Abstract:
A hand tool that is automatically self-adjusting by alternately squeezing and relaxing the hand grid on the two handles; that has constantly parallel jaws at any adjustment; that actually grips the work object with at least an 8-to-1 compound gripping leverage; and that can be locked onto an object when desired with a selectively light or strong grip. All of the operations, except the resetting the adjustable jaw to a wide open position, can be done with just the hand holding the tool and it can be made in the form of an adjustable plier, an adjustable wrench, or an adjustable pipe wrench, plus many other applications.

Description:
This is a CIP of 08/089,764, filed Jul. 7, 1993, abandoned. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to hand tools in general, and more particularly to a tool that grips a work object, is automatically self-adjusting, can be locked on the work object easily and quickly, and can be released from the locked position just as easily and quickly. 
     BACKGROUND 
     This invention is an improvement over the hand tools contained in U.S. Pat. No. 5,176,049 issued to applicant on Jan. 5, 1993, entitled &#34;COMPOUND LEVERAGE GRIPPING TOOL WITH CONSTANTLY PARALLEL JAWS&#34;. 
     The improvement consists of a combination of all the outstanding features contained in the above referenced documents to provide a single tool having all of those features as follows: (a) can be adjusted quickly and automatically; (b) constantly parallel jaws; (c) can be used in a fast, ratchet-like manner; (d) can be locked on an object very simply and effectively; and (e) can automatically be released from a locked position by just squeezing the two handles. 
     A locking tool and numerous copies of it have been on the market for over 50 years, but they have a number of disadvantages not present in the instant invention. The dominant locking tool is contained in U.S. Pat. No. 2,280,005, issued to Petersen Apr. 14, 1942. The locking means utilized in the present invention is superior to that used by Petersen and his copiers as will be obvious from the description and claims presented herein. 
     The first of these disadvantages is the manner in which the jaws are adjusted to an object. In making such an adjustment, a threaded screw is located in the extreme end of one of the handles. In order to adjust the jaws to an object, this screw must be turned inward to widen the jaw gap and outward to narrow the jaw gap, a procedure that must be done several times before the proper jaw gap is obtained. For every object of a different size, the jaws must be adjusted precisely in order for the locking operation to satisfactorily take place. This results in a tedius and time-consuming operation. 
     A second disadvantage occurs when the tool is adjusted so that the lock is extremely tight on a work object. When this occurs, it is very difficult to squeeze the release mechanism hard enough to effect the release, and very often the handles fly apart very abruptly and can injure the user&#39;s fingers and cause him to drop the tool. 
     A third disadvantage lies in the fact that the tool is difficult, if not impossible, to use as common ordinary pliers or wrench because the spring attached to the pivoting adjustable jaw and to the handle containing the fixed jaw urges the handles to spring apart and spread the jaws out of position for the job at hand as the jaws cannot maintain a fixed opening without being locked. This feature not only is frustrating to the operator, but is also time-consuming. 
     Other attempts have been made to eliminate the screw adjustment of the basic patent issued to Petersen, but they have all been failures as the Petersen tool is still the predominent tool in this field after more than fifty years. For example, the U.S. Patent issued to Westby etal, U.S. Pat. No. 3,208,319, Sep. 28, 1965, which has a large number of parts that would be difficult to make and assemble, plus having a cam lever or an adjusting screw projecting outwardly from one or the other of the two handles, presenting a very uncomfortable grip for the user. 
     Another example is U.S. Pat. No. 3,793,914, Feb. 26, 1974, issued to Helms, which has a finger tab 43 projecting outwardly from one of the handles, presenting the same problem as the Westby etal invention. 
     Another disadvantage found in all three of the inventions discussed above is that they all have jaws that &#34;scissor&#34; in order to open and close them on an object, which means that there is only one point in the adjustment range of the jaws where they are parallel to each other in the optimum gripping position. 
     As can be seen, no such proliferation of parts or disadvantages exist in the present invention. 
     Accordingly, several objects and advantages of the present invention are to provide: 
     (a) a hand tool that can be operated with a fast, ratchet-like action without the use of a standard ratchet mechanism, and which can be locked on an object of round, square, hexagonal, or irregular shape; 
     (b) a hand tool of various jaw configurations having a compound gripping leverage ratio of at least 8-to-1; 
     (c) a hand tool that has jaws which are always in parallel alignment throughout their entire adjustment range; 
     (d) a hand tool that automatically adjusts the jaw gap by the squeezing and relaxing of the grip pressure on the handles; 
     (e) a hand tool whose jaws can easily be locked on an object with either a light or a strong grip at the choice of the operator with just a flick of the thumb of the hand holding the tool; 
     (f) a hand tool that can be released from said locked position automatically by just squeezing the two handles together; 
     (g) a hand tool that can be operated as an ordinary plier or wrench without interference or problems caused by the adjusting, locking, or releasing mechanisms; and 
     (h) a hand tool as described that can be produced and sold economically to a wide spectrum of the population. 
     Other objects and advantages appear in the combination of the elements, arrangement of the various parts, and unique features of construction and usage which will be pointed out more fully hereinafter and disclosed in the accompanying drawings and detailed description wherein some preferred forms of the invention are presented. 
     It will be understood that these preferred forms are for illustration purposes only and the invention is not necessarily limited to such, but may be adapted and used for any purpose for which it is found to be suitable. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view of the front side of a first preferred embodiment in the form of a plier having serrated jaws with the gripping jaws fully closed and the locking pawl engaged. 
     FIG. 2 is a plan view of the tool in FIG. 1 with the gripping jaws fully open and the locking pawl disengaged. 
     FIG. 3 is a plan view of an edge, or bottom side, of the tool as shown in FIG. 2. 
     FIG. 4 is a portion of the first preferred embodiment with the adjustable jaw in section and the handles cut away. 
     FIG. 5 is another portion of the tool of the first preferred embodiment, partly in section, showing the locking mechanism unlocking with the jaws and handles cut away. 
     FIG. 6 shows a portion of a second preferred embodiment in the form of an adjustable wrench having straight smooth jaws, with the handles cut away. 
     FIG. 7 shown in a portion of a third preferred embodiment of the invention in the form of a pipe wrench, with the handles cut away. 
     FIG. 8 shows a portion of a fourth preferred embodiment of the invention as applied to a wrench having V-shaped jaws, with the handles cut away. 
    
    
     DETAILED DESCRIPTION 
     In the drawings: 
     FIGS. 1, 2, and 3 show one of the preferred embodiments of the invention in the form of a pliers having a body 10, a fixed serrated jaw 12, and a fixed handle 14. A bifurcated adjustable jaw 16 straddles a rail section 18 on body 10, and is held thereon by a pin 20. Pin 20 is attached to adjustable jaw 16 and is slidably mounted in an elongated slot 22. 
     A leaf spring 24 is attached by a lower end 26 to an inner wall 28 of a bifurcated section 30 on adjustable jaw 16, and its upper end 32 bears forcefully against rail section 18, pushing the upper portion 34 of adjustable jaw 16 away from rail section 18 and the lower portion 36 toward gear teeth 44 on pivoting handle 38. Spring 24 also holds jaw 16 in a stationary position by frictional contact with rail 18 until moved by the pivoting of handle 38 or until jaw 16 is pulled away from rail 18 to reposition jaw 16 away from fixed jaw 12. 
     Pivoting handle 38 is bifurcated in a similar manner to jaw 16 and straddles body 10, being held thereon by a pivot pin 40. A jacking action that quickly moves jaw 16 toward jaw 12 is accomplished by the shade of gear teeth 42 on adjustable jaw 16 and gear teeth 44 on pivoting handle 38. Both sets of gear teeth have long flat sides 46 and 48, and shorter flat sides 50 and 52. As pivoting handle 38 is moved away from fixed handle 14, the long flat sides 48 on gear teeth 44 slide down the long flat sides 46 on gear teeth 42 while the adjustable jaw 16 is held stationary by the friction of spring 24 against rail section 18 until gear teeth 42 and 44 are reengaged at a lower position on adjustable jaw 16. The pivoting of handle 38 back toward handle 14 brings short sides 50 and 52 into contact and, because of their relatively obtuse angle in relation to rail section 18, remain engaged until the movement of handle 38 is again reversed, thereby moving adjustable jaw 16 toward jaw 12 in a series of jacking movements. This action is repeated rapidly and closes jaws 16 and 12 on an object very quickly in just a few seconds. 
     The travel of pivoting handle 38 away from fixed handle 14 is limited by the length of spring 54 between the two handles and by the depth of the bifurcation in handle 38 so that the jaws of the tool will not inadvertently change their gap adjustment if the tool is temporarily laid down during a pause in the job at hand. 
     To reset adjustable jaw 16 to an open position in relation to fixed jaw 12, raised knobs 56 and 58 are grasped and the lower portion of jaw 16 is pulled outward and downward in a single motion which disengages gear teeth 42 and 44. While disengaged, jaw 16 may be set at any point between the top and bottom of its travel within the confines of elongated slot 22 and reengaged at the option of the user. 
     FIG. 4 shows the internal construction of the adjustable jaw 16 and the position of the leaf spring 24 attached to inner wall 28 of the bifurcated section. 
     FIG. 5 shows the mechanism and parts thereof that perform a preferred locking and unlocking operation. A yoke 60 extends outwardly from pivoting handle 38. An arm 62 is attached to yoke 60 and held in place by a pin 64. Arm 62 extends freely through a channel 66 in fixed handle 14. A pawl 68 is disposed within channel 66 and pivotably held in position by a pin 70. Pawl 68 has a tooth 72 which is manually engaged with serrations 74 on one edge of arm 62 by turning lever 80 in a clockwise direction. This action locks arm 62 tightly between pawl 68 and wall 82 of channel 66. A spring 84 has one end attached to pawl 68 and the other end to a pin 86 in handle 14 and is biased to pull bawl 68 in a counter-clockwise direction to keep pawl 68 from inadvertently engaging serrations 74 during the normal usage of the tool. Spring 84 is also used to release jaws 12 and 16 from a locked position on an object. This is accomplished by again squeezing handles 14 and 38 tightly together and releasing the frictional contact between Pawl 68 and serrations 74, thereby activating spring 84 which pulls pawl 68 out of contact with serrations 74. 
     FIG. 6 shows a portion of a second preferred embodiment of the invention in the form of an adjustable wrench having straight smooth jaw gripping surfaces 88 and 90 primarily for use in turning nuts and bolts. 
     FIG. 7 shows a portion of a third preferred embodiment of the invention as applied to an adjustable pipe wrench having pipe gripping jaw surfaces 92 and 94 distinguished by much larger teeth than those of the plier embodiment. In this embodiment, the tool can automatically be adjusted to any pipe, pipe connection, or other object within its jaw capacity and operated with the same advantages offered by the other preferred embodiments presented herein. As far as is known or can be determined, no other pipe wrench is capable of being operated in this manner. 
     FIG. 8 shows a fourth preferred embodiment of this invention with the jaws 96 and 98 in the form of opposing V&#39;s with the corners having small radiused recesses to prevent the jaws from contacting the corners of hexagonal fittings, especially those made of materials that are softer than steel such as brass, copper, aluminum, and plastic. 
     All of the actions required to adjust the various embodiments of the tool rapidly to an object, lock the jaws on an object, and release the jaws from the locked position can be accomplished with just the hand holding the tool. The only operation requiring the use of a second hand is the opening of the jaws, which can be done very quickly in about one second. 
     OPERATION OF THE ADJUSTING MECHANISM 
     The adjustable jaw can be jacked toward the fixed jaw to grip an object in increments of one, two, or three gear teeth at a time by hooking the fixed jaw over the object and controlling the distance the pivoting handle is pivoted outward away from the fixed handle. A short distance will move the adjustable jaw one gear tooth closer to the fixed jaw, a medium distance will move it two gear teeth closer, and a longer distance will move it three gear teeth closer at the option of the operator, depending on the size of the work to be gripped. For example, a larger item with the jaws in the widest jaw gap will not need any adjustment by the jacking action, a slightly smaller object may require one gear width of movement, a medium-sized object may require two or three gears of movement, all of which can be done with just one swing of the pivoting handle. For smaller objects, two swings of the pivoting handle will be required to cover 4, 5, and 6 gear teeth, and finally, three swings will be required to move the adjustable jaw 7 and 8 gear teeth. These movements may all be done very rapidly. 
     OPERATION OF THE LOCKING MECHANISM 
     The locking mechanism is activated by first adjusting the adjustable jaw against the work object as described above. The handles are then squeezed tightly together and the locking pawl, by means of the pawl lever, is engaged with the serrations on the locking arm with the thumb of the hand holding the tool and the handles are then released. The jaws will remain locked tightly on the work object until the release mechanism is activated by again squeezing the handles tightly together which permits the pawl spring to pull the pawl out of engagement with the serrations on the locking arm.