US2596689A

US2596689A - Floor sanding machine

Info

Publication number: US2596689A
Application number: US750845A
Authority: US
Inventors: William E Holt
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-05-27
Filing date: 1947-05-27
Publication date: 1952-05-13
Anticipated expiration: 1969-05-13

Description

May 13, 1952 w. E. HOLT 2,596,689

FLOOR SANDING MACHINE Filed May 27, 1947 4 Sheets-Sheet 1 Summer z'am E 170/15 Gttorneg May 13, 1952 w. E. HOLT 2,596,689

FLOOR SANDING MACHINE Filed May 27, 1947 4 Sheets-Sheet 2 c?) x Q 0 a C o Gttorneg May 13,1952 HOLT 2,596,689

FLOOR SANDING MACHINE Filed May 27, 1947 4 Sheeqs-Sheet 35 Imventor 7 anon leg W. E. HOLT FLOOR SANDING MACHINE May 13, 1952 4 Sheets-Shaw's. 4

Filed May 27, 1947 I Snventor 1U; [/z'amf 354% Gttomeg.

Patented May 13, 1952 FLOOR SANDING MACHINE- William E. Holt, Oakland, Calif.

Application May 27, 1947, Serial No. 750,845

4 Claims. (Cl. 51-176) This invention relates to the construction and operation of floor sanding machines of the general type disclosed in *U. S. Patent 2,001,099 in which. a housing, enclosing a sanding drum at its forward end and supporting an electric drive motor and blower fan, is tiltable by the operator about a horizontal transverse axis forming the axis of rotation of a pair of supporting wheels, to lower the sanding drum to its operating position.

In-sanding machines of the type described, the electric drive motor is generally located on the top of the housing with its axis of rotation horizontal and its center of gravity slightly forward of the vertical plane containing the axis of rotation of the pairof supporting wheels when the housing is in its horizontal traveling position, so that when the housing is tilted, or allowed to tilt, forwardly, the dead weight of the drive motor, which forms a substantial part of the weight of the machine, efiects' a substantial downward thrust on the sanding drum which is supplemented by a variable loading pressure exerted on the drum by the operator through the drum tilting mechanism, permitting a light or heavy cut as floor conditions may require. The motor has drive connections to the sanding drum and fan through separatebelt and pulley drives. The power requirements for such service have resulted inthe use of sanding drums of relatively short transverse length, e. g. eight inches, due to limitations on motor size and weight in the particular motor location described. Sanding drums "of greater length would require an electric motor of greater horsepower having a larger diameter and greater weight, resulting in a higher center of gravity for such a motor, whereby tilting of the machine housing would result in an excessive dead loading of the sanding drum.

In accordance with the present invention, a sanding machine of the type described is provided with an electric motor power capacity permitting the use of a sanding drum of greater length, e. g. twelve inches, and'therefore correspondingly greater floor sanding capacity, while retaining a motor weight distribution on the housing which will provide a desirable loading pressure on the sanding drum when the housing is tilted to the drum operating position. A further feature of the invention is a drive motor mounting which permits the motor to be readily detached from the housing to facilitate transportation of the machine. The improved motor mounting is used in conjunction with a belt tightening mechanism for maintaining the belt drive connections to the sanding drum and fan in a efficient operating condition. A still further feature of the invention is a supporting connection between the machine housing and portable carriage which permits an adjustment of the housing about itstilting axis to maintain the sandin surface of the drum in uniform contact throughout its length with the floor. Another feature of the invention is the provision of an auxiliary housing tilting mechanism for exerting a variable resilient loading pressure on the sanding drum.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which is illustrated and described a preferred embodiment of the invention.

Of the drawings:

Fig. l is a perspective view of a floor sanding machine constructed in accordance with'the invention; e i r Fig. 2 is an elevation of the machine shown in Fig. l with parts removed and cut away;

Fig. 31s a front end view of the machine;

Fig. 4 is a bottom view of the housing and supporting carriage;

Fig. 5 is a front view of a motor mount;

Fig. 6 is an end view of a motor mount Fig. 7 is a plan view of one of the belt adjusting rods;

Fig. 8 is a front view of the drum pulley;

Fig. 9 is a front view of the front motor pulleys;

Fig. 10 is a front view of the rear motor pulley on a different scale; v

Fig. 11 is a front view of the fan pulley;

Fig. 12 is a front view of the ratchet tension handle; and

Fig. 13 is a vertical section taken'on the line l3-l3 of Fig. 2.

The floor sanding machine illustrated comprises an elongated wheeled housing 20 having a top plate 2! and depending

vertical side plates

22 and 23, the forward end of the housing being closed by a weightedangulardrum cover plate 24 hinged to the top plate. A transversely elongated sanding drum 25 is journaled in the front portion of the side plates, with a drum axle projecting beyond the side plate 22 and carrying a double drive pulley 26. The housing is tiltably mounted on a three-wheeled supporting carriage 30, as hereinafter described, the carriage having an angle from its forward end extending the full housing width adjacent the lower part of the drum periphery to a point adjacent the-rear end of the housing, as shown in Figs; 2 -and;4.

The rear portion of the duct opens through the top plate 2| to the inlet of an exhaust ran '38 mounted on the top plate. The fan outlet connects with a stationary 'vertical tube 39 which terminates in a swivel mounted goose neck 49 'ongwhich'a dust bag 41 is supported, as indicated "in Fig. 1. 'A removable clean out plate 42 is arranged in the bottom of the duct 39 below the fanto provide access to the fan inlet and duct.

,The 'spaced pairs of wheels 31 and 3-2 are rotatab'lyfmounted on the axle 29,- one end of whichis shaped to fit into and through a countersu'nk opening 45 in the housing side plate 22 with sufiicient clearance to permit adjustment of theopposite end of the axle29 in the desired range of movement. This end of the axle is positioned in an opening 44 in one leg 48 of a 'bell crank lever 41 which is mounted on a threaded portion of a bolt 49 passing through an unthreaded opening in the housing side plate 23. With this construction the bolt 49 is loosened to permit angular adjustment of the lever 41 and tightened to hold the lever in its adjusted position. The other leg of the lever '41 has "a transverse flange 59 with a'vertically elongated slot 5| through which a threaded axle adjusting rod 52 extends. The rod 52 is held in the slot by a fixed collar 53 and flat washer 54 at the rear side of the flange 59 and a flat'washer55,

felt or spring washer 56 and nut 51 at the front 'side of the flange. The-ro'd passes rearwardly through an unthreaded guide opening in the forward leg of a U-shaped bracket 59 secured on the side plate 23 and a threadedopening 69 in the other leg, terminating in a hand wheel 6| externally of'thehousing. A lo cknut 62 at the rear side of the rear bracket leg holds1the rod 52 in its' adjusted'position With the described construction, the floating endfof the axle 29 can'be adjusted relative to the housing to bring the s'and in'g'drum into uniform contact with the floor throughout the drum length by first loosening the lockziut 62 and pivot bolt 49 and then adjustingithe rod 52 to arouately raise or lower the position of the bell crank lever opening 44 carrying'the axle end. The felt or spring. Washer maintains a resilient contact between the flange 59 and rod 52, while permitting relative movement of the ro'd'and flange slot.. When the desired adjustment -has been made; thebolt 49. and 'locknut 62 are tightened to lock the parts in the adjusted position. v

The housing is tiltable about the axis of the axle 29 to depress the sanding drum by means of a drum pressure lever 19 having a-forwardly ofiset handle portion 11 and pivotally mounted on one side of a bracket H surrounding the upper part. of the column 34. The-bracket ll has atoolsocket 12J'andcarries aswingable coiled wire .;l;3 which acts as. a power. cable support..-

The lower end of the lever 10 is connected through a clevis 14 to a rod l5 Which is adjustable in length, having its lower end adjustably connected to a clevis l6 pivotally mounted on the rear end of the housing top plate. The ofiset handle section of the lever 'HJ contacts with the handle 35 in the lever raised position illustrated, in which position the pivot connection of the rod 15. and clevis 14 is .beyond the dead cent'erposition. The lever is moved forwardly to the dotted line position shown in Fig. 2 to allow the housing to tilt forwardly about the tilting axis and thereby depress the drum into contact with the floor to be surfaced. Manual pressure on the lever 79 by the operator correspondingly increases the drum pressure on the -fioo'rr H A predetermined pressure is resiliently exerted and maintained on the drum when in use through a pair of links 89 hingedl y connected to the rea'r'edge of the'hou'sin'g top pla'te 21 and having theirother'ends connected to a common coiled spring '81. p The spring 81 is connected to a'ratchet'handle 82 pivoted on a bracket'BB secured onthe column 34 and carrying a ratchet plate 84. The particular se'tting' of the pivoted handle 82 in the notched'plate M'determinesthe tension on the spring 8| and thereby the pressure resiliently maintained on'th'e sanding drum. In use the lever 19 is first moved to allow the sanding drum to lower into contact with the floor due to the weight distribution on the housing. The ratchet handle '82 is then adjusted to exert the desired resilient pressure onfthe drum. 'Any desired "additional loading pressure on the drum is then exerted by the operator pressing forwardly on the lever 19. Arelativ-ely wide range of drum operating pressures' isthus attainable. 7

In accordance with the invention, the power requirements of the machine are supplied by a pair of electric motors B6 and 8-? arranged 'in tandem. The motors are mounted on the housing to'p'plate as hereinafterd'escribed withtheir axes-of rotation horizontal and along with their respective centers of gravity, at opposite sides of the 'verticalplane containing the tilting axis, both when'tlie housing'is'in its traveling position and also inits drum operating position. 'lntlie embodiment illustrated, the motorsare -"of equal size and horsepower and arranged' so that the vector resultant of the combined m'ot'or weights is 'slightly-torwa'rd of 'the'de's cri be'd vertical plane when the housing is in the position shown-in "Fig. 2, s'o'that-the housing willtil't forw'ardly'unv with the usual starting and changeover switches and power connections to the motors and power source. n I

As illustrated, the shaft oithemotdrfBB oarries-a pair of double pulleys- 99 and9l, the outer pulley being connectedto the-larger diameter drumpulley -26 by a pairof belts '92. Theinner pulley 9i is connected to-a sim'ilar sizedouole pulley 93 on'the shaftpf the motor'8lby belts '94. This shaft also carries a larger innerpulley 95 which :is' connected by a belt 96*to a' smaller .tors to the sanding drum and fan. As shown in Fig. 1, the drive pulleys and belts are enclosed by a guard member 99 which is detachably connected to the housing.

In accordance with the invention, the

motors

86 and 81 are mounted in a manner to permit the various belts to be readily adjusted as to tightness and the motors to be quickly detached from the machine to facilitate its transportation. For this purpose a flattened U-shaped bracket Hill is transversely secured tothe housing top plate rearwardly of each motor, and as shown in Figs. 2, 5 and 6, a flattened U-shaped motor support cradle I! is pivotally mounted on a removable rod I02 which extends through the pairs of end flanges of the bracket and cradle. Each motor casing is secured to the corresponding cradle. so that each motor and cradle can be arcuately moved on the rod M2 to adjust the associated drive belts. The mechanism for this purpose consists of a threaded rod I05 having its rear end pivotally connected to a bracket 35 mounted on the upper side of the motor 81, as shown in Fig. 7. The forward end of the rod extends through a bracket IE6 secured on the top of the motor 86. A hand wheel I0! is then threaded on the projecting end of the rod and is manually adjusted to tilt the motor 86 about its supporting rod I62, and thus regulate the tension of the belts 92. .A second adjusting rod IDS is vertically arranged between the motors with its lower end in contact with the housing top plate and threaded through a bracket I09 fixed to the lower part of the motor 81. The rod extends through a guide opening in the motor bracket I05 and carries a hand wheel H0 at its upper end. Movement of the handwheel H0 tilts the motor 81 about its supporting rod [02 to regulate the tension on the belts 96. The drive belt 94 to the fan is adjusted by an adjustable idler roll H2 in a well known manner. The belt adjusting devices are successively regulated to provide the desired tension in the various drive connections. The mounting of the

motors

86 and 81 facilitates this adjustment.

The sanding machine illustrated is designed to permit its transportation bodily by one man by a relatively simple disassembly of the motors and drive belts by withdrawing the motor support rods I02, disconnecting and separately carrying the motors 8'6 and 81. Transportation of the machine is also facilitated by a U-shaped tubular pull-out handle H5 slideably mounted in brackets H6 on the forward part of the housing top plate and normally held therein by set screws Hi. The handle is extended to its forward position when two men are available to carry the machine and returned to its retracted position when the machine is to be put into service, permitting the drum cover plate 24 to be then raised for access to the drum.

While in accordance with the provisions of the statutes, the best form of the invention known has been disclosed, those skilled in the art will understand that changes may be made without departing from the spirit of the invention covered by the claims, and that certain features of the invention may sometimes be used to advantage without a corresponding use of other features.

I claim:

1. A floor surfacing machine comprising a, supporting carriage, a housing tiltably mounted on d said carriage about a transverse axis, a sanding drum rotatably mounted'in the forward end of said housing, meansfor controlling'the tilting of said housing, an exhaust fan on said housing having a vacuum connection to saidsandin drum, and drive means for said sanding drum and fan including a pair of electric motors mounted in tandem on said housing with their drive shafts arranged transversely of said housing and with their centers of gravity arranged at opposite sides of the vertical plane containing the tilting axis of said housing and the vector resultant of their combined tilting effects relative to said tilting axis being located forwardly of said vertical plane when the housing is in an untilted position, and endless belts forming drive connections between said motors and between said motors and said sanding drum and fan.

2. A floor surfacing machine comprising a supporting carriage, a housing tiltably mounted on said carriage about a transverse axis, a sanding drum rotatably mounted in the forward end of said housing, means for controlling the tilting of said housing, an exhaust fan on said housing having a vacuum connection to said sanding drum, drive means for said sanding drum and fan including a pair of electric motors mounted on said housing with their drive shafts arranged transversely of said housing and with their centers of gravity arranged at opposite sides of the vertical plane containing the tilting axis of said housing and the vector resultant of their combined tilting effects relative to said tilting axis being located forwardly of said vertical plane when the housing is in an untilted position, endless belts forming drive connections between said motors and between said motors and said sanding drum and fan, and means for detachably supporting each of said motors on saidhousing.

3. A floor surfacing machine comprising a supporting carriage having a transverse axle at its forward end, a pair of transversely spaced supporting wheels on said axle, an elongated housing having depending side plates and a sanding drum rotatably mounted in the forward end of said side plates, means for tiltably mounting said housing on said supporting carriage comprising a housing side plate arranged to support one end of said axle, a bell crank lever pivotally mounted on the opposite side plate and having an arcuately movable lever arm supporting the opposite end of said axle, an axle-adjusting screw horizontally mounted in said housing and having a connection with the other arm of said lever permitting relative movement of said parts, means at the rear of said housing for operating said adjusting screw, and means for looking said adjusting screw and said lever in their adjusted positions.

4. A floor surfacing machine comprising a supporting carriage having a transverse axle at its forward end, a pair of transversely spaced supporting wheels on said axle, an elongated housing having depending side plates and a sanding drum rotatably mounted in the forward end of said side plates, means for tiltably mounting said housing on said supporting carriage comprising a housing side plate arranged to support one end of said axle, a bell crank lever pivotally mounted on the opposite side plate and having an arcuate- 1y movable lever arm supporting the opposite end of said axle, an axle-adjusting screw horizontally mounted in said housing and having a connection with the other arm of said lever per-