Patent Publication Number: US-6219870-B1

Title: Lock release mechanism for a folding combination tool or the like

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional application of application Ser. No. 09/099,367, filed Jun. 18, 1998, now U.S. Pat. No. 5,963,999, which is in turn a continuation of Ser. No. 08/724,963, filed Oct. 7, 1996, now U.S. Pat. No. 5,791,002, whose disclosure is substantially the same as Ser. No. 08/724,964, filed Oct. 7, 1996, now U.S. Pat. No. 5,781,950. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a multi-purpose folding tool, commonly referred to as a compound or combination tool, since it includes a plurality of independently used tools, or as a survival tool, since it has rapidly become the tool of choice of outdoorsmen. A typical compound tool may incorporate pliers, flat-head and Phillips-head screwdrivers, knife blades, an awl, a pick, a fish cleaning serrated blade, a ruler, a wire insulation trimmer, and a bottle/can opener. Each of these independently used tools are typically housed in a single tool capable of folding into an easily carried, compact unit. Compound tools of this type are especially useful to those who need to maximize the utility of what they carry while minimizing the size and weight thereof, e.g. back-packers, bikers, campers, electricians, fishermen, hikers, and hunters. 
     2. Description of Related Art 
     Combination tools, i.e., those in which several different types of tools, e.g., a knife blade, an awl, or an assortment of screwdrivers and wrenches, are individually rotatable into and out of a housing for storage and use, respectively, have been the subject of U.S. patents for some time; see, for example, Barnard &amp; Brace, U.S. Pat. No. 97,154, issued Nov. 23, 1869, and Pierce, U.S. Pat. No. 234,378, issued Nov. 8, 1880. Combination tools which include a pair of scissors or pliers, in which the crossed jaws fold into or adjacent to their handles, were developed around the turn of the twentieth century; see, respectively, Klever, Kaiserliches Patentamt, Patentschrift No. 30,788, issued Mar. 12, 1885, and Klever, U.S. Pat. No. 858,003, issued Jun. 25, 1907. The latter allows other tools, e.g., a knife blade, to be joined therewith, although the other tools are stored separately from the folded tool by inserting their base into a notch formed by the closed handles. Pliers having handles pivotally connected to the tangs of the pliers jaws, such that the handles fold adjacent the pliers jaws, are also known (e.g., Garrison, U.S. Pat. No. 1,461,270). 
     Combination tools including folding pliers in combination with other, supplemental tools, usually stored within the handles, the so called “survival tools”, did not achieve widespread popularity until relatively recently with the patenting of such tools by Leatherman, U.S. Pat. Nos. 4,238,862, 4,744,272, and 4,888,869, and as evidenced in European Patent Application No. 513,937. Others followed quickly, e.g., Collins et al., U.S. Pat. Nos. Des. 368,634, and 5,062,173, Sessions et al., U.S. Pat. Nos. 5,142,721 and 5,212,844, and Frazer, U.S. Pat. Nos. Des. 368,634, and 5,267,366. All of these prior art tools are generally satisfactory for their intended purposes, but they do have drawbacks associated therewith. 
     In all of the folding tools cited above, from Klever to Frazer, the folding tools include straight handles. Thus, when the folding tool is closed, the jaws of the pliers are stored within the confines of the handles. Not only are the handles weakened by removing portions of the walls of the handles to receive the pliers, the space inside the handles is diminished, thereby decreasing the room available for the supplemental tools, which must perforce be made smaller and weaker. 
     Many folding tools position the plier head over some of the supplemental tools when completely closed. It is then necessary to go to the inconvenience of opening the plier portion of the tool when desiring only to access a supplemental tool. This then requires fully closing the plier portion of the tool again before you can actually use the supplemental tool. 
     The handles of Leatherman, Collins et al., Sessions et al., and Frazer are channel-shaped, open along their entire length, which may make them more susceptible to bending under heavy strains, particularly near the pivotal connection of the handles with the plier jaws&#39; tangs, depending upon the thickness of the material. 
     The channel openings of Leatherman and Frazer (Design Pat. No. 368,634) open outwardly along the outer edge of the handles, i.e., outwardly in the plane of the handles. When squeezing the handles, the open channels and supplemental tools therein present rough surfaces and raw edges to the hands. 
     Prior art survival tools latch or lock the supplemental tools in their stored and extended positions by means of either (1) a leaf spring coacting with a flat on the periphery of the supplemental tools (e.g., Leatherman, Collins et al., Sessions et al., and Frazer), or by providing a projection at the end of the leaf spring to mate with a recess or notch in the periphery of the supplemental tools (Leatherman). The latter is the time-honored method used in related arts as well, such as, in jack-knives, vanity kits, or other specialized combination tools; see Halivarson, U.S. Pat. No. 1,556,788, Nielsen, U.S. Pat. No. 1,561,993, Bovee, U.S. Pat. No. 2,575,652, Bassett, U.S. Pat. No. 2,798,290, Zoeller, U.S. Pat. No. 2,851,704, and Felix-Dalichow, U.S. Pat. No. 4,442,600. In each of these, a projection on a separate lever or spring, or a flange on a resilient portion of the housing, fits into a notch on the supplemental tool to lock the tool in place. Alternatively, a projection on the tool mates with a seat or notch on the housing. Either way, a projection is designed to mate with a notch. Projections or flanges are difficult and costly to manufacture, and notching a tool to receive the projection usually results in lost material, and thereby lost strength, in the mounting end of the tool. 
     Though supplemental tools may lock in extended position to some degree, many tools have little or no provision for a completely positive lock. One reason is the resulting problem of providing an unlocking means that is safe, convenient and cost effective. With supplemental tools locking in a less than completely sure manner in the extended position, safe use can be questionable. 
     The jaws of pliers, wrenches, etc., have in the past occasionally been of a laminated construction, i.e., a plurality of sheets bound together by some means, often by rivets; see, e.g., Bernard, U.S. Pat. No. 526,480, McLeran, U.S. Pat. No. 831,676, Chen et al., U.S. Pat. No. 4,660,241, and Warheit, U.S. Pat. No. 4,662,252. In each of these, the laminations reinforce each other against forces acting transversely to the jaws, but they provide little to no resistance to shearing forces along the planar surfaces between the laminates. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     The present invention overcomes the difficulties described above by: 
     tapering the handles inwardly to create recesses which, when the tool is folded, provides storage for the plier jaws, maintaining the integrity and strength of the handle walls while providing more room for larger, heftier supplemental tools; 
     reinforcing the handles with a box-beam construction in the area of the handle-to-tang pivots; 
     opening the channels in a direction away from the palm of the hand when the plier is operational, so that the user&#39;s hand squeezes on relatively smooth handle surfaces; 
     forming a stock on the end of a leaf spring to mate with a notch in the mounting end of the supplemental tool to lock it in place; 
     interlocking the laminates of plier jaws against shear forces along their planar surfaces by providing mating countersinks and daps in their facing surfaces; 
     storing supplemental tools outside the closed plier handles for quick, safe and convenient access; and 
     providing a lock release mechanism that conveniently works with a completely positive locking design for the supplemental tools. 
     Accordingly, it is one object of the present invention to taper inwardly the folding handles of a multi-purpose folding tool, making the pair of handles more comfortable while in the process creating a recess which, when the tool is folded, stores the plier jaws externally of the handle walls. 
     Another object of the present invention is to reinforce the handles by providing a box-beam construction adjacent the pivotal connections with the folding pliers. 
     A further object of the present invention is to provide smooth, comfortable handle surfaces for contact with the user&#39;s hands when the tool is in use. 
     A still additional object of the present invention is to provide a stock on a flange-less leaf spring to mate with a small notch on the mounting end of the tool to lock the tool in place. 
     Another object of the invention is to provide a stronger jaw structure for a gripping tool, e.g., a pair of pliers, by including complementary, mating countersinks and daps in the laminates, thereby constraining the laminates against lateral shifting. 
     The foregoing and other objects are achieved in accordance with one aspect of the present invention through the provision of a multi-purpose folding tool which comprises a pliers having a pair of crossed jaws. Each of the jaws includes a gripping end with a tip, a pivot bearing, and a tang. The jaws are rotatably connected to each other by a jaw pivot pin extending through each of the pivot bearings. 
     The folding tool further includes a pair of handles each having a secured end and a free end. A pivot bearing is located at the secured end of each handle and is rotatably connected to one of the tangs by a pivot pin. The axes of the jaw pivot pin and the tang pivot pins are substantially parallel to one another. The handles each further include a pair of upstanding sidewalls integrally connected by a web, the sidewalls and the web forming a U-shaped channel open outwardly from the plane of the handles. 
     The pair of sidewalls comprise an outboard sidewall facing away from the opposite handle and an inboard sidewall facing toward the opposite handle, each of the outboard sidewalls of the handles including an inwardly tapered portion to define a recess adjacent to a respective one of the pivot bearings. 
     The handles also include a channel pivot pin journaled in the sidewalls transverse of the channel adjacent the free end of the handle. The axis of the channel pivot pin is substantially orthogonal to the axes of the jaw and tang pivot pins. 
     A plurality of supplemental tools are pivotally mounted on the channel pivot pin. Each of the supplemental tools is individually rotatable between a closed position within the channel and an open position extending from the channel. 
     The inwardly tapered portions of the outboard sidewalls are configured such that when the folding tool is folded by pivoting the handles about the tang pivot pins, the inwardly tapered portions of the outboard sidewalls cam the tips of the jaws towards one another to assist in the folding of the multi-purpose folding tool. 
     In addition, when the folding tool is folded, the outboard sidewalls enclose the jaws between the recesses. The inboard sidewalls may include a second tapered portion to provide a separation between the free ends of the handles, while the outboard sidewalls preferably include protrusions or nubs formed thereon to improve the grip of a user&#39;s thumb and fingers on the folding tool. 
     In accordance with another aspect of the present invention, the web includes a flat, resilient leaf spring located at one end of the channel, and a slot through the free end of the leaf spring. The slot is bordered across the free end by a transverse, flat, flange-free stock. Each of the supplemental tools comprises a body and a mounting end, the body being shaped as appropriate for the function of the supplemental tool. The mounting end is pivotally mounted on the channel pivot pin. 
     At least one of the supplemental tools includes a mounting end having a peripheral notch positioned to snugly receive the stock therein, when such supplemental tool is extended, to positively lock same. 
     In accordance with another aspect of the present invention, release means are provided for unlocking such supplemental tool from its extended, locked position. The release means preferably comprises an outwardly directed bulge positioned on another of the supplemental tools on the body thereof. The bulge protrudes above the longitudinal edges of the sidewalls when its supplemental tool is closed. The mounting end of such supplemental tool is configured such that depression of the bulge causes the mounting end to deflect the leaf spring, lifting the stock out of the notch. In addition, the mounting end of such supplemental tool includes a peripheral flat which coacts with the leaf spring to bias such supplemental tool closed. Such flat has a corner which contacts and deflects the leaf spring when the bulge is depressed. 
     Another of the supplemental tools includes a mounting end having first and second peripheral flats. The first flat coacts with the flat leaf spring to bias such supplemental tool into its closed position, while the second flat coacts with the leaf spring to bias such supplemental tool into its open position, thereby retaining such supplemental tool in its closed and open positions, respectively. 
     In accordance with yet another aspect of the present invention, each of the pair of jaws preferably comprises at least three laminated sheets. Each pair of adjacent sheets is preferably reinforced with at least one mating countersink and dap. Binding means, preferably in the form of a rivet, passes through the laminated sheets to secure them together. The laminated sheets preferably comprise a central body and a pair of outer strips. The countersinks are preferably formed in the central body while the daps are preferably formed in the outer strips. 
     In accordance with another aspect of the present invention, the handles further include a fourth wall folded over a portion of the outward opening of the U-shaped channel so as to form a box-beam construction. One of the walls of the box-beam construction further may include an aperture therethrough which is adapted to receive a lanyard. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other objects, aspects, uses, and advantages of the present invention will be more fully appreciated as the same becomes better understood from the following detailed description of the present invention when viewed in conjunction with the accompanying drawings, in which: 
     FIG. 1 is a top perspective view which shows the preferred embodiment of the present invention as it appears when opened with the plier jaws closed; 
     FIG. 2 is a bottom perspective view of the opened inventive tool with the plier jaws closed; 
     FIG. 3 is a top view of the open compound tool with the plier jaws open; 
     FIG. 4 is a top view of the compound tool partially closed; 
     FIG. 5 is a top view of the compound tool almost closed; 
     FIG. 6 is a top view of the closed compound tool; 
     FIG. 7 illustrates a use of the present invention clamping a cable; 
     FIG. 8A is a sectional top view of the ends of the handles of the compound tool with two supplemental tools extended, showing the latching and locking mechanism in operation; 
     FIGS. 8B and 8C show side views of two supplemental tools; 
     FIG. 9A is a side view of the compound tool illustrating the release of the latching mechanism; 
     FIG. 9B is a cross-sectional side view of one of the supplemental tools releasing the locking mechanism; 
     FIG. 10 is a sectional side view of one of the handles of the compound tool with the supplemental tools stored therein in varying degrees of extension; 
     FIG. 11 is a reversed sectional side view of the other of the handles of the compound tool with the supplemental tools stored therein in varying degrees of extension; 
     FIGS. 12 and 13 show side views of the two plier jaws separated and facing one another; 
     FIG. 14 is a side view of one of the jaws of the pliers from the outside as seen along the lines  14 — 14  in FIG. 12; 
     FIG. 15 is a side view of the jaw of FIG. 14 from the inside as seen along the lines  15 — 15  in FIG. 12; 
     FIG. 16 is a front end view of the jaw of FIG. 14 as seen along the lines  16 — 16  in FIG. 12; 
     FIG. 17 is a sectional, cross-sectional view of the laminated structure of the plier jaws as seen along the lines  17 — 17  in FIG. 12; and 
     FIG. 18 is an enlarged side view of a preferred embodiment of a rivet used with the plier jaws of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A preferred embodiment of a multi-purpose folding tool, combination tool, compound tool of the present invention is indicated generally by reference numeral  10  and is seen in its opened or unfolded state in FIG.  1  and its closed or folded state in FIG.  6 . When opened, it has the overall form of a pair of pliers. When closed, tool  10  is box-shaped and occupies a relatively small amount of space with relatively smooth external surfaces. 
     For the sake of clarity in the drawings, the reference numerals in FIGS. 1-6 have been placed on a figure only if a particular feature is most clearly shown in that figure. In other words, including reference numerals for all of the features shown in each figure has been avoided in the interest of clarity. 
     In FIG. 1, compound tool  10  is shown in the form of a cross-jawed pliers  12  comprising a gripping end  14  and a handle end  16 . Gripping end  14  includes a pair of plier jaws  18  and  20 ; handle end  16  includes a pair of handles  22  and  24 . Pliers  12  are cross-jawed pliers inasmuch as jaw  18  is connected across a pivot pin  26  to handle  24  and jaw  20  is connected across pivot pin  26  to handle  22 . Pliers  12  preferably comprise needlenose pliers, and, while this is the preferred embodiment, any other plier shape could be substituted. 
     As seen in FIGS. 4,  12 , and  13 , jaw  18  is functionally divided into a nose  28 , a bearing  30 , and a tang  32 . Jaw  20  is preferably although not necessarily a mirror image of jaw  18  and also comprises a nose  34 , a bearing  36 , and a tang  38 . Jaw  18  and jaw  20  are rotationally joined together by aligning apertures  40  and  42  in bearings  30  and  36 , respectively, and extending pivot pin  26  therethrough (FIGS.  1  and  4 ). Jaws  18  and  20  present opposing, generally flat surfaces  44  and  46  for gripping flat objects, arcuate surfaces  48  and  50  for gripping round, square, or hexagonally shaped objects, and cutting surfaces  52  and  54  for cutting materials such as wire, all as is well known in the art. Surfaces  44 - 50  may be serrated as desired to improve their gripping abilities. The remaining features of jaws  18  and will be introduced as they arise in the following description of the invention. 
     Returning to FIG. 1, handle  22  is pivotally attached to tang  38  of jaw  20  by a pivot pin  56 , while handle  24  is pivotally attached to tang  32  of jaw  18  by a pivot pin  58 . Pins  56  and  58  extend through a pair of apertures  60  and  62 , respectively, formed in tangs  38  and  32  (FIGS.  12 - 13 ). 
     Pivot pins  26 ,  56 , and  58  are parallel and extend generally outwardly from the plane of the drawings, providing rotational movement thereabout in the plane of the drawings. This is an important feature for it provides the pliers  12  of the present invention with more structural stability than prior art compound tools in which the plier jaws fold into the handles along axes perpendicular to the plier&#39;s pivot, such as round in Collins et al., U.S. Pat. No. 5,062,173, and Frazer, U.S. Pat. No. 5,267,366. 
     The structure of handles  22  and  24  are best seen in the perspective views of FIGS. 1 and 2 to which attention is now directed. Common features in each handle will be given the same reference numeral for simplicity and clarity of description. 
     Handles  22  and  24  are channel shaped with each handle being formed by a pair of upstanding sidewalls, namely by an interior sidewall  64  and an exterior sidewall or outboard wall  66 , which are connected by a web  68 . (“interior” and “exterior” are relative terms and are used here with reference to the views in FIGS. 1-3, where compound tool  10  is shown in its opened state. In the closed state of FIGS. 4-6, the relationship between “exterior” and “interior” obviously reverses.) Sidewalls  64  and  66  and web  68  define an internal channel  70  partially open toward the bottom of tool  10 , as seen in FIG. 2. A partial web  72  (FIG. 2) is folded and extends integrally from the pivot end of sidewall  64  towards the pivot end of sidewall  66 , thereby effectively enclosing the pivot end of channel  70  in a box-beam construction which further strengthens the handles  22  and  24  of pliers  12 . The sloped edges  74  of partial webs  72  increase the torsional strength of handles  22  and  24 . 
     Prior art compound tools which also include channel-shaped handles for housing supplemental tools, such as Leatherman, (U.S. Pat. Nos. 4,238,862, 4,744,272, and 4,888,869), European Patent Application 513,937, Collins et al. (U.S. Pat. Nos. Des. 368,634 and 5,062,173), Sessions et al. (U.S. Pat. Nos. 5,142,721 and 5,212,844), and Frazer (U.S. Pat. Nos. Des. 368,634 and 5,267,366), show U-shaped channels throughout the length of their handles. Since the foregoing do not have the enclosed, box beam construction of the handles of the present invention, they lack the torsional resistance required when twisting pliers  12  against a heavy load. 
     Channel  70  houses a plurality of supplemental tools  76  (FIG. 2) which may be stored therein and retrieved therefrom. More particularly, sidewalls  64  and  66  and webs  68  and  72  leave an opening to channel  70  through which supplemental tools  76  may be rotated about a pair of pivot pins  78  (that extend between the ends of sidewalls  64  and  66 ) from their stored positions shown in FIG. 2 to their extended positions, some of which are shown, for example, in FIGS.  8 A and  9 - 11 . 
     As seen in FIG. 2, channel  70  opens toward the bottom of tool  10 , in contrast to the side tool openings shown in so many of the prior art compound tools mentioned above, so supplemental tools  76  of the present invention are facing away from the palm of the hand when pliers  12  are being used. Sidewalls  64  and  66  and webs  68  of handles  22  and  24  are solid sheets, so that there are no rough surfaces or standing handle edges to cause discomfort to one&#39;s hand when squeezing handle end  16  of the present invention. A plurality of raised, rounded nubs  80  or various other configurations may be added to exterior sidewalls  66  to improve the user&#39;s grip on handles  22  and  24  without adding potentially painful sharp edges. 
     Referring to FIGS. 3-6, the shape of handles  22  and  24  provides important functional results which distinguishes the present invention from the prior art. More particularly, as seen in FIG. 3, webs  68  of handles  22  and  24  include a tapered portion  82  positioned between two portions having substantially constant widths, namely, a wider end portion  84  adjacent end  86  and a narrower waist portion  88  adjacent pivot bearing  90 , to delineate a pair of recesses or jaw recess portions  92  positioned on exterior sidewalls  66 . 
     The disclosed shape allows for many advantages. First, recesses  92  afford a very comfortable nesting area for the thumb and fingers to grip pliers  12 . Second, recesses  92  combine to provide an area for storing plier jaws  18  and  20  when compound tool  10  is fully closed, as seen in FIG.  6 . Tapered portions  82  are dimensioned and located so as to complement the shape of a pair of tapered portions  94  formed on plier jaws  18  and  20  (FIGS.  3  and  12 - 13 ); the smaller, constant width waist portion  88  mates with a pair of flat sides  96  of plier jaws  18  and  20 ; and the curved portion  89  between waist portion  88  and annular bearing  90  snugly fits around annular bearings  30  and  36 . Third, external recesses  92  store gripping end  14  of the pliers  12  externally of the handles&#39; walls, leaving more interior room in the handles for supplemental tools  76 . Fourth, storing the gripping end  14  externally of compound tool  10  allows pliers  12  to be used to clamp items, hands-free, for an extended period of time, as will be seen in FIG. 7 to be discussed in greater detail below. 
     FIGS. 3-6 illustrate the manner in which pliers  12  fold into the closed state of compound tool  10 . Handles  22  and  24  are pulled apart, as in FIG. 3, until a pair of outer shoulders  98  (FIGS.  3  and  12 - 13 ) come into contact with vertical portions of shoulders  104 , at which time jaws  18  and  20  cease to diverge. Further outward pressure on handles  22  and  24  overcomes the inherent friction between handles  22  and  24  and tangs  32  and  38 , and the plier&#39;s handles  22  and  24  begin to converge, as seen in FIG. 4. A pair of tip portions  100  of jaws  18  and  20  are substantially separated from each other in their fully open position, as shown for example in FIGS. 4 and 5. Further movement of handles  22  and  24  towards one another results in the orientation of handles and jaws as shown in FIG.  5 . In this orientation, tips  100  of jaws  18  and  20  contact tapered surfaces or contact portions  82  of exterior (now interior) sidewalls  66  which cam the jaws  18  and  20  together, also forcing tangs  32  and  38  and handle bearings  90  towards one another. Continued pressure brings compound tool  10  finally to the fully closed position shown in FIG.  6 . In the latter position, tip portions  100  touch each other. 
     Referring again to FIGS. 3,  12 , and  13 , when squeezing pliers  12  together from the FIG. 3 position to seize an object, edges  102  at the pivot end of interior sidewalls  64  adjacent bearings  90  are in contact with shoulders  104  of tangs  32  and  38  (FIGS.  12 - 13 ). The forces generated by squeezing handles  22  and  24  are directed from edges  102  through shoulders  104 , which, being offset from their pivot pins  26 ,  56 , and  58 , applies a force rotating jaws  18  and  20  of pliers  12  together. Each of the interior sidewalls  64  is a relatively planar, solid sheet which is integrally connected with web  68  and sidewall  66 . With the force vectors essentially lying within the plane of sidewalls  64 , a very stable structure is provided which can withstand high clamping pressures. 
     One use of tool  10  to clamp items like a vise is shown in FIG. 7. A multi-strand cable  106  is clamped in jaws  18  and  20  with tool  10  in a semi-closed state. An aperture  108  is preferably formed through web  68  of handle  24  and is adapted to receive, when desired, a lanyard  110 . Lanyard  110  provides a convenient way to carry tool  10  on a belt or back-pack. It also allows tool  10  to clamp cable  106 , or other desired item, by closing tool  10  with cable  106  between the jaws  18  and  20  of pliers  12 , and by wrapping lanyard  110  tightly around handles  22  and  24 . Tool  10  will continue to clamp cable  106  without the necessity of gripping the pliers in one&#39;s hands. As noted above, this advantage is due to the storing of gripping end  14  externally of the handles when tool  10  is closed. 
     Supplemental tools  76  and their relationship to tool  10  will now be described with reference to FIGS. 8-11. 
     The selection of which supplemental tools to include in any particular model of tool  10  is discretionary with the manufacturer of tool  10 , depending on its intended audience. For example, a fisherman&#39;s tool might include supplemental tools useful for fishing, e.g., a serrated blade for cleaning fish, a whetstone for sharpening fish hooks, scissors for cutting line, and an assortment of knife blades, whereas an electrician&#39;s tool might include an assortment of screwdrivers, a wire insulation cutter and stripper, a saw, a file, and a ruler. The supplemental tools included in this preferred embodiment are therefore only exemplary of the possibilities. 
     Referring first to FIG. 10, a side view of a section of handle  22  is shown with five supplemental tools  76 : a bottle/can opener  112 , a Phillips head screwdriver  14 , a scribe  116 , a clip blade  118 , and a file  120 . FIG. 11 shows the other handle  24  with five additional tools: a small screwdriver  122 , a combination large screwdriver/wire stripper  124 , a scraper  126 , a sheepfoot blade  128 , and a ruler  142 . The supplemental tools  76  have been rotated to varying degrees of extension to illustrate them better; they would not normally be used as shown. Normally, only one supplemental tool  76  would be extended at any given time. For example, when one needs to use Phillips head screwdriver  114 , it would be extended alone (as shown in the lower portion of FIG.  8 A). Tool  10  should be closed, as in FIG. 8A (note the location of nubs  80 ), to provide a hefty handle for the screwdriver. 
     FIG. 8A is a partial top view of the ends of handles  22  and  24  intended to illustrate, along with FIGS. 8B,  8 C,  9 A and  9 B, the operation of the latching and locking mechanism of the present invention. It should be understood that in FIG. 8A, both screwdriver  114  and ruler  142  are shown extended from their respective handles  22  and  24 ; however, during actual use, only one such tool will be normally extended at any given time. 
     As shown in FIGS. 6 and 8A, webs  68  of handles  22  and  24  each include a resilient tongue  132  integral with and cantilevered from web  68 . Tongue  132  is separated from sidewalls  64  and  66  by slits  133 , and, being free from contact with handles  22  and  24  except where joined to web  68 , tongue  132  comprises a leaf spring which is free to flex when deflected. A pair of recesses  134  inwardly and oppositely extend at the side junction between tongue  132  and web  68  to aid in the flexibility of tongue  132 . A rectangular aperture or slot  136  is formed adjacent the free end portion  137  of tongue  132  and is bordered by two side strips  138  and a transverse stock or latch  140 . Stock  140  has an outer edge  158  defining the outer edge surface of free end  137 , and an interior edge surface  157  defining the locking edge surface of slot  136 . Flat tongue  132 , flat stock  140 , and flat web  68  are essentially coplanar when tongue  132  is in its at-rest, unflexed state. Compare FIGS. 10-11 where tongue  132  is at rest with FIGS. 9A-9B where tongue  132  has been deflected into its flexed state. 
     Ruler  142  (FIGS. 8A and 8B) is typical of a supplemental tool  76  mounted on pivot pin  78  outboard of the other tools in handle  24  and, therefore, in alignment with one of the side strips  138 . File  120  is another such outboard mounted supplemental tool which is, however, located in the other handle  22 . Ruler  142  (FIG. 8B) includes a tool body  144  and a mounting end or shank  146 . Tool body  144  is unique to the type of tool  76  included in compound tool  10  and includes whatever working surfaces are important to that particular tool. Mounting end  146  is constructed substantially the same as the mounting end of other outboard-mounted supplementary tools, such as file  120 . Mounting end  146  includes an aperture  148  for receiving pivot pin  78  and a camming surface  150  having a first flat  152  formed adjacent a stop  154  and a second flat  156  positioned diametrically opposite to first flat  152 . The radial width of camming surface  150  is slightly more than the distance between pivot pin  78  and tongue  132 , whereas the radial width of flats  152  and  156  are substantially equal to that distance. 
     In operation, when ruler  142  is in its fully extended position in longitudinal alignment with handle  24  (as shown in FIG. 8A, or when file  120  is in its fully extended position as shown in FIG.  9 A), flat  152  is flush with the unflexed tongue  132 , and stop  154  is in contact with outer edge  158  of stock  140 . Stop  154  and edge  158  prevent ruler  142  (and any other similar supplemental tool such as file  120 ) from rotating beyond its alignment with handle  24 . The flex-resisting force of tongue  132  urges stock  140  against flat  152  and thus biases ruler  142  and file  120  toward their fully extended positions, not preventing closure thereof but requiring an additional force be applied to overcome the bias. As such, ruler  142  and file  120  will be latched, as opposed to being positively locked (as some of the interior tools can be which will be described in greater detail shortly). 
     When in its closed position, housed within channel  70  of handle  22 , file  120  is biased to its closed position by resilient tongue  132  pressing on flat  156 , effectively holding file  120  in place. When being closed from its fully open position, as indicated by arrow A in FIG. 9A, camming surface  150  flexes tongue  132  (arrow B in FIG. 9A) slightly outwardly from the plane of web  68 . If flats  152  and  156  were not of slightly less radial distance from pivot pin  78  than the remainder of camming surface  150 , file  120  might not be held in its closed and extended positions, but could flop about uncontrollably. 
     File  120  and ruler  142  are merely illustrative of outboard mounted tools, or possibly an inboard mounted tool, which do not need to be positively locked in their open, extended positions. Clip blade  118  (FIG. 8C) is illustrative of an inboard mounted supplementary tool which needs for safety reasons to be positively locked in its open, extended position. 
     Clip blade  118  is shown having a body  144  appropriate to its function. Included in body  144  of clip blade  118  is a nail nick  159  to facilitate opening of clip blade  118 . Some outboard tools, such as file  120  and ruler  142 , have a notch  160  on their top edge when they are closed, to allow access to interior tools having nail nicks  159 , such as bottle/can opener  112 , scribe  116 , clip blade  118 , large screwdriver/wire stripper  124 , and scraper  126 . Handles  22  and  24  likewise include notches  162  (FIGS. 1,  9 A and  10 ) for the same reason. 
     The mounting end or shank  146  of clip blade  118  includes a pivot pin aperture  148 , a camming surface  150 , and a flat  156 , all of which may be provided for the same purposes as described in connection with ruler  142 . Mounting end  146  of clip blade  118  differs, however, from those of non-positively locked outboard tools in that in place of flat  152  and stop  154 , mounting end  146  of clip blade  118  has a U-shaped locking transverse notch or keeper  164  located to mate with stock or latch  140  of tongue  132 . 
     As with all other supplemental tools  76 , clip blade  118  is preferably biased toward its closed position by tongue  132  acting upon flat  156 . As clip blade  118  is rotated about pivot pin  78  (opposite to arrow A in FIG. 9A) to its open position, tongue  132  flexes (arrow B), because it is riding on the radially enlarged camming surface  150 , until stock  140  snaps into U-shaped notch  164  of clip blade  118 . 
     The width of aperture  136  (the smaller of its rectangular dimensions) is preferably large enough to enclose the portion of camming surface  150  that is located to the right of notch  164  as viewed in FIG. 8C in order to prevent the camming of stock  140  out of notch  164  by camming surface  150 . Other than that, the dimensions of aperture  136  are not significant except for structural considerations. 
     The width of stock  140  (the smaller of its rectangular dimensions) is critical, however. It must be such that stock  140  fits snugly in notch  164 . Stock or latch  140  will remain in notch or keeper  164  until positively, forcibly removed. Before that occurs, therefore, clip blade  118  is positively locked in place. When tool  144  is in its extended open state, the upstanding edge surfaces  165  and  167  (FIGS. 8A and  8 C) of U-shaped notch  164  abut edge surfaces  158  and  157 , respectively, of stock  140 . The coaction of edge surfaces  158  and  167  prevents rotation of tool  144  in one direction, thereby preventing tool  144  from opening beyond the desired extended position. The coaction of edge surfaces  157  and  165  prevents rotation of tool  144  in the other direction, thereby preventing tool  144  from unintentionally closing, i.e., leaving the desired extending position. 
     The locking mechanism described herein is a radical departure from prior art locking mechanisms, and has profound benefits associated therewith; as such it is an important feature of the present invention. 
     Bassett (U.S. Pat. No. 2,798,290) is representative of prior art patents which utilize a transverse slot or a leaf spring, but not both together, in the handle of a compound tool as part of a locking mechanism for tools. Bassett&#39;s knifeblade  41  has a detent lobe  28  on the peripheral surface of its mounting end. Locking of blade  41  is effected by a radially projecting, smoothly arcuate lobe  28  either “engaging slot 42 with detent action (FIGS. 6-7, and column 3, line 72 of Bassett) or being allowed to flex leaf spring 29 “to assume a position on spring  29  past dead center” (FIGS. 1-3, column 3, lines 30-31 of Bassett). In the former, lobe  28  includes an arcuate camming surface which bends the edges of slot  42  in fixed base  43 , when lobe  28  is being placed therein or removed therefrom; there is no leaf spring involved. In the latter, there is no notch for lobe  28  to enter; leaf spring  29  merely provides a bias for an over-dead-center latch. In any event, a projection on mounting end  146  is not equivalent to a notch  164  being formed therein. Provision of a radial projection on the mounting end requires a reduction in the radial width of the annular ring surrounding the pivot pin which provides the structural support for the blade; a notch does not remove any material except to form the relatively small notch. 
     Prior art locking mechanisms which include a locking aperture in the housing include a projection on the blade to enter the locking aperture. Those members of the prior art which utilize a notch in the blade also traditionally provide a projection which fits in the notch to lock the blade, e.g., an L-shaped flange on the end of a separate element. Representative of this time-honored class, which are legion, are Barnard &amp; Brace, U.S. Pat. No. 97,154, issued in November of 1869, and Evrell, U.S. Pat. No. 4,669,188. The addition of the extra locking element decreases the number of supplemental tools which can be housed in the tool while increasing the number of elements required for a functional tool and concomitantly the manufacturing costs. 
     A few patents, e.g., Hallvarson, U.S. Pat. No. 1,556,788, and Leatherman, U.S. Pat. Nos. 4,238,862 and 4,888,869, include a resilient spring on the housing with an L-shaped flange on the outer edge of the resilient spring that serves as a latch to lock within a notch that serves as a keeper in the blade. This is in line with the conventional wisdom of the art, for it perpetuates the teachings of the prior art to include a projection or lug for entering the notch. 
     Referring back to the present invention, the release means for the locking mechanism is illustrated in FIGS. 9A-9B. At least two of the supplemental tools  76 , one in each handle, shown as scribe  116  in FIGS. 9A,  9 B, and  10 , and scraper  126  in FIG. 11, have a depressable portion preferably in the form of a bulge  166  on their upper surfaces which protrudes above the open side edges  170  of sidewalls  64  and  66  when tools  76  are closed. Manual depression (arrows C, FIGS. 9A-9B) of bulge  166  into the handle  22  rotates scribe  116  counter-clockwise (as viewed in FIGS. 9A-9B) about pivot pin  78 , until the leading edge or corner protrusion portion  168  of peripheral portion or flat  156  depresses and deflects tongue  132  downwardly, thereby lifting stock or latch  140  out of the notch or keeper  164  of an extended tool. This means of release does not necessarily need to be incorporated into a supplemental tool but would function equally as well as a single function release lever. The combination of a supplemental tool and a release lever into one component, however, adds utility to the compound tool. By way of comparison with the prior art, Leatherman (U.S. Pat. No. 4,238,862; FIG. 6) shows a locking mechanism for a supplemental tool in which flange  90  on tongue  86  detents into notch  91  on the tool mounting end. Leatherman releases the lock by “partially opening one of the other tools on pivot pin 70 causing its cam surface 87 to retract the flange 90 out of notch 91” (column 7, lines 32-35). The preferred embodiment of the instant invention constitutes a major improvement over this prior art by: (1) eliminating the flange, as discussed above; and (2) by depressing another tool rather than partially opening one. In particular, depressing a tool, rather than partially opening it, has significant advantages. Depression of a closed tool requires no more than one hand or thumb squeezing the tool handle until bulge  166  descends below the open side edges  170  of sidewalls  64  and  66 , where it will stop, keeping the tool within the handle. In contrast, partially opening a tool to release a locking mechanism (Leatherman) requires two hands, one to hold the handle and the other to grasp and lift the tool. As just alluded to, depressing the tool keeps it in the handle, out of the way, whereas opening a tool places it outside the handle where it is at least inconvenient and could be potentially dangerous (e.g., if it had a sharp point or edge). 
     An important feature of the present invention is the laminated construction of the plier jaws, illustrated in detail in FIGS. 14-17, where the same reference numerals used in FIGS. 12-13 identify the same features. 
     In FIGS. 14-17, jaw  18  is shown as comprising a central body  172  laminated with two outer strips  174  and  176 . FIG. 17 is a sectional view of jaw  18  (taken along lines  17 — 17  of FIG.  12 ), wherein central body  172  and outer strips  174  and  176  are not shown to scale; in practice, central body  172  is much thicker than outer strips  174 ,  176 , closer to the illustrations of FIGS. 14 and 15. As seen in FIG. 17, central body  172 , being the heftier of the pieces, includes countersinks  178  which mate with daps  180  formed in outer strips  174  and  176 . Countersinks  178  and daps  180  are preferably circular, but any convenient shape will do so long as they mate snugly. The countersink/dap combination prevents lateral sliding of the two outer strips relative to the central body and maintains the pieces in their relative orientations. Central body  172  and outer strips  174  and  176  can be secured together by any known means which is not detrimental to the use of pliers  12 . A preferred method of securing the laminates (body  172  and outer strips  174  and  176 ) utilizes rivets  182 , countersunk at  184  (FIG.  18 ), to provide added strength and to positively prevent separation of the laminates. 
     The laminated central body  172  and outer strips  174  and  176  are shaped as plier jaws as shown in FIGS. 14-16, jaw  20  being a mirror image of jaw  18 , though some other shape, if advantageous, could be desirable. Central body  172  extends the full length of jaw  18  from tip  100  through bearing  32 . Outer strip  176  extends similarly except that its forwardmost portion  187  does not extend as far as tip  100 . Outer strip  174  terminates at its lower end at recess  186  adjacent bearing  30  which receives bearing  36  from jaw  20 , when the two jaws are rotatably joined by pivot pin  26 . The upper end of outer strip  174  terminates in a tip  187  that is the same as the uppermost tip of outer strip  176 . Tip  100  of central body  172  is tapered on both sides thereof as at  188 . Similarly, tips  187  of outer strips  174  and  176  are each tapered on both sides thereof as at  189 . Taken together with the outer taper  94  of jaws  18  and  20  (FIGS.  12 - 13 ), the net effect is that jaws  18  and  20  comprise a pair of needlenose pliers. This needlenose effect is enhanced by having the tips  187  of outer strips  174  and  176  terminate rearwardly of tip  100 , as previously described. 
     The laminated construction of plier jaws  12  as shown and described above is believed to be significantly stronger than non-laminated plier jaws. 
     It is clear from the above that the objects of the invention have been fulfilled. 
     Those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention as defined in the appended claims. 
     Further, the purpose of the foregoing Abstract is to enable the U.S. Patent and Trademark Office, and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The Abstract is neither intended to define the invention of the application, which is measured solely by the claims, nor is intended to be limiting as to the scope of the invention in any way. 
     It can be seen from the above that an invention has been disclosed which fulfills all the objects of the invention. It is to be understood, however, that the disclosure is by way of illustration only and that the scope of the invention is to be limited solely by the following claims.