US3068919A - Shaper guard for radial saw machine - Google Patents

Description

Dec. 18, 1962 R. c. KALEY 3,068,919

SHAPER GUARD FOR RADIAL SAW MACHINE Filed Sept. 22, 1959 4 Sheets-Sheet l FIGJ W IH'IH [7 O INVENTOR.

ROBERT C.KALEY 'ATTORN EY Dec. 18, 1962 R. c. KALEY 3,068,919

SHAPER GUARD FOR RADIAL SAW MACHINE Filed Sept. 22, 1959 4 Sheets-Sheet 2 FIG.?)

INVENTOR.

ROBERT C. KALEY V BYW ATTORNEY Dec. 18, 1962 R. c. KALEY 3,068,919

SHAPER GUARD FOR RADIAL SAW MACHINE Filed Sept. 22, 1959 4 Sheets-Sheet 3 FIG.6

22 INVENTOR.

ROBERT C.KALEY ATTORN EY Dec. 18, 1962 R. c. KALEY SHAPER GUARD FOR RADIAL SAW MACHINE 4 Sheets-Sheet 4 Filed Sept. 22, 1959 INVENTOR ROBERT C. KALEY United States Patent f 3,068,919 SHAPER GUARD FOR RADIAL SAW MAQHINE Robert C. Kaley, Landisville, Pa., assignor, by mesne assignrnents, to De Walt, Inc., a corporation of Delaware Filed Sept. 22, 1959, Ser. No. 841,616 7 Claims. (Cl. 144-251) This invention relates to safety guards for power tools, and more particularly to an adjustable safety guard for a rotary cutting tool which is mounted on a rotating vertical shaft which may be tilted from the vertical to perform a variety of operations.

When radial saws and the like are locked in a vertical position for shaping operations, they may have aifixed a suitable safety guard such as that shown in the US. Patent No. 2,785,716 to Joseph B. Lutton. This type of guard is quite suitable for the protection of an operator performing a shaping operation, but when the tool shaft is tilted from the vertical to perform rabbeting, rafter notching, or like operations, a more versatile guard is needed to protect the operator as the guard must be adjustable so that it can extend horizontally above the workpiece with a uniform clearance. It is, therefore, an object of this invention to provide a safety guard which may be adjusted vertically and also tilted in relation to a cutting tool to effectively prevent inadvertent injury to an operator performing a wide variety of operations.

Another object of this invention is to provide a more easily attached vertically adjustable safety guard which may be simply tilted and securely locked in a wide range of positions.

A further object of this invention i to provide a vertically adjustable tilting safety guard which is assembled from a small number of parts that can be ruggedly fabricated with less expense to withstand hard usage.

Yet another object of this invention is to provide an adjustable, tilting safety guard which does not reduce the space in which a cutter may rotate when the guard is tilted in relation to the cutter.

Still another object of this invention is to provide a vertically adjustable, tilting safety guard which occupies a minimum space and which is adjusted and then locked in position by tightening three easily reached thumb nuts.

Additional objects, advantages, and features of invention reside in the construction, arrangement and combination of parts involved in the embodiment of the invention as will be understood from the following description and accompanying drawings wherein:

PEG. 1 is a perspective view of a radial saw equipped with a safety guard and set with its shaft inclined from the vertical to perform a rafter notching operation;

FIG. 2 is a top view of the safety guard shown removed from the radial saw;

FIG. 3 is a front View of the safety guard shown fixed to a fragment of a vertical radial saw motor with a small piece of one of the side protective members broken away to show the configuration of the top plate;

FIG. 4 is a side view of the safety guard shown fixed to a fragment of a radial saw motor which is positioned to perform an angled rabbeting operation;

FIG. 5 is a rear elevational view of the safety guard;

FIG. 6 is a bottom view of the safety guard, as taken on line 6-6 of FIG. 5;

FIG. 7 is a section of a fragment of the safety guard taken on line 77 of FIG. 5; and

FIG. 8 is a section of a fragment of the safety guard taken on line 8-8 of FIG. 5.

FIG. 9 is an exploded view of the components of the shaper guard in relationship to the motor of the tool.

Referring to the drawings in detail, FIGS. 2, 3, 5, 6, 7 and 8 show the construction of the safety guard and the 3,068,919 Patented Dec. 18, 1962 configuration of its parts. A top plate 10 has a thicker center portion 11. from which there projects upward the arcuate bracket 12. The thicker center portion 11 terminates in the accurately machined, semi-circular inner edge 13. An outer area 14 of the top plate 10 may be offset downwardly and then terminate in the downward extending, vertical flanges 15 and 16. The front of the top plate 10 has the thicker, rectangular lug 28 formed integrally with it to extend between the inwardly disposed ends of the flanges 15 and 16.

A central slide 17 has a vertical channel 18 formed in its back surface into which the front of the lug 28 extends. The central slide 17 is then slidably secured to the lug 28 by means of a threaded stud 21 which projects forward from the vertical. front face of the lug 23 to pass through a vertical slot 22 in the slide 17. The stud 21 may be used to lock the lug 17 to the vertical slide 28 by tightening the knurled thumb nut 2t? to clamp it. The vertical recess 23:, which is formed in the back of the slide 17 and which may be seen in FIG. 5 and FIG. 8, serves no functional purpose except to lighten the structure. As shown in FiGS. 5, 6, and 8, a bolt 24 passes through the flanges of the end of channel 18 to pivotally secure the side protective members 30 and 31 by their inwardly turned end flanges 32 and 33. As shown the bolt 24 is secured with a lock nut 25 so that it cannot work loose. Washers 29 ensure a smooth pivotal connection between the slide 17 and the side protective members 36 and 31.

The side members 36 and 31 contain the vertical slots 34 and 35 through which the bolts 36 and 37 extend after passing through the elongated horizontal slots 26 and 27 in the vertical flanges 15 and 16. The heads of the bolts 36 and 37 extend inwardly and have one flat side lying against the underside of the outer area 14 of the top plate 1b. This prevents the bolts 36 and 37 from turning when the thumb nuts 38 and 39 are tightened about them to lock the rear portion of the side protective members 30 and 31 to the top plate 1% in a given position. The horizontal flanges $5 and 56 project inward from the top of the side members 30 and 31 to add strength to the side members and to improve the appearance of the safety guard. In the lowermost position of the side members 30 and 31, as shown in FIG. 5, the flanges and 56 rest on Y the outer area 14 of the top plate iii.

Operation The invention may be used as follows. As may be seen in FIGURE 4, the motor it? has a circumferential groove 41 at its end where the shaft 42 extends to rotate the cutter i6. Above this groove 41, there projects the stud 43 about which there may be turned the wing nut 45. The safety guard is installed by sliding the inner semicircular edge '13 of the top plate 10 into the groove 41 of the motor 4% so that the stud 43 extends through the slot id of the bracket; This mounting allows the safety guard to be rotated about the motor 44 through the number of degrees described by the slot 44 and then to be locked to the motor at in a desired position by tightening the wing nut 45, thus enhancing the overall versatility of the safety guard.

For an ordinary or normal shaping (or rabbeting) operation, the motor would be secured in a vertical position as shown in PEG. 3. The thumb nuts 30, 38 and 39 would be loosened and the safety guard would be moved upwards relative to the top plate 16 in a horizontal position to allow a cutter attached to the motor 49 to extend below the bottoms of the side members 3i and 31 and the slide 1'7. When the guard would clear the workpiece to be subjected to the shaping operation with a suitable working clearance, the thumb nuts 2%, 38 and ace-e919 39 are tightened to lock the safety guard in position. When such a vertical adjustment of the safety guard is made, the bolts 56 and 37 slide in the slots 34 and 35 (see FIGURES 5 and 7) as the stud 21 moves in the slot 32 of the slide 27. With the safety guard in such a position (as is usually desirable for a normal shaping operation), it will be appreciated, of course, that the safety guard will be so adjusted as to be substantially parallel ,to the top surface of the workpiece, it being noted (as shown in FIGURE 3) that the side protective members 39 and 31 will be coplanar with respect to each other. Moreover, in such a position for a normal shaping operation, the slide 17 (when tightened by means of the thumb nut 26 and stud 21) will usually be normal to the plane of the top plate 10, it being further noted (as aforesaid) that the slide 17 has a vertical channel 18 which embraces the integral lug 2%, as shown in FIGURE 2.

Under certain circumstances, however, as when it is desired to perform an operation resulting in an angled rabbct strip, or perhaps a rafter notching operation, it

is then necessary to tilt the motor (and its associated cutting element) rearwardly or forwardly, respectively, that is to say, the motor 4% is angularly pivoted with respect to its supporting yoke; and it is in such situations that the inherent features of the present invention may find more particular utility.

For example, and as shown more clearly in FIGURE 4, in order to perform an angled rabbeting operation in the work 47 (by means of a suitable cutting element denoted by the numeral 46), it is necessary to tilt the motor rearwardly (or backwardiy); and it will be appreciated, naturally, that the motor 40 will be so tilted (or pivoted) and then lowered as to obtain (not only the proper angular relationship) but the proper depth of cut as well. During this time, when the motor 40 is being so positioned by the operator, the adjustable members of the safety guard (namely, the side members 3i) and and slide 1'7 may be raised, that is to say, temporarily positioned or secured out of the way; and thereafter, the side members 34 and 31 (as well as the slide 17) may be lowered and I positioned such that the respective lower edges of the side members 3%) and 31 sufficiently clear the top surface of the work 47. It will be appreciated that in this manipu lation of the side members 3%) and 31 and slide 17, that is to say, suitably lowering and positioning these elements as aforesaid, that the side members 3 3 and 31 may be pivoted (upwardly as in FIGURE 4) about the bolts 36 and 37, respectively, and that simultaneously, the slide 17 may be pivoted about bolt 24 so as to obtain, as an end result, the proper location or positioning of the side members 30 and 31. It will be further appreciated, of course, that the aforesaid pivoting action, in combination with the slotting arrangements, the latter comprising (for example) slot 3 in side member 3% and slot 26 in vertical flange 15, provides in effect an almost infinite number of adjustments so as to ultimately accommodate the proper disposition of the elements (3%, 3!. and 17) with respect to the motor 49, cutting element 46, and work 47. Consequently, it will be appreciated that depending upon a number of factors, such as the angle of tilt, depth of cut, width and diameter of cutter, and which of the thumb nuts are first tightened (29 on the one hand, or 33 and 39 on the other hand), that the slide 17 (when secured by the stud 21 and thumb out 2:; to the lug 28) may be substantially normal to the plane of the plate 10, or more often than not, may be disposed at a slight acute angle with respect to the normal of the plane of the plate it as shown more particularly in FIGURE 4.

Although the tightening of the thumb nut 20 tends to draw the slide 17 flush against the front face of the lug 28, nevertheless, in this position, either the slots 34' and move the bolts 36 and 37 to the rearmost position within the slots 26 and 27 (respectively) until their motion is arrested, or else the front surfaces of the flanges 1S and 16 of the top plate 16 contact the front inner surfaces of the side protective members 36 and 31. This limiting of the rearward motion of the side members 3-3 and 31, relative to the top plate it limits the forward pivoting action of the slide I7 so that the upper end of the slide 17 does not project so far forward that it interferes with the operator. Thereafter, the thumb nuts 33 and 39 may also be tightened to secure the safety guard in position for a particular rabbeting operation as shown in FIGURE 4.

When it is desired, on the other hand, to perform a rafter notching operation, the motor 40 must be tilted forwardly, as contradistinguished from the rearward tilting of the motor 40 in the course of the aforesaid angled rabbeting operation illustrated in FIGURE 4. Hence, as shown more particularly in FIGURE 1, the workpieces 49 are placed under the radial arm 50 and at right angles to it. The yoke 51, which is slidably mounted on the arm 50, holds the motor 40 at the proper forward angle so that a cutter will correctly notch the workpieces 49 as it is pushed back and forth over tiem. As may be seen in FIGURE 1, the side members are adjusted to pass over the workpieces with a slight clearance. In this rafter notching operation, as distinguished from the aforesaid angled rabbeting operation-and again depending upon a number of similar factors-the tightening of the thumb nut 29 holds the slide 17 against the front surface of the lug 28 such that the slide 17 will probably be substantially normal to the plane of the plate 10 (as shown in FIGURE 1) or perhaps may be disposed at a slight acute angle with respect to the normal. This allows a large cutter to be used, inasmuch as any adjustment of the side protective members 30 and 31 will not move their front portions inwards towards the cutter, these members pivoting about the bolt 24 at the bottom of the slide 17. When such an adjustment is made and the side members 30 and 31 are pivoted upwards about the bolt 24-, the bolts 36 and 37 slide forwardly in the slots 26 and 27, respectively.

Moreover, it will be further appreciated from a close inspection of FIGURE 1, that the safety guard may be so adjusted that the side protective member 39 (that is to say, the leading side protective member) is substantially parallel to the top surface of the workpiece 49; while the other side protective member 31 (designated in this case as the trailing side protective member) may be so adjusted as to be parallel to the cutter and hence to the notch being made in the workpiece 49. There fore, it will be appreciated that the side protective members 39 and 31, while usually being coplanar, are not necessarily so; and FIGURE 1 illustrates a particular in stance Where it is possible (within limits) to so adjust the safety guard that the side protective members 30 and 31 are slightly skewed with respect to each other. This feature of the present invention enhances the inherent safety of the guard, inasmuch as the maximum degree of coverage, which is synonymous with maximum safety, may be provided. Besides, such an arrangement further prevents chips from being thrown towards the operator. In addition, the slot 44 allows the plate 10 and hence the overall guard to be rotated (within limits) about the motor 40, thus providing a desirable degree of versatility.

FIGURE 1 illustrates a rafter notching operation, wherein (looking into the radial arm 59) the motor 4!} is tilted to the right or forwardly. In FIGURE 4, an angled rabbeting operation is illustrated. Here, the motor 40 (and its associated cutter 46) are tilted to the left or rearwardly. In FIGURE 1, the slide member 17 will usually be normal to the top plate 10 and, of course, to the front face or surface of the integral lug 28. In FIGURE 4, however, the slide member 17 will usually make a slight obtuse angle with respect to the top plate 10. The inherent utility of the present invention lies in its extreme versatility and in its ability to provide a maximum degree of protection or safety coverage in each of the various positions to which the motor 40 may be adjusted. Moreover, the maximum safety is provided commensurate with overall compactness, so that the guard does not interfere with the operator, nor with the size of the cutter 46.

The side protective members 30 and 31 are ordinarily co-planar with respect to each other, but not necessarily so. In a normal shaping operation, such as is illustrated in FIGURE 3, the axis of rotation of the cutter 46 (and the motor 40) will be vertical, that is, normal to the workpiece; and in this position, the side protective members 30 and 31 are in a sense aligned with each other, such that their bottom and top edges are substantially co-planar with respect to each other, with the bottom edges having a slight clearance with respect to the workpiece. Now, suppose a different operation is to be performed on the machine, say an operation which requires the axis of rotation of the cutter 46 to be tilted either rearwardly or forwardly. In FIGURE 4, the motor 40 is tilted rearwardly, or to the left as viewed in FIGURE 4, with the machine positioned for an angled rabbeting operation. The side protective members are aligned with each other, with the top and bottom edges being coplanar, and with a slight clearance existing between the bottom edges and the workpiece 47; and the slide 17 is slightly skewed with respect to the top plate 10. If the machine is adjusted for a rafter notching operation, as is shown in FIGURE 1, the motor 40 is tilted forwardly or to the right looking into the radial arm 50. In this position, the slide 17 will more than likely be perpendicular to the top plate 10, and the top plate will itself be skewed slightly with respect to the horizontal plane, but nevertheless, still perpendicular to the axis of rotation of the cutter 46. Moreover, the leading side protective member is parallel to the top horizontal surface of the workpiece 49, while the trailing side protective member 31 is tilted to correspond to the tilting of the motor 40 and its cutter 46. The side protective members 30 and 31, in this position,,Wlll not be aligned, nor will their'top and bottom edges be coplanar with respect to 'each other. '1'his is one of the features of the invention. 'The side protective members 30 and 31 may be individually adjusted both with respect to each other and with 'respect'to' the top plate 10, as is shown by the difference in the vertical shading between the leading side protective member 30 and the trailing side protective member 31 in the position illustrated in FIGURE 1. The top and bottom edges of the leading side protective member 30 are parallel to the top surface of the workpiece 49, that is, these edges lie in a horizontal plane, while the top and bottom edges of the trailing side protective member 31 are skewed with respect to the horizontal plane, actually being parallel to the skewed top plate 10 and thus perpendicular to the axis of rotation of the cutter 46. Consequently, a maximum degree of coverage, which is herein synonymous with safety, is provided in the rafter notching operation shown in FIGURE 1.

Naturally, it will be appreciated that any adjustment which necessitates a tilting of the side protective members 30 and 31 (forwardly or rearwardly relative to the plane of the top plate ltl) will not lessen the space in which a cutter may revolve within the safety guard. For example, for the rafter notching operation illustrated in FIGURE 1, the slide 17 does not swing inwardly appreciably, with the result that the slide members 30 and 31 are held away from the cutter; and by the same token, for the angled rabbeting operation illustrated in FIG- URE 4, the slide 17 does not have its top portion protruding so far away from the safety guard as to otherwise interfere with the operator.

It will be further appreciated, of course, that in performing a rafter notching operation as illustrated in FIGURE 1, that the work 49 may remain stationary, while the yoke 51 carrying motor 40 (and naturally the cutter) may be traversed along the radial arm 50, it being recalled that the motor had previously been tilted forwardly. On the other hand, in performing an angled r-abbeting operation as illustrated in FIGURE 4, the motor 40 is tilted rearwardly; and for relatively short pieces of the work 47, the motor '40 may be traversed along the radial arm 50 in the same manner as that for the rafter notching operation. FIGURE 4, then, may represent the view that is presented when looking directly into the end of the radial arm 50 of FIGURE 1 (and into the end of the work 47); but of course it should be understood that for relatively long pieces of work (which is prob ably the general case), that the yoke 51 and motor 40 may be indexed or pivoted 90 with respect to the radial arm 50 (in a manner well-known in the art) such that the yoke 51 may be locked into place, while the work 47 is itself pushed along the surface 48 by the operator.

In summary, then, the safety guard of the present invention has the following main advantages: first, means are provided whereby the elements of the safety guard may be adjusted so as to compensate for any required tilt of the motor 40 with respect to the work, thus allowing the side protective members 30 and 31 to be adjusted parallel to the top surface of the work with just a slight working clearance therebetween; secondly, the side protective members 30 and 31 may (if desired) be individually or independently adjusted so as to be slightly skewed (Within certain limits) with respect to each other, that is to say, the leading side protective member may be adjusted parallel to the top surface of the ,workpiece, while the trailing side protective member may be adjusted parallel to the cutter, thus enhancing the degree of safety; thirdly, the entire safety guard may be rotated (or-pivoted) about the motor 40 (by means of the slot 44), thus enhancing the overall versatility of the guard; fourth, the safety guard does not reduce the space in which the cutter may rotate when the guard is tilted in v relation to the cutter; and fifth, the safety guard is easily adjustable, and when adjusted, does not protrude so far as to interfere with the movements of the operator.

While I have disclosed my invention in the best form known to me, it will nevertheless be understood that this is purely exemplary and that modifications may be made without departing from the spirit of the invention, except as it may be more particularly limited in the appended claims wherein I claim:

1. In combination with a rotary cutter having a vertical axis of rotation, a safety guard comprising, in combination, an ordinarily-horizontal top plate secured above said rotary cutter, a slide member adjustably clamped to said top plate and depending therefrom, said slide member being disposed radially of the cutter and having a substantially perpendicular adjustment with respect to said top plate and a pair of side protective members including respective forwardly-disposed portions having said slide member pivotally secured therebetween and further including respective rearWar-dly-disposed portions, each having a vertical slot formed therein, and means in cluding a fastening member passing through each of said slots to pivotably clamp said side protective members to said top plate, whereby each of said side protective members may be individually adjusted with respect to each other and with respect to said top plate.

2. A safety guard for a woodworking machine of the type including a vertically-disposed motor having a generally cylindrical motor housing and further including a rotary cutter driven by the motor and depending therefrom, said safety guard comprising, in combination, an ordinarily-horizontal top plate, an arcuate bracket extending upwardly from said top plate and including an arcuate slot parallel to said top plate, means extending through said slot in said arcuate bracket to adjustably clamp said arcuate bracket to the motor housing, a lug projecting radially and downwardly from said top plate and having a front surface substantially normal to said top plate, a pair of vertical flanges depending from said top plate on either side of said lug, a slide including a rearwardly-facing channel, said slide being slidably positioned upon said lug and having a depending portion intermediate said pair of vertical flanges, manuallymanipulatable means to adjustably clamp said slide to said lug, each of said pair of vertical flanges including a rearwardly-disposed portion having a respective horizontal slot, a pair of side protective members including respective forwardly-disposed portions having said depending portion of said slide pivotally secured therebetween and further including respective rearwardlydisposed portions each having a vertical slot, and a pair of manually-manipulatable fastening means, one each passing through a respective one of said vertical slots and a respective one of said horizontal slots to adjustably clamp each of said pair of side protective members to said top plate, whereby each of said pair of side protective members many be individually adjusted within certain limits with respect to said top plate.

3. The combination according to claim 2 wherein said motor has a circumferential groove formed in its lower end and wherein said top plate has an inner semicircular edge which extends into the circumferential groove in said motor.

4. In combination with a rotary cutter having a normally vertical axis of rotation and means to adjustably tilt the axis of rotation in at least a single plane, a safety guard surrounding at least a portion of the cutter, said safety guard comprising a fixed fiat substantially-horizontal member on and tilting in unison with the tilting of the cutter, a slide member, means to adjustably mount said slide member to said fixed member radially of said cutter for movement substantially perpendicular to said fixed member, a pair of side protective members, one on each side of said slide member and each surrounding a portion of said fixed member, means to pivotably secure said slide member intermediate said side protective members, and means to pivotably secure each of said side protective members to said fixed member, said slide member and said side protective members having a pivot axis therebetween, and each of said side protective members having respective pivot axes with respect to said fixed member, said last-named pivot axes being parallel to each other and to the pivot axis between said slide member and said side protective members, and all of said pivot axes being perpendicular with respect to the plane of tilting of said cutter, whereby each of said side protective members may be individually adjusted with respect to each other and with respect to said fixed member.

5. A safety guard as described in claim 4, wherein said fiat substantially-horizontal member has an integral radially-projecting lug, said lug having a flat face which is perpendicular to said flat member, a stud carried by said lug and projecting radially of said flat face, said slide member having a rearward channel formed therein and further having a longitudinal slot formed therein parallel to said channel, said channel engaging said lug, and said stud of said lug projecting through said slot in said slide member, and a manually-manipulatable lock nut engaging said stud, whereby said slide member may be adjusted substantially perpendicularly of said fiat member.

6. A safety guard as described in claim 5, wherein each of said side protective members depend downwardly of said flat substantially-horizontal member.

7. A safety guard as described in claim 6, wherein said flat substantially-horizontal member has a pair of flanges depending downwardly therefrom, one on each side of said lug, each of said flanges having a rearward horizontal slot formed therein away from said lug, each of said side protective members having a rearward vertical slot formed therein, and wherein respective fastening means including manually-manipulatable lock nuts are provided, said fastening means being operative through said vertical slot in said respective side protective member and said horizontal slot in said respective flange of said fixed member, whereby said side protective members are pivotably secured to said flat member.

References Cited in the file of this patent UNITED STATES PATENTS 694,835 Cook Mar. 4, 1902 720,039 Lemmon Feb. 10, 1903 907,734 Butterfield Dec. 29, 1908 2,258,828 Trebert Oct. 14, 1941 2,785,716 Lutton Mar. 19, 1957 2,841,194 Koberle July 1, 1958

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