US3540161A - Vibratory tool - Google Patents

Description

Nov. 17, 1970 N. 'r. ANTON ETA!- I 3,540,161

7 VIBRATORY TOOL I Original Filed May 25. 1966 3 Sheets-Sheet 1 INVENTOR Nov. 17-, 1970 N. 'r. ANTON EI'AL VIBRATORY TOOL 3 Sheets-Sheet 2 Original Filed May 25, 1966 N. T. ANTON Em 3,540,161

Nov. 17,- 19.70

VIBRATORY TOOL 3 Sheets-Sheet 3 Original Filed May 25. 1966 ATTORNEY United States Patent 3,540,161 VIBRATORY TOOL Nicholas T. Anton, Park Ridge, and Lew H. Daughetee,

Northbrook, Ill., assignors to Wen Products, Inc., Chicago, Ili., a corporation of Illinois Original application May 25, 1966, Ser. No. 552,814, now Patent No. 3,434,247, dated Mar. 25, 1969. Divided and this application Nov. 4, 1968, Ser. No. 793,629

Int. Cl. B241) 23/00; B24d 17/00 U.S. Cl. 51-170 Claims ABSTRACT OF THE DISCLOSURE A clamping assembly for releasably affixing a sheet of working surface defining material to the base of a vibratory tool comprising an upstanding flange and pivotally mounted clamping member movable between open and closed positions relative to said flange, the clamping mem- 'ber constituting a lever made of resilient material and being resiliently deformed in the closed position to press the sheet against the flange.

This application is a division of our parent application Ser. No. 552,814 filed May 25, 1966, now Pat. No. 3,434,- 247.

SUMMARY OF THE INVENTION It is contemplated by the present invention to provide a vibratory tool of the hand sander type wherein a working surface defining sheet clamp assembly releasably aflixes a sheet such as sandpaper or the like to a base unit. A pivotally mounted clamping member is joined to an operating lever which, as it moves into its closed or locked position, resiliently deforms relative to an upstanding flange to maintain the clamping member against the sheet under pressure to achieve a better captivation of the sheet.

On the drawings:

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 parts 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 hand-sander 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 indicated at 13 upon which a working surface-defining sheet, such as a sheet of sandpaper 14, may be releasably affixed in a generally planar configuration with gently upcurving front and rear portions 140 and 14b.

The housing 12 is formed in two symmetrical portions 12a and 1211 which are afiixed together at the junction 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 aflixed together by means of screws 12d afiixed in set-in receiving portions 126 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 121 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 aflix the portion 12a and 12b together in the area of the handle 11, a pair of spaced screws 12 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 aflixing the sandpaper 14 on the base 13. The base 13 comprises a generally rectangular planar plate 19 on the underside of which is aflixed 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, aflixed 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 aflixing 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 to the plane of the member 24. The lever 26 is made of a resilient material such as tempered steel so as to maintain the cross bar 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 5 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 10 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% inch by 9 inch sheet size, the line 14b is set one 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 the 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 mount 17b is shown affixed. The portions 21, 21' are positioned about and spaced along the longitudinal center line 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 afiixed 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 center line of the rectangular plate 19 but canted to both the plate 19 and to a normal plane along its longitudinal center line, 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 20 has an access opening 200 formed therein to provide access to the underside of the plate 19 in 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 17b 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 sufficient 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. and 6, a power unit 50 and associated wiring are depicted. The cord 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 U.S. 115 volt, 60 cycle power line 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 connected to a 115 volt power diode 39, the other end of which is connected to one terminal of th 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 in electrical contact via a line 41 to the other terminal of the switch 16. Thus, an electrical circuit is defined comprising a 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 multi-laminated magnetic flux path defining member 50 which comprises three parallel laminated parts, the core 50a and a pair of parallel side arms 5% 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 U-shaped stator assembly with the coil 40 wound about the center member 50a.

An armature assembly 51 is provided including a cross member 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 aflixed 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 500. The armature 51 further includes a downwardly projecting drive pin 55, best shown in FIG. 5, having an exterior diameter sized so as to fix within the drive cup 33 of the base 13.

The mounts 17 are each affixed 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 transfering 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 between 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 enregy 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 we desire 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. A clamping assembly for releasably aflixing a sheet of working surface-defining material to a vibratory tool comprising:

means forming a base,

an upstanding flange disposed at an end of said base and forming an outwardly facing upright clamping surface disposed in a plane at a substantially right angle with respect to the plane of said base,

a clamping member pivotally mounted to pivot between an open position clear of said flange and a closed position pressing a portion of the sheet against said upright clamping surface,

an operating and biasing lever coupled to the clamping member for moving it between said open position and said closed position, said lever being made of resilient material and being resiliently deformed in the closed position to cause said clamping member to press the portion of said sheet against said upright clamping surface, and

said flange having an outwardly projecting ridge disposed below an area against which said clamping member presses the sheet to enhance the engagement therewith.

2. The clamping assembly as claimed in claim 1 which is further characterized by having said clamping member and said operating and biasing lever constructed in a unitary assembly and by having said lever formed in a plane normal to the plane of the clamping member and by having said lever releasably detented when said clamping member is in its closed position.

3. The clamping assembly as claimed in claim 2 in which said clamping member and lever are formed from a single bar and said lever is releasably detented by means of an upstanding tab on said base.

4 The clamping assembly as claimed in claim 1 and further characterized by said ridge comprising an out standing embossment formed in said flange.

5. A vibratory tool comprising:

a housing,

a base for supporting a sheet of working surfacedefining material;

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;

a power unit interconnecting said base and said housing for moving said base along said essentially one line of motion; and

clamping means for releasably afiixing said sheet of material to said base and including:

an upstanding flange disposed in an end of said base and forming an outwardly facing upright clamping surface disposed in a plane at a substantially right angle with respect to the plane of said base,

a clamping member pivotally mounted to pivot between an open position clear of said flange and a closed position pressing a portion of the sheet against said upright clamping surface,

an operating and biasing lever coupled to the clamping member for moving it between said open position and said closed position, said lever being made of resilient material and being resiliently deformed in the closed position to cause the clamping member to press with a portion of said sheet against said upright clamping surface, and

said flange having an outwardly projecting ridge formed below an area against which said clamping member presses the sheet to enhance the engagement therewith.

References Cited UNITED STATES PATENTS OTHELL M. SIMPSON, Primary Examiner U.S. Cl. X.R. 51382

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