US2873561A

US2873561A - Sander

Info

Publication number: US2873561A
Application number: US646599A
Authority: US
Inventors: Aaron J Levine
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-03-18
Filing date: 1957-03-18
Publication date: 1959-02-17
Anticipated expiration: 1976-02-17

Description

Feb. 17, `1959 A. J. LEVINE SANDER Filed March 18, 1957 United States Patent O 2,873,561 SANDER Aaron J. Levine, Chicago, Ill.

Application March 18, 1957, Serial No. 646,599

8 Claims. (Cl. 51-170) This invention relates to power driven sanding devices adapted to be mounted upon and driven by a portable electric drill, and has for its principal object the provision of a new and improved device of this kind.

It is a main object of the invention to provide a sanding device which can be readily atatched to and removed from a portable electric drill from the shaft of which the usual drill chuck has been'removed.

Another object of the invention is to provide a power sanding device for mounting on a portable electric drill, which device is of light weight and balanced properly for ease of handling during operation.

Another object of the invention is to provide a sanding attachment for a portable electric drill, which attachment can be manufactured economically without sacricing quality and can remain in proper operating condition with a minimum of maintenance.

Further objects of the invention not specifically mentioned here will be apparent from the detailed description and claims which follow, reference being had to the accompanying drawings in which a preferred embodiment of the invention Vis shown by way of example and in which:

Fig. 1 is a side elevational view of the sanding device attached to a portable electric drill;

Fig. 2 is a cross sectional view taken substantially along the line 2-2 of Fig. l, looking in the direction of the arrows;

Fig. 3 is an end view of the device, partly in section, along the line 3--3 of Fig. 1, looking in the direction of the arrows; and

Fig. 4 is a fragmentary cross sectional view along the line 4 4 of Fig. 2, looking in the direction of the ar rows and drawn to an enlarged scale.

Handymen and hobbyists have frequent use for a power sanding device, and since most such men are equipped with a portable electric drill it is advantageous to provide a sanding device which can be readily attached to and detached from an electric drill from which the usual chuck has been removed, thereby to form a power driven sanding tool that is economical to purchase and maintain. The present invention provides ysuch a sanding device and employs a bracket such as that shown in my copending application Serial No. 640,# 109, led February 14, 1957, which forms the base of the sanding tool and permits its ready attachment to and detachment from the casing of a portable electric drill.

In one instance, a quarter inch electric drill, available on the open market, has a free running speed of 2000 R. P. M.; and when the sanding attachment of the present invention is mounted upon such a drill, the sanding plate of the device is oscillated at a speed approach-ing 2000 oscillations per minute. Obviously, with an abrasive element of proper coarseness mounted upon the sanding device, finish sanding of a piece of work The invention will be best understood from the draw;V

ings in which, in Fig. l, the device is shown attached to a portable electric drill of known make. The sand ing attachment comprises a bracket 1 which may conveniently be of the type shown in the above mentioned application, which bracket is secured to the casing 2 of the drill by suitable means such as screws 3. Depending below the drill casing encompassing portion of the bracket 1 are feet 4 and 5 which have flat bottoms 6 disposed in a plane that is parallel to a horizontal plane through the axis of the drill shaft. The outer edges 7 of the feet 4 and 5 are planar and disposed in parallel vertical planes disposed equidistantly on the two sides of the axis of the drill shaft.

The sanding device includes a base plate 8 out of the upper surface of which ribs 9 are projected, these ribs having straight inner sides which engage the planar edges 7 `of the feet when the plate is mounted upon the bracket 1.

In order to mount the plate upon the bracket land to provide for oscillatory movement thereof in the direction of the axis of the drill shaft, feet 4 and 5 are each provided with upwardly facing ledges 10 which are the bottoms of arcuate indentations 11 formed in the feet. Ribs 9 are provided with circular bosses 12 that extend above the ribs at the longitudinal centers thereof, which bosses and ribs are threaded to receive screws 13 by which the base plate 8 is secured upon the bracket.

As will be seen best in Fig. 4, when the `head or screw 13 is tightened down upon the upper surface of the boss 12, the portion of the head of the screw which overhangs the upwardly facing ledge 10 of the foot of the bracket is spaced away from that ledge, thereby to insure that tightening of the screws will not clamp the feet 4 and 5 onto the base plate 8 so as to prohibit movement therebetween.

Fixed upon the drill shaft is a driving wheel 15 which is inclined with respect to the axis of the shaft, so that as the shaft and wheel are rotated the lowermost periphery of the wheel moves back and forth in a direction parallel to the axis of the shaft.

Fixed upon the base plate 8 by suitable means, such as screws 16, are low friction bearings, either ball bearings or roller bearings, the outer rotatable cones 17 of which are disposed on opposite` sides of the rim of drive wheel 15 and in engagement therewith. Thus rotation of the shaft moves the base plate in oscillatory motion with respect to the bracket 1, this movement extending for a distance depending upon the degree of angularity between the disk-like portion of the driving wheel 15 and the axis of the shaft. In one instance, 4the total movement of the plate with respect to the feet is approximately one-quarter of an inch.

Mounted upon the bracket 1 is a guard 20 which overhangs the drive wheel 15, partly encompassing the same, thereby to protect the wheel and operator of the device during operations of the device. The guard 20 is secured to the bracket by suitable means such as screws 21 and may be composed of metal or plastic as desired.

Upstanding from the top of the bracket 1 is a boss 22 containing a cavity into which the bottom of a suitable handle 23 is projected, the handle being secured to the bracket by a screw 24 that is threaded into a tapped hole at the bottom of the cavity.

Mounted upon the lower face of the base plate 8 is a resilient pad 25 which preferably is composed of either synthetic or natural rubber, which pad serves to cushion the abrasive material.

8 'att'h' endsof the ribs `9 therein are locking means 26 by which ends 27 of a sheet of abrasive material that is folded over onto the top of the base plate 8 are clamped to the base plate. The particular forni of clamping means 26 is not of the essence of the present invention, the clamp shown by way of example beingof the type shown in the Scace Patents 2,683,336 and 2,683,337. It is sulicient to note here that the clamping bar 26 is pivoted bypintles 2S in journals at the ends of the ribs 9, and that the 'operating handle 29 thereof may be grasped and swung outwardly into dotted position shown in Fig. 2, to permit raising the ciampiiig bar off of the upper surface of the base plate 3, thereby to permit registering lthe end 27 of the abrasive material with that plate. The arm 29 is then raised to move the clamping portion 26 into engagement with the end 27 and the arm 29 then swung inwardly past a boss Sti at the edge of the base plate to secure the abrasive material on the plate.

Sanding'devices of this type will most generally employ sandpaper having fairly line grit; however, if desired, emery paper or eni'ery cloth may be used as an abrasive with 'the device.

I. The bracket 1 and base plate S are preferably formed by casting from a metal alloy which is self-lubricating, with the result that no other lubrication is needed between the feet of the bracket and ribs and base plate against which these feet arerengaged. The device is of simple construction andV may be manufactured at low cost without sacr'icing quality and is capable of giving satisfactory performance for the purposes intended, over a long period of time without maintenance.

While I have chosen to illustrate my invention by showing and describingT a preferred embodiment of it, I have done so by way of example only, as there are many modifications and adaptations which can be made by one skilled in the art within the teachings of the invention.

Having thus complied with the statutes and shown and described 'a preferred embodiment of my invention, what I` consider new and desire to have protected by Letters Patent is pointed out in the appended claims.

What I claim is:

1. A power sander for attachment tothe motor casing of a portable electric drill, comprising a bracket detachably secured to the casing at the shaft end thereof and having a perforation through which the shaft projects; a driving wheel fixed upon the shaft and inclined with respect to the axis of the shaft; feet upon said bracket; a base plate; ribs upstanding from said base plate and engaging said feet to 'position the plate with respect to the bracket in a direction at right angles to the axis of the shaft; means securing said base plate upon the bracket, said means permitting limited movements of the plate with respect to the bracket in directions parallel to the axis of the shaft; means for establishing a driving connection between said driving wheel and base plate; an abrasive member upon the base plate; and means for 'securing said abrasive member upon said base plate.

2. A device as specified 'in claim 1, in which the feet on the bracket terminates in planar bottoms that lie in a plane that is parallel to a horizontal plane through the axis of the shaft and have planar outer edges positioned in planes that are parallel to and equidistant from t that axis and in which ythe ribs on the baseplate'engage said outer edges and have sliding t with respect thereto.

3. A device as specified in claim 1, in which the means for securing the base plate to the bracket includes an upwardly facing ledge formed in each foot adjacent the outer edge thereof, screws threaded dinto the base plate having heads which overlie said ledges and bosses on the ribs against which the `screw heads are drawn tight with clearance remaining between th ledges Vand screw heads. y

4. A device as specified in claim l', in which the driving connection between the wheel and base plate includes a pair of low friction bearings xed upon the base plate on opposite sides of the wheel and engaging the opposite faces of the wheel at the rim thereof,

Y the wheel engagingportions of which bearings are rotatable on the plate. y

`5. A device as specified in claim 1, inV which` a pad of resiiient material is secured to the face of the base plate away from the bracket to cushion the abrasive 7. A device as specified iii-claim l, in which a handlel projects above the bracket at the center thereof and in which a guard fixed upon the bracket partially encases the driving wheel to protect the same..

8. A device as specified iiirclaim l, in which the bracket and base plate are cast from metal which forms self-lubricating joints between the bracket and plate.

References Cited in the tile of this patent l UNITED srAras PATENTS 2,639,620 Bamfcrd A May 26, i953 2,743,557 `Larson May l, 1956 2,755,673 Dixon July 24, 1956