Power Driven Shaper Apparatus

Abstract

A shaper spindle and cutter are received in bearings in a hollow retaining quill and this assembly of parts is mounted for vertical adjustment in a shaper housing having a split cylindrical body suspended from the underside of an upright work table member. A special pulley housing attached at the lower end of the shaper housing contains a drive pulley isolated in vertically spaced bearings. The pulley is formed with a vertical spindle aperture in which is fixed a female spline drive element and within which is slidably supported a male spindle spline section. Stationary power driving means in the table member carries a pulley belt which engages around the drive pulley in constant alignment and with radial load imposed by the tension of the belt being effectively taken up by the vertically spaced bearings without transfer of any appreciable part of the load to the spindle.

Description

FIELD OF THE INVENTION

This invention relates to power driven apparatus and more particularly to a power tool of the class commonly referred to as a shaper in which a cutter element is supported at the upper end of a vertically adjustable spindle and is driven at high speed about a vertical axis of rotation.

DESCRIPTION OF THE PRIOR ART

In conventional shaper apparatus construction, certain problems may develop in connection with mounting the shaper spindle for rotative movement about a vertical axis at relatively high speeds where a motor driven pulley is belted to a driver pulley for the spindle. The radial load forces imposed on the unsupported end of a shaper spindle as driven by conventional pulley means may cause bending and flexing of the spindle resulting in vibration of an undesirable nature at higher operating speeds. Misalignment of the pulleys and the belt member may result in the belt becoming stretched or in undesirable increase in belt tension may develop, or the belt may be thrown off from the driver pulley or repeated stretching of the belt may result in its service life being materially shortened. It becomes more difficult to deal with these conditions while at the same time providing for vertical adjustment of the spindle and ease of adjustment in a range of cutting positions.

SUMMARY OF THE INVENTION

It is a chief object of the invention, therefore, to provide an improved power tool of the shaper class and to devise an improved method of driving the unsupported end of a shaper spindle in a manner such that radial load forces imposed on the spindle are eliminated or greatly reduced and flexing and vibration are controlled.

Another object is to devise an improved pulley drive for a shaper spindle in which difficulties in belt alignment are eliminated.

Another object is to devise in combination with a spindle and cutter assembly a mechanism for vertically adjusting the spindle while it is being driven without imposing undesirable loads on the spindle and without causing misalignment of a motor driven pulley belt for actuating the spindle.

Still another object is to provide an independently housed pulley and pulley driven belt for a spindle and cutter assembly, which is vertically adjustable, wherein load forces exerted radially or at right angles to the axis of the spindle are taken up by bearing members located at upper and lower sides of the pulley member.

The nature of the invention and its other objects and novel features will be more fully understood and appreciated from the following description of a preferred embodiment of the invention selected for purposes of illustration and shown in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a work table illustrating a shaper cutting element in one position of adjustment.

FIG. 2 is another fragmentary perspective view of a work table illustrating the shaper cutting element in another position of adjustment.

FIG. 3 is a fragmentary plan view of the work supporting surface of the table and illustrating the shaper cutting element in a typical operative position.

FIG. 4 is a fragmentary elevational view of a main shaper housing and a separate pulley housing secured together and suspended from the underside of the work table shown in FIGS. 1 - 3, inclusive.

FIG. 5 is another fragmentary elevational view of the shaper housing and pulley housing viewed from another side thereof.

FIG. 6 is a vertical cross section taken on the line 6--6 of FIG. 4.

FIG. 7 is a plan cross sectional view taken on the line 7--7 of FIG. 6.

FIG. 8 is a fragmentary cross sectional view showing the splined spindle portions and splined spindle driving means on a somewhat larger scale and indicating in broken lines another position of adjustment of the spindle.

FIG. 9 is a cross section taken on the line 9--9 of FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In general, the present invention proceeds from a recognition of the need for an improved method of driving an unsupported end of a shaper spindle so as to protect the spindle from the effects of belt misalignment and radial load forces customarily exerted by power driving means as conventionally employed in a power tool of the shaper class.

From a recognition of this need, I have conceived of an improved method and apparatus for driving an unsupported end of a shaper spindle. In my improved method, rotative movement is imparted to a male splined spindle end by means of a special female splined driver element. The female driver element, in accordance with the invention, is held in a protectively contained manner in a pulley section which is located inside of a fixed bearing assembly in concentric relationship such that the splined female driver is rotated and yet radial load forces exerted by the power driving means are substantially all absorbed and carried by the bearing means, and thus the lower splined end of the spindle is protected from flexing and vibration.

The structure shown in the drawings comprises one preferred embodiment of means for carrying out my improved method. As noted therein, numeral 2 denotes a table member of the type usually employed in supporting a shaper and having a top section 4 along which a work piece W may be guided by means of fence elements 6 and 8 into contact with a cutter 10. The table is more clearly shown in FIGS. 1 and 2 and as noted therein, the cutter element 10 is secured at the upper end of a spindle 12 also shown in FIGS. 6 and 8.

As a part of the invention structure, I provide a special shaper housing 14, the upper portion of which has a shape as indicated in dotted lines in FIG. 3. This upper portion of the housing is solidly secured to the outside of the top 2 by means of bolts as 16, 18, etc., in suspended relationship as is more clearly shown in FIGS. 4, 5 and 6. Included in the housing 14 is a split cylindrical body portion which extends vertically downwardly around the spindle 12 as shown in FIG. 6 and this split cylindrical body portion is fitted with locking screws 20 and 22 adjustably located through threaded split ends 24 and 26 of the housing section, as shown in FIGS. 3 and 7.

Located in the housing 14 in spaced relation around the spindle 12 is a hollow shaft or quill 30 which is vertically adjustable in the cylindrical body portion when the locking screws 20 and 22 are suitably loosened. Quill 30 has opposite ends thereof recessed to provide retaining shoulders against which are received upper and lower bearing members 32 and 34. These bearing members are snugly fitted around upper and lower shouldered portions of the spindle 12 as shown in FIG. 6.

As a further highly important part of the invention structure, I also provide a special pulley housing 38 which is of a form suitable for being solidly secured to the lower end of the main shaper housing 14 by means of bolts as 40, 42, etc., best shown in FIGS. 6 and 8. This pulley housing 38 is designed to house a pulley member 44 in isolated relationship and for this purpose the pulley housing is formed with depending bracket part 38a having a pulley supporting base 38b, shown in FIGS. 5, 6 and 8.

In accordance with the invention I construct the pulley 44 with reduced upper and lower end portions 44a and 44b. Around the lower reduced end 44b, there is located a bearing 48 supported on the pulley base 38b as indicated in FIGS. 6 and 8. A second bearing member 50 is similarly mounted around the upper reduced end 44a of the pulley in snugly fitted relationship with adjacent surfaces of housing 38, as shown in FIGS. 6 and 8. The pulley assembly described, including the pulley and its upper and lower bearings, are contained by means of a snap ring 52 which is mounted in a ring groove in the housing 38 and which is arranged to hold all of the parts firmly together against the pulley supporting base 38b in substantially fixed relationship.

In combination with the fixed pulley assembly described, I also provide a further important component consisting in a female splined drive member 56 which is mounted in a recess formed at the upper pulley end 44a, as shown in FIGS. 6 and 8 in concentric relationship with respect to the bearing member 50 and the intervening pulley section. This female splined drive member 56 is solidly secured to the pulley 44 by means of bolts as 60 and 62, and is thus rotatable with the pulley 44, and it will be observed that by means of this arrangement of parts, any radial load force exerted through the pulley 44, for example, by the tension of pulley belt 64 and transmitted to the female splined drive member 56, will necessarily be taken up and carried by the concentrically arranged bearing member 50 together with the lower bearing 48.

Cooperating with the female splined drive 56 is a male splined spindle portion 12a formed at the lower end of the spindle 12 as shown in FIGS. 6 and 8 and arranged to slidably engage in the member 56 as is further shown in FIG. 9. It is pointed out that the male splined spindle end 12a in this internally mounted position in the driver 56 is protectively held for rotation at any speed against any radial load force since the bearings 48 and 50 function to carry such load forces and contain them, and thus it is impossible for the splined end of the spindle to undergo bending or flexing in any appreciable degree.

By means of the isolated pulley mount disclosed, it becomes possible to employ a stationary pulley 70 for driving the belt 64 from a motor M which may be solidly secured to a supporting part 72 in the table 2, as shown in FIG. 6. By suitably positioning the stationary motor pulley 70 in alignment with the pulley 44 and by securing the parts in this relative position to one another, any possible misalignment of the belt 64 is prevented and constant alignment and belt tensioning may be realized.

An important feature of the independently housed pulley 44 and its splined driver part 56 is its adaptability to carry out vertical adjustment of the spindle 12 either while the machine is at rest or while operating at any desired cutting speed with a minimum of effort. It will be observed that the splined end 12a is slidably contained in the female splined part 56 and by reason of the housing mounting described, the part 12 is free to be moved up and down within desired limit as suggested by the broken line showing of the part 12a in FIG. 8.

With these splined parts 12a and 56, I further combine a special quill and spindle adjusting mechanism which is supported at one side of the main housing as shown in FIGS. 4 - 8, inclusive. As noted in FIG. 4, the housing 14 is formed with an opening 80 which communicates with the outer surface of the quill 30 and secured through this opening by screws 83 and 85 to an exposed surface of the quill is a block 82. Supported in the block 82 is a threaded lug 84 through which is threaded a vertical adjusting screw 86. Located around the lower end of the screw 86 is a helical gear 88, best shown in FIG. 6, and in mesh with the gear 88 is another gear 90 on a shaft 92 (FIG. 7) rotatably mounted in a gear box 94. The box 94 is fastened to the housing 14 by bolts as 96 and 98. As the end of the shaft 92 is a hand wheel 100. It will be apparent that by loosening the locking screws 20 and 22 and turning the hand wheel 100, the screw 86 may be turned in either direction to quickly and easily raise or lower the lug 84 and the attached quill and spindle assembly into any desired position.

From the foregoing disclosure of parts, it will be evident that I have provided a novel and effective means for operating a shaper cutting tool. It is pointed out that in conventional machines when a shaper spindle is subjected to a radial load at its unsupported end, a certain amount of bending occurs. Of course, if the spindle is not rotating, the amount of bending is relatively small for a given radial load. As the spindle begins to rotate, however, the bending changes to flexing and the flexing becomes greater in magnitude as the spindle r.p.m. is increased. This, it should be realized, is due to the increased centrifugal force associated with an increase in spindle r.p.m. The increase in flexing with increased spindle speed is evidenced as an increase in vibration of the machine.

As pointed out above, in my improved method and apparatus, the bearings 48 and 50 necessarily must carry a radial load imposed by tension in the belt 64 because the pulley is mounted between its own set of ball bearings, and therefore, the radial load cannot be transferred to the shaper spindle, and the latter member is free to rotate without flexing at any speed. I have also found that by thus removing any appreciable radial load on the lower end of the shaper spindle, the latter member rotates concentrically in balance thus providing much higher r.p.m. capability. This is a material advantage since to the user of the machine, higher r.p.m. capability means that the work piece can be cut faster, smoother, and therefore, more efficiently. I find that with my new shaper design, I am enabled to keep vibration to a minimum. This results in the spindle bearings 32 and 34 having a much longer life potential, and because of ease of setup and adjustment and smooth, vibration-free running, the operator may make accurate setups fast and easily.

Claims

We claim:

1. In a power tool having a table formed with a work-supporting surface at an upper side thereof and fence means for guiding a workpiece in a desired path of travel along the said surface, the combination of a shaper housing secured to the table at an underside of the work supporting surface in suspended relationship therewith, a spindle and hollow supporting quill adjustably secured in the housing, means for raising and lowering the spindle and supporting quill, power driving means operatively connected to the lower end of the spindle for imparting rotative movement thereto, said power driving means including a stationary motor driven pulley, a belt member and a driver pulley located in alignment with the motor driven pulley and said driver pulley having a female splined driver element fixed internally of the pulley for slidably engaging with a male splined end of the spindle, said power driving means further including a driver pulley housing secured at the lower end of the shaper housing and having spaced bearing members for rotatably supporting the driver pulley in the housing at upper and lower portions thereof, said driver pulley being formed with shouldered end portions against which the respective bearing members are recessed, and the said driver pulley housing further including a retaining ring recessed in the housing in a position to maintain the bearing members and pulley in constant alignment with the said stationary motor driven pulley, said shaper housing being formed with an opening at one side thereof and the said means for raising and lowering the spindle and supporting quill including adjusting gear mechanism extending through the opening in the housing, and attached to the hollow quill member for vertically adjusting the spindle in the driver pulley bearing, said adjusting gear mechanism including a gear adjusting lug block having an adjusting lug portion anchored thereto, a vertically disposed screw in threaded engagement with the adjusting lug, vertical gear means for turning the screw and said shaper housing consisting in a split cylindrical body fitted with locking screw means for releasably containing the quill and spindle in desired positions of adjustment.

2. In a power tool, the combination of an enclosure body including a table portion formed with a work-supporting surface at an upper side thereof and fence means for guiding a workpiece in a desired path of travel along the said work-supporting surface, stationary power driving means including a motor fixed to the base of the enclosure body and having a motor driven pulley mounted at the upper side thereof, a depending shaper housing located within the enclosure body and solidly secured to the underside of the table in suspended relationship therewith, said shaper housing being formed with a downwardly extending split cylindrical part, a shaper spindle and spindle supporting quill assembly vertically adjustable in the cylindrical part of the shaper housing, means located externally of the shaper housing for raising and lowering the quill in the housing, clamping means for tightening the split cylindrical part of the housing and securing the spindle supporting quill and spindle in desired positions of vertical adjustment, bearing means mounted in the upper and lower ends of the quill for supporting the shaper spindle for substantially vibration-free rotative movement about a vertical axis, a pulley supporting member attached to the lower end of the cylindrical part in co-axial relationship, a driver pulley received in the suspended pulley supporting member and mounted in vertically adjustable driving relationship around the lower end of said spindle, said driver pulley being positioned in substantially horizontal alignment with the said motor driven pulley, and upper and lower bearing means arranged between upper and lower ends of the driver pulley and respective portions of the suspended pulley, supported for protectively isolating the lower end of the spindle from radial stress forces when the driver pulley is actuated by the said motor driven pulley.

3. A structure according to claim 2 in which the lower extremity of the spindle is formed with a male splined end which is in driving relationship with a female splined element and the said female splined element having a retaining ring recessed in inner peripheral portions of the suspended pulley housing.

4. A structure according to claim 2 in which the means for raising and lowering the quill includes a hollow bracket portion formed at one side of the shaper housing, a screw member rotatable therein, a vertical threaded member operatively connected to said screw and block means connected through an opening in the housing to the said quill.

5. A structure according to claim 2 in which the said clamping means for tightening the split cylindrical part includes upper and lower threaded clamping rods which project outwardly through one side of the enclosure body for manual adjustment.