US2919631A

US2919631A - Shaving tool

Info

Publication number: US2919631A
Application number: US707535A
Authority: US
Inventors: Arthur R Skaran
Original assignee: Boeing Co
Current assignee: Boeing Co
Priority date: 1958-01-07
Filing date: 1958-01-07
Publication date: 1960-01-05
Anticipated expiration: 1977-01-05

Description

Jan. 5, 1960 SKARAN 2,919,631

SHAVING TOOL Filed Jan. 7, 1958 INVENTOR. g Aer/me 7,. [AKA/V A from/5y Unite States SHAVING TOOL Application January 7, 1958, Serial No. 707,535

4 Claims. (Cl. 90-12) This invention relates to a cutting tool and more particularly to a portable tool for shaving down local protuberances from a generally flat surface, and more particularly for shaving down the heads of rivets which are countersunk and are intended to be flush fitted.

Heretofore various types of shaving tools have been provided for shaving local protuberances such as rivets. In the case of aluminum rivets a shaving tool is utilized whose cutter rotates about an axis that is perpendicular to the work. For shaving aluminum rivets this prior art tool is satisfactory. However, this same tool is totally unsatisfactory for shaving rivets made of titanium since it is substantially impossible to hold the cutter on the rivet owing to the high tensile properties of the work. In addition when using this prior art tool extensive sparking is produced which effects a hazardous condition where dust or other combustible material is in the air.

Shaving tools have also been provided in which the cutter rotates about an axis which is perpendicular to the axis of the primary drive shaft. When such a prior art shaving tool is applied to a titanium rivet a surface is produced which is not level but rather consists of a plurality of troughs and crests. Further, when utilizing such a prior art tool there is a tendency for the tool to veer off the work thus requiring the operator to exert a relatively large restraining force to hold the tool in position.

Therefore, an object of this invention is to provide a tool capable of shaving protuberances such as rivet heads constructed of high strength steel or titanium to a close flushness tolerance.

Another object of this invention is to provide for minimizing the lateral thrust on the cutter end of a shaving tool when shaving a protuberance such as a titanium rivet head, to thus minimize the pressure required. to be exerted by the operator on the tool when performing the shaving operation.

A further object of this invention is to provide for so constructing a shaving tool that a minimum of sparks are produced during the shaving operation, to thus render the tool non-hazardous.

Still another object of this invention is to provide a tool capable of shaving in one operation titanium or high strength steel rivet heads so that they are flush with the panel through which they extend and have a smooth polished surface.

A more specific object of this invention is to provide for effecting a rotation of a rotary cutter about the axis of its own shaft which is perpendicular to the axis of the primary drive shaft and for simultaneously effecting a rotation of the rotary cutter about the projected axis of the primary drive shaft, to thus provide a shaving tool capable of shaving a protuberance to a close flushness tolerance.

Other objects of this invention will become apparent when taken in conjunction with the accompanying drawing in which:

Fig. 1 is a cross-sectional view of a shaving tool embodying the teachings of this invention, and

atent O Patented Jan. 5, 1960 Fig. 2 is a schematic perspective view of the rotary cutter and its associated drive and gear means for effecting a rotation of the cutter about two axes.

Referring to Figs. 1 and 2 there is illustrated a shaving tool 10 embodying the teachings of this invention. In general, the shaving tool 10 comprises a rotary cutter 12 which is keyed to a cutter shaft 14, the cutter 12 and the shaft 14 being carried by a head 16; a primary drive shaft 18 and a secondary drive shaft 20 disposed to be driven by an actuating means, specifically a motor 22; gear means 24 interconnected between the primary drive shaft 18 and the cutter shaft 14 for effecting a rotation of the rotary cutter 12 about the axis 26 of the cutter shaft 14, the axis 26 being substantially perpendicular to the axis 28 of the primary drive shaft 18; gear means 29 for rendering the secondary drive shaft 20 responsive to the rotation of the primary drive shaft 18; gear means 30 interconnected between the secondary drive shaft 20 and the head 16 for effecting a rotation of the cutter 12 about a projection of the axis 28 of the primary drive shaft 18; and means 31 for interconnecting the motor 22 with the shaver enclosure 32. The rotary cutter 12 is of substantially cylindrical shape and has disposed about its outer periphery a plurality of cutting edges, specifically equally spaced teeth 33. In practice, it has been found that 40 teeth for the rotary cutter 12 elfect a satisfactory result.

As illustrated in Fig. 2, the motor 22 is mechanically connected to a chuck 34 by means of a shaft 35, the primary drive shaft 28 being inserted in the chuck 34 and suitably secured thereto in a well-known manner.

In particular, the gear means 24 includes meshed bevel gears 36 and 33 which are provided to effect a degree change in the plane of rotation. In practice, the bevel gear 36 is keyed to the primary drive shaft 18 while the bevel gear 38 is keyed to an intermediate shaft 40. A spur gear 42 is also keyed to the intermediate shaft 40 and is disposed to mesh with an idler gear 44 which is suitably secured to an idler gear shaft 46 which is free to rotate in a passageway 48 disposed in the head 16. As can be seen from Figs. 1 and 2, another spur gear 50 is dis posed to mesh with the idler gear 44, the spur gear 50 being keyed to the cutter shaft 14. By providing the idler gear 44 the size of the shaving tool 10 is minimized since if the gears 42 and 50 were so enlarged as to mesh together additional space would be required.

Ball bearings 52 and 54 are disposed in counterbores 56 and 58, respectively, and function as the bearing surfaces for the intermediate shaft 40. The bearing surfaces for the cutter shaft 14 are provided by needle bearings 60 and 6-2 which are disposed in counterbores 64 and 66, respectively.

In order to prevent a lateral thrust of the head 16 relative to the shaver enclosure 32 a needle bearing 70 and a ball bearing 72 are disposed between the head 16 and the shaver enclosure 32. As illustrated in Fig. l, the inner race 74, of the ball bearing 72, is snugly disposed between a gear retainer ring 76 and a shoulder 78, of the head 16, the gear retainer ring 76 being secured to the head 16 by means of screws 80. v

As hereinbefore mentioned, the secondary drive shaft 28 is rendered responsive to the rotation of the primary drive shaft 18 by means of a gear train 29. As illustrated, the gear train 29 includes a worm 84 which is keyed to the primary drive shaft 18, a worm gear 86 disposed to mesh with the worm 84, the worm gear 86 being keyed to a worm gear shaft 88 which is carried by a gear housing 90 so as to maintain the worm gear 86 in position relative to the worm 84. In this instance, the gear housing 9%) is held in fixed relationship with respect to the shaver enclosure 32 by means of screws 92. ,Also included in the gear train 29 is a bevel gear 94 which is as Q) also keyed to the Worm gear shaft 88 and is disposed to mesh with another bevel gear 96, which is keyed to the secondary drive shaft 20, to thus effect a change of 90 degrees in the plane of rotation.

The gear means 3% is interconnected between the secondary drive shaft 2t and the head 16 in order to effect a rotation of the cutter 12 about a projection of the axis 23 of the primary drive shaft 18. In this instance, the gear means 38 includes a pinion gear 88 which is keyed to the secondary drive shaft 2% and which is disposed to mesh with an internal gear 953, the internal gear 99 being 7 secured to the gear retainer 76 by means of screws 92.

The bearing surface for the secondary drive shaft 2D is provided by a needle bearing 93 while the bearing surfaces for the primary drive shaft 13 is provided by the ball bearing 19% and needle bearings M2 and 1nd.

in order to be able to vary the magnitude of the cut to be made by the rotary cutter 12 a nose piece 1% is threadedly engaged with and disposed for cooperation with a collar 1%. The collar 1% has a plurality of vertically disposed slots 11%, as shown, which are equally spaced about the inner periphery of the collar 1%. Pins 112 which are secured to the shaver enclosure 32 are disposed to slide within the slots 12 so as to permit an axial movement of the collar 1% within predetermined limits as determined by the length of the slots 112 and yet prevent a peripheral movement of the collar A com pression spring 114 is disposed between the collar 1% and an integral flange 11b of the shaver enclosure 32. The compression spring 114 functions to force the nose piece 106 to an extended position in which the nose piece 1% extends out beyond the rotary cutter 12. Thus, when the tool it is not in use the cutter 12 cannot be easily damaged. in addition, the compression spring 114 in cooperation with the other associated components 108, 112 and 116 functions to increase the stability of the tool 16 since the lower tip of the nose 1% engages the surface surrounding the protuberance to be out before the cutter 12 engages the protuberance. in other words, the compression spring 114 helps to prevent lateral movement of the nose piece 1% during the cutting operation, thus also helping to prevent a lateral movement of the cutter 12 during the cutting operation.

A collar 113 which is disposed around the shaver enclosure 32 and is suitably secured thereto functions to prevent lateral movement of the nose piece 1% relative to the shaver enclosure 32, there being freedom of movement between the collar 118 and the nose piece 105.

The operation of the shaving tool it} will now be briefly described. However, before putting the tool 1% into operation the nose piece 1% is adjusted so as to obtain the desired cutting depth. The nose piece 1% is then placed against the surface surrounding the protuberance to be cut and pressure is exerted downwardly on the tool 1 3 until the cutter 12 engages the protuberance. Upon further pressure being exerted downwardly on the tool the pins 112 reach their limiting positions within the slots 119, the latter position being represented in Fig. 1.

In operation, the motor 22 efiects a rotation of the primary drive shaft 18 which in turn effects a rotation of the bevel gears 36 and 38, the spur gear 42, the idler gear 44, the spur gear 54) and finally a rotation of the rotary cutter 12 about the axis Simultaneously, the rotation of the primary drive shaft 13 effects a rotation of the worm 84 and thus a rotation of the worm gear 36, the bevel gears 94 and 95, the pinion gear 68 and finally a rotation of the internal gear which is secured to the head 16 through the gear retainer ring 76, to thereby effect a rotation of the head 16 and thus a rotation of the cutter 12 about a projection of the axis 23 of the primary drive shaft 13. In practice, it has been found that best results are obtained when the speed of rotation of the cutter 12 about the axis 25 is between 175 and 700 times the speed of rotation of the cutter 12 about the projection of the axis 23 of the primary drive shaft 18.

The apparatus embodying the teachings of this invention has several advantages. For instance, protuberances constructed of high strength steel or titanium can be shaved to a close fiushness tolerance. in addition, a minimum of pressure is required to be exerted by the operator when performing the operation since there is no large lateral force tending to cause the cutter 12 to veer off the work, such as a rivet head. Further, a minimum of sparks are produced during the shaving operation, thus rendering the tool non-hazardous. it is also possible to effect the shaving to a close fiushness tolerance in one single operation.

Since numerous changes may be made in the above apparatus and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all matter contained in the foregoing description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. In a shaving tool, the combination comprising, an actuating means, a primary drive shaft and a secondary drive shaft disposed to be driven by said actuating means, a rotary cutter having an outer periphery and being carried by a cutter shaft, the axis of the cutter shaft being substantially perpendicular to the axis of the primary drive shaft, a head for carrying the cutter shaft and the rotary cutter, means interconnected between the primary drive shaft and the cutter shaft for effecting a rotation of the rotary cutter about the axis of the cutter shaft, means interconnected between the secondary drive shaft and said head for rotating said head and for efiecting a rotation of the rotary cutter about the projected axis of the primary drive shaft, and a nose piece connected to said head and adjustable with respect to the outer periphery of said cutter in a direction parallel to said axis of the primary drive shaft to vary the magnitude of the cut to be made by said cutter.

2. in a shaving tool, the combination comprising, an actuating means, a primary drive shaft and a secondary drive shaft disposed to be driven by said actuating means, a rotary cutter having an outer periphery and being carried by a cutter shaft, the axis of the cutter shaft being substantially perpendicular to the axis of the primary drive shaft, a head for carrying the cutter shaft and the rotary cutter, means interconnected between the primary drive shaft and the cutter shaft for efiecting a rotation of the rotary cutter about the axis of the cutter shaft, means interconnected between the secondary drive shaft and said head for rotating said head and for effecting a rotation of the rotary cutter about the projected axis of the primary drive shaft at a substantially lesser speed of rotation than the speed of rotation of the rotary cutter about the cutter axis, and a nose piece connected to said head and adjustable with respect to the outer periphery of said cutter in a direction parallel to said axis of the primary drive shaft to vary the magnitude of the cut to be made by said cutter.

3. in a shaving tool, the combination comprisin an actuating means, a primary drive shaft and a secondary drive shaft disposed to be driven by said actuating means, a rotary cutter having an outer periphery and being carried by a cutter shaft, the axis of the cutter shaft being substantially perpendicular to the axis of the primary drive shaft, a head for carrying the cutter shaft and the rotary cutter, means interconnected between the secondary drive shaft and said head for rotating said head and for effecting a rotation of the rotary cutter about the projected axis of the primary drive shaft, means interconnected between the primary drive shaft and the cutter shaft for effecting a rotation of the rotary cutter about the axis of the cutter shaft at a speed of rotation of between and 700 times as great as the speed of rotation of the rotary cutter about the projected axis of the primary drive shaft, and a nose piece connected to so... omPw-w.

5 said head and adjustable with respect to the outer periphery of said cutter in a direction parallel to said axis of the primary drive shaft to vary the magnitude of the cut to be made by said cutter.

4. In a shaving tool, the combination comprising, a cutter shaft having an axis, a rotary cutter having an outer periphery and being carried by said cutter shaft, means connected to said cutter shaft for effecting a rotation of said rotary cutter about the axis of said cutter shaft, means connected to said cutter shaft for simultaneously effecting a rotation of said rotary cutter about an axis that is substantially perpendicular to the axis of said cutter shaft, and a nose piece connected to said last mentioned means and adjustable with respect to the outer periphery of said cutter in a direction parallel to said perpendicular axis to vary the magnitude of the cut to be made by said cutter.

References Cited in the file of this patent UNITED STATES PATENTS 1,388,496 Wadsworth Aug. 23, 1921 10 2,367,555 Arney Jan. 16, 1945 FOREIGN PATENTS 693,026 Great Britain June 17, 1953