Same-RPM Rotary Motion to Eccentric Rotary Motion Conversion and Waste Product Collection
A device and method to convert ordinary rotary motion of input frequency Ω into a composite motion with the same primary frequency Ω plus an eccentric motion at a higher frequency ω enables a low speed rotary input to drive a higher-speed eccentric motion. A preferred embodiment enables an existing rotary motion machine to be easily adapted to provide compound rotary and eccentric motion. Optional attachments are used to collect waste products generated by rotary motion machine.
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This application is a continuation of pending U.S. application Ser. No. 10/605,634 filed Oct. 15, 2003, which in turn is a continuation of U.S. application Ser. No. 09/673,813 filed Oct. 21, 2000, now U.S. Pat. No. 6,634,437 issued Oct. 21, 2003. Said U.S. Ser. No. 09/673,813 is a U.S. national stage application of PCT/US99/08689 filed Apr. 21, 1999, and is a continuation-in-part of U.S. application Ser. No. 09/065,821 filed Apr. 23, 1998, now U.S. Pat. No. 6,009,767 issued Jan. 4, 2000.
BACKGROUND OF INVENTIONThis invention relates generally to the field of rotary-motion sanders, polishers, buffers, carpet cleaners, etc., and specifically to the conversion of rotary motion to eccentric rotary motion without altering the number of revolutions per minute (RPM) of the rotary motion, and to the collection of dust, water, and similar waste products generated by the aforementioned rotary-motion devices.
Conventional generic orbital sanders, buffers, polishers and carpet cleaners typically drive a sand plate, polishing brush, sand screen pad, carpet brush/sponge at a low speed—typically 175 RPM though sometimes as high as 1000 RPM—in a circular path. This action produces circular scratches on the sanded surface or carpet. Other random orbital sanders or carpet cleaners in existence rely on a high-speed motor to drive an eccentric random action. The action of the high-speed motor is reduced to the desired speed (e.g., 175 RPM) through various mechanical interactions among the gears, shafts, cams, etc. that comprise the sander/cleaner.
Illustrative of the prior art is U.S. Pat. No. 3,857,206 for a compound-motion machine in which an eccentric shaft (19) rotates about a motor shaft (14) to produce an eccentric rotation, and a secondary motion is produced by a secondary rotation about the axis of the eccentric shaft, using interacting gear wheels (31 and 32). (Column 2, lines 45-57) The eccentric shaft is fixed to, and rotates at the same speed as, the drive shaft. (Column 2, lines 16-20) The motor needed to drive this device must be a high speed motor on the order of 4000 to 6000 RPM (column 2, line 33), which establishes an eccentric rotation at the motor speed (4000 to 6000 rpm), while the secondary rotation about the eccentric shaft is reduced in speed by virtue of the gear wheel interaction, to perhaps 300 or 600 rpm depending on the gear ratio and the motor speed. The net motion is rotation at the lower speed, with eccentric motion at the higher speed, requiring and being driven by a high speed motor. There is nothing disclosing or suggesting how this might be achieved with a low-speed motor, nor is there anything suggesting or disclosing how to convert the ordinary circular motion of an existing machine to such a compound motion, without having to simply replace the machine entirely. U.S. Pat. Nos. 4,322,921, 4,467,565 and 4,845,898 all have similar limitations.
In all of this prior art, an eccentric plate sander is driven by a high-speed (RPM) motor. The eccentric movement is produced directly by the high-speed motor. This high-rotation speed produced by the motor is gear reduced by the gear system into a lower speed rotation. The main drive shaft drives an eccentric drive shaft which in turn drives the gear reduction. This does produce a slow reciprocating action, but requires a high-speed input motor and does not lend itself to adaptation to a low-speed input motor. Nor does it enable a pre-existing low-speed machine to be easily adapted to provide high-speed eccentric action.
Additionally, sanding is typically a very messy job, with dust particles permeating the area being sanded. An inordinate amount of cleanup is required following a sanding job, and it is usually advisable to remove as many movable items as possible from the area to be sanded, prior to sanding, so that these will not become permeated with dust. This introduces much extra work which is preferably avoided. For carpet cleaning, water and other cleaning fluids are applied to the carpet being cleaned, and the rotary motion (or rotary and eccentric motion) is used to create the desired cleansing action. Here, it is often necessary to wait for a day or so for the water and cleaning fluids to dry before using the carpet again, which is inconvenient. Additionally, since much of the dirt being cleaned becomes suspended in the water or cleaning fluid, removal of as much of this water or fluid as possible will simultaneously remove as much dirt as possible. Allowing water or fluid with dirt in suspension to simply dry on the carpet does nothing to remove that dirt, and results in a cleaning job of much lesser quality.
It would be desirable to have available a means and method for producing eccentric sanding or cleaning motion using a low-speed (e.g., 125 to 1000 RPM) input motor in which the speed of rotation of the output is precisely the same as the input speed, and in which gear increment—rather than gear reduction—is used to convert the low-speed input into a higher-speed eccentric movement.
Because many lower-speed input (e.g. 125 to 1000 RPM) sanders and cleaners are already in use in the market, it would further be desirable to provide a modular attachment for such sanders and cleaners which converts this lower-speed input into a higher-speed eccentric movement coupled with a rotation identical in speed to the lower-speed input, with minimum use of space and without major modifications to the original sander or cleaner, thereby avoiding the need to purchase a separate high-speed input sander or cleaner in order to achieve this motion and expanding the range of applications that can be performed by a single piece of sanding or cleaning equipment.
It is further desirable to provide a generic method for converting a lower-speed input of, for example, 175 RPM, into a rotary motion still operating at the example input speed of 175 RPM, but adding eccentric motion at a higher frequency.
It is further desirable for this method to be applied to other rotating sanding devices in existence such as floor sanding edgers, milling machines, and other low speed grinders, as well as hand drill and other rotary motion devices including carpet cleaners.
It is further desirable to provide a means and method for removing as much dust as possible during sanding, so that dust cleanup afterward, as well as the removal of movable items beforehand, can be avoided.
It is further desirable to provide a means and method for removing as much water and cleaning fluid as possible, during carpet cleaning.
SUMMARY OF INVENTIONThis invention uses a low-speed motor input (frequency) to drive a low-speed rotation at the same speed as the motor input, and through gear increment, to drive a much higher-speed eccentric movement. In the prior art, a high-speed motor input is used to drive a similar high-speed eccentric movement, and through gear reduction, a much lower-speed rotation.
First, a fixed gear housing of the device is fixed to a fixed (non-rotating) component of a rotary motion machine. Second, a drive shaft of the device is affixed to that component of the rotary motion machine which generates rotary motion of the given input frequency. Through various combinations of gear interactions and secondary (eccentric) motion driving bars, the device adds a higher-frequency eccentric oscillation to the original rotary motion. The net output is a primary rotational motion at the original input frequency, and a secondary eccentric oscillation of substantially higher frequency.
Waste products such as sand (from sanding) and water/fluids (from carpet cleaning) are collected by attaching a vacuum outlet through the fixed gear housing of the device and through the fixed (non-rotating) component of the rotary motion machine, and by adding a plurality of suction apertures through the pertinent operating attachment and other pertinent components of the machine. A vacuum skirt is used to enhance the suction from the vacuum outlet and to better contain dust and water.
BRIEF DESCRIPTION OF DRAWINGSThe features of the invention believed to be novel are set forth in the appended claims. The invention, however, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawing(s) in which:
Operating attachment 101, on the other hand, attaches (mates) to pass-through rotary motion component means 102′ of conversion module 2, which is substantially identical in structure to input rotary motion component 102. Similarly, the method of mating attachment receptacle 103 to pass-through rotary motion component 102′ according to arrows 105″ is substantially identical to the method of mating conversion module receptacle 103′ to input rotary motion component 102 according to arrows 105′, and to the prior art method of mating attachment receptacle 103 to input rotary motion component 102 according to arrows 105 as in
To convert the concentric rotary input motion 104 to an eccentric rotary output motion, shaft driving disk 101′ is integrally affixed to a drive shaft 201 which runs substantially through the center of a fixed gear housing 202 and substantially through the center of a non-rotating center gear 203 immovably affixed to fixed gear housing 202. The region above fixed gear housing 202 and center gear 203 in
Fixed gear housing 202, importantly, is fixed so that it does not in any way rotate in response to the rotation of input rotary motion component 102. This is achieved by means of a housing fixing device 205 which in the preferred embodiment is an attachment arm as shown. This arm is fixed to the bell of the sanding or cleaning machine 7 as shown and later described in more detail in
To add eccentric motion, the teeth of a pair of rotating outer gears 206 engage the teeth of non-rotating inner gear 203 as shown. Secondary drive shaft means 207 are integrally affixed to rotating outer gears 206 as shown, so as to rotate with the same frequency as outer gears 206. Secondary drive shafts 207 also pass through and are free to rotate with respect to lateral driving connector 204, with bearings and/or appropriate lubrication provided at the region again illustrated by the thicker lines to facilitate free rotation. Eccentric motion driving bar means 208 are integrally affixed to secondary drive shafts 207, and so also rotate at the same frequency as outer gears 206. Finally, a pair of eccentric motion drive shafts 209 are integrally affixed to secondary driving bars 208, again, so as to also rotate with the same frequency as outer gears 206. The combined means comprising components 206, 207, 208 and 209, which is responsible for introducing the eccentric motion into the system, shall be generally referred to as “eccentric motion generating means.”
Eccentric motion drive shafts 209, are in turn tapped into a composite motion pass-through means 210 such as the illustrated disk, allowing free rotational movement of eccentric motion drive shafts 209 within composite motion pass-through means 210, again, with bearings and/or appropriate lubrication at the region illustrated with thicker lines. Pass-through rotary motion component 102′ is affixed proximate the center of composite motion pass-through means 210, and so when operating attachment 101 is finally attached to pass-through rotary motion component 102′ via rotary motion receptacle 103 as per arrows 105″, as described earlier, the motion imparted to operating attachment 101 will be that of composite motion pass-through means 210 and pass-through rotary motion component 102′, rather that of input rotary motion component 102.
The eccentric motion is introduced, in particular, by eccentric motion driving bar means 208, and generally by the eccentric motion generating means comprising components 206, 207, 208 and 209. The magnitude of the eccentric motion is directly proportional to the displacements 211 between the center of secondary drive shafts 207 and the center of eccentric motion drive shafts 209. By virtue of the connections outlined above, the rotation 104 of input rotary motion component 102 is imparted directly to lateral driving connector 204 via drive shaft 201 and shaft driving disk 101′. The rotation of lateral driving connector 204 causes secondary drive shafts 207 to rotate (orbit) concentrically about primary centerline 106 along arrow 108, while the interaction between rotating outer gears 206 and non-rotating center gear 203 further causes rotating outer gears 206 to rotate (spin) about secondary rotational centerlines 272 along the path illustrated by (right-hand-rule) arrows 213. From the bottom-up view, the rotation of outer gears 206 about secondary rotational centerlines 272 is as shown by arrows 274. This rotation (spin) of outer gears 206 is further imparted to secondary driving bars 208 and, via eccentric motion drive shafts 209, ultimately to composite motion pass-through means 210, pass-through rotary motion component 102′, and operating attachment 101.
In particular, composite motion pass-through means 210, pass-through rotary motion component 102′, and operating attachment 101 are imparted a net composite motion that captures both the orbit of rotating outer gears 206 about primary centerline 106 (primary orbital motion 108), and the spin of outer gears 206 about secondary rotational centerlines 212 in combination with the eccentric displacements 211 introduced by eccentric motion driving bars 208 (secondary eccentric motion 214). Note that it is the boring of drive shaft 201 directly through the fixed gear housing 202 and center gear 203 and its rotation therein that serves to impart to operating attachment 101 a primary orbital motion 108 that is identical in speed (RPM) to input motion 104.
If the input frequency (RPM) 104 of the motor is designated by Ω (e.g. 175 RPM for a typical low-speed sander), then the primary orbital motion will be at precisely this same frequency Ω because of the manner in which drive shaft 201 passes straight through the center of center gear 203 and causes outer gears 206 to orbit about center gear 203. If the number of teeth upon center gear 203 is designated generally by N (N=61 in
ω=(N/n)×Ω, (1)
with both rotations (214 and 108) occurring in the same direction. Thus, in the illustration of
To maximize sanding, polishing or buffing variation, it is also desirable to choose the number of teeth on each gear so as to introduce the longest possible time (maximum number of cycles) before a particular “grit” upon operating attachment 101 returns to the same radial and angular location (position). In
Also, it is possible, alternatively, to replace center gear 203 (which has teeth facing radially-outward) with a gear having teeth facing radially inward, running to the outside of outer gears 206, and engaging the teeth of outer gears 206 along the dotted gear line indicated by 215. In this configuration, outer gears 206 would then spin about secondary centerlines 212 in a direction opposite their revolution about primary centerline 106. That is, 214 would run opposite 108. This naturally introduces a higher gear gain ratio (N/n), because of the larger circumference of gear 215 compared to gear 203.
θ(t)=2πΩt. (2)
Similarly, if φ designates the angular orientation of secondary driving bars 208 as shown, it is to be recalled that this orientation will also move with constant angular frequency ω as given eq. 1, that is:
φ(t)=2πωt=2πGΩt=2π(N/n)Ωt, (3)
where G=N/n is the gear gain ratio. Finally, r is used to designate the eccentric displacements 211 (see also
With all of the above, one can readily calculate the (x,y) coordinates of point P with respect to the origin of rotation at the center of drive shaft 201 to be:
P(x,y)=P(R cos θ+r cos φ, R sin θ+r sin φ) (4)
Thus, if R′ designates the radial distance, and θ′ designates the angular orientation, of point P with respect to the center of drive shaft 201, i.e., primary centerline 104 (rather than operating attachment center point 107), one can readily calculate that:
R′=sqrt[R2+r2+2Rr cos(θ−φ)] (5)
and
sin θ′(t)=(R sin θφr sin φ)/sqrt[R2+r2+2Rr cos (θ−φ)]. (6)
To express these over time rather than in terms of angles, one merely substitutes eqs. (2) and (3) into eqs. (5) and (6) above, to yield:
R′(t)=sqrt[R2+r2+2Rr cos (2π(G−1)Ωt)] (7)
and
sin θ′(t)=(R sin 2πΩt+r sin 2πGΩt)/sqrt[R2+r2+2Rr cos (2π(G−1) Ωt)]. (8)
In contrast, for the prior art configuration of
In heavy use, the region where drive shaft 201 affixes to lateral driving connector 204 undergoes perhaps the highest degree of physical torque-related stress. In the configuration of
It was noted in connection with
When input rotary motion component 102 rotates drive shaft 201 as earlier described, the upper driving connector of 204 rotates upper outer gears 206′ in precisely the same way that outer gears 206 are rotated in
First step up gears 607 are immovably affixed to upper outer gears 206′ via first step-up gear connectors 604 which run through the upper driving connector of 204 just as secondary drive shafts 207 runs through driving connector 204 in
Finally, the teeth of third step-up gears 603 directly engage the teeth of lower outer gears 206″, which have a smaller radius and less teeth than third step-up gears 603. Thus, lower outer gears 206″ will rotate at an even higher frequency (and reverse direction) than third step-up gears 603, as now illustrated by four arrows. Lower outer gears 206″, of course, drive secondary drive shafts 207, eccentric motion driving bars 208 and eccentric motion drive shafts 209, and thus, the frequency of eccentric rotation 213 (also now showing four arrows) is the same as that of lower outer gears 206″. Note that lower outer gears 206″ are connected on top into a bore on the lower portion of first step up gears 601, via lower outer gear attachments 607that rotate freely within this bore. On the bottom, lower outer gears 206″ are connected through the lower arms (or crosses for
In particular, if N(203), N(206′), N(601), N(602), N(603) and N(206″) denote the number of teeth for the particular gears associated with the parenthetical numbers, then the step up gear ratio G, which was G=N/n=N(203)/N(206) for
G=[N(203)/N(206′)]×[N(607)/N(602)]×[N(603)/N(206″)] (9)
Thus, even with an approximate 2 to 1 ratio for each gear interaction, the eccentric frequency can be stepped up by a factor of 23=8, and with a 3 to 1 ratio, this provides a factor of 27 to 1. Generally, with a G′ to 1 ratio for each gear interaction, G=G′3. The overall motion of a given “grit”, however, is unchanged from that of eqs. 1-8; all that changes is the gear gain ratio G. Thus, the motion of a grit on operating attachment 101 in
FIGS. 7 illustrates how rotary-motion conversion module 2 from any and all of
To modify a preexisting sanding or cleaning machine 7 of input frequency Ω to accept rotary-motion conversion module 2, one first affixes a housing fixing device receptacle means 73 directly to the bell 77 as shown in both
Next, one inserts and locks (105′) shaft driving disk 101′ into input rotary motion component 102 via attachment receptacle 103′, as first described in connection with
Because housing fixing device 205 is locked into housing fixing device receptacle means 73, fixed gear housing 202 and non-rotating center gear 203 which are integrally attached thereto are prevented from moving in a rotational direction. This enables the outer gears 206 (or 206′ plus assorted step up gears from
The various configurations described above can be used generally to convert a rotary motion input of given frequency Ω with no eccentricity, into rotary motion of the similar primary frequency Ω, compounded with eccentric motion at a stepped-up frequency ω=G Ω, and described in detail by eqs. 7 and 8. This is true whether the subject invention is embodied as a module to be attached to a preexisting rotary motion machine (as presented in detail herein), or is embodied directly, non-removably, within a given machine as a way of generating high-frequency eccentric oscillations from a lower-frequency input rotation motor. Either alternative is encompassed by this disclosure and its associated claims. Of course, stepped-down eccentric motion can also be achieved if desired, by appropriate alteration of gear ratios.
While this discussion has referred generally to a sanding or cleaning machine 7 as the device to which this invention is applied, it is understood that this invention can be used in connection with any rotary motion machine for which it is desired to introduce a (higher-frequency) eccentric oscillation. In all cases, what is needed are simply two points of contact with that machine. First, the fixed gear housing 202 must be fixed to some fixed (non-rotating) component of the machine via a housing fixing means that serves the function of component 205. Second, the drive shaft 201 must be affixed to (driven by) that component of the machine which generates the rotary motion, such as input rotary motion component 102. Thus, for example, a modified version of this device using all of the principles outlined herein can be non-rotatably fixed (205), say, to the arm of a standard power drill, with its drive shaft 201 driven by the rotational output of the drill. With, for example, an operating attachment 101 that is a buffer, and with pass-through rotary motion component 102′ designed to accept drill attachments in the same manner that the drill itself normally accepts these, the drill can then be used to provide rotating buffing with eccentric oscillations. This also has application, for example, not limitation, to milling machines and low-speed grinding machines.
To introduce a vacuum attachment, rotary-motion conversion module 2 and machine 7 are modified as follows. Machine 7 and fixed gear housing 202 are modified to further comprise a machine vacuum receptacle 85, a housing vacuum receptacle 80, and a vacuum aperture 87, all allowing air passage therethrough. When rotary-motion conversion module 2 is mated with machine 7 as described earlier in connection with
It is to be observed that while the vacuum attachment of
While the various embodiments of this invention have been illustrated using “toothed” wheels, it is fully understood that “friction” wheels are an obvious, equivalent substitute for these wheels, and that this substitution is included within the use of the terms “gear” and “wheel” as defined and utilized in this specification and its associated claims. Similarly, a wide variety of alterations and adjustments to the particular gear interactions illustrated herein, which would be obvious to someone of ordinary skill in the mechanical arts, are encompassed within the scope of this disclosure and its associated claims.
Finally, while the operating attachment 101 has been described herein generally as a sander, buffer, polisher, or carpet cleaner, this is illustrative, not limiting. Any type of attachment that one ordinarily attaches to a rotating machine to produce a desired effect on a work product such as wood, stone, marble, metal, glass, ceramic, or any other substance to be finished, the work effect of which can be enhanced by introducing eccentric oscillations over the primary rotary motion, is considered within the scope of the invention as disclosed and claimed. Similarly, any application, whether to wood finishing, stone or marble finishing, metal, glass or ceramic finishing, or any other substance finishing or cleaning, is also considered within the scope of this disclosure and its associated claims.
While only certain preferred features of the invention have been illustrated and described, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.
Claims
1. A method of converting a rotary motion machine to a compound eccentric rotary motion machine, comprising the step of:
- converting an input rotary motion of a given input frequency Ω produced by said rotary motion machine to a compound eccentric rotary motion by attaching a separate rotary motion conversion module to said rotary motion machine.
2. The method of [claim 1], said compound eccentric rotary motion comprising an output motion of the same said frequency Ω about a primary rotational centerline, compounded by an eccentric motion frequency ω about at least one secondary rotational centerline.
3. The method of [claim 1], further comprising the steps of:
- mating said rotary motion conversion module with an input rotary motion component of said rotary motion machine to receive said input rotary motion; and
- mating an operating attachment with said rotary motion conversion module to receive said compound eccentric rotary motion in substantially the same manner as said mating said rotary motion conversion module with said input rotary motion component.
4. The method of [claim 1], further comprising the step of:
- mating said rotary motion conversion module with an input rotary motion component of said rotary motion machine to receive said input rotary motion, in substantially the same manner that an operating attachment is mated with input rotary motion component to receive said input rotary motion absent said rotary motion conversion module.
5. The method of [claim 1], further comprising the step of:
- affecting a vacuum to collect waste products, through and using said rotary motion conversion module.
6. An apparatus for converting a rotary motion machine to a compound eccentric rotary motion machine, comprising:
- a rotary motion conversion module separate from and attachable to said rotary motion machine, converting an input rotary motion of a given input frequency Ω produced by said rotary motion machine to a compound eccentric rotary motion.
7. The apparatus of [claim 6 ], said compound eccentric rotary motion comprising an output motion of the same said frequency Ω about a primary rotational centerline, compounded by an eccentric motion frequency ω about at least one secondary rotational centerline.
8. The apparatus of [claim 6 ], wherein:
- said rotary motion conversion module mates with an input rotary motion component of said rotary motion machine to receive said input rotary motion in substantially the same manner that an operating attachment mates with said rotary motion conversion module to receive said compound eccentric rotary motion.
9. The apparatus of [claim 6 ], wherein:
- said rotary motion conversion module mates with an input rotary motion component of said rotary motion machine to receive said input rotary motion, in substantially the same manner that an operating attachment mates with input rotary motion component to receive said input rotary motion absent said rotary motion conversion module.
10. The apparatus of [claim 6 ], further comprising:
- a vacuum affected to collect said waste products, through and using said rotary motion conversion module.
11. A method of adding the capability to collect waste products to a rotary motion machine, comprising the step of:
- attaching a vacuum module separate from said rotary motion machine to said rotary motion machine;
- mating an operating attachment with said vacuum module passing an input rotary motion produced by said rotary motion machine through said vacuum module to said operating attachment; and
- affecting a vacuum to collect said waste products, through and using said vacuum module.
12. The method of [claim 11], further comprising the step of: said vacuum module passing said input rotary motion compounded with an added eccentric motion through to said operating attachment.
13. An apparatus for adding the capability to collect waste products to a rotary motion machine, comprising:
- a vacuum module attachable to and separate from said rotary motion machine;
- pass-through rotary motion component means (102″) of said vacuum module, mating with an operating attachment;
- an input rotary motion produced by said rotary motion machine passed through said vacuum module to said operating attachment; and
- a vacuum affected to collect said waste products, through and using said vacuum module.
14. The apparatus of claim 13, further comprising:
- said input rotary motion compounded with an eccentric motion added by and passed through said vacuum module to said operating attachment.
Type: Application
Filed: Jan 4, 2005
Publication Date: Apr 28, 2005
Applicant: (Esperance, NY)
Inventor: Gary Rudolph (Esperance, NY)
Application Number: 10/905,432