US2948088A - Abrading machine - Google Patents

Description

Aug. 9, 1960 Filed Sept. 6, 1957 l. JEPSON ABRADING MACHINE 3 Sheets-Sheet 1 Aug. 9, 1960 I. JEPSON ABRADING MACHINE 5 Sheets-Sheet -2 Filed Sept. 6, 1957 1960 l. JEPSON ABRADING MACHINE 3 Sheets-Sheet 3 Filed Sept. 6, 1957 IIIII"'.

III will!!! 4 j? ki 415 States ABRADING MACHINE Filed Sept. 6, 1957, Ser. No. 682,349

3 Claims. (C1. 51-166) This invention relates to an abrading machine, and more particularly to a combined grinder-sander-honer.

There have been provided in the past abrading machines of the type having a motor having grinding wheels mounted on the ends of its shaft and a second or honer shaft connected by a Worm gear to the motor shaft and mounting a honer turntable thereon. The motor housing is split so that access is provided to the interior parts of the motor and one end of the housing carries one shaft bearing while the other end of the housing has bearings for the other end of the motor shaft and the second shaft. Since the grinding wheels are heavy and must be rotated at high speed, the motor shaft and the bearings and housing have had to be heavy. Since the housing is split, there has been difficulty in aligning the motor shaft bearings and keeping the bearings aligned during use. Another problem existing in the prior art devices has been that of maintaining lubricating material in the shaft bearings and in the gearing connecting the motor shaft to the honer shaft. Also, since abrading elements are connected directly to the shaft of the motor,

the motor must have a speed near the optimum for the abrading elements, and this speed is much lower than the optimum for the electric motor. As a result, the motor has had to be large and heavy to provide the necessary power at the slower speed of operation. Another disadvantage of the prior art machines has been that the machines have either been of the type described above in which the abrading discs are fixed directly to the motor shaft so that repair and maintenance of the motor is diflicult or of a type where an external separately mounted motor is connected by a belt to the driving Patented Aug. 9, 1960 a boner turntable shaft is connected by a worm gearing to the drive shaft with seals at the openings in the walls of the recess through which the drive shaft extends.

Other objects of the invention will become apparent from the following detailed description. of a grindersander-honer forming a specific embodiment thereof, when read in conjunction with the appended drawings, in which:

Fig. l is a top plan view of a grinder-sander-honer forming one embodiment of the invention;

, Fig. 2 is a side elevation of the grindersander-honer shown in Fig. 1;

Fig. 3 is a side elevation of the grinder-sander-honer shown in Fig. 1;

Fig. 4 is a fragmentary, bottom plan view of the grinder-sander-honer shown in Fig. 1;

Fig. 5 is. an enlarged vertical section taken along line 5-5 of Fig. 1;

Fig. 6 is a fragmentary enlarged vertical section taken along line 66 of Fig. 5;

Fig. 7 is a vertical section of the housing of the grinder-sander-honer shown in Fig. 1; and

Fig. 8 is a bottom plan view of the housing shown in Fig. 7.

The present invention provides a grinder-sander-honer in which a motor is detachably mounted as a unit in the machine. A one-piece housing serves to mount both the motor and a drive shaft mounted independently of the motor. The drive shaft carries a grinding wheel on one end and a sanding disc on the other end. The

shaft passes through openings in a cup-shaped grease shaft and the motor and grinder or abrader are in no sense unitary. Also, the prior art abrading machines of the unitary type are heavy and diflicult to move around, this being a disadvantage particularly where the machines are used in a home workshop where portability is important.

It is, accordingly, an object of the invention to provide a new and improved abrading machine.

Another object of the invention is to provide a grindersander-honer of rugged construction and high power while being light in weight.

Still another object of the invention is to provide a grinder-sander-honer in which the abrading elements and the driving motor form a unitary assembly with the motor being detachable as a unit from the other elements.

Yet another object of the invention is to provide a grinder-sander-honer in which'a grinderand a sander are mounted on opposite ends of a shaft and a second shaft mounts a honer and is connected by gearing to the first shaft in a socket formed in a housing with seals to make the socket a tight grease container,

A further object of the invention is to provide a grinder-sander-honer having a housing in which a motor is detachably.rnounted and the housing mounts a drive shaft separate from the motor ina position passing through a grease-containing recess in the housing in which container in the top of the housing, and is connected by worm gearing in the container to a homer shaft mounted in a bearing supported by a cover for the recess. Since the motor is mounted separately from the drive shaft, the motor may beof the series-wound, high speed type which provides a high power to weight ratio, and reduction gearing is provided to connect the motor to the drive shaft.

In the grinder-sander-honer shown in the drawings, there is provided-a one-piece cast housing 10, which may be composed of die cast aluminum or the like, and the housing serves to mount a main or drive shaft 11 in bushings 12 and .13 (Fig. 5). The bushings are press fitted in journals 14 and 15 formed in the one-piece housing 10. To provide alignment of the bushings, the journals are line reamed so that they are perfectly in alignment with one another. The shaft 11 has a grinding wheel 17 keyed to one end thereof and a sanding disc or plate 18 mounted on the other end thereof and is driven by a toothed pulley or sprocket 19 secured rigidly thereon by a pin 20. The shaft 11 is driven through the pulley 19 by means of a toothed belt 21 of a known type driven by a toothed pulley 22 mounted on an armature shaft 23 of an electric motor 24.

The motor 24 is a series-wound motor of known construction with self-aligning bearings and has a fan therein for cooling purposes. The motor rotates its armature shaft 23 at a higher rate of speed than that desired for the grinding wheel 17 and the sanding disc 18, and, to provide the proper speed for the elements 17 and 18-, the pulley 22 is made substantially smaller than the pulley 19 so that a speed reduction is effected therebetween. The motor is provided with slotted mounting brackets 28 secured to the housing 10* by means of screws 29 projecting into tappedbores 30 (Fig. 8) formed in posts 31 cast integrally with the top wall of the housing 10 and reinforced by cast Webs 32.

A bottom cover plate 35 (Figs. 4 and 5) having air openings'36 is secured to the bottom of the housing by screws 37 threaded to tapped post portions 38 formed integrally with the housing 10. To form a grease-retaining compartment, the housing 10 is also provided with a cup-shaped container 41 opening at the top thereof and integral with the top wall of the housing 10, and the container 41 is provided with aligned bores 42 in which are mounted grommets '43 of neoprene (polymeriz cd chloroprene). A sin-tered bronze bearing 47having a mounting flange 48 is secured in the lower portion of the container 41 by screws 45 threaded into tapped bores '50 formed in an annular shoulder 51 of the container 41. A cover plate 52 rests on the shoulder 51 to retain grease in the container 41, and is held in place by the flange 48. The bearing 47 mounts a honer shaft 55 rotatably therein. A worm gear 56 is pinned to the lower end of shaft '55, and meshes with a worm gear 57 formed on the shaft 11. A turntable'cup 61 has a sleeve portion 62 keyed to the upperend of the shaft 55, and serves to support 'and rotate a honerdisc or stone 63 of a fine abrasive material with a felt grip pad 64 positioned between the cup 61 and the disc 63. To form an enclosed chamber formed in the lower portion of the container41, the flange 48 'of the bearing 47 holds the cover 52 against the shoulder 51, and the chamber is filled with aknown non-liquid grease and is made grease-tight by the grommets 43 so that the Worm gears '56 and 57 are immersed in grease. There is a substantial speed reduction eifected by the gears 56 and 57 between the shafts '11 and 55 so that the honer 63 is rotated at an optimum speed for honing. The grinding disc 17 and the sanding disc 18 are rotated at a speed ideally suited for grinding and sanding. For the purpose of supporting articles to be honed, and 'L-shaped rod 71 is mounted in aboss 72 cast integrally with the housing "10, and held in adjusted position by a set screw 73.

To mount the grinding disc 17 on the shaft 11, the disc 17 is clamped between a flanged sleeve 82 and a Washer 83 (Figs. 2 and the sleeve 82 being provided with notches 85 through which a pin 84 extends to key the sleeve 82 to the shaft 11. A nut 86 is screwed onto a threaded end 87 of the shaft 11 to press the washer 83 toward thesleeve 82 to tightly clamp'the wheel .17 and drive the wheel 17 by means of frictional engagement 'therebetween. A cup-shaped guard 88 is secured by screws 89 to .the housing and has a wedge-shaped opening 90 to provide access to one portion of the periphery of the wheel17 for grinding purposes. The left hand'face of the wheel '17., .as'viewed in Fig. 1, also is accessible for grinding purposes. A mounting bracket 92 is secured to the housing .10 by means of screws 93, and a tool sup.- port or rest 94 is adjustably mounted on the bracket by means of abolt 9 5 and a slot 96. 'To prevent tools from accidentally being introduced between the wheel 17 and the support 94, the tool support 94 is provided with a lip portion 97 extending along and spaced from the disc 17. A transparent guard 101 is supported by a frame 102 pivotally secured to the guard 88 by post 104 and -a bolt 103., and may be adjusted to desired positions. The frame 102 is connected rigidly to the post 104, which is pivotally connected to the guard 88 by means of the bolt 103.

At the right hand .end of the shaft 11, as viewed in Fig. 5 a thrust nut 111 is screwed overa threaded end 112 of the shaft 11 and a washer 113 being positioned between the bushing 13 and the nut 111 to minimize friction between the nut 111 and the bushing 13. The sanding disc plate 18 is provided with a tapped bore 115 which isthreaded over the end 112 until the plate l tl engages the nut 111. The threads of the shaft 11 and the plate "18 are in a direction relative to rotation of the shaft; by the motor 24 such that the plate 18 tends to be threaded further on the shaft by rotation of the shaft the motor. A disc of sandpaper having a pressure sensitive adhesive backing may be secured to the face 11'? of the plate 18. The sandpaper disc may. also be glued to the wheel 18. Re-enforcingwebs v are provided for the 4 plate 18 along with a .re-enforcing periphery 121. A cupshaped guard is secured to the housing 10 by screws 126 and covers the upper portion of the plate 18. A sander work rest 130 is generally L-sh-aped and is reenforced by webs 131 and 132. The work rest 130 has slots 133 formed therein so that the work rest may be removed from the grinder merely by unloosing screws 134 threaded into tapped bores formed in bosses 135 (Figs. 3 and 4) cast integrally with the housing 10.

Molded rubber feet 141 are mounted in openings formed in the corners of the housing 10 and serve to support the housing in an elevated position from the top of a bench or the Whereit is to be used. This permits cooling air to flow through the openings 36 in the cover plate 35 from'the action of the fan in the motor 24. A switch 15 1 (Figs. 3 and 4) is mounted in the front wall of the housing 10, and is connected by conductors152 and,153 (Fig. 4) to conductors 154 and 155, respectively, by connectors 156. A connector 157 serves to connect a conductor 158 of the motor 24 to a conductor 15,9 of a jacketed cord 160 leading to a plug (not shown) which may be inserted into a socket to connect the grinder to a source of electric power. The cord 160 passes through a grommet 1'61 mounted in the rear wall of the grinder, and the grommet serves. to grip the cord 160 to relieve strain from the connectors 156 and 157. 'It will be seen that the motor 24 may be readily removed from the: housing merely by unscrewing the connectors 156 and 157 and removing the screws 29 (Figs. 5 and6), all this being done after the bottom cover plate 35 is. removed from the housing 10, of course.

For 'lnbricating'purposes, the bushings 12 and 13 (Fig. 5) are composed of porous bronze, and to provide lubrication between the bushings 12 and 13 and the shaft 11, there are provided oil holes 171 and 172 open at the top to receive oil and at the bottom to the bushings 12 and 13,. The bores 171 and 172 are filled with oil-retaining absorbent material 173 such as wicking, felt or the like. Perforated'discs 174 are provided for covering the upper ends of the bores 171 and 172 and serve to provide oil holes to permit oil to be introduced into the wicking 173 and maintain oil on'the bushings 12 and 13. A U-ring 176 mounted in a counterbore 177 formed in the housing 10 seals the shaft and bushing 12 against leakage. of; oil into the guard 88. Similarly, the washer 113 restricts seepage of oil into the housing 125 cover ing the sanding disc 119.

Itshould be noted that-the above-described grindersander honeris provided with a light-weight, high powered,.heavy duty, series-wound motor 24 which, although op rating at a high speed; drives the grinding wheel 17 and sanding plate. 18-at an optimum speed, for grinding andsandfing. The, motor 24 is detachable as a unit from the rest of- .the. machine for maintenance, and repair purposes thereon. 'The motor 24 has only standard size bearings since its armature shaft 23 does not mount the heavy wheel,17 and plate 18. Hence, the shaft 23 may be much smallerqt-han the shaft 11. The honer assembly including the, disc 63, shaft 55, the worm gear 56,. and the flanged bearing sleeve 47 is remoyahlefrom the housing :10. as a unit and holes 58. and 59 are provided in the felt disc 6i4=and the wheel 61 to permit the screws 49 to-be loosened for removal of the honer assembly. The container-41 of the housing and cover plate 52' along with the grommets 43*f orm a greaseti'ght container for retaining the grease therein.

While there has been illustrated and described a par ticular' embodiment of the. present invention, it be apparent to those skilled in thefthat various modifications may bendade without departing from the invention in. i b oad r. a pe and .it, is theref re. i ed in the app nd d c aim fl-Gover all suchhange modifies:

, ags. as fa l; Mthint e true sp t and. scop it-he present 75 V r I ment on, q

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. In an abrading machine, a unitary inverted cupshaped housing having a recess in one wall thereof and also being provided with horizontally aligned openings in the walls of said recess, a first shaft extending through said openings, bearing means supported by said housing for rotatably mounting said first shaft, seals mounted in said openings, a second shaft, a cover plate closing said recess and having an opening for said second shaft, bearing means supported in said recess and mounting said second shaft for rotation about a vertical axis, gear means in said recess below said cover plate connecting said first and second shafts, said seals and said cover plate serving with the walls of said recess to form a grease-tight compartment, a motor mounted on the inside of said unitary housing displaced from said first shaft, power transmission means interconnecting said motor and said first shaft, and abrasive wheels mounted on the ends of said first shaft and on the top of said second shaft outside of said unitary housing.

2. In an abrading machine, a housing open at the bottom and having a cup-shaped re-entrant portion opening at the top thereof, said portion being provided with aligned openings in the side walls thereof, a cover plate covering the upper side of said portion and having an opening therein, a first shaft, bearing means mounted in said opening in said cover plate mounting said shaft rotatably, sealing grommets mounted in said aligned openings, a drive shaft extending through said grommets, said housing having openings in the outer walls thereof through which said drive shaft extends, bearing means mounted in the last-mentioned openings, a motor detachably secured to the top of said housing in a position enclosed in said housing, means connecting said motor to said shaft, a cover for the bottom of said housing, and abrading means mounted on the ends of said shafts.

3. An abrading machine comprising a one-piece housing member having an open bottom and a cup-shaped re-en-trant portion in the top wall thereof, said cup-shaped portion having a mouth opening upwardly, said portion being provided with aligned openings in the side walls thereof, a plate covering said mouth and having an opening therein, a first shaft, bearing means for said first shaft mounted in said portion and extending through said opening in said plate, a drive shaft extending through said aligned openings perpendicular to said first shaft, sealing means positioned in said aligned openings to sealingly engage said drive shaft, said housing having openings in the outer walls thereof through which said drive shaft extends, bearing means mounted in said last-mentioned openings, said housing having posts extending along opposite sides of said re-entrant portion to a level below said re-entrant portion, a motor secured to said posts in a position enclosed in said housing, power transmission means connecting said motor to said drive shaft, and abrading means mounted on the ends of said drive shaft and on the upper end of said first shaft.

References Cited in the file of this patent UNITED STATES PATENTS

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