US3434247A - Vibratory tool - Google Patents

Description

March 25, 1969 N. T. ANTON ETAL VIBRATORY TOOL Sheet I of 3 Filed May 25, 1966 I N VENTORS jL/zajzglazs 235 222012 March 25, 1969 N, T. ANTON ETAL 3,434,247

VIBRATORY TOOL Filed May 25, 1966 Sheet 2 of 5 null" w Milli v ATTORNEYS m a March 25, 1969 ANTON ETAL 3,4345247 VI BRATORY TOOL Filed May 25, 1966 Sheet of s Q Q i W'Q y it I I l M *4 F; v)

M v a w? a? WE R F $9 5 '1 I N VENTORS AZZC/ZQZQST 19223012 lewfzfla z zgflfzeee HYW @M a A'VTORNEYS z United States Patent 3,434,247 VIBRATORY TOOL Nicholas T. Anton, Park Ridge, and Lew H. Daughetee, Northbrook, Ill., assignors to Wen Products, Inc., Chicago, Ill., a corporation of Illinois Filed May 25, 1966, Ser. No. 552,814 Int. Cl. B24b 23/04 US. Cl. 51-170 8 Claims ABSTRACT OF THE DISCLOSURE A vibratory tool of the hand-sander type wherein the shoe or plate means is afiixed to the frame by means of a plurality of resilient mounts disposed in angular relationship relative to the plane of the shoe or plate means to confine the shoe or plate means for essentially a single longitudinal line of motion. A power unit comprises an electromagnet including a core and an armature pivotally mounted on the core for swinging movement toward and away from the core in a plane parallel to the shoe or plate means, thereby producing a driving movement along the line of relative motion prescribed by the resilient mount arrangement. A working surface defining sheet clamp assembly releasably affixes an abrading sheet to the base unit and includes a pivotally mounted clamping member joined to an operating lever which, as it moves into its closed or locking position, resiliently deforms to maintain the clamping member against the sheet under pressure to achieve a better releasable captivation of the sheet.

Other features of the invention relate to the cooperation between the motor unit and the base to produce vibratory resonance of the base unit which results in greater base travel, and the employment of a rectifying diode to convert alternating current into pulsating DC current to be applied to the motor unit.

The primary object of the invention is the provision of a new and improved vibratory tool such as an electric hand-operable vibratory sander.

The organization and manner of operation of the in vention, together with further objects and advantages thereof may best be understood by reference to the following description t-aken in connection with the accompanying drawings, in the several figures of which like reference numerals identify like elements, and in which an exemplification of the invention is illustrated.

FIG. 1 is a perspective view of a vibratory tool of the sander type constructed in accordance with the present invention;

FIG. 2 is a perspective partially exploded view of an important part of the tool of FIG. 1;

FIG. 3 is a plan view of a sheet of working surfacedefining material, such as a sheet of sandpaper, illustrating a method of adapting the sheet for use with the tool of FIG. 1;

FIG. 4 is an elevational front end view with par-ts broken away to show interior construction, of the tool of FIG. 1;

FIG. 5 is a longitudinal sectional elevational view of the tool of FIG. 1 showing internal parts thereof; and

FIG. 6 is a plan view, partially in schematic diagram form, of part of the tool of FIG. 1.

Referring now to FIG. 1 there is depicted a vibratory tool generally indicated by the numeral 10 and constructed in accordance with the principles of the present invention. The vibratory tool 10 is of the electric powered handsander type and includes a handle 11, formed on a housing generally indicated at 12, for grasping the tool 10, and a generally rectangular platform or base portion 3,434,247 Patented Mar. 25, 1969 ice - indicated at 13 upon which a working surface-defining line 120, line 120 lying on a plane normal to the plane of the base 13 which bisects the housing 12 vertically. The housing portions 12a and 12b are affixed together by means of screws 12d atfixed in set-in receiving portions 12e formed in the outer surface of the housing 12a at the base of generally cylindrical cavities 12] formed thereon at the forward and rearward facing surfaces. Similar cavities 12g are formed in a housing portion 12b to provide a screw-receiving portion and to preserve the symmetry of design of the sander 10. The housing 12 is further provided with a plurality of vents 12i formed in rows and each of a generally parallelogram shape. The vents are formed along each of the outer sides of the housings 12a and 12b. To more firmly atfix the portions 12a and 12b together in the area of the handle 11, a pair of spaced screws 12j are provided therein.

In accordance with the invention, and as better shown in FIG. 2, the base 13 is provided with unique mounting and operating provisions, and with a novel sheet clamping means generally indicated at 22, for releasably afiixing the sandpaper 14 on the base 13. The base 13 comprises a generally rectangular planar plate 19 on the underside of which is affixed a conformingly shaped felt pad 20. The pad 20 bears the larger and employed portion of the sheet of sandpaper 14. The clamping means 22 are positioned at ends of the plate 19 and include an upstanding rectangular clamping surface flange 23, along each transverse end of the plate 19 which flange 23 may be formed as a unitary lip or extension from the plate 19. The flange 23 also includes a curved portion 23a, adjacent the plate 19, against and over which the sandpaper 14 is supported in the shown clamped position. Cooperating with the outstanding portion 23a for releasably clamping the sandpaper 14 thereagainst is a clamping member 24 in the form of a bar which is pivotally mounted at outstanding pivots 25a, 25b, affixed at opposite ends of the flange 23 and positioned outwardly from the outstanding ridge 23a. The pivots 25a, 25b pivotally support the clamping bar 24 for movement between an open position, as shown in FIG. 2, free of the plate 23, and in a closed position as shown in FIG. 1, in which the bar 24 is against the sandpaper 14, pressing and aflixin-g it against the plate 23. The clamping assembly 22 includes a combined operating and biasing lever 26 which may be formed to be a continuous extension of the bar 24. The lever 26 is related to the plane about which the member 24 is formed, at an angle less than whereas in its fixed position, under the restraining tab 27 (FIG. 1), it is resiliently deformed or bent to be in approximately 90 relationship tothe plane of the member 24. The lever 26 is made of a resilient material such as tempered steel so as to maintain the crossbar of the member 24 under pressure against the upstanding clamping plate 23 and to thereby captivate the sandpaper or other abrasive material therebetween. The provision of this assembly 22 at each end of the base 13 provides an easily operated clamping assembly which is both easy to assemble and economic to employ in manufacture.

The flange 23 extends along the front and rear edges of the plate 19 between the pivots 25. The sheets of working surface-defining material such as the sheet of sandpaper 14 are conventionally sized to a rectangular shape. One conventional size for such sanders is 3% inches by 9 inches. Sheets of this size are readily commercially available or may be readily made by dividing other conventional sized sheets. To provide increased strength at the areas of greatest pressure between the material sheet and the clamping member 24, and to adapt such conventionally sized sheets for use with the sander in accordance with one feature of the invention, a novel method of forming the sheet is provided. Referring to FIG. 3, there is depicted a sheet of working surface-defining material 14 of the sandpaper type. The sheet 14 is prepared for insertion in the clamping apparatus 22 by folding the corner 14a back along a line 14b. For one particular model of the sander 10 using the 3 /s-inch by 9-inch sheet size, the line 14b is set 1 inch from the corner along the transverse edge and 1% inches from the corner along the longitudinal edges.

Although the folding of the sheet 14 is preferred for increased strength and decreased tendency to tear, it is not necessary to use this folding method as the sheet 14 may be also prepared for use with the sander 10, for example, by cutting away the corners.

Referring again to FIG. 2, the novel mounting of the base 13 to housing 12 will be described. The mounting comprises a plurality of resilient mounts 17, preferably of rubber, arranged to define essentially one path of travel for the base 13 relative to the housing 12. The mounts 17 are each of a generally solid cylindrical shape and are provided with threaded screw sections 18 projecting from opposite circular ends of mounts 17 and aligned with the cylindrical axis of the mounts. The mounts 17 are arranged in two pairs, a front pair 17a, 17b, and a rear pair 17a, 17b, and each pair is affixed to one of a pair of upraised portions 21, 21', of the base plate 19. The mounts 17a, 17a and 17b are shown in exploded view above and aligned with their eventually assembled position, while the amount 17b is shown affixed. The portions 21, 21' are positioned about and spaced along the longitudinal centerline of the base 13 with the front portion 21 being centered approximately halfway between the center and the front of the plate 19 while the rear portion 21 is positioned approximately halfway between the center and the rear of the plate 19. The base 13 is driven by a base drive cup 33 of resilient material such as plastic, formed in the shape of a hollow cylinder open at its upper end and aflixed at its lower end to the base plate 19. The base drive cup 33 and its function will be described in greater detail in connection with the discussion of the power unit in conjunction with the discussion of FIG. 5.

Each of the raised portions 21, 21' includes a pair of planar mount receiving surfaces 21a and 21b, and 21a and 21b, canted to the plane of the plate 19. The surfaces have a central hole 30 for receiving one projecting screw section 18 of the mounts 17 and are positioned so as to support the mounts 17 so that each pair 17a and 17b, 17a and 17b lies in a plane normal to the plane of the plate 19 and normal to the longitudinal centerline of the rectangular plate 19 but canted to both the plate 19 and to a normal plane along its longitudinal centerline, i.e., each pair is arranged in a V-shape with the point of the V at the base 13 and the mounts 17 forming legs of the V and extending upward at approximately 45 to the plate 19.

The method of attaching the mounts 17 at the base 13 is best depicted in FIG. 4. The mount 17a has one projection 18 passing through the hole 30. The felt pad has an access opening 200 formed therein to provide access to the underside of the plate 19in the vicinity of the hole 30 to allow a lockwasher 31 and a hexnut 32 to be threaded upon the projection 18 to thereby affix the mount 17a to the base plate 19. It should be noted that the raising of the portion 21 cooperates with the access opening 200 to keep a sufiicient clearance between the sandpaper 14 and the projection 18 and the nut 32. Similar access openings are provided below each of the mounts 17.

Referring now to FIGS. 5 and 6, a power unit 50 and associated wiring are depicted. The cord 15 enters the handle 11 via an opening 11a which has a conventional cord-receiving means including a strain relief 11b and a cord spring 11c. The cord 15 includes three insulated wires 35, 36 and 37, two of which are, in operation, connected between the conventional US. volt, 60 cycle powerline source, and the third of which is grounded as a safety measure. Within the handle 11, the ground wire 37 is electrically connected to the metal housing 12 in a conventional manner at 38. The electrical line 35 is con nected to a 115 volt power diode 39, the other end of which is connected to one terminal of the switch 16. The other line 36 is connected directly to one side of a multiturn coil 40. The other side of the coil 40 is an electrical contact via a line 41 to the other terminal of the switch 16. Thus, an electrical circuit is defined comprising a 115 volt, 60 cycle source, indicated at 43 in FIG. 6, which is connected through a rectifying diode 39 and activating switch 16 to the coil 40. With the switch 16 open, no current flows through the coil and the sander 10 is deactivated. With the switch 16 closed, a pulsating DC current is caused to flow therethrough.

As best shown in FIG. 6, the coil 40 is mounted on the center core 50a of a multilaminated magnetic flux path defining member 50 which comprises three parallel laminated parts, the core 50a and a pair of parallel side arms 50b and 50c which flank coil 40 on opposite sides. The three members 50a, 50b and 50c are all connected in a unitary structure by a cross member 50d forming a generally E-shaped stator assembly with the coil 40 wound about the center member 50a.

An armature assembly 51 is provided including a crossmember similar to the member 50d and two projecting arms 51a and 51b which project toward the ends of the core 50a and arm 50b to form a backward F configuration. When the armature is in the closed position, the surface of the members 50b and 51b, and members 50a and 51a are conforming in shape so that a closed magnetic path exists therethrough. Both the stator 50 and the armature 51 are mounted on a mounting bracket 52 which is afiixed by conventional means to the housing 12. The stator 50 may be afiixed to the bracket 52 by means of rivets 53. The armature 51 is pivotally affixed to the bracket 52 by means of a flapper pivot rivet and pivot bearing sleeve assembly 54, at a point adjacent to the edge of arm 50c. The armature 51 further includes a downwardly projecting drive pin 55, best shown in FIG. 5, having an exterior diameter sized so as to fit within the drive cup 33 of the base 13.

The mounts 17 are each aflixed to the housing 12 at receiving extensions 60 which include an interior threaded portion for receiving and holding the threaded projections of each of the mounts 17. The arrangement of the drive cup 33 is such that the armature 51 is pivotally displaced from its closed position shown in solid lines in FIG. 6 to a partially open position shown in dashed lines in FIG. 6 and in FIG. 5 when no power is supplied to the power unit.

The mass of the base 10 is preferably related to the energy transferring properties of the mounts 17 so as to be in natural resonance therewith at the frequency of the impressed vibratory movement. This enables the base to travel further and more easily, producing a better sanding.

As is now apparent a new and improved vibratory tool power unit has been provided in which the travel is materially improved and thus greater sanding, grinding or polishing may be achieved. This results directly from the employment of the rectifying diode. Previous power units for this type of sander were connected directly to the alternating current source. As the force of attraction be tween the stator and the armature is directly related to the current flowing through the coil and not to its direction of flow, vibratory tools vibrated at a rate of approximately 14,400 cycles per minute for conventional AC power sources. By employing the rectifying diode, this rate is lowered to approximately one-half that previously used or to 7,200 cycles per minute for conventional power. With this change, a material increase in the travel of the base is achieved and much better operating results are achieved. This improvement, combined with the orientation of the. pivoting armature so that it pivots in a plane parallel to that of the base to provide improved energy transfer and the unique mounting of the base results in greatly improved operation.

As is now apparent a new and improved vibratory tool has been described which has many advantages over prior vibratory tools.

It will be understood that various modifications may be suggested by the embodiment disclosed, but wedesire to claim within the scope of the patent warranted hereon all such modifications as come within the scope of our invention.

We claim as our invention:

1. Avibratory tool comprising:

a housing,

a base for supporting a vibratory working surface, and

means -for mounting said base to said housing comprising a plurality of resilient mounts which cooperate to define essentially one line of relative motion between said base and said housing,

each of said resilient mounts being of a generally cylindrical shape and each having two ends of generally circular shape and each afiixed at one end to said housing and the other end to said base,

said base comprising a generally rectangular shaped plate having two up-raised portions each with two planar receiving surfaces for receiving circular ends of said mounts and aflixing the mounts in two pairs, each pair forming a V about a plane normal to said plate with the point of the V at said plate and the individual mounts extending upward at an angle to the plane of said plate.

2. The vibratory tool as claimed in claim 1 in which said resilient mounts are of rubber and are each affixed at approximately 45 to the plane of the generally rectangular shaped plate formed by said base.

3. In an abrading machine having a frame, a shoe deflectively supported by and below the frame, drive means on the frame and connected to the shoe to give the shoe a vibratory motion, the improvement of support means between the shoe and the frame comprising at least two pairs of longitudinally spaced apart resilient legs,

each respective pairs of legs being arranged in V shaped disposition for operatively confining the shoe to essentially a single line of motion relative to the frame.

4. In an abrading machine as defined in claim 3, said drive means comprising an electromagnet having a core, a winding on said core,

an armature having an elongated leg pivotally connected at one end of said core and being pivotable on a vertical axis intersecting said shoe for movement in the line of motion prescribed by said support means.

5. In an abrading machine as defined in claim 4, a handle on said frame located at the null point of vibration of said electromagnet.

6. In an abrading machine as defined in claim 4, electric circuit means for energizing said electromagnet comprising a one-half wave rectifier diode thereby to reduce the number of vibratory strokes while increasing the throw of the shoe.

7. A vibratory tool comprising:

an elongated plate means,

an alternating electromagnet including a core and an armature pivotally mounted on said core for swinging movement toward and away from said core upon operation of said electromagnet,

a frame carrying said electromagnet,

and support means for movably supporting said plate means on said frame for vibratory movement by said electromagnet comprising,

a plurality of resilient cylindrically shaped mounting members on opposite sides of the longitudinal centerline of said plate means,

each of said mounting members being disposed in angular relationship relative to the plane of said plate means to diverge respectively outwardly in a transverse direction relative to the longitudinal centerline of the plate means,

thereby confining the plate means for essentially a single longitudinal line of motion relative to said frame.

8. A vibratory tool as defined in claim 7 and further characterized by electric circuit means for energizing said alternating electromagnet comprising a one-half wave rectifier diode thereby to reduce the number of vibratory strokes While increasing the throw of said plate means on said longitudinal line of motion.

References Cited UNITED STATES PATENTS 1,741,145 12/1929 Drennon 51-170 2,054,590 9/1936 Wahl l2841 2,193,418 3/1940 George 51-170 2,434,337 1/ 1948 Soderstrom 31029 X 2,786,950 3/1957 Carmichael et a1. 51170 X 2,809,631 10/1957 Smith et a1. 12841 2,817,192 12/ 1957 Amsden 51-170 3,083,508 4/1963 Fegley et al. 51-170 LESTER M. SWINGLE, Primary Examiner.

US. Cl. X.R.

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