US2431613A - Floor sander - Google Patents

Description

F. HE DEMARK moon SANDER Filed Sept. 3, 1945 I Nov. 25, 1947.

2 Sheets-Sheet 1 4 IINVENTOR.

J/LMQ I Nov. 25, 1947. F. i-IEDEMARK FLOOR SANDER Filed Sept. 8, 1945 2 Sheets-Sheet 2 INVENTOR.

BY 3M Patented Nov. 25, 1947 FLOOR SANDER Fred Hedemark, Prospect Heights, 111., assignor to Skilsaw, Inc., Chicago, 111., a corporation of Delaware Application September 8, 1945, Serial No. 615,205

8 Claims.

The present invention relates to improvements in floor sanders or the like.

Floor sanders have been manufactured and sold heretofore for finishing new floors and refinishing old floors in homes, factories, hospitals and ofiices. These machines generally have been heavy and cumbersome, requiring the services of an expert operator. Machines of this type at times in the past have been rented to home owners who wished to finish their own floors but the weight of the machines, the difficulty of carrying these large machines, the difficulty of fitting them into a renters. auto, and the necessity for expert operation has tended to slow this field of rental machines and has forced the home owner in most instances to rely upon the services of a contractor.

One of the objects of the present invention is to provide a floor sander meeting the special requirements of the rental field.

Another object is to provide a sander that is compact and easy to operate.

Another object is to provide a machine that is relatively light for the work to be performed and easily carried from. car to house or around a house or store.

A further object is to provide a tool that will not gouge floors near walls under inexperienced operation and one that may be easily maintained or adjusted by a local dealer or home owner.

Yet another object is to provide a machine that can be carried, maintained and operated by an inexperienced person.

Various other objects of this invention will be pointed out hereinafter with reference to the drawings.

In the drawings:

Fig. 1 is a View in side elevation of the machine with a portion of the main housing cut away.

Fig. 2 is a view in front elevation of the machine.

Fig. 3 is a view in rear elevation with a portion of the housing cut away Fig. 4 is a view in enlarged detail of the carrying handle for the machine.

As exemplified herein, the invention is disclosed in connection with a machine for sanding floors. The invention was created having in mind an inexperienced operator who might be performing the work only occasionally, who probably is not used to long hours of work of this type and ordinarily might tire quickly or be likely unintentionally to cause unwanted damage to floors or machines. For these reasons the invention relates to improved structure that enables the machine to be made most compact and light in Weight. Most structures heretofore thought mandatory has been omitted. For instance heretofore shafts have been mounted for swinging movement away from each other for belt tightening or releasing purposes. This has meant enlarged castings and extra mechanisms. Fixed centers on shafts, a single driving belt and novel tightening means for the belt without altering these centers with respect to each other has decreased the size and weight of the machine and made adjustment most simple.

Novel carrying means has been installed, normally hidden and out of the way, that permits the operator to carry the machine from place to place without undue strain on himself and less likelihood of damage to the machine. The occasional operator is never at a loss to know how to handle or carry the machine.

In the momentary change of direction of the former machines adjacent walls or similar obstacles, the driven abrasive-covered drum tended to grind, sand or gouge a piece from or a groove in the floor that was most difiicult to remove. An experienced operator, by manual manipulation of the handle of the machine, could compensate for this gouging. An inexperienced operator might find that his operation of the usual floor sander gouged the entire floor area'adjacent the walls. Through the present invention the sanding drum is automatically lifted from the floor adjacent obstacles such as walls in a feathering action actually preventing this gouging, even though the machine is carelessly operated.

With reference to the drawings the machine as shown includes a main frame I0 upon or to which the various mechanisms and structure are mounted. A motor housing I2 is suitably mounted to the frame in any desired manner and encloses a motor (not shown) having a driving shaft l4 carrying a motor sheave IS. A handle l3 for the machine is likewise suitably mounted in a socket I 5 attached to said frame.

A drum shaft I8 carrying a drum sheave 20 is likewise rotatably mounted in said frame In and 'mally rests on a floor surface 24.

has keyed thereto a sanding drum 22 that nor- Supporting wheels 25 for the machine are rotatably mounted on the frame l0 and normally carry the greater part'of the weight of the machine.

Where it is desired to pick up the dust created by the action of the sanding drum on a surface 24, a further rotatable shaft 26 may be rotatably mounted in said frame l0 carrying an exhaust fan 28 at one end thereof and a fan sheave 34 at the other end and in substantial alignment with the motor and drum sheaves. An exhaust chamber 32 surrounds said fan while an exhaust conduit 34 leads from adjacent the drum Ill, through fan chamber 32 to exhaust pipe 36 and thence to a bag (not shown) or other receptacle for the dust.

A driving belt 38 passes around the driving motor sheave I6, drum sheave 20 and fan or idler sheave 2B and drives them at speeds that may be predetermined for no load or normal load by fixing the size of the sheaves. The centers or axes of these shafts may be fixed relative to each other and as close to each other as possible for compactness. If these axes were made adjustable with respect to each other for tightening belt 38, the housings l2, belt guard 49 and the motor and drum guard 42 would have to be considerably enlarged to allow one or more of these shafts to be adjustably swung away from the others to take up slack in the belt as it wears and elongates. Two methods of adjustment have been used heretofore. One was to swing the entire motor assembly up and away from the other shafts to tighten the belt while another was to insert an additional movable idler pulley for this purpose. The extra structure involved for thus permitting relative movement of the shafts added weight and expense to the machine. Instead, applicant simplifies this materially by making one of the sheaves such as fan sheave 31] (Fig. 3) adjustable and in the nature of a split pulley,

As shown, the split pulley may comprise an inner flange member 44 formed on an exteriorly threaded hub 43 keyed to the shaft 26. An outer flange member 42 interiorly threaded, may be screwed over hub 43 to vary the distance between flanges and thus form a variable or adjustable inwardly converging slot or guideway for the belt 38 that causes said belt to travel adjacent to or away from hub 43 and the axis of shaft 26 in its path around the sheave and thus enlarge or restrict the path of travel of said belt.

By tightening the outer portion or flange 42 of the sheave over the threaded hub 43 and toward the rear portion 44, the belt 38 is caused to ride higher in the slot formed thereby thus enlarging the path of the belt and tightening it as it wears or stretches. The slight alteration necessary to tighten the belt does not serve to appreciably change the relative speed of the rotation of the shafts but acts substantially only to tighten belt 33.

The frame I is open in front to permit access to the drum 22 for changing abrasive paper. This opening is normally closed by a cover 46 hingedly mounted to the housing to swing upwardly and to be closed by gravity to shut in dust and protect the drum from obstacles. When closed, it further protects walls and the sides of door openings from damage from the drum.

Within the opening to the drum, a carrying handle for the machine may be mounted. As shown, a bracket 41 having depending lugs 43, 49 is welded or otherwise secured to frame l6 within the opening. A shaft 53 is mounted through openings in said lugsand a substantially U-shaped handle member 52 is mounted over said shaft. This handle member is mounted to swing forwardly through said opening into operative position (dotted lines, Fig. l) when cover member 4!; is raised, through the action of spring 54 suitably mounted on shaft 50.

To prevent the handle from dropping onto the drum upon a loosening of spring 54 or its breakage, a stop means may be provided as by continuing the ends of the U-shaped handle member rearwardly of their mounting as at 55 and providing a stop member 58 on the frame It! to positively prevent further downward movement of the handle beyond a. spaced position from the drum as shown. The handle member 52 engages the frame I0 in its operative position and may be used to lift the entire machine from the floor with comfort to the hand. To prevent injury to the cover hinge 59 or the housing l2, a raised lug 50 may be incorporated on the handle member to contact the frame l0 when in operative position and hold the handle member in spaced relation to the remainder of the machine and so the lift on the handle is from the main frame itself.

Spring member 54 preferably is of such force that the weight of the cover member 48 will cause the handle member yieldingly to withdraw into its inoperative position ready for release when the cover is raised. Upon lifting the cover 46 the handle is thus positively forced into operative position extending outwardly through the drum opening and is yieldingly pressed into inoperative position within the frame upon dropping the cover.

With reference to Figs. 1 and 2 one embodiment of the automatic lift for the drum is disclosed. As shown, this includes an arm 62 pivoted to the frame l0 through a screw 63 and held free of the frame through a spacing member 64. At its lower end an axle shaft is mounted at right angles to the arm and a wheel 68 preferably of rubber or other resilient material is mounted thereover and held in place by a cap nut 69. The belt guard casting 40 is cut away as at H to permit the arm and its roller to extend outwardly in front of the machine.

When roller 68 strikes a quarter round or wall, a continuing forward movement of the machine causes the forward end of the machine to rise upwardly, lifting the drum from the surface 24 as arm 62 is forced toward a vertical position. The arch-like rise of the drum through the action of arm 62 stimulates the feathering action of a professional operator obtained through proper lpessure and manipulation of the machine handle Without this drum lifting member, an inexperienced operator may permit the cover 46 to bump or strike a wall without a gradual lift of the drum from the surface 24. This slight pause for a change of direction permits the drum to sand longer in this spot adjacent the wall than it does on the remainder of a floor. Unsightly gouging or grooving results in the surface at this spot. To prevent scratching the wall by the cover 46 and to prevent the arm from striking the drum or drum pulley a stop means may be used that halts the machine, except for roller 68, in spaced relation to the wall. As shown a stop member or pin 70 is mounted to the frame 10 behind the arm 62 and in a position such that the arm 82 may impart a lifting feathering action to the drum but will not be permitted to pass sufficiently beyond dead center as to strike the revolving drum, shaft or sheave. It is also mounted sufficiently forward to permit the arm to lift the drum but to prevent the cover 46 from coming into contact with a wall The arm and stop members thus act as a limiting means or bumper for the machine.

, Upon backing the machine from the wall, the arm 62 likewise permits a reverse. feathering action for the drum and preferably is positively but yieldingly pressed from its lifting position into the inoperative position as shown in Fig. I through the use of a spring 12 that may be mounted at one end to the frame If! as at 14 and caused to yieldingly press the arm 62 forwardly at its free end.

Various modifications coming within the spirit and scope of the invention will be apparent to those skilled in the art upon a study of this specification, the drawings and attached claims.

I claim:

1. The combination in a floor sanding machine, including a frame and a power operated sanding drum rotatably mounted in said frame of carrying means for said machine, including a handle member pivotally mounted on said frame, resilient means for pressing said handle into operative position, a cover member for said drum hingedly mounted to said frame adjacent to said handle, said cover when closed holding said handle yieldingly confined therewithin in inoperative position and said cover when open permitting said handle to assume its operative position.

2. The combination with a fioor sanding machine having a frame and a power operated rotatable sanding drum mounted therein, of carrying means for said machine, including a cover member hinged to said frame and enclosing a portion of said drum when closed, a handle member mounted for limited movement to said frame within the confines of said cover when in closed position, said handle member being movable beyond the closed confines of said cover member to an operative position for grasping by a hand when said cover member is in opened position and means for positively moving said handle member into operative position upon the opening of said cover member.

3. The combination as defined in claim 2 wherein said cover member is hinged to said frame for upward swinging movement and may yieldingly press said handle member inwardly within the closed confines of said cover member through the weight of the cover alone.

4. The combination as defined in claim 2 wherein a stop means is provided to prevent contact of said handle member with the sanding drum when within the closed confines of the cover member.

5. In a floor sanding machine the combination of a frame, a power driven sanding drum rotatably mounted in said frame, said frame being open to permit access to said drum, a cover member hinged to said frame to close said access opening, a handle member for said machine, pivotally mounted to said frame between said drum and said cover when the latter is closed,

6 spring means mounted adjacent to said handle member tending to press said handle member beyond the closed position of said cover member, said spring means being sufficiently yielding to permit said handle member to swing inwardly under the weight of said cover member in closing.

6. In a fioor sanding machine, the combination with a frame having a power driven drum mounted thereon at its forward end for finishing floor surfaces and frame supporting means positioned rearwardly of said drum, of means for lifting said drum from an operative position against the floor surface, said means including a lifting arm pivotally mounted at one end adjacent the forward portion of said frame and extending downwardly and forwardly to a position adjacent the fioor surface in front of said drum, said arm being free at its other end and being adapted upon being halted as by striking a wall or the like, with a continuous forward movement of machine, to tend to assume a substantially vertical position, lifting said frame and raising said drum from its operative position against a fioor surface.

7. The combination as defined in claim 6 wherein spring means is mounted on said frame to cooperate with said arm in tending to hold said arm in its position adjacent the floor surface in front of said drum, and wherein said spring means yieldingly permits said arm to assume a substantially vertical position on being halted by an obstacle upon a continuous forward movement of the machine.

8. The combination as defined in claim 6 wherein a stop member is mounted on said frame to prevent the machine from passing forwardly of said arm when raised thereby and spring means is mounted on said frame to cooperate with said arm to positively return the same to its position adjacent the floor surface in front of said drum upon removal of the arm from contact with said wall.

FRED HEDEMARK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,752,965 Robertson Apr. 1, 1930 1,934,814 Myers Nov. 14, 1933 2,087,642 Forsberg et al July 20, 1937 2,112,157 Hatcher Mar. 22, 1938 2,118,818 Okun May 31, 1938 2,262,197 Otto et a1 Nov. 11, 1941 2,323,082 Ballard June 29, 1943 2,325,649 Batterson Aug. 3, 1943

Images