US2786496A - Safety guard for circular saw - Google Patents

Description

March 1957 w. A. ESCHENBURG SAFETY GUARD FOR CIRCULAR SAW 2 Sheets-Sheet 1 Filed Dec. 6, 1955 IN VEN TOR.

March 26, 1957 w. A. ESCHENBURG SAFETY GUARD FOR CIRCULAR SAW 2 Sheets-Sheet 2 Filed Dec. 6, 1955 I INVENTOR.

Ma WW Illa/2% United States Patent SAFETY GUARD FOR CIRCULAR SAW William A. Eschenburg, South Beloit, Ill., assignor to Yates-American Machine Company, Beloit, Wis., a corporation of Delaware Application December 6, 1955, Serial No. 551,254

9 Claims. 01. 143-159 This invention relates to safety devices for a power operated tool and is more particularly concerned with improvements in a safety guard for a circular saw or similar material cutting tool.

It is a general object of the invention to provide a safety guard for a circular saw or the like wherein a baskettype guard is pivotally mounted for bodily swinging movement with respect to the work supporting surface or table toand from its operating position relative to the saw blade and wherein an improved mounting is provided on which the guard will swing freely without deflection, misalignment, rattles or vibration, thereby insuring effective movement of the guard without interference with the movement of the work and with adequate protection to the operator.

It is another object of the invention to provide a safety device for a circular saw blade which comprises a baskettype guard swingably mounted upon the forward end of a pair of pivoted supporting bars, the latter being hingedly mounted at their rear ends upon a splitter plate which is rigidly connected with the support for the saw arbor and mechanism for guiding the basket guard as it is swung about its pivotal connection to prevent sidesway of the same relative to the splitter plate.

It is another object of the invention to provide a guard for a circular saw blade which comprises a splitter plate rigidly connected with the supporting members for the saw arbor and extending in upstanding relation inthe plane of operation of the blade so that it enters the saw kerf in the work, a basket-type guard member which is swingably connected to the splitter plate by a pair of connecting links, which links are pivoted at one end to the basket guard and at the other end to the splitter plate with the pivots being characterized by ball bearings which take up all the play between the pivoted members and of a saw guard assembly embodying the principalfeaturesof the invention with the guard being in its normal position relative to the saw blade and the work table therefor; Fig. 2 is a top plan view of the saw guard assembly; Fig. 3 is a cross section on the line 3-3 of Fig. 1 to an enlarged scale and with portions broken away;

' Fig. 4 is a cross section on the line 44 of Fig. l

to an enlarged scale;

Fig. 5 is a cross section on the line 5-5 of Fig. 1 to an enlarged. scale; and

ice

Fig. 6 is a perspective view, to an enlarged scale, of the guide mechanism for the guard.

The saw guard and splitter assembly which is illustrated in the drawings and which embodies therein the principal features of the invention is adapted to be employed in connection with a table saw, or like tool, such as the combination tool disclosed in my copending application Serial No. 548,614, filed November 23, 1955. The illustrated device is not, however, limited to a particular saw construction but is adapted for use on any bladelike tool having a frame or other supporting structure for the blade on which the splitter plate can be mounted.

The illustrated assembly comprises a basket-type guard 10 and a supporting splitter plate ll which is rigidly mounted on a bracket 12. The bracket 12 comprises an elongate-casting or similar structural member which is provided at its forward end with bolts 12 or other suita-- ble means for attaching the same to a trunnion support (not shown) or other frame portion of the saw supporting structure which is adapted to be tilted with the blade when the saw is adjusted for operation in a non-vertica plane. The splitter plate 11 is rigidly attached to the other or rearward end of the bracket 12 by a pair of bolts 14 or equivalent fastening means and projects in upstanding relation in the plane of operation of the saw blade, the latter being indicated at 15. The splitter plate 1.1 is of generally rectangular outline with a bracket forming projecting corner portion 16 which is apertured to receive the fastening bolts 14. The lower forward edge 17 of the splitter plate 11 is curved to conform approximately to the curvature of the blade 15 and is adapted to be positioned in confronting relation with the peripheral edge of the blade 15. The adjoining upper forward edge 18 of the splitter plate 11 has a convex curvature of predetermined radius.

The basket guard 10 is supported in swinging relation on the splitter plate 11 by a pair of connecting link members 20 and 20' which extend in parallel spaced relation along the side faces of the splitter plate 11. The connecting links 20 and 20' are supported at their rear ward ends on a pivot pin 21 which is journalled in a pair of roller bearings 22 and 22', the latter being spaced from the side face of the splitter plate 11 by a spacer member 23. The links 20 and 20' are connected to the basket guard 10 at their forward ends by means of a pivot pin 24 which is journalled in a pair of roller bearings 25 and 25' (Fig. 3), the latter being mounted in recess 26 and 26 in opposite faces of the basket guard 10 at a point near the top of the latter and approximately in its center in the lengthwise direction thereof.

- The basket" guard 10 comprises side face plates 27,27 of generally segmental outline which are joined at the forward portion thereof by in integral top web 28 having an aperture 29 which permits the operator to observe the blade 15 at its point of engagement with the work. The one plate 27 is somewhat shorter or of lesser depth thanthe opposite plate 27 so that the basket 10 may tilt with the saw blade Without interference with the table. The rear portions 30, 30 of the side plates 27 and 27 form rearwardly extending wings which are in parallel spaced relation with the side faces of the splitter plate 11 and which are open along their curved upper edges to provide clearance for movement of the basket 10 relative to the splitter plate 11 and its associated members.

The rearward marginal edge portions of the wings 30 of the recesses limiting the movement of .the basket.10-

relative to the links in the clockwise direction as viewed in Fig. l. The side plate portions 30 and 30' of the basket guard are apertured at 32 and 32 to receive a plug member 33 .(Fig. 6) which is secured therein .;by a set screw 34 and which is provided with a radially extending slot 35. The slot 35 issomewhat wider than the thickness of the splitter plate 11 and is located so as to accommodate therein the upper edge 18 of the splitter plate 11. The plug 33 is cut away on both sides of the slot 35 and a pair of' anti-friction rollers 36 and 36' are mounted on radially extending supporting pins $7 and 37' in the recesses formed "by the cut away portions. The pins 37, 37' are spaced at the sides of the slot 35 so that the rollers 36 and 36 engage the marginal portionsof the splitter plate 11 at the forward .edge portion 18 thereof and guide or steady the basket 10 as it moves or pivots on .the links it) and relative to the {splitter plate :11. The rollers .36, 36 act as guides to prevent any sidewise movement of the basket 10 relative to the splitter plate 1 1 while ,permittingfree movement of the basket in the vertical direction.

The splitter plate 11 carries a plurality of anti-kick back plates 38, 3 and 40 which .are mounted in swinging relation on a supporting pivot pin 41 projecting laterally of the splitter plate 11 at one side thereof. The anti-kick back plates 38, 39 and 40 are of generally rectangular outline with their downwardly facing edges being :on a diagonal and having work engaging points 42, 43 atopposite ends thereof. The anti-kick back plates 38, 39 and 40 are of different lengths so that they are operative to prevent the kick back of work of varying thickness. A stop pin 44 prevents counterclockwise movement of these plates.

In using the illustrated assembly the splitter plate 11, with the basket guard 10 connected thereto by the links 20 and 20' and with theanti kick : back plates 38, 39 and 40 mounted thereon, is rigidly attached by the bolts 14 to the supporting bracket '12 so that the splitter plate 11 is in the plane of operation of the saw blade. The basket guard '10 is normally positionedover the exposed. portion of the blade 15 in covering relation thereto. The lower edge of the basket 10 may, of course, rest on the upper face of the table portions, indicated at 45 in Figs. 1 and 5, which are adjacent the work slot for the saw blade 15. A work piece may then be fed to thesaw blade i5 beneath the basket guard 10 with the 'linksJZt), .20 .and the rollers 36 and 36' guiding the basket 10, as it is raised by passage of the work, :and holding the same in position without interference with the movement of the work piece therebeneath. The roller bearings 22 and 22' and 25, cooperate with the pivot pins 21 and 2410 insure smooth swinging operation of the basket 19 as it swings about the pins during its use.

While specific materials and particular details of construction have been referred to in describing the illustrated form of the invention, it will be understod *that different materials and other details of construction may be resorted to within the spirit of the invention.

1. In a circular saw having a work supporting table, a splitter plate, means for mounting said plate in rigid upstanding relation -.over the table behind the saw and in the plane of rotation thereof, a basket saw guard, and a pair of connecting link members pivotally connected at their opposite ends to the splitter plate and the basket guard, respectively, said basket guard having side wall members disposed in spaced relation on opposite sides of :the splitter plate and the saw blade, and anti-friction rollers rotatablvmounted in the side walls of the basket guard in position to engage on opposite sides of the splitter plate and-guide the basket in its swing-ingmovement relative toithe splitter plate.

.2. in combination "with a-saw table and a saw-blade supporting mechanism tiltable upon an axis'lying stibstantia-lly in the plane of the table top, a safety guard device comprising a bracket carried by said mechanism and tiltable therewith, a splitter plate connected with said bracket and projecting above the table, a basket guard having side wall portions which are spaced on opposite sides of the blade and extend in spaced relation along opposite faces of the splitter plate, said outside faces of the side Wall portions having recesses in the upper edges thereof and a pair of links pivotally connecting the basket guard with the splitter plate, said links being connected at one of their ends to the splitter plate by ball bearing members, said links extending at their other ends into the edge recesses of said side wall portions and being connected to the basket guard by ball bearing members seated in said recesses.

3. A guard assembly for a circular saw which is characterized by a work supporting table top and a saw supporting mechanism which is tiltable relative to the top, a bracket secured'onsaid'saw supporting mechanism and a splitter .plate rigidly connected with said bracket extending above the table top, a basket guard adapted to rest on the table top and having side wall portions in spaced relation on opposite sides of the saw blade, a pair of link members hingedly connecting the basket guard with the splitter plate, said link members being hinged to the basket guard and the splitter :plate by pins mounted in ball bearings, and said basket guard having anti-friction means mounted 'in the upper portions of the side Walls thereof and engageable with side ,face portions of the splitter plate to guide the basket guard in its swinging movements relative tothe splitter plate.

4. A guard assembly for a power tool which is characterized by a work supporting table top and a blade supporting mechanism which is tiltable relative to the table top, a bracket secured to said supporting mechanism and a splitter plate secured to said bracket and extending a substantial distance above the table top forwardly of the blade and inthe plane of operation there-.

of, the splitter plate having the edge thereof adjacent the blade convexly curved, a basket guard for the blade having side wall portions which are spaced on opposite sides of the plane of operation of the blade and which extend in spaced relation along the opposite faces of the splitter plate, a pair of links pivotally connecting the intermediate upper portion of the basket guard and a portion of the splitter plate which is forwardly of the blade to permit the basket guard to swing upwardly relative to the blade, the side wall portions of the basket guard having aligned apertures and aslotted plug member secured in the apertures, said plug member being arranged 'to encompass the curved edge of the splitter plate, and a pair of anti-friction rollers carried by the plug member and spaced .laterally of each other for engagement with opposite side faces of the splitter plate adjacent the curved edge thereof.

5. In a circular. saw, a safety device comprising .a splitter plate, means for mounting said plate :in rigid upstanding relationbehind the saw and in the plane .ofrotation thereof, a basket saw guard, a pair of link members pivotally connected at their opposite ends to the splitter plate and the basket guard, respectively, said basket guard having side wall members disposed in spaced relation on opposite sides of the splitter plate and the saw blade, and anti-friction members mounted on the side walls of the basket guard and spaced to engage on opposite sides of the splitterplate and guide the basket in its swinging movement in the plane of the splitter plate.

6. In combination with a table saw having a saw supporting mechanism mounted .to tilt relative to the table, a safety guard device comprising an .upright bracket carried by said supporting mechanism and tiltable therewith, a splitter plate connected with said bracket andprojecting above the table, a basket guard having side wall members spaced on opposite sides of the splitter plate and the saw blade, a pair of spaced parallel link members pivotally connecting side wall members of sa'idibasket award with the splitter plate, said link members being connected adjacent their opposite ends with the splitter plate and said side wall members by ball bearing members, said basket guard having anti-friction members mounted on the inner faces of the side Wall members thereof which are spaced to engage on opposite sides of the splitter plate and guide the basket in its swinging movement.

7. A guard assembly for a circular saw which is characterized by a work supporting table top and a saw supporting mechanism which is tiltable relative to the top, a bracket secured on said saw supporting mechanism and a splitter plate rigidly connected with said bracket and extending above the table top, a basket guard having side wall portions in spaced relation for positioning on opposite sides of the saw blade, a pair of link members hingedly connecting the 'basket guard with the splitter plate, said link members being hinged to the basket guard and the splitter plate by ball bearing formations, and said basket guard having anti-friction means mounted in the side walls thereof and engageable with opposite side face portions of the splitter plate to guide the basket in its swinging movements relative to the splitter plate.

8. A guard assembly for a power tool which is characterized by a work supporting table top and a blade supporting mechanism which is tiltable relative to the table top, a bracket secured to said supporting mechanism and a splitter plate secured to said bracket and extending a substantial distance above the table top adjacent the blade and in the plane of operation thereof, the splitter plate having the edge thereof immediately adjacent the blade convexly curved, a basket guard for the blade having side walls which are spaced on opposite sides of the plane of operation of the blade and which have wing-like extensions arranged in spaced relation along the opposite faces of the splitter plate, a pair of links pivotally connecting the upper portion of the basket and a portion of the splitter plate which is spaced from the blade to permit the basket to swing upwardly relative to the blade, said side wall extensions having aligned apertures and a plug member secured in the apertures, said plug member being cut away to encompass the curved edge of the splitter plate, and a pair of antifriction rollers mounted on the plug member and spaced laterally of each other for engagement with opposite side faces of the splitter plate adjacent the curved edge thereof. 9. In a cir-cular saw having a work supporting table, a splitter plate, means for mounting said plate in rigid upstanding relation over the table behind the saw and in the plane of rotation thereof, a basket saw guard, and a pair of connecting link members pivotally connected at their opposite ends to the splitter plate and the basket guard, respectively, said basket guard having side wall members disposed in spaced relation on opposite sides of the splitter plate and the saw blade, said side wall members having aligned apertures, a plug-like member in said apertures and anti-friction rollers rotatably mounted on said plug-like member in position to engage on opposite sides of the splitter plate and guide the basket in its swinging movement relative to the splitter plate.

References Cited in the file of this patent UNITED STATES PATENTS 1,037,843 Ackley Sept. 10, 1912 1,381,612 Anderson June 14, 1921 2,095,330 Hedgpeth Oct. 12, 1937 2,623,555 Eschen'burg Dec. 30; 1952

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