referring to fig1 - 3 , a preferred embodiment of the present invention has a base member 12 which may be secured to any suitable , rigid table , bench , or the like by fasteners , such as bolts or screws extending through holes 14 . a first upstanding support member 16 is fixedly attached to the base and carries a floating head member 18 in reciprocable engagement therewith . the head member 18 defines a pair of holes each fitted with bearings 20 which preferably are ball bushings . through these bushings 20 are disposed a pair of guide pins 22 which are press fit or otherwise firmly attached to and project upwardly from support member 16 . the guide pins 22 cooperate with the bushings 20 to allow free , reciprocal motion of head member 18 on the support 16 . this relationship is best viewed in fig4 - 6 . a biasing element 24 , such as a coil spring , is provided to urge head member 18 away from support member 16 . as best viewed in fig4 the spring 24 is disposed in opposing bores 26 , 28 in head member 18 and support member 16 , respectively , and is held in compression therebetween . the degree to which head member 18 may be displaced from support member 16 by means of spring 26 is determined by an adjustable stop in the form of a threaded bolt 30 freely extends through a bore 31 in head member 18 and . the bolt 30 has an enlarged head portion 32 which passes partially through head member 18 in a counterbore 34 . bolt 30 is threaded into a tapped hole 36 ( fig5 ) in the base member 16 and is thereby adjustable to permit a fairly wide range over which head member 18 may move on guide pins 22 relative to support member 16 . floating head 18 is also provided with a transverse bore 38 having one or more bearings 40 , preferably ball bushings , disposed therein . screws 42 extend through threaded holes 44 in head member 18 in order to secure the bushings 40 against rotation or other movement relative to bore 38 . retaining clips 46 , best viewed in fig3 are provided to reduce end play of bushings 40 . the bore 38 and bushings 40 have radially disposed , longitudinally extending aligned slots 39 , 41 opening through the bottom surface of head member 18 . the sharpening element , generally designated as 50 , is comprised of a standard file 52 having a handle member 54 and an abrasive portion 56 . the file is attached to a support member 58 by screws 60 , as best viewed in fig3 . the support 58 is formed with a rail portion 62 , which extends radially from a guide shaft 64 and passes through slots 39 , 41 . guide shaft 64 is designed to travel axially within the bearings 40 , and allows the file to freely reciprocate across a path limited by the terminal ends of the shaft . it is important that the face of the file 52 be restricted within a single plane of motion , i . e ., that no rocking or side motion be allowed . to prevent such undesired motion , a pair of rollers 66 are disposed , one on each side of the rail 62 , on the underside of the head member 18 . rollers 66 , which may be manufactured from any suitable material , such as ptfe , or which may be small roller or ball bearings , are secured to head member 18 by axel bolts 68 . rollers 66 preferably are machined to have an angular face which contacts the mating angular face of rail member 62 , as shown in fig3 although other suitable configurations may be used . a second support member 70 is attached to the base member 12 and is designed to receive a tool , such as spatula 72 , to be sharpened . the support member 70 has an inclined face 73 on which is provided a plate 74 attached thereto by means of bolts 76 . the spatula 72 is inserted between the inclined face 73 of support 70 and the bottom face of plate 74 , as shown in fig5 - 7 , and bolts 76 are then tightened to securely lock the spatula in place with the leading edge thereof in the reciprocable path of sharpening element 50 . a positioning plate 80 is carried upon support 70 , for the accurate alignment of spatula 72 on the support member . positioning plate 80 is generally rectangular and has a pair of elongated slots 82 , as shown in fig3 . the plate is attached to the inner side face 85 of support 70 by a pair of threaded bolts 84 which pass freely through slots 82 in plate 80 and are mounted in tapped holes ( not shown ) in the side face 85 of support member 70 . the bolts 84 are provided with a pair of springs 86 each of which is compressed between the head 87 of bolt 84 , and a washer 88 , so as to urge positioning plate 80 into frictional engagement with side face 85 of the support member . in this manner , the plate may be moved between an upper position , shown in fig5 and a lower position , shown in fig6 . when the spatula is to be inserted , positioning plate 80 is slid upwardly as shown in fig5 thereby to provide a stop against which the working edge of spatula 72 may be positioned . the spatula is then secured by tightening down bolts 76 of the clamping bar 74 . thereafter , positioning plate 80 may be returned to its lower position , as shown in fig6 out of the path of travel of the sharpening file 56 . as best illustrated in fig7 support member 70 is positioned at a slight angle with respect to the path of travel of the file 56 . the angle is designed to be sufficient for the working edge of the spatula to contact the face of the file across at least a substantial portion of its width , preferrably its entire width to prevent selective loading of metal in the file , to thereby improve the life thereof , and to minimize the force necessary to effect sharpening of the spatula . in operation , the floating head 18 will normally be biased away from support member 16 to the extent permitted by the adjustment of bolt 30 . this adjustment is normally made so that the face of file 52 is somewhat above the upper end of positioning plate 80 , when raised , as shown in fig5 . a spatula is inserted beneath plate 74 and rests on the inclined face 73 of support member 70 . the position of the spatula is accurately determined by raising positioning plate 80 , as shown in fig5 and abutting the end of spatula 72 thereagainst . bolts 76 are then tightened and positioning plate 80 returned to its normal position , as shown in fig6 . the path which the sharpening element 50 may traverse is confined to two independent , substantially perpendicular directions dictated by the movement of head 18 on guide pins 22 and the movement of guide shaft 64 within ball bushings 40 as limited by the rollers 66 . because of the design of the guide pins , and further because of the presence of rollers 66 , no other motion is permitted . thus , at the beginning of the sharpening stroke , the apparatus generally will be in the configuration illustrated in fig5 . as the user applies force to handle member 54 of the file , floating head 18 will move downwardly against the biasing force provided by spring 24 to the position illustrated in fig6 so that the abrasive surface 56 of the file contacts the working edge of spatula 72 . continued movement on the forward stoke causes the file face to rub across the spatula edge as guide shaft 64 moves through the bushings 40 in the floating head . at the end of travel , as the user withdraws the file on the return stroke for the next sweep , release of downward force applied during sharpening allows bias spring 24 to return floating head 18 to the retracted position of fig5 . in the above manner , there is accomplished the sharpening of the spatula only on forward movement of the file . on the reverse sweep , the file is in an &# 34 ; up &# 34 ; position which produces a superior , straight working edge on the spatula , lengthens the life of the file , and minimizes the loading thereof thus reducing the need for frequent cleaning of the file grooves . because of the angular relationship between the end of spatula 72 and the file face , the operation is smooth and &# 34 ; jerk free &# 34 ; and proceeds in a simple yet highly efficient manner requiring the exertion of little physical force . thus , the apparatus is capable of use by inexperienced individuals who may quickly , efficiently , and accurately sharpen the ends of spatulas as the need arises . inasmuch as the present invention is subject to many variations , modifications and changes in detail , it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense .