Abstract:
The pair of cutting blades are pin joined to each other at their terminal webs which are joined to bow handles. A ball bearing is mounted to the pivot pin by way of an antifriction spacer for providing a permanent spacing between the terminal webs in order to prevent the same from abrasion and consequent uneven wear. A clamp is coupled at one end to the pivot pin projecting from one of the terminal webs, and anchored at another end to the other terminal web, in order to bear the component of cutting resistance which tends to spread the pair of blades in opposite directions away from their parallel planes of motion.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     This invention relates generally to scissors inclusive of those commonly classified as shears. More particularly, the invention deals with an abrasion-free, light-action, long-lasting pair of scissors well suited for use in hairdressing salons or barbershops, permitting the hairdressers or barbers to cut and trim hair using the latest, most fashionable techniques, although no unnecessary limitations to this particular application are intended.  
         [0002]     Among the simplest of man-made tools, the pair of scissors consists essentially of two blades, complete with handles, which are medially pin-jointed to each other for pivotal motion in parallel planes. The blades, or their cutting edges to be exact, slide across each other to provide the cutting action when the handles are closed. When cutting, the blades encounter resistance not only in a direction to resist the closing of the handles but, additionally, in a direction to spread the blades in opposite directions away from their parallel planes of motion.  
         [0003]     With the conventional scissors in general, the second recited component of the cutting resistance caused the blades to frictionally engage each other flatwise in limited areas on their terminal webs where the blades are pivotally coupled to each other. These limited areas of the terminal webs, on the handle side of the pivot pin, are herein termed “contact zones” and will be referred to time and again as they are closely associated with the gist of the instant invention. The contact zones delineate arcuate shape, centered about the axis of the pivot pin, as the blades swing in sliding engagement with each other.  
         [0004]     For cutting, therefore, the handles must be pressed toward each other with a sufficient force to overcome the resistance. The cutting edges of the blades will then slide one over the other, with the confronting faces of the blades closely held together, as the contact zones on the terminal webs of the blades are conventionally urged by reaction against each other and slide in frictional interengagement, fully bearing the cutting resistance tending to spread the blades away from their parallel planes of motion. The scissors will thus operate successfully only if a force is exerted thereon that is great enough to defeat the cutting resistance.  
         [0005]     In some instances, however, the manual effort on the handles may fall short of the force demanded by the particular scissors for cutting the particular object, regardless of whether the scissors is being used by some specialist or otherwise. One such instance in the case of specialists manifests itself when the scissors are held in other than the normal fashion by hairdressers or stylists owing to the customs or requirements of their occupations. The cutting edges of the blades may not be urged sufficiently strongly against each other in such cases and so fail to cut smoothly or to cut at all.  
         [0006]     Let us now consider how scissors are being used today by hair stylists or dressers and some barbers. A variety of novel hair styles are being advocated year after year, or season after season, and with them, novel hair cutting methods that match these styles. Currently in vogue among such novel cutting methods are those which involve the speedy flourishing of the scissors for finely trimming the hair. The flourishing of the scissors, however, is counteractive to the manipulation, in the narrower sense of the word, of the scissors which involves the application of a constant closing force on the bows or handles by the thumb and fingers. It is indeed a professional feat to flourish the hand and manipulate the scissors with that flourishing hand as this same hand must be intricately bent and twisted for cutting different parts of the scalp hair at different angles. For proper scissors manipulation, moreover, an application of sufficient compressive forces to the handles by the thumb and fingers is a prerequisite for keeping the cutting edges of the blades in proper sliding engagement with each other.  
         [0007]     A hairdresser confesses that it has not been rare, while practicing the flourishing cutting styles, for him to yank at the customer&#39;s hairs and even pull some off. These mishaps have so far been avoidable only by unfailing exertion of utmost manual, as well as digital, effort on the handles of the scissors, a practice that led infallibly to hand fatigue and inflammation, sore thumb, and stiff shoulders.  
         [0008]     Barbers and hairdressers alike have therefore long awaited the advent of lighter-action, smoother-cutting scissors that meet the requirements of the latest cutting fashions. Japanese Unexamined Patent Publication No. 11-244550, filed by the applicant of the instant U.S. application, represents a conventional attempt at provision of such scissors ( FIGS. 1 and 2  of the drawings attached hereto), which is closest to this invention as far as the applicant is aware. This prior art pair of scissors has a cantilever spring embedded at one end in the handle end of the top blade (i.e. blade with the thumb bow). The other, free end of the cantilever spring is bored to fit over the bolt joining the two blades of the scissors and is urged against the bottom blade (i.e. blade with the bow in which one or more fingers are placed) by the nut on the bolt.  
         [0009]     Thus the handle ends of the two blades, including the noted contact zones, of the prior art scissors are spring-biased into face-to-face sliding contact with each other. No matter how they are used, no matter how wildly they are brandished, the spring-assisted scissors will cut smoothly with the exertion of minimal digital effort on the handles. It is not surprising that this prior art implement is winning acceptance among some hairdressers and barbers.  
         [0010]     There does, however, exist a problem yet unresolved in connection with the prior art spring-assisted scissors above. Sprung against each other, the contact zones of their blades are susceptible to abrasion, as are those of all the more conventional scissors relying on the contact zones for bearing the cutting resistance. The resulting uneven wear of the blades is detrimental to the performance of the scissors. The hairdressers and barbers who currently favor the spring-assisted scissors are certain to find it increasingly more difficult to manipulate them with the lapse of time. This is because, with the progress of abrasion, the contact zones become less and less capable of bearing the cutting resistance, demanding an exertion of more and more manual effort. The scissors with the worn contact zones will offer no such good run, no such even, clear cut without hesitation, as when they were unworn. Of course, the uneven wear of the blades is repairable, or avoidable by periodic reconditioning, but at the costs of considerable time and expenses as the scissors must usually be sent back to the manufacturer for such purposes. Local repair services often prove unsatisfactory or even damaging.  
         [0011]     It might be contemplated to preclude the uneven wear of the blades by spacing the handle ends of the blades from each other. Such scissors, having no contact zones to bear the cutting resistance, would not cut at all because, as has been explained above, the cutting edges of the blades would be displaced away from their cutting planes.  
       SUMMARY OF THE INVENTION  
       [0012]     It is among the objects of this invention to provide a materially improved, in a sense even revolutionary, pair of scissors which is perhaps best suited for hairdressing applications, among others, permitting use of the latest, scissors-flourishing cutting styles without any of the accompanying inconveniences or difficulties pointed out above with respect to the conventional scissors.  
         [0013]     Another, more specific object of the invention is to create a permanent spacing between the terminal webs, including the easy-to-be-worn conventional contact zones, of the pair of blades in order to preclude the mutual abrasion of the blades at these parts and hence to render the scissors fit for use over incomparably longer periods of time then hitherto without repair or reconditioning.  
         [0014]     Yet another object of the invention is, despite the permanent spacing created between the terminal webs of the pair of blades, to cause their handle end regions to be constantly urged toward each other in opposition to the cutting resistance and hence to make the scissors just as cutting as if the blades were directly held against each other at the contact zones as in the prior art.  
         [0015]     Still another object of the invention is to minimize the friction of the blades between themselves and with other parts thereby making the scissors as light in action as feasible in order to save barbers and hairdressers from their professional ailments.  
         [0016]     Briefly, the present invention may be summarized as an abrasion-free, lighter-action, longer-lasting pair of scissors particularly well suited for hairdressing or styling applications, among others. Included are a pair of blades each having a terminal web through which the blade is joined to a handle. A pivot pin conventionally extends through the terminal webs of the pair of blades to permit pivotal motion of the blades relative to each other in parallel planes. A spacer is mounted between the terminal webs of the pair of blades for creating a spacing therebetween. Also included is a clamp having one end which is coupled to one end of the pivot pin projecting outwardly from one of the terminal webs and which is held against said one terminal web, and another end anchored to the other terminal web, in order to enable the terminal webs to bear that component of cutting resistance which tends to spread the pair of blades in opposite directions away from their parallel planes of motion.  
         [0017]     Thus the scissors is saved from the abrasion and consequent uneven wear of the terminal webs of the pair of blades as they are totally spaced from each other. The spacing of the terminal webs does not adversely affect the performance of the scissors at all, thanks to the provision of the clamp. Unlike the cantilever spring in the prior art scissors cited above, this clamp needs no resiliency as it functions to bear the resistance component tending to spread the pair of blades out of their parallel cutting planes, just as firmly as if the terminal webs were directly urged against each other at what were conventionally termed the contact zones. The operator may therefore exert only minimal manual effort for cutting. Furthermore, since the terminal webs are not to be worn at all, the scissors will remain as cutting as at the time of purchase as long as the edges of the blades do not dull.  
         [0018]     A bolt is recommended for use as the pivot pin joining the two blades of the scissors. The nut (usually cap nut) on the bolt may then be used for adjustment of pressure under which the clamp is held against the terminal webs.  
         [0019]     It is also recommended that a ball bearing, or simply a set of balls, be used as the spacer between the terminal webs. The spacer balls may be confined around the pivot pin for rolling engagement with both of the terminal webs of the pair of blades. The scissors will then be assured of even lighter action by virtue of the absence of friction between the terminal webs.  
         [0020]     According to an additional feature of the invention, another set of antifriction balls may be rollably confined around the pivot pin for rolling engagement with both clamp and one of the terminal webs. Still lighter action of the scissors will result from the absence of friction between the clamp and one of the terminal webs.  
         [0021]     The above and other objects, features and advantages of this invention will become more apparent, and the invention itself will best be understood, from a study of the following description and appended claims, with reference had to the attached drawings showing the closest prior art and a preferable embodiment of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]      FIG. 1  is a partial perspective view of the prior art pair of scissors being particular pertinence to the present invention;  
         [0023]      FIG. 2  is a slightly enlarged section through the prior art scissors of  FIG. 1 ;  
         [0024]      FIG. 3  is a perspective view of the scissors built on the novel principles of this invention; and  
         [0025]      FIG. 4  is an enlarged, fragmentary section through the inventive scissors of  FIG. 3 . 
     
    
     DETAILED DESCRIPTION  
       [0026]     A closer examination of the prior art spring-assisted scissors according to Japanese Unexamined Patent Publication No. 11-244550, supra, will redound to a better appreciation of the features and advantages of the spaced-blade scissors according to the invention. With reference to both  FIGS. 1 and 2  the prior art pair of scissors  10  has a cantilever spring  12  having a bent end embedded in the handle end of one blade  14 , and another end held against the other blade  16  and bored to fit over a bolt  18  pivotally joining the two blades  14  and  16 . A cap nut  20  on the bolt  18  is tightened to force the blades  14  and  16  against each other via the cantilever spring  12  and an adjusting leaf spring  22 .  
         [0027]     Sprung as above, the prior art scissors makes it mostly unnecessary for the operator to exert an additional force for holding the contact zones  24  and  26  of the blades  14  and  16  in sliding engagement with each other during cutting. These contact zones  24  and  26  will sooner or later be worn to such an extent as to become unable to bear the cutting resistance, demanding an application of a proportionately greater -force to the handles for cutting. Although the cap nut  20  on the bolt  18  is retightenable by the user, the blades  14  and  16  when worn excessively are repairable only by skilled artisans.  
         [0028]     Reference may now be had to  FIG. 3  for a detailed study of the general configuration of one preferred form of abrasion-free, longer-lasting, lighter-action pair of scissors embodying the principles of the present invention. Generally designated  30 , the illustrated scissors has a pair of blades  32  and  34  having terminal webs  36  and  38  which are joined to handles  40  and  42 , respectively. The blade  32  with a thumb bow  44  on the handle  40  is conventionally called the “A” blade, and the blade  34  with a finger bow  46  on the handle  42  the “B” blade. Both “A” and “B” blades  32  and  34  have their terminal webs  36  and  38  joined together by a pivot pin which in this particular embodiment takes the form of a bolt complete with a cap nut  48 .  
         [0029]      FIG. 4  reveals at  50  the bolt joining the blades  32  and  34 . The bolt  50 , with a head  52 , slidably extends through a hole  54  in the terminal web  36  of the “A” blade  32  and a hole  56  in the terminal web  38  of the “B” blade  34 . The noted cap nut  48  is fitted over the threaded end  58  of the bolt  50  projecting outwardly of the hole  56 . Thus the blades  32  and  34  are pivotable in parallel planes about the bolt  50  as the handles  40  and  42  are opened and closed.  
         [0030]     Installed between the blades  32  and  34  and encircling the bolt  50  is what may be termed an antifriction spacer  60  for providing a permanent spacing between the terminal webs  36  and  38  without itself introducing friction as it contacts these terminal webs. The antifriction spacer  60  is shown as a ball bearing received in part in a recess  62  in the terminal web  36  and in part in a recess  64  in the terminal web  38 . The ball bearing  60  comprises an annular row of balls  66  rollably confined by a ring  68  around the bolt  50 . It is the balls  66  that make antifriction contact with both terminal webs  36  and  38 . The balls  66  are sufficiently large, in relation to the depths of the recesses  62  and  64  in which they are received, to create a permanent spacing between the terminal webs  36  and  38  including their surface portions that have so far been called the contact zones by the scissors specialists.  
         [0031]     It is understood that the blades  32  and  34  are both conventionally equipped with bow and twist, such that, despite the spacing between their terminal webs  36  and  38 , the blades have their tips held against each other when the handles  40  and  42  are closed. Further, while the handles  40  and  42  are being opened and closed, the cutting edges of the blades  32  and  34  slide across each other for cutting.  
         [0032]     Preferably, the spacing between the terminal webs  36  and  38  should be adjustable. Employed to this end are a washer or washers  65  between terminal web  36  and ball bearing  60  and another washer or washers  67  between terminal web  38  and ball bearing  60 . The number of washers  65  and  67  may be varied to optimize the spacing between the terminal webs  36  and  38 .  
         [0033]     The creation of a permanent spacing between the terminal webs  36  and  36  represents a departure from, or indeed a negation of, the long-familiar scissors design. Any conventional type of scissors would not cut at all should their terminal webs be left spaced from each other. The scissors  30  according to the instant invention cuts just as well as if they had contact zones in sliding engagement with each other, thanks to the provision of a clamp  70  seen in both  FIGS. 3 and 4 . This clamp  70  is designed to prevent the cutting edges of the pair of blades  32  and  34  from being displaced away from their parallel cutting planes under the influence of the cutting resistance, that is, to hold the handle ends of the terminal webs  36  and  38  urged against each other in the face of the cutting resistance, as hereinafter described in detail.  
         [0034]     Made of a rather elongate piece of sheet metal, the clamp  70  has a bore  72  adjacent one end  74  thereof to fit over the end of the bolt  50  projecting from the “B” blade  34 . The clamp  70  extends from the bolt  50  over the terminal web  38  of the “B” blade  34  toward its handle and has another end  76  thereof bent over the handle end of this terminal web  38  toward the terminal web  36  of the “A” blade  32 . The bent end  76  of the clamp  70  is engaged in a depression  78  formed in the inside surface of the terminal web  36  at or adjacent of what was conventionally the contact zone of this terminal web. The clamp  70  is thus locked against pivotal displacement about the bolt  50  relative to the “A” blade  32 , but the “B” blade  34  is free to turn relative to the clamp and, of course, to the “A” blade.  
         [0035]     It is recommended that a second antifriction spacer  80  be installed between the “B” blade  34  and the clamp  70  for minimal sliding resistance. This second antifriction spacer may also take the form a ball bearing operably engaged in a recess  82  in the outer surface of the terminal web  38  of the “B” blade  34  and concentrically surrounding the bolt  50 . The ball bearing  80  comprises a row of balls  84  and an outer confining ring  86 . The balls  84  make rolling engagement with both “B” blade  34  and clamp  70 , permitting the former to be turned frictionlessly with respect to the latter.  
         [0036]     The bolt  50  has its screw-threaded end projecting further outwardly of the clamp  70  for mating engagement with the cap nut  48 . The tightening of this cap nut  48  on the bolt  50  will therefore cause the clamp  70  to be held both against the outside surface of the terminal web  38  of the “A” blade  32  and, via the ball bearing  80 , against the inside surface of the terminal web  36  of the “B” blade  34 . Thus, even though the terminal webs  36  and  38  are spaced from each other, they are equivalently urged against each other via the clamp  70  at their handle sides of the bolt  50  in opposition to the component of the cutting resistance tending to spread the blades  32  and  34  away from their cutting planes.  
         [0037]     The cap nut  48  may be retightened on the bolt  50  in cases where more than normal resistance is expected in use of the scissors  30  for cutting some objects. The terminal webs  36  and  38  will then be urged harder toward each other via the clamp  70 , enabling the scissors  30  to cut well despite the unusually great resistance.  
         [0038]     Whatever object is to be cut, the scissors will demand an exertion of literally minimal manual effort not only because of the constant urging of the handle sides of the terminal webs  36  and  38  toward each other via the clamp  70  but, additionally, of the absence of frictional resistance between the terminal webs  36  and  38  and between the terminal web  38  and clamp  70 . The scissors  30  is therefore particularly well suited for use by hairdressers or barbers who have to manipulate the implement over prolonged periods of time and sometimes in extraordinary manners.  
         [0039]     Notwithstanding the foregoing detailed disclosure it is not desired that the present invention be limited by the exact showing of the drawings or the description thereof. It is understood that the principles of this invention are applicable to various types of scissors or shears in addition to that for hairdressing represented here. Further a variety of modifications or alterations of the illustrated embodiment will suggest themselves to the specialists to conform to design preferences or to the requirements of each specific application of the invention, without departing from the proper scope or fair meaning of the invention as expressed in the claims which follow.