US1873011A - Electric surfacer - Google Patents

Description

Patented Aug. 23, 1932 g UNITED STATES PATENT OFFICE- SHELDON A. MODGLIN, OF SAN FRANCISCO, CALIFORNIA ASSIGNOR OF ONE HALF TO GEORGE M. COLLINS, OF SAN FRANCISCO, CALIFORNIA ELECTRIC suaraonn Application filed" January 2, 1930. Serial No. 417,936.

This invention relates to surfacing machines as used for grinding, sanding, scraping or polishing of any surfaces which may require such operations, and especially to a portable electric driven hand tool which will perform a variety of such operations.

The objects of the invention are to rovide such a tool which is small yet power ul, will grind or otherwise finish a surface on wood or metal with straight strokes to thus leave a straight scratch finish instead of the objectional circular scratches heretofore resulting from such machines, also which while of high-speed reciprocatory type will be sub- 1 stantially balanced against undue vibration or tendency to crawl along the work, and which may readily be adapted to all kinds of work by simple changing of the surfacing blocks or tools mounted on the reciprocating 20 chucks of the device.

In the drawing accompanying this application Fig. 1 is a side elevation partly in section showing my improved electric surfacer with a couple of cutting stones in place ready 25 for operation.

Fig. 2 is a cross section of Fig. 1 as seen from the line 22 thereof.

Fig. 3 is a cross section of a portion of Fig. 2 taken along the line 3-3 showing the slid- !0 ing bearings for one of the driving cranks.

Fig. 4 is an enlarged section ofa portion of a slid ng chuck plate engaging at its edge one of the supporting idlers mounted in the channel housing.

5 The tool is a portable device resembling generally a carpenters plane as seen in Fig.

1 and it is handled in much the same way except that it need merely be pushed or dragged over the workwhile holding it more 0 or loss hightly thereagainst.

The tool comprises a main frame 1 provided with a handle 2 at one end and a knob 3 at the other arranged as on a plane, while on top of the frame within a protective shell 5 4 is a vertical electric motor 5 provided with a flexible power cord 6 of any desired length and which motor may be switched on and off by a finger of the holding hand manipulating switch buttons 7. The motor is preferably of very high speed so as to get sufiicient power in small space and weight and it is geared down by gearmg 8, 9, 10, 11, 12 to two reci rocable chuck plates 13, 14 fitted with grin ing blocks 15 which are detachably held in place as by flanges 16 engaging grooves in the edges of the blocks and secured by screws 17 or in any other desired manner so that other blocks, cutters, scrapers, or polishing blocks, pads, or the like, may be substituted to suit the character of the work being done.

It will be observed by reference to Fig. 2 that the surfacing or cutting blocks are in line with the right-hand side of the machine so that an inside corner ma be reached, though if desired the cutting locks may of course extend slightly beyond the right-hand side of the machine, or be of any particular form either at the edges or bottom to fit into any special recess.

The gears are secured to small shafts 18, 19, operating in ball bearings as indicated and all enclosed between frame plates so that they may be run in soft grease without throwing same about, and also so that the grindings made by the device will not gain access'to the gears or bearings.

The two reciprocable chucks .13, 14 are spaced endwise in the device and are driven by oppositely set cranks 18, 19 extending from the lower ends of shafts 18, 19 of gears 11, 12 secured thereto. These cranks engage ball bearing 22 revolvable and transversely movable i'n ways 24 forming part of or secured to the upper side ofthe chucks so that in the revolving of the cranks the chucks will be reciprocated lengthwise of the tool as the bearings 22 travel back and forth crosswise of the chucks in yoke-like ways 24.

The side edges of the chucks are guided for reciprocable motion by a plurality of vertically disposed grooved rollers 25 pivotally mounted in chann lal ike housings 26 formed with an oven slof ttilong the inner or confronting sides ,or t he reception of laterally projecting flarlfges 27 of the chucks. The slots and flanges aiie formed at an angle as shown best in Figil i, so that dust and grindings produced by'the machine will tend ,to work out rather than into the roller housings. The housings are also closed at the ends so that the idlers may be kept packed in soft grease without same being thrown out.

In the drawing the chucks are fitted with coarse grinding blocks 15 such as carborundum or emery stones, though as suggested, the nature of the blocks, tools, pads, or scratchbrushes used on the chucks will depend on the work to be done.

In operation, theidevice is held and guided much like a carpenters plane and when the switch 7 is turned on the chucks and grinding blocks reciprocate in opposed relation from the full line to dotted line position shown in Fig. 1, and as the device is moved along either forwardly or backwardly, a beautifully ground surface is produced free from rotary scratches or markings.

I claim:

1. In an electric surfacer having a frame, an electric motor mounted thereon, a chuck plate mounted for reciprocation alongth'e chuck plate for reciprocation,'channelrlike housings along 0 poslte sides of the frame in which said rol ers are mounted provided with an open slot along confront ng sides and flanges on said chuck plate extending through the open slots of the housing engaging the rollers, said flanges extending at an angle'upward from the vertical sides of said chuck plate and the opposed edges of said slots formed at a corres onding angle to the flange extending theret rough.

SHELDON A. MODGLIN.

- under side of the frame and bearing a rubbing surface, and power transmission mechanism connecting the motor to said plate arranged for reciprocating the same. a plurality of guide rollers carried by the frame said guide rollers supporting and guiding the chuck plate for reciprocation. channel-like housings along opposite'sides of the frame in which said rollers are mounted having confronting walls provided each with an open slot there along and flanges on said chuck plate extending through the open slots of the housings engaging the rollers.

2. In an electric surfacer having a frame, an electric motor mounted thereon, achuck plate mounted for reciprocation along the under side of the frame and bearing a rubbing surface, and power transmission mechanism connecting the motor to said plate arranged for'reciprocating the same, a pair of channel-like housings inside the frame on opposite sides adjacent the lower edges thereof, said housings having confronting walls provided each with an open slot there along, a row of vertically pivoted rollers mounted in each of said housings, each of said rollers having a horizontal groove intermediate their ends, flanges on said chuck plate extending through the open slots of the housings and into the grooves'in the rollers whereby said chuck plate is guided and supported by the rollers for reciprocation each of the housing walls in confronting relation overlying the ends of the rollers on opposite sides of the slot respectively.

3. In an electric surfacer having a frame, an electric motor mounted thereon, a chuck plate mounted for reciprocation along the under side of the frame and bearing a rubbing surface, and power transmission mechanism connecting the motor to said plate arranged reciprocating the same, a plurality of guide rollers carried by the frame, said guide rollers supporting and guiding the

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