US 2452149 A
Description (OCR text may contain errors)
P. RICHARTZ' 9 9 METHOD AND APPARATUS FOR COVERING A SCALE OF A POCKET KNIFE FOR THE HANDLE 4 Sheets-Sheet 1 Filed Sept. 22, 1945 I-nvenzah Paul Riclarl:
Ga. 26 1948. P. RICHARTZ 2,452,149
/ METHOD AND APPARATUS FOR' COVERING A SCALE FOR THE HANDLE OF A POCKET KNIFE a 4 Sheets-Sheet 2 Q Filed Sept. 22, 1945 fi;/'%Z1" 12011221 22 L'cZLa Get. 26, 194
Filed Sept. 22, 1945 METHOD AND FOR TH P. RICHARTZ APPARATUS FOR COVERING A SCALE E HANDLE OF A POCKET 'KNIFE 4 sheets-sheet 5 (Willi-\Wlllll/I/I/I/I/III P 2112 Hickgrl:
Filed Sept. 22, 1945 P. RICHARTZ 0D AND APPARATUS FOR COVERI FOR THE HANDLE OF A POCKET me A SCALE KNIFE 4 Sheets-Sheet 4 Patented a. 2c, 1948? I UNITED STAT METHOD AND A SCALE FOR KNIFE APPARATUS THE HANDLE OF A POCKET FOR COVERING This invention relates to an improved method and apparatus for covering a scale for the handle of a pocket knife with a sheet of deformable material, such as thermoplastic sheet and has for an object to provide means for mechanically applying the sheet material without harmful effects to it.
It has already been proposed to apply a sheet of thermoplastic material to a knife scale by employing a sheet of sufficient size as to provide marginal edges which may be folded over the edges of the scale, and by applying heat more intensely to the folds than to the remainder of the material, and by engaging said marginal edges by members which during their inward movement over the scale, are arranged to compress the thermoplastic material between them and the edges of the scale so as to subject the material to tension. It is found in practice that the folds thus formed are liable to be weakened by the combined heating and stretching, and the present invention has for an object to avoid that defect.
According to this invention, a method for cov ering a scale for a pocket knife with deformable sheet material consists in placing the sheet material over the cavity in a mould shaped to the contour of the scale, placing the scale on the sheet material over the cavity, forcing the scale and sheet material into the cavity, which material is so dimensioned that its marginal edges project away from the mould and from the edges of the scale, applying lateral forces to said marginal edges over an area spaced away from the edges of the scale by an amount greater than the thickness of the material, whereby the material is bent over the edge without excessive stretching. If necessary, the above steps are followed by applying pressure to said bent-over marginal portions in a direction towards the face of the scale. This latter step is'particularly suitable when a hollow-pressed metal scale is employed, and wherein the marginal edges of the material are required to lie wholly within the hollow of the scale.
In the case where a thermoplastic sheet is employed, it is heated substantially uniformly over its area so as to render it permanently deformable, so that when said marginal edges are folded over the scale, they reman permanently set.
. In the case where the metal scale is provided ment of the shutters, the
4 Claims. (Cl. 1819) with upraised bolsters, the deformable material is so dimensioned that its end marginal edges are located adjacent the upraised bolsters.
The invention is also applicable to covering a scale with deformable material around an upstanding ornamentation such as a shield, in which case the cavity in themould is provided with a recess having sharp edges conforming to the shape of the upraised ornamentation, so that when the scale and the sheet material are forced into the cavity, the upraised portion enters into a recess and the sharp edges cut through the material, whereby the cut portion may be removed to expose the ornamentation.
An apparatus for carrying out the above process may comprise a press, a mould having a cavity shaped to the contour of the scale, a reciprocable press tool operated by said press and adapted to force said sheet material backed by the scale into the mould, which material is so dimensioned that itsmarginal edges project from the mould, laterally slidable shutters associated with said mould and adapted to engage said marginal edges at a distance away from the edges of the scale by an amount greater than the thickness of the material, means for applying reciprocable movement to said shutters. In the case where a thermoplastic sheet is employed, means are provided for heating said mould. Preferably, means are provided for locating the sheet material backed by the scale over the cavity in the mould.
In'order to prevent the sheet material from being compressed and stretched during the movedepression in the mould may either be arranged so that the edges of the scale lie substantially flush with the face of the mould and the shutters are guided so as to be spaced away from the top of the mould by an amount greater than the thickness of material, or the depression in the mould may be such that the edges of the scale lie beneath the top face of the mould by an amount greater than the thick ness of material, and the shutters are arranged to slide over the top face of the mould.
Movement may be imparted to the shutters by a flexible element attached to each of them and passing over a guide pulley and by a pedal lever attached to the ends of the flexible element, resillent means being provided to resist the movement applied to the shutters by the pedal.
The reciprocable press tool may also be arranged to be operated by a foot pedal. Thus, when the first said pedal is depressed to open the shutters by one foot, the other pedal is operated by the other foot.
The means for heating the mould may oomprise a base plate on which the mould and sliding shutters are mounted, to the back of which base plate there is secured an electric heating element. By these means, the whole of the mould and the'shutters are heated to a uniform temperature,
The following is a description of one form of apparatus, and two alternative constructions of mould for forming a knife scale according to this.
invention, reference being made to the accompanying drawings, in which Figure l is a side elevation of the apparatus;
Figure 2 is a plan view on an enlarged scaleof one form of mould and associated shutters;
Figure 3 is a section on the line 3-3 of Figure 2;
Figure 4 is an enlarged view of a part of Figure- 3. showing the initial position of the sheet Celluloid covering and hollow metal. scale in relation to the mould;
Figure 5 to. 7 show the covering and scale after successive operations carried out by the apparatus;
Figure 8 is a similar view of Figure 2, showing an alternative form of mould;
Figure 9 is a cross-section on the line 9-9 of Figure 8;
Figure 10 is a crossesection on the line l0l0 of Figure 8;
Figure 11 is a. mould block; and
Figure. 12 is a. section through a hollow pressed metal scale having an ornamentation and which iscoyered by means of the mould block of Figure 11.
Referring to the construction shown in Figure 2, the mould comprises a base plate 10 on which are secured end blocks II and 12 by setscrews [3. The blocks are provided with vertically-extending grooves l4 and I5 facing one another, and the contours of which grooves correspond with the contours of the bolster of the knife. A main mould block I6 is disposed between, the end blocks H and I2 and is provided with'a depression I! in the upper face thereof corresponding in shape to the shape of the knife scale. The main mould block [6 is provided with end pieces I 8 and [9 which engage the grooves nd blocks, thereby maintaining the main block in position, but so that it can be readily removable. In the case where the bolster end of the metal knife scale is provided with a lug by which it is attached to the skeleton of the knife, the block I I may be provided with a recess 28 extending'partly down the depthof the block for initially accommodating thelug, but which serves to bend the lug during the operation of the apparatus, as hereinafter described; Mounted in slideways 2| on either side of: the main'mould block. are fiat shutters 22, which slideways are so, located that the shutters may move over the top of the mainmould block I6 and meet one another, as shown in Figure 3. The shutters are urged towards one another by means of tension springs 23 secured at one end 24. to the shutters, and at the other end 25, to
plan view of an alternative the. base plate 40. The shutters: may be moved spacing members 632 at its apart by chains 26 secured to them at 21 and passing over sprocket wheels 28 mounted in suitable recesses 25) at the sides of the base plate. The base plate is heated beneath the main mould block it by an electric heating element 38 attached to the underside of the base plate. The degree of heating may be controlled by a switch 3! which connects in varying lengths of the resistance to the electric supply,
An alternative form of mould is shown in Figures 8 to 10. In this arrangement, the mould block 16 is mounted to slide vertically in 2. casing part 61 secured to the base plate l0. As in the. previous construction,v shutters 22 are arranged to slide in slideways 2i and are operated against the action of springs by means of chains 26. In. th s instance, however, the top face of the casin Part 6! is recessed at 54 to provide channels in which the shutters may slide, either by forming the recesses in the material of the casing .part,.or as shown in Figure 10, providing ends, and the slides 2| are prevented from rising in these recesses by a. cover plate 55 secured over the top of the casing part 6| by studs 56. The cover plate is provided. with an aperture having edges: 5'! and 58.so shaped and disposed as toregister the $heet Celluloid correctly over the recess in. the mould. It is also provided with other edges 59 and. 60 shaped to correspond with the bolster ends of the scale and guide it correctly into engagement with the depression I 1 in the mould block l6, except, in. this instance, the shutters. 22 slide over the top face of the mould block 15 within, the aforesaid'casing, The depth oi the portion it of the mould part is suffieiently great that when the metal. scale and Celluloid sheet havev been pressed into it, the edges. of the metal scale lie below the top of-the mouldblock by an. amount greater than the thickness of the Cellue loid sheet. Thus, when the Celluloid Sheet. is bent over the edges of the metal scale by the slides 22, it is not subjected to compression or excessive stretch, as referred. to above.
It is usual for the covering of the scale to. lie flush with or slightly below the surface of the bolstera, andfor this purpose, the scale is ini tially hollow-pressed,toprovide a countersunk portion between the bolsters which are left up: standing, and. the edges of the scale are recessed between the bohters by an amount equal to or greater than the thickness. of the Celluloid sheets. In order that the mould block 16 may be readily removed from. the casing part 61., the, bottom wall as of the casing provid d with two holes at through which extend two. pins 55. actuated by the forked end of a lever arm 46 having. a manipulating handle .47.
As, will be seen from Figure. 1, the base plate Ill and the. mould on it arev secured to the base 32 of a foot-operated press 3 3.mounted on a podestal 34. The press. is provided with afsquaresection plunger 35. reciprocably mounted in. bear-- ings 36 at the ends. of cantilever arms 31., The plunger is provided. with a slot. 38 in which located the end of a lever-.arm..39., The. leverarm is pivoted at, .40; in the main, upright portion of the press, and is provided with. a double, cranked arm 4| extending downwardly, andthen forwardly, where. it is provided with a. pedal extremity 42. The. two chains 26 extend downwardly from. the sprocket wheel 28' and are. at. tached attheir lower ends to afootelever 4 3.-piv. oted at .44 to. the bee of the pedestal, and pro-.- vicled, with a. pedal. 45. Thus, by depressing the pedal 45 the aforesaid shutters 22 are drawn apart against the action of the springs 23. The lower end of the plunger 35 has secured to it a press tool 48, the end of which is shaped to correspond with the internal contour of the hollow-pressed metal scale.
The operation of applying the Celluloid sheet covering to the metal scale is now described with reference to Figures 4 to 7, which embody a mould and shutters as described with reference to Figures 2 and 3. The temperature of the base plate Ht is so adjusted to a degree which will render the Celluloid sheet pliable. The foot pedal 45 is depressed so as to separate the shutters 22, and, as seen in Figure 4, the Celluloid sheet 49 is first laid over the main mould block it, which sheet is so dimensioned as to extend between the bolster ends of the sheet metal scale 50 and is sufficiently wide as to permit it eventually to be bent around the curved contour of the scale, and then inwardly over the edges of the scale, as shown in Figure '7. The Celluloid sheet while in the position shown in Figure 4 is raised to substantially the same temperature over the whole of its area so as to render it deformable.
As indicated earlier in the specification, the bolster ends of the scale may be provided with lugs 5|, and the metal scales are inserted between the blocks II and I2, with the lugs in the slots 20. The slots are of sufficient depth to permit the scale to rest on the Celluloid sheet 49, as shown in Figure 4.
The next operation consists in forcing the hollow metal scale and Celluloid covering into the mould part l6 by means of the press tool 14 which is forced downwardly by pressure on the foot-pedal 42 by one foot, while the other foot maintains the other pedal 45 depressed. The marginal edges 52 of the Celluloid sheet are caused by this operation to extend upwardly, and the parts remain in this position during the operation of withdrawing the press tool 48. The next operation, which is shown in Figure 6, consists in moving the shutters comparatively rapidly inwardly and outwardly. This is effected by momentarily releasing the pressure on the footpedal 45. The above steps follow one another in such quick succession that although the marginal edges momentarily leave the face of the mould they remain at substantially the same temperature as the remainder of the sheet which is sufiicient to render the sheet deformable.
It will be noted that the shutters 22 are so disposed in their slides 2| as to leave a gap 52 of greater width than the thickness of the Celluloid sheet between the shutters and the mould part It and the edges of the scale. The sheet is thus bent over the edges of the hollow-pressed metal scale 50 by a simple bending movement, without submitting it to any excessive stretching action which might otherwise fracture it at the bend. As already indicated, the Celluloid sheet has been rendered pliable over its whole area, including the region of the edges of the metal scale, and the efiect of this folding operation is permanently to distort the material at the bend, so that when the shutters are removed, it remains substantially in the same condition as that shown in Figure 6.
In order that the marginal portions 52 may be made to lie flush against the inside of the hollow metal scale, the press tool 48 is again lowered, as shown in Figure '7, and after withdrawal thereof, the operation is complete.
The hollow-pressed metal scale may also be embossed to provide an upstandingornamentae tion, such as a shield 55, at a location between the bolsters and the mould may initially be pro vided with a recess 56 having aisharp cutting edge shaped to register with the upstanding ornamentation, so that afterthesheetscale has been subjected to pressure in themould, theorna-r mentation lies flush with the surface thereof. Iclaim: .xI-Lw.
1. An apparatus, for coveringuga scaleufor aa pocket knife with deformable-sheet-materiaLcomprising a press, a mould having a cayitysshaped to. fit said scale andso that the edges of the scale lie beneath the face of the mould by an amount greater than the thickness of the sheet material, a reciprocable press tool vertically operated by said press and adapted to force said sheet material backed by the scale into the mould, said press tool having a width equal to the width of the scale to contact the entire width of the scale during the pressing operation and said material having its marginal edges projecting from the mould, laterally slidable shutters movable horizontally and associated with said mould to engage said marginal edges, means for applying reciprocable movement to said shutters so that they slide on the surface of said mould into engagement with the marginal edges of the material, and means for applying reciprocable movement to said shutters, and means for heating said mould.
2. An apparatus for covering a scale for a pocket knife with deformable sheet material, comprising a press, a mould having a cavity shaped to the contour of the scale, a reciprocable press tool, a foot pedal connected to operate said press tool and to force said sheet material backed by the scale into the mould, said material having its marginal edges projecting from the mould, laterally slidable shutters, slideways for said shutters adapted to guide them into engagement with said marginal edges, a flexible element attached to each shutter and passing over a guide pulley, a foot pedal lever attached to the ends of the flexible elements, resilient means resisting the movement applied to the shutters by the pedal and means for heating said mould.
3. A method of covering a scale for a pocket knife with deformable sheet material which consists in placing the sheet material over the cavity in a'mould shaped to the contour of the scale, placing the scale on the sheet material over the cavity, applying vertical pressure over the greater part of the area of the scale so as to force it and the sheet material into the cavity, said material being so dimensioned that its marginal edges project away from the outer face of the mould and from the edges of the scale, applying horizontal forces to said marginal edges over an area spaced away from the edges of the scale by an amount greater than the thickness of the material to bend the material over the edge of the scale without excessive stretching, and applying vertical pressure to said bent-over marginal portion in a direction towards the base of the scale to force them arginal portion against the inside cavity of the scale.
4. A method of covering a scale for a pocket knife with deformable sheet material which consists in placing the sheet material over the cavity in a mould shaped to the contour of the scale, placing the scale on the sheet material over the cavity, vertically moving a press tool on the scale and sheet material to force them into the cavity and thereafter moving the press tool out of the cavity, said material being so dimensioned that 7 its marginal :edges profiept away from the 'mmld and lrqm thfe edges of the scale, applying lateral fqrges-td-said marginal edges by horizontally movable shutters eover an' area spaced away from REFERENCES CITED The following references are of record 111 the file of this patent:
UNITED STATES PATENTS Number Name Date Miranda et a1 June 2, 1942