US1804523A - Edging machine - Google Patents

Description

May 12, 1931.

H. H. WQLFE ET AL 1,804,523

EDGING MACHINE Filed Dec. 1'7, 1927 6 Sheets-Sheet l FVQHZQ M 47- a0 r I 4-8 ill I a 3 5! 26 "35 I0 56 1 ,7 v l 46 I Inventor:

Harry H Wolfe Harry Myers Alto rn ey M y 1931. H. H WOLFE ET AL 1,804,523

EDGING MACHINE Filed Dec. 17, 1927 e Sheets=-Sheet 3 A I v 30 T1 9. 3.

In wen to Ham" HJAfoZ e Harry L.M ye1 Attorney May 12, 1931.

H, H. WOLFE ET AL Filed Dec. 1'7, 1927 1 n v I pf E: 6 n r 3 .:.w W 4 Q 1 In, I y/w I n W h l n U Haw May 12, 1931. H. H. WOLFE ET AL 1,804,523

EDGING MACHINE Filed Dec. 17, 1927 6 Sheets-Sheet 5 Inventans Har1- y HWOZ e Harry L.M ye1 Attormgy a May 12,1931. H. H. WOLFE ET AL 1,804,523

EDGING MACHINE Filed Dec. 17, 1927 6 Sheets-Sheet 6 lnvcnmm Haw fly H. W0 Zfe Harry L .Z Jyer;

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Attornqy Patented May 12, 1931 UNETE SATSE$ ATENT OFF-ICE HARRY H. \VOLI E AND HARRY L; R EYERS, TQLEDO, OI-LTQ, A$SIGNORS TO THE AMERP CAN FLOOR SURFACING MACHINE CGIl'ZPANY, GE TOLEDO, QHIO Enema MACHINE Application filed December 17, 1927. Serial No. 240,837.

This invention relates to new type of loor surfacing machine to be commercially known as an edging machine.

' In finishing around the marginal edge portions of a floor, the work is usually accomplished with a small hand tool. This class of work is commonly referred to in the trade as hand jerking.

Having noted. the inconvenience of such weak and the laborious'tasks encountered with the hand scraping tools on stair treads, doorways, small closets, and the like, we have developed a comparatively small portable machine which overcomes the innumerable objections known to the trade.

Briefly stated, the improved edging machine comprises a supporting base in the form of an especially designed metallic casting having a central elongated gear casing, oil-opposite sides of which are overhanging top flanges defining open side compartments for accommodating abrasive belts. There is a pair of these compartments in the present machine, and they are ing and retention "devices over which endless belts are trained in a manner to act on the floor adjacent the customary mopboards.

An appropriate prime mover is mounted on the base and has driving connection with the belts and also serves to operate the fan of a dust collecting device which is employed in association with the dust. There are operating handles properly located and an especially prepared truck on which the rear end of the base is fulcrumed.

, Particularly, do we aim to produce an especially constructed.machine for edging work, which is capable of fulfilling the requirements of a machine of this class, one which is exceptionally efficient in performance, is smooth, quiet, and dependable, in operation, economical, practicable, a me- 4 chanical achievement beyond similarly constructed machines, and characterized by the presence of prominent and indispensable structural features.

A primary feature of construction is the dual arra ement of endless abrasivebelts,

constructed to contain a series of belt guid arranged in spaced parallelism in the open s de compartments on-opposite sides of the supporting 'base. The distinction to be noted about these belts, is that they are trained in a somewhat triangular manner over a series of guide and retention devices,

the lower one oat-which serves to yieldably press a comparatively small portion of the belt into firm surfacing contact with the floor.

An equally important structural distinction is a resilient pressure producing shoe, a detail employed in association with each belt and the means which maintains the active portion of the belt in contact with the floor. ,The shoe has numerous advantages which will be made more evident'as the description proceeds. I

A further distinction, worthy'of note, is a a novel belt tensioning means employed in association with each belt, and individualized by an arrangement of details capable of causing the belt to cling to a power pulley by exerting a longitudinal elastic stress upon the belt, and simultaneously twisting the belt transversely of its direction of movement.

The belt tensionii'ig means has the additional advantage of providing a structure ably mounted operating handle, cooperating with a hand gripping means to aid in the use of the machine in small closets, and other similar places dihicult ofaccess.

Then too, we aim to increase the efliciency of the structure by the addition of a small wheeled truck on whose central portion, the rear end portion of the base is rockably fulcrumed to permit self leveling and to promote positive handling and easy manipulation.

The foregoing arethe outstanding structural features which. serve to. characterize the new entit and the advantages derived from their use, will be evident, as the de-.

scription goes on.

' In the drawings Figure lis a side elevational view, on a slightly reduced scale, showing an edging machine, as constructed in accordance with this invention, and indicating the approximate manner in which it is used.

' Fig. 2 is an enlarged side view in section and elevation, showing the internal mechanism and other associated details.

7 Fig. 3 is a rear elevational View showing the special relationship of the fulcrumed truck.

Fig. l is a front end elevational view with one portion broken away, to expose the belt tensioning and releasing means.

Fig. 5 is an enlarged vertical section thru the lower portion of the machine, showing the belt guiding bracket, and a portion of the gear casin Fig. 6 is a perspective belt guiding brackets.

Fig. 7 is an enlarged detail view shoi'ving the manner in which this bracket cooperates with one edge of the abrasive belt.

Fig. 8 is an enlarged perspective detail view one of the view with the belt tensioning means removed from the body of the macaine.

Fig. 9 is a perspective view of a part hereinafter referred to in the detailed description as a presser foot.

Considering now the specific construction of the various details of the invention, it will be observed that the reference chara-cter l0 designates generally what is'broadly defined as supporting base; This base comprises a single metall c uniting having a central horizontal top portion constr mtion for reception of a small vertical electric motor 11. v

The front wall curves gradua wardly assuming the con'iigi :ation in Fig. 2, being provided with a slot 12, and having its bottom e ge tern1i nating in spaced relation from the floor. Bolted or otherwise suitably fastened front wall is an appropriate buffer 13. opposite rear end portion depends at a substantial right angle to the top portion and carries a'removable housing 1% for a rotary suction fan 15, (see Fig. 2).

This wall is provided with a bearing 16, and a forwardly and downwardly inclined branch coupling 17 communicating with the fan housing. Formed centrally on the she wn to this under side of the casting is a compartment defined by spaced walls cooperating in pro viding a gear casing. EXtending down to.

this casing shown in Fig. 2 isthe motor 'tion to a vertical upstanding position.

v rtical shaft. carrying a gear 18 below which is a beveled pinion 19. The beveled ninion is in mesh with the beveled gear 20, on a horizontal power shaft 21 (see Fig.

T he gearlS is meshed with a small pinion 22 on a vertical shaft 23, suitably journaled in appropriate bearings. Motion is transmitted from the shaft 23 to a complemental stated that the reference numeral 27 designates generally, a unit (see Fi 2), which is fastened on the branch 17, takearms 28 whose intake ends are located toward the front and in spaced relation with respect to each other. Vhile considering the construction of the casting, we desire to point out further that the same includes a,

shelf-like extension 29 constituting a mounting for the handle 30. The handle includes a special metallic fitting 31, having a fork, with curved arms 32 which are pivotally mounted on the shelf to permit the handle.

to he swung from a rearwardly inclined posi- In addition, this litting includes a pair of relatively short centrally located arms 33 having arcuate slotted portions 34 which en-v gage about a pin 35 to limit the forward swinging of the handle, and to stop it in a vertlcal upstanding position, as shown in Fig. 2.

The reason for having structures permit ting the two positions of the handle, will become more readily apparent from the followdescription. Also forming a part of the base is a depending web underneatl'i of the aforesaid suction branch 17, (see Fig. 2), this being equipped ith a horizontal bearing 37. \Vhile considering these details, it is obvious that the purpose of the portions 36 and 37 is to provide a means for attaching a small truck 38 to the machine. The construction of this truck is plainly evident as shown in 3. It embodies an axle 39 having upturned ends equipped with hearings in which the axle This axle is fulcrumedin the bearing 37 through the medium of a rocking and pivot pin 38a. At longitudinally spaced points, are integral outstanding screw threaded lugs all, each carrying an adjusting and a stop screw Q2. The stem of the screw is threaded upwardly thru the lug and carries a lock nut 48. T hat portion of the stem extending above the lug is encircled with a coiled spring 44-, having its lower end engaged with and includes inbetween the truck axle. and thebody of the machine.- hile considering this figure, attention is invited to a side connection l6, leading from the fan housing.

This connection is intended to accommodate a suitable swivelly mountec conduit' l7, which leads to a dust collecting bag (not shown). in this instance, it might be necessary to say that in the actual machine, there is a dust collecting bag, provided so that the dust from the abrasive action can be collected in the bag and disposed in any convenient marine As is apparent from Figs. 4 and 5, the central top portion of the casting is such in construction, as to provide outstanding flange portions which overhang the pulleys 26. lnfact, these flanges are such, that they deiine open side compartments, for accommodating each abrasive endless belt 48 (see Fig.1). From this figure, it will be noted that each belt is trained over a set of guide and retention devices, including the pulleys, in such a way that the belt assumes a some what triangular form.

Only a small portion of the lower corner of the triangle is pressed into engagement with the floor. One of :the devices over which the belt is trained in each instance, comprises the tensioning means, as well as the means forreleasing the belt to allow eX- changing belts.

The particular construction of this device ishighly important, particularly because of the double function that it has. The device under consideration is detailed in Fig. 8.

Reference being had to this figure, it will.

be seen that an essential part comprises a yoke 49, having the curvature represented. The yoke includes a bearing 50 at its bottom, rockably mounted on a relatively stationary journal pin 51. The yoke embodies a web 52 at'the upper end of the arms of which are bearings 53, disposed at right angles to the bearing 50. Also one arm, carries an outstanding shoulder forming flange 5%, whose function will be clear later.

Moreover, the numeral 55 designates an abutment. This yoke is, obviously, swingable in a direction longitudinally of the abrasive belts. Mounted on the yoke is a pulley bracket, generally designatcdat 56. This embodies a curved arm portion 57 carrying a set screw 58, engaging the abutment 55. In addition, it is formed in its upper endwith a bearing 59 rockable on an appropriate journal pin in the bearing '53. It includes an upstanding part 60,

carrying a right angularly disposedhpintle 61 on which a pulley 62 is rotatably mounted for idling motion.

In connection withzthis bracket, we would also mention a plate-like portion 63 having a curved recess in its bottom, receiving the head 64 on the upper end of a pin 65; This pin extendsdown through a hollow boss 66 on the horizontal arm of a spring adjusting bracket 67. The bracket 67 is of right angular form, and is held in placeby the turning bolt 68. The bracket canbe turned about this bolt and set in any position to varythe vertical position of the pin 65.

Incidentally, a coiled spring 69 surrounds the pin and the boss, and bears against the bracket at its lower end and against the head 64: at its upper end. The spring pressed pin is so located with respect to the curved yoke 49, that it rocks the yoke in adirection from right to left around the pivot pin 51,: thus maintaining theresilient pressure upon the idling pulley 62, and tensioning the belt 48.

Attention is now invited to the reference numeral 70, designating a substantially. U-shaped member, whose right portion 71 forms a part of a clamp for a resilient shoe 72. The shoe comprises a resilient plate slit to provide pliablefingers 7 3 whose free ends are upturned, the opposite end of the plate loo being clamped between the part and a removable retaining bar 74. This U-shaped part 70 or. clamp, has its arm portion provided with bearings 75 and 76 which are in alinement with theaforesaid bearing 50, as;;

shown in Fig- 8, and which slip over the same journal pins 51.

The bearing 76 is provided with an outstanding lug 77 located between the adjusting andretaining screws 7 8 on the stationary ears 79 carried by the body of the machine.

l Vith this arrangement, it obvious "that the U-shaped clamp 70 can be adjusted through the medium of the screws 78,

thereby; moving the shoe 72 up or down to effect angular adjustment of same.

From Fig. 1, it is evident that the shoe in each instance, is located so that the upturned ends of the fingers is substantially beneath the aforesaid rubber bumper 13: With this arrangement, the abrasive surfaces of the belts can be brought close to the mop board 80, as is shown in Fig. 1.

Attention is invited now to Fig. 9, which shows a specially designed presser foot 81 3125 which isclamped upon a rock shaft 82 on which an operating lever 83 is also mounted. This lever 83 extends up, through the aforesaid slot 12 and is provided with a hand grip. The pressure foot 81 bears againstg wo the Shoulder 5a (see Fig. 8, and Fig. 2).

Obviously, by pulling forwardly and downwardly on the lever 83, the presser foot 81 will'be moved rearwardly, e erting pressure upon the yoke 49 and rocking this yoke.

upon its pivot 50 and 51 and permitting the pulley 62 to move toward the stationary drive pulley 26, thereby loosening the belt and permitting it to be removed and replaced.

The operation of the combined belt tensioning means and releasing means is therefore obviously seen. Itmay be conveniently stated again, that the stress of the aforesaid spring 69, is such as toexert' an upward and forward thrustupon the peculiarly curved yoke. Since this yoke carries the idling pulley, it is obvious that this yielding pressure is exerted upon the inside of the abrasive belt which is trained thereover.

To; overcome the tension of this spring, whenever it is desired to change the belt, the lever 83 is grasped and pulled forwardly and downwardly, and acting through the medium of the rock shaft, and the presser foot 81 carried thereon, the yoke 49 is swung rearwardly upon its pivot moving the idling pulley away from the belt in such a manner as to permit it to be easily removed and replaced. If desired, suitable retaining means for the lever, (not shown), can be provided in practice to hold the idling pulley in this swung-down position to facilitate exchanging of belts.

It is to be noted that the triangular shape of the belt, follows the general outline of the walls of the base. Thus the machine is allowed to approach the mop board 80, at a direct right angle as shown in. Fig; 1, with out interference from any projections or obstructions carried by the machine. Moreover, the rearward inclination, of the belts at this time prevents them from striking or coming into contact with the mop boards. Consequently, the structure is especially adapted for edging work. 7

From the foregoing description and drawings, it is obvious that we have evolved and produced an edginginachine of a comparatively small portable type, wherein the base or body has its rear end portion rockably mounted on a fulcrum with comparatively I small portions of the abrasive sides of the two belts, pressed down firmly on the floor at the front of the machine. These belts are in spaced parallel relationship, and when trained over the guiding andretention devices, they assume the triangular shape shown. The compartments in which they are located are completely open to facilitate exchanging and to expedite regulation.

As the belt operates, the dirt and dust is sucked in through the arms of the dust col- ,lection device, an indispensable feature in a machine of this class. In a machine of this kind, particularly of the light weight portabletype, it can be appreciated how difiicult it is to maintain the abrasive belts properly trained over the guiding and operating means. Naturally, considerable resistance is set up during the operation of the belt, and this has a tendency to accidentally displace the belt. Thus in practice, the driving pulleys 26 at the ends of the shaft 21', are of a straight face rubber covered type, to insure no er drivin action.

By the cooperation of the headed spring pressed pins 65 (Fig. 8), and the idling pulley 62, this pulley is able to maintain a. longitudinal thrust upon its belt, thus maintaining the belt stretched in a taut manner. This avoids, longitudinal displacement of the belt, by picking up excessive slack. However, it has been noted, that this longitudinal pressure alone, is not sufiicient to hold the belt in place. Therefore, it becomes necessary to virtually twist the belt transversely of its direction of movement, and this is accomplished by having the idling pulley 62 mounted on a separate and individuallyadjustable bracket 56, wherein the axis of swinging motion of this bracketis at right angles to the axial motion of the yoke 4L9. In other words, the yoke a9 is swingable longitudinally of the belt and held forwardly by the spring-pressed pin 65, while the bracket 56 swings in a direction at right angles, or transversely of the abrasive belts. 100

However, the adjustment of action of the belt is not restricted to the cooperation of these parts 49 and 56, since the shoe 72 individually adjustable by the screw 78 operating through the ears 79 and connecting upon the lugs 77. Then too, the presence of the resilient lingers on the shoes renders the same adaptable to irregularity in the face traversed. I

At this time attention invited to F 5, G, and 7, wherein it will be observed the reference character 85 designates generally, a bracket. There are two of these brackets provided, one for each bolt. Each bracket comprisesa strip of metal 86 having an elongated slot at one end portion, and having its intermediate portion 87 twisted. The free ends terminate in an especially shaped head 88. These brackets are adjustably bolted on the bottom of the gear casing v as shown in Fig. 5, and extend out at right angles, so that the heads 88 are in the path of movement of the belt and in fact, engage the edge of the belt in each instance. These constitute guides and stop members for limiting the inward or transverse slippage of the belts.

Obviously, owing to the abrasive material on the belts, they would ordinarily soon wear away the metal of the head 88. Howy in this manner.

ever, by shaping the head as shown in Fig. 7

7,, the edge of the belt is turned outwardly, as shownat 89 in Fig. 7, thereby overcoming undue wear on the head.

One of the principal advantages of this improved edging machine is that it is characterized by a base or body of, convenient construction, which includes the means for supporting a prime mover-in the form of a vertical motor, being further constructed-to provide a housing or a casing for the gearing and driving mechanism. both for the belt and for the dust collecting fan, and being further individualized by the presence of the two open sided compartments in which the belts run. I

A further advantage is based upon the utilization of the bumper on the, properly shaped front wall, whichis so located as to come into engagement with the mop board, and to=limit the movement of the machine However, due to the location of the resilient shoes beneath this bumper, it is obvious that the edging opera.

tion can be carried on within about onequarter of an inch of the mop board. In cidenta-lly, it is usually advisable to removethe molding strip or shoe so that this close up edging action can take place. Then when the shoe is replaced, the small portion which was not surfaced, will be substantially un noticeable. I

Not only is the spacedparalleldual belt-' ing arrangement thought advantageous in this; particular machine, but novelty is predicated upon the three-point bearing, action which is accomplished with the structure. In other Words, the forward points constitute the transmission of the weight on. the two resilient adjustable shoes at the front. A-central rear portion of the ma chine,,however,. is suspended from the cen tralized fulcrum of the truck. However, the truck wheels are constantly onthe floor and, within this arrangement, itis possible to shift the weight of thermotor of tlie inachin'e from either one side to theother, to bring about anequalizing action onthe belts.

Sometimes, one-belt will drag, and the other belt will slide, setting up somewhat-of an undesirable differential action which will decrease the cfiiciency. Under ordinary circumstances, however, the, interpositioning of the springs between the f'ulcrumed truck and body permits a substantial self-leveling actionandrelicves the belts and forces them to have jsubstantially equal action. If the operator desires, however", he can, through themedium' of the rigidhandle, e ert'pressure on eitherone belt or the other by tilting the body ,of the machinein any direction desired. This is a highly'important; feature, to be remembered.

Likewise, the resilient adjustable shoe is very "important,- liecause of the "swinging Itis to be further added that the shifting of the load of the machine has a great dea to do with the belt alinement, asthe contact of the abrading is increased, so is't'he tendency of the belt to run from their proper alinement. This however, is overcome by, the novel belttwisting and idler pulley adjusting means.

Further, in connection with the shoe, it essential that the shoe be so constructed and made of such a materialthat the transmission of heat generated by friction as the belt passes over the shoe and floor be held to a minimum. In fact, the'thin nature. ofthe metal from which the shoe is constructed, prevents the .metal from absorbing too'much heat, and permits the heat to radiate freely and rapidly. Thus it is not transmitted to the adjacent mechanism, and this is important.

.A careful analysis of the description in the presence of the drawings, will enable the reader to recognize the importance and:

distinctions, and to appreciate the structural features, which adapt this machine 3 particularly for edging floors. As the method of use, operation, and advantages appear clear, a more lengthy description is thought and regarded une'ssential.

Having thus described .our invention, what we claim as new I 1. In an edging machine of the class de scribed, a body comprising a longitudinally elongated gear casing provided with outwardly; extending side flanges. defining opensidedbelt compartments, the forward side of said body including an outwardly and downwardly inclining portion terminating in spacedrelation tothe floor, a horizontal bumper. carried by the lower end portion (hereof, adjustablyv mounted resilient shoes supported inthe forward and lower .portions of said compartments, substantially beneath said buffer,-a driving pulley located in each compartment, operating means for the ,pulley including a prime mover supported on' said body, endless abrasive belts located in the. compartments, and trained overi'he. pulleys and shoes, an operating handle connected to theb ody, and dust col lecting means including outwardly directed branches having their intake ends located beneath the bottom flights of saidabrasive V belts,together with spring pressed belt tensijoningv means locatedin' each compartment, and cooperable Wlbli' the complemental bearings, and a manually operable means for acting upon the tensioning means for moving it in a'direction to release the belts to facilitate replacement.

2. In an edging machine of the class dethereto, an idler 'pulley bracket, means swingably mounting said bracket on said yoke, the axis of movement of the bracket being at right angles to the axis of said yoke, spring pressed means cooperable with the yoke for swinging it around its pivot in a direction longitudinally of said compartment, a shoe in said compartment, an endless belt trained over said idler pulley, operating pulley, and shoe, and confined in 'said compartment, a motor supported on said base, an operating connection between the motor and driving pulley, and a handle connected with the base.

3. In an edging machine of the class described, a base provided witha belt compartment, an operating pulley in said compartment, a motor on the base, an operating connection between the motor and pulley,*a handle connected to the base for manipulating the base, a shoe mounted in the compartment, a yoke swingably mount ed in the compartment, the yoke being swingable in a direction longitudinally of the compartment, a bracket pivotally mounted on the yoke and swingablevin a direction at right angles to the yoke, an adjusting screw carried by the bracket and engageable withthe yoke, a spindle carried by the bracket,,an idling pulley on the spindle, and adjustable spring means engaging the bracket for moving it in a forward and longitudinal direction in the compartment, a belt trained over the idler pulley, the driving pulley, and shoe.

4-. In an edging machine of the class described, a base provided with a belt compartment, an operating pulley in saidcompartment, a motor on the base, an operating connection between the motor and pulley, a handle connected to the base for manipulating the base, a shoe mounted in the compartment, a yoke swingably mounted in the compartment, the yokebeing swingable in a direction longitudinally of the compartment, a bracket pivotally mounted on the yoke and swingable in a direction at right angles tovthe yoke, an adjusting screw carried by the bracket and engageable with the yoke, a spindle, and adjustable spring means engaging the bracket for moving it in a forward and longitudinal direction in the compartment, a belt trained over the idler pulley, the driving pulley and shoe, together with a guide bracket mounted on said base and having an enlarged curved head with which one edge of said belt has sliding contact, said head being constructed to turn the belt edge outwardly.

5. In an edging machine of the class described, a base provided with a belt compartment, an operating pulley in said compartment, a motor on the base, an operating connection between the motor and pulley, a handle connected to the base for manipulating the base, a shoe mounted in .the compartment, a yoke swingably mounted in the compartment, the yoke being swingable in a direction longitudinally of the compartment, a bracket pivotally mounted on the yoke and swingable in a direction at right angles to the yoke, an

adjusting screw carried by the bracket and engageable with the yoke, a spindle, and adjustable spring means bracket for moving it in a forward and longitudinal direction in the compartment,

a belt trained over the idler pulley, the driving-pulley and shoe,-together with a guide bracket mounted on said base and having an enlarged curved head with which one edge of said belt has sliding contact, said head being constructed to turn the belt edge outwardly, a rock shaft mounted on thebase, a presser foot carried by the rock shaft and in engagement with the yoke for moving the yoke in a direction against the tension of the spring means, and an operating lever mounted on the rock shaft.

6. A new product of manufacture for use in association with an edging machine of the class herein described, comprising, a guide bracket in the form of a flat metal strip provided at one end with an elongated slot, said strip being twisted intermediate its ends and terminating at its outer end in an enlarged head, said head having an arcuate belt engaging surface designed for turning the edge of a belt outwardly to minimize wear'on thehead. t

7 As a new product of manufacture, a belt tensioning device for use in association with anedging'machine of the class described, comprising a substantially V-shaped yoke provided at its lower end with a bear ing, provided intermediate its ends with an abutment, having the upper ends of its arms terminating in additional bearings disposed at right angles to the first named bearing, a shoulder forming flange "carried by one of the arms of the yoke, an idler pulley bracket comprising an arcuatearm provided intermediate its ends with a bearing disposed between the second-named bearings and the upper ends of said yoke arms, a connecting pin between the bracket bearing and said last-named yoke bearing, a set screw carried bythe lower end of said bracket arm engaging the and engageable with said abutment, an upstanding part carried by the upper inner end of said bracket, and a spindle on said upper end together With an idler pulley mounted on said spindle, an additional bracket for adjustable mounting, a pin carried by said additional bracket, said pin having a head at its upper end engageable with the corresponding end of said spindle 1Q bracket, and a spring surrounding said pin, hearing at its lower end against the adjusting bracket and at its upper end against the head of said pin;

8. In a portable floor sanding machine 15 adapted to rest on the floor or other surface that is being treated, two parallel transverse rollers, a stationary shoe extending forwardly below and in advance of the forward roller, the bottom of the shoe adjacent to 20 the front end being approximately horizontal and the said end being of compara-V tively small vertical height, and an endless abrading elt embracing the rollers and the shoe, that part of the belt underlying the 25 forward portion of the shoe serving as a support for the machine.

In testimony whereof We aiiix our signatures.

HARRY H. WOLFE. 30 HARRY L. MYERS.

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