  252 , so that the base  280  of the spring  274  is free of the catch  60  to rotate through a small angle about the spring pivot when the folding scissors  250  are in the extended position shown in  FIG. 22 . The base  280  is carried along with the base  254  when the first scissors leg  252  rotates about the pivot pin  50 , when the catch  60  is not engaged in the notch  272  in the base portion  254  of the first scissors leg  252 . Movement of the base  280  of the spring  274  about the spring pivot is limited to an angle of several degrees, for example, 8°, with respect to the base portion  254 , by engagement of a limiting structure such as a pin  284  protruding within an opening such as the hole  286  defined in the base portion  254 . The spring pivot pin  283  and the pin  284  may be separate pieces fixedly fitted in corresponding holes defined in the base  280  of the spring  274 , or, preferably, the spring pivot pin  283  and the pin  284  may be produced by coining or semi-piercing the base  280  using suitable punch and die combinations. 
   The pin  284  is located at a front end of a leg  288  of the base  280  extending generally parallel with a leg  289  of the spring  274 . The spring  274  extends rearwardly from the pin  284  and has a curved, or U-shaped portion  291  that is located alongside the base  254  of the first leg  252 , and then extends forward along the first scissors leg  252 . The generally U-shaped portion  291  extends around the pivot pin  50  but is always clear of it by at least a small distance so that the spring  274 , except for the base  280 , is free to flex along its entire length and with respect to the base  280  during use of the scissors  250  in response to pressure exerted by the back surface  278  of the handle  264 . 
   Thus, in use of the scissors  250 , when the thumb tab  266  is pressed toward the handle  42 , the spring  274  urges the base  280  to rotate counterclockwise about the spring pivot pin  283  as seen in  FIG. 23  until the pin  284  engages the interior surface of the hole  286 . Further movement of the handle  264  in a clockwise, blade closing direction about the blade pivot joint  258  causes the spring  274  to flex elastically. By reaction, the spring  274  urges the handle  264  in the opposite direction to reopen the moving blade  262  away from the fixed blade portion  256  when pressure on the thumb tab  266  is relaxed. Rotation of the handle  264  with respect to the base portion  254  of the first scissors leg  252  is limited by the leg  288 , which blocks the back surface  278  once the edges  268  have closed alongside each other, and thus prevents further movement of the moving blade  262  toward or past the fixed blade portion  256 . 
   When it is desired to stow the scissors  250  in the handle  42  the blade latch release mechanism is operated as described previously to remove the catch  60  from the notches  272  and  282 , allowing the base portion  254  of the first scissors leg  252  to be rotated about the pivot pin  50  toward the position shown in  FIG. 24 , carrying the second scissors leg  260  and the spring  274  along with it. The second scissors leg  260  is also rotated counterclockwise as shown in  FIG. 23  about the blade pivot joint  258 , toward the position shown in  FIG. 25 , in which the moving blade  262  extends along the base portion  254  of the first scissors leg  252 , opposite the direction of the fixed blade portion  256 , so that the edges  268  extend substantially oppositely away from the blade pivot joint  258 . In order for there to be room for the moving blade  262  to extend alongside the base portion  254 , the spring  274  and its base  280  rotate clockwise about the spring pivot with respect to the base portion  254  of the first scissors leg  252 , until the pin  284  reaches the position in the hole  286  shown in  FIG. 25 . Further movement of the folding scissors  250  relative to the handle  42  counterclockwise from the position shown in  FIG. 25 , as by pushing against the base portion  254  and the handle  264 , takes the folding scissors  250  the remaining distance into the cavity  70 , to the stowed position shown in  FIG. 26 , in which the spring  274  is free of contact with the back surface  294 . Nevertheless, there is room for the spring  274  to rotate counterclockwise slightly with respect to the base portion  254  of the first scissors leg  252  and come into contact with the back surface  294 , as a result of the freedom of the pin  284  to move within the hole  286 . When the folding scissors  250  are stowed within the cavity  70  the thumb tab  266  lies against the interior surface of the channel base portion  56  leaving room for the jaws  200  of the pliers to be folded into the cavity. 
   The scissors  250  can be unfolded from the stowed position to prepare them for use by engaging the hook  290  in the base portion  254  of the first scissors leg  252  to rotate it up a small distance from the base portion  56  of the handle  42 , about the pivot pin  50 , until the peripheral surface  293  of the base portion  254  encounters the catch  60 . As the first scissors leg  252  reaches the position shown in  FIG. 25 , a peripheral, or outer surface  292  of the U-shaped portion  291  of the spring  274  also encounters the catch  60 , which urges the spring  274  to pivot about the pivot pin in a clockwise direction with respect to the base  254  of the first scissors leg  252 , until the pivot pin  283  moves past the catch  60 . This keeps the tip  276  of the spring  274  clear of a back surface  294  of the moving blade  262  as the scissors are moved toward the operational configuration shown in  FIGS. 22 and 23 . Finally, once the first scissors leg  252  is fully extended and latched with respect to the handle  42 , the second scissors leg  260  is manually moved clockwise about the blade pivot joint  258 , bringing the handle  264  toward the base portion  254  of the first scissors leg  252 . This makes the scissors ready for use. 
   In order to distribute the pressure of the catch  60  sufficiently to resist undesirable wear on the peripheral, or outer surface  293  of the base portion  254  of the first scissors leg  252 , the shape of the outer base surface  292  corresponds closely with the arcuate peripheral surface  293  of the base portion  254 , except for the difference between the notch  282  and the notch  272 . 
   Container Opener 
   One of the folding tool bits of the folding multipurpose tool  40 , as shown in  FIG. 22 , is a combined can opener and bottle opener  300  mounted at the blade pivot end  48  of the handle  44 , where its base  302  is mounted on the pivot pin  50 , for rotation between a stowed position within the cavity  72  and an extended position, in which the catch  60  on the latch spring  58  of the handle  44  engages a notch  106 , as shown in  FIGS. 27 and 28 . A bore  304  which fits about the pivot pin  50  defines a pivot axis  306  that coincides with the central axis of the pivot pin  50 . 
   The container opener  300  has a generally planar body  308  with opposite sides defining opposite side planes, a right side plane  310  and a left side plane  312 , as viewed when using the opener  300 . A generally flat back surface  314  is perpendicular to the side planes  310  and  312  and defines a reference plane. Although the back surface  314  need not be precisely planar it does, nevertheless, define generally the location of the reference plane extending perpendicular between the side planes  310  and  312 . A nose portion  316  has a front end  318  and is directed forward at a downward angle  319  from the back surface  314  and the corresponding reference plane. 
   A hook  320  has a tip  322  located in or adjacent the side plane  310 . The tip  322  is directed forwardly, generally in line with a bottom margin  324  of the body  308 . A surface  323  extends diagonally rearward from the tip  322  toward the right side plane  312 , and is seen clearly in  FIG. 28 . The tip  322  is thus pointed and able to engage a rim of a crown cap easily. A surface  325  parallel with the left side plane  310  is recessed laterally from the side plane  310  and defines a throat space between the tip  322  of the hook  320  and a more rearwardly located portion of the body  308 . A rearward surface of the tip portion  322  extends transversely with respect the body  308  and is generally vertical and thus approximately perpendicular to the side plane  310  and the reference plane corresponding to the back surface  314 . A sharp edge  326  lies substantially in the side plane  310 , aligned with the tip  322 , and is defined by a beveled or diagonally extending surface  328  extending obliquely forward from the edge  326  toward the side plane  312 . The tip  322  may be spaced rearwardly from the front end  318  by a distance  329  of 0.72 inch in a preferred embodiment of the invention. 
   The shape of the tip  322  and the location of the throat space enable the tip  322  to extend to the left to be hooked beneath the crimped rim of a “tin” can or similar container whose top is to be removed using the opener  300  so that the rim extends into the throat space while the edge  326  cuts the top of the can. This configuration also enables the opener  300  to have a conveniently small depth  327  of 0.5 inch or less between the back  314  and the bottom  324 , to avoid needing excessive space for stowage in the cavity  72  or in another tool handle. 
   A groove or nail nick  330  may be provided to facilitate raising the opener  300  from a stowage position within the handle  44  to extend it to the position shown in  FIG. 22 . 
   A wire stripper  332  in the form of a beveled notch is provided along the bottom  324  and includes a sharpened edge  334 . 
   The opener  300  may be machined from a suitable steel blank, or may be manufactured by metal injection molding and sintering methods, if desired. 
   As shown in  FIGS. 29 ,  30 , and  31 , a somewhat similar opener  340  may be manufactured by laminating to one another a pair of layers which may be fine blanked and coined or semi-pierced. A first layer  342 , which is the left side when the opener is in use, includes a nose portion  344  on a body  346 . A forward lower margin portion  348  of the body  346  faces diagonally downward and forward. A second layer  350 , which is the right side when the opener is in use, is located closely alongside the first side layer  342 , and the two layers  342  and  350  are aligned with each other by pin-like projections  352  and a bar-like projection  354  on the second side layer  350  which extend into corresponding apertures  356  and  358  defined in the first side layer  342 . The projections  352  and  354  may be produced by semi-piercing the second side layer  350  while the openings  356  and  358  may be provided by fine blanking procedures. 
   At the bottom of the second side layer  350  is a hook  360  extending forward from the body portion  346  of the opener. The hook  360  is bent at an angle of about 15°, for example, to project forward diagonally into the space beneath the first layer  342 , ahead of the lower margin  348 . The hook  360  and the lower margin  348  cooperatively define a throat space  362  behind the tip of the hook  360 , so that the tip of the hook  360  can engage the bottom of the crimped rim of a “tin” can with the rim extending into the throat  362  as the nose portion  344  of the opener  340  is used to pierce and cut away the top member of the container. Since the first side layer  342  has a thickness of only 0.050 inch and has sharp corner edges  364  as a result of being cut from a sheet of steel stock, it performs effectively, if not particularly efficiently, in cutting away the lid of a “tin” can. 
   A wire stripper  366 , similar to the wire stripper  332 , may be provided in the lower margin of the left side layer  342 . 
   It will be understood that the openers  300  and  340  could also be made as mirror opposites of the openers described. 
   Interlocking Blades 
   In order to stabilize the handles  42 ,  44  with respect to each other during use of one of the folding blades of the multipurpose folding tool, an interlock portion  370  may be provided on one of the tool bits such as a straight screwdriver  372  stowed within the handle  42 , while a mating interlock portion  374  is provided on another folding tool bit such as a cruciform screwdriver  376  stowed within the handle  44  in a position opposite the screwdriver  372 . As may be seen in  FIGS. 17 and 32 , the interlock portions  370  and  374  include respective sloping, inclined surfaces that fit against each other, while face surfaces  378  and  380  that are extensions of the sides of the screwdrivers  372  and  376  extend alongside other tool blades or bits stowed within the opposite handles, so that the relationship between the interlock portions  370  and  374  resists lateral movement of the handles  42  and  44  in respect to each other during use of one of the tool blades or bits stowed ordinarily in either of the handles  42  and  44 . Since the interlocks  370  and  374  protrude only a small distance above an imaginary plane defined generally by the rims  62 ,  64  and the generally coplanar back surfaces of the blades and tools stowed in each of the handles  42  and  44 , the interlocks  370  and  374  do not detract noticeably from comfort during use of the pliers jaws  200 . They do, however, provide hooks to be engaged by one&#39;s fingernail to open a blade or tool bit from its position of storage within a respective one of the handles of a multipurpose tool so that tool bits or blades stowed between other tool bits can be opened easily from the handle in which they are stowed. 
   It will be understood, as may be seen in 
     FIG. 33 , that an additional pair of interlocks  370 ′ and  374 ′ may be provided on another pair of oppositely located tool blades in the handles  42  and  44 , so that two pairs of interlocks are available to keep the handles  42  and  44  aligned with each other during use of a selected tool bit or blade including one of the interlocks. 
   As may be seen with reference to  FIGS. 34 ,  35 ,  36 ,  37 , and  38 , not only may such interlocks be in the form of portions  370  and  374  with inclined mating surfaces and defining hooks, but a respective portion of each tool blade may be machined to a reduced thickness, leaving interlocking flat portions  382  and  384  of reduced thickness able to interlockingly overlap one another as shown in  FIGS. 35 and 36 . Such overlapping interlocking portions  382  and  384  may each include an almond-shaped opening  385  serving as a nail nick extending through the interlock portion, or overlapping portions  386  and  388  as shown in  FIGS. 37 and 38 , may be shaped to present a hook to be engaged by one&#39;s fingernail to open a particular blade or tool bit from position between other blades or tool bits. 
   Blade Latch Security 
   Referring next to  FIGS. 4 ,  39 , and  40 , a flat surface  400 , between the cam lobe  116  and the inner face  110  of the notch  106 , in a base  114  of a folding blade or tool bit such as the screwdriver  46 , rather than being precisely parallel with the channel base or back surface  56 , is inclined outwardly, away from the pivot axis  112  seen in  FIG. 4 , by an angle  402  which is slightly smaller than the angle  404  by which the inner surface  403  of the latch spring  58  diverges outward from the plane  405  defined by the channel base  56  as a result of deflection of the latch spring  58  by the cam lobe  116 . The outwardly inclined orientation of the flat surface  400  relative to a surface parallel with the plane  405  of the channel base  56  gives the notch  106  a slightly, but significantly, deeper surface  110  located opposite the inner face of or in contact with the catch  60  when the inner surface of the latch spring  58  rests on the cam lobe  116 . Where the angle  402  is 2°, sloping the flat surface  400  closer to the orientation of the spring  58 , while still maintaining an angular divergence of about 1° of arc, gives a depth of engagement of about 0.003 inch, or 6% greater than when the flat surface  400  is parallel with the plane  405 . Pressure of the latch spring  58  against the cam lobe  116  still urges the blade, for example, the screwdriver  46 , in a counterclockwise direction until the outer face of the catch  60  encounters the shoulder  108  of the blade, as shown in enlarged view in  FIG. 39 . 
   Preferably, the notch  106  has a depth  406  beneath the flat surface  400  that is great enough to permit manufacture by use of a blanking die with a radius large enough to have ample strength. This depth  406  will be greater than the depth  408  of the catch  60 , which is limited by the ability of the latch spring  58  to flex far enough for the catch  60  to be removed from the notch  106  without exceeding the elastic limit of the latch spring  58 . 
   As shown in  FIG. 40 , in a multipurpose tool in which the latch spring  58 ′ includes no catch corresponding with the catch  60 , the flat surface  400  is inclined outward at an angle  402  with respect to the plane  405  defined by the base portion  56 . The flat surface  400  thus diverges slightly, preferably by about 1°, from the orientation of the inner surface of the deflected latch spring  58 ′ that bears on the base  114  of the blade. As a result, the spring  58 ′ presses against the cam lobe  116  and urges the blade in a counterclockwise direction as seen in  FIG. 4 , keeping the shoulder  108  engaged against the outer end  410  of the latch spring  58 ′, as shown in  FIG. 40 . 
   Alternative Handle Configuration 
   The present invention may also be embodied in a folding multipurpose tool including a handle  412 , shown in  FIGS. 41–48 . Such a tool might be similar to the tool  40  described above and shown in  FIG. 1 , but would incorporate the handle  412  in place of the handle  44 , and a similar, mirror-image handle could be substituted also for the handle  42  of the tool  40  shown in  FIG. 1 . 
   The handle  412  has generally the form of an elongate channel with a pair of opposite ends, a blade pivot end  414 , and a tool jaw end  416 . 
   Folding blades (not shown) such as the straight screwdriver blade  46  and other screwdriver blades, knife blades, files, and folding scissors may be mounted in the same fashion as in the folding tool  40  at the tool blade end  414  of the handle  412 , arranged to pivot about an axis defined by a pivot pin  418  similar to the pivot pin  50  described above. For the sake of simplicity, while the heads of the pivot pin  418  are shown in  FIGS. 41 ,  44 ,  47 , and  48 , the pivot pin  418  is omitted from  FIGS. 42 ,  43 ,  45 , and  46 . 
   The handle  412  is of sheet metal blanked and pressed into the form shown, in which a main channel includes a channel base  420  and a pair of sidewalls  422  and  424 . The sidewall  422  is connected with the channel base  420  in a smoothly curved bend providing a rounded corner for a comfortable grip. A latch spring  426  extends from the channel base  420  and carries a catch  428 . 
   A latch release mechanism similar to that provided in the tool  40  may be associated with the handle  412 , as is shown by the inclusion of a latch release operating lever  430  attached to the sidewall  422  by a fastener such as a rivet  432 . The operating lever  430  projects outwardly through an opening  434  defined in the channel base  420  and outer sidewall  422 , as seen best in  FIGS. 41 and 42 . 
   An inwardly directed rim  436  extends along a margin of the sidewall  422  from the tool blade end  414  toward the jaw pivot end  416 , following the contour of the margin of the sidewall  422 , including a nail nick access indentation  438 . The rim  436  merges with the outer sidewall  422  giving a smoothly rounded surface and additional area to be gripped and squeezed, as described above with respect to the rims  62  and  64 . 
   A hole  440  is provided in the channel base portion  420  of the handle  412  to receive a fastener to attach a spring such as the spring  216  shown in  FIG. 15 , to act on a tang of a tool such as a pliers jaw. 
   As in the handle  44  shown in  FIG. 15 , the sidewalls  422  and  424  include a pair of flanges  442  and  444  at the jaw pivot end  416  of the handle  412 , and the flanges  442 ,  444  define respective openings  446  and  448  to receive a jaw pivot pin  449  shown partially cutaway in  FIG. 44 . The channel base  420  includes an end surface  450  corresponding with the end surface  238  described above in connection with the tool handle  44 . 
   Interconnected with the sidewall  424  is a side wing portion  452  that initially extends away from the sidewall  424 , curving arcuately as shown at  454 , and then extends flat and approximately parallel with the sidewall  424 , to define a side trough  456  facing in a direction opposite that of the main channel defined between the sidewalls  422  and  424 . This aspect of the handle  412  is similar to a portion of the tool described in copending U.S. patent application Ser. No. 08/961,055, of which the disclosure is hereby incorporated herein. 
   The sidewall  424  is cut to define a blade locking member  458 , bent with respect to the sidewall  424  to project at a small angle into the side trough  456 , in position for its front surface  459  to engage the base of a folding outer blade  460  shown in its extended position in  FIG. 48 . A large radially extending axial bearing  461  mounted on the jaw pivot pin  449  keeps the blade  460  attached to the handle  412 , supporting it and allowing it to pivot between a folded position shown in  FIG. 47  and the extended position shown in  FIG. 48 . A small detent bump  462  is provided on the blade locking member  458 , and an upper surface of the blade locking member  458  defines a notch  464  to receive a projecting member (not shown) associated with the folding outer blade  460 , to establish properly the folded position of the outer blade  460 , shown in  FIG. 47 . 
   A front margin portion  466  of the side wing portion  452  is arcuately curved so as to provide access to push the blade locking member  458 . A portion  468  of the margin of the side wing portion  452  is shaped to provide access to a nail nick  470  in the tip of the folding outer blade  460  in order to begin moving it from its folded position in which it is held by interaction of the detent bump  462  with a corresponding dimple (not shown) in the folding outer blade  460 . 
   A bolster  472  is mounted on the handle  412  at the blade pivot end  414 , closing the end of the side trough  456  and presenting a smoothly rounded surface having a desirable appearance. 
   The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.