US1912046A - Sanding machine - Google Patents

Description

May 30, 1933. P. A. soLEM SANDING MACHINE Filed Oct. 16. 1925 2 Sheets-Sheet 1 May 30, 1933. P. A. SOLEM SANDING MACHINE Filed Oct. 16. 1925 2 Sheets-Sheet 2 IIIIIIIIIIII Patented May 30, 1933 EiC E PETER A. SOLEM; OF ROCKFORD, ILLINOIS V SANDING MACHINE Application filed. October 16, 1925. Serial No. 62,694.

This invention relates in general to abrading machinery and is particularlyconcerned with sanding machines of the endless bed type which employ rotating sandlng or abrading drums or cylinders.

In machines of the kind mentioned, the drums are usually given a positive, oscillating, endwise movement to secure a smooth finish on the stock operated upon. One of the principal objects of the present invention is to provide an improved means for accomplishing the oscillating movement which 1mposes no weight on the drum shafts, such as ordinarily caused uneven contact of the drums with the stock because of a whipping v action produced at the free end of the drum shafts,and was furthermore a cause of quick wearing of the bearings of the drum shafts. lt has also been the custom to provide separate motors for the separate drum shafts, usuallv coupled to the shafts in such a way as'to permit adjustment of the elevation of the abrading drums relative to the work. M This usually resulted in the motor armature shaft being considerably out of llne wi ththe drum shaft, giving poor power transmissmn, imposing heavy loads on the shaft bearings, and resulting in noisy operation, while at the same time necessitating separate supporting brackets for the motors and greater over-all dimensions of the machine as a result of the intermediate drive couplings. A further object of this invention is to eliminate these objectionable features of previous machines by the provision of built-in motors giving direct drive for the drum shafts. As a. re? sult of the rotors being part of the drum shafts, the motor remains in line with the drums whether the heaviest or lightest cuts are made. Greater compactness and aconsiderable reduction in the over-all dimensions are secured and a saving in floor space is effected. 7

Still other objects and advantages of. the present invention will be "discussed more fully in the following detailed description in which reference is made to the accompanying drawings, wherein Fig.1 is a side elevation of a sander of the endless bed type incorporating the improvements of my invention;

Fig. 2. is a transverse section through the machine and is taken on the line 2--2 of Fig. 1 looking in the direction of the arrows, portions of the drum and frame being broken away to conserve space in the'drawings;

Fig. 3 is an enlarged fragmentary sectional detail of the motor housing andits mounting, an intermediate portionof the shaft for the drum and armature being broken away at the armature;

Fig. 4 is a similar enlarged sectional detail taken at the opposite end of the shaft for the drum and armature and showing the'connection with the rock-er arm; and i Fig. 5 is an enlarged sectional detail of one of the eccentrics for actuating the rocker arms and is taken on the line 5-5 of Fig. 2 looking in the direction of the arrows.

Throughout the views the same reference numerals are applied to corresponding parts.

The sanding machines of the type to which the present improvements are intended to be applied usually comprise a base 6 having heavy upright side frame pieces? and 8 extending therefrom and suitably fixed together in spaced relation. The frame'provides supports for ways over which an endless bed 9 is arranged to move. The bed 9 consists of steel slats with rubber pads secured thereon, the slats being in turn secured on roller chains operatingon sprockets having bearings at 10 and 11 at opposite ends of the machine. The driving of the bed is through the intermediary of suitable transmission from a shaft 12 bearing in'the frame of the machine and suitably driven by a motor supported on a bracket at the side of the machine. The shaft 12 is shown in section and the motor referredto is not shown. 7 'Apulley 13 suitably mounted on the shaft 12 is provided for driving pulleys'14 and 15'. The

- pulley 14; by virtue'of its position above the bed 9 is arranged to drive a brush for clean ing the stock passing out of the machine and the pulley 15 by virtue of its position below the bed is arranged to drive a brush for cleaning the under side of the bed 9. The belt 16, passing about the pulleys referred plurality of pressure bars 22 are provided between the abrading drums which have polished under faces for the passage therebeneath of the stock operated upon. The abrading drums are capable of adjustment as to elevation for lightor heavy cuts, usually by the simultaneous adjustment of the elevation of the drum shaft bearings, by the operation of worms 23 on the ends of shafts 24. The latter are fitted with hand Wheels 25 for convenient manual operation from the side of the machine. The worms .23 mesh with worm wheels 26 to operate jack screws 27 to raise and lower the shaft bearings rela tive to bosses 28 provided on the frame of the machine. is given simple rotation for the initial rough finishing out. In this case, the drum 18 is arranged for simple rotation at the intake end of the machine. -The other drums 19 and20 are arranged to have endwise oscillation or reciprocation during rotation. By this compound movement it has been found that the grade of finish on the stock is highly improved as the fibers of the wood are not drawn or strung out and left in loose fuzz or fur on the surface of the stock. The drums are usually oscillated by rocker arms orrbeams 29 which have a suitable thrust bearing connection with the drum shafts.

' 3 The rocker arms-are suitably driven by a direct gearing connection with the shaft 12, consisting of bevel gears 30and 31. The gear 31 is fixed on the shaft 32, which operates eccentrics, as will presently appear, to

' I communicate a rocking motion to the arms 29. In this way the oscillating motion of the drums with the drum shafts occurs only during the feeding movement of theendless bed 9, that is, during the normal operation of the machine. For the mostpart, the foregoing arrangement is commonly employed in sanding machines of this type and no invention is claimed: therein except injso far as the improvements hereinafter referred to are tied 7 up with this arrangement.-

Referring now more particularly to Fig. 2, the drum 19, or for that matter the drum 20, is mounted on a shaft 33 supported in bearings at 34 and '35 on the frame pieces 7 and 8 at opposite ends of the drum. Ac-

cordingto the present invention, the housing 36 of the motor 21 is supported in the bearing 35 in a'manner more particularly described hereinafter for adjustment as to elevation simultaneously withthe bearings 34 and 35. The shaft 33is in a single con- Usually the first drum of the set tinuous piece without the interposition of a coupling or any intermediate transmission for the driving of the drum shaft from the armature shaft, since the rotor or armature shaft is integral with the drum shaft. This improvement thus broadly defined, it will be appreciated, accomplishes several highly desirable advantages. First of all, it is definitely insured that the armature and the drumwill remain in line at all times regardless of whether a heavy or light cut is being made, the two being kept in the same rela tion to one another in any state of adjustment. Furthermora the mounting of the motor housing on the same vertically adjustable support with the shaft bearing insures keeping the same relation between the armature and its field coils in the housing, regardless of the amount of adjustment. The directness of the driving connection resulting from the shaft for the armature and drum being in one piece gives smooth and noiseless operation. There is avoided the pounding and vibration at the coupling which, besides being noisy, was a contributing factor in the wearing out of the drum shaft bearings. Thearrangement conduces toward the best obtainable compactness and the over-all dimensions are very much reduced so that in trunnions provided on the forked end 40 r of therocker arm. The rocker arm 29 is pivoted at 41 to a link 42, which in turn is pivoted at .43'on a bracket 44 bolted 'tothe side of the adjacent frame piece 7. The bracket 44 provides a ledge at 45 on which one end of a coiled compression'spring 46 rests, while its other end is in contact with the under side of the link 42. The lower end of the arm 29 is pivoted at 47 to a link 48 having a split strap end 49 enclosing an eccentric 50 secured on the shaft 32, as by means of a tapered pin 51 (see Fig. 5). The shaft 32 is supported in bearings provided in brackets 52 on the side of the frame piece 7. The eccentric- 50 and the end 49 of the link 48 are maintained in proper relation by a collar 53 secured on .theend, of the shaft 32 by a tapered pin '54. It will appear that the weight of the rocker arm 29 is substantially counterbalanced by the compression of the spring 46 and none of the weight of the arm is imposed on the shaft 33. The arm is in floating relation to the collar 38 and the shaft 33. This avoids the deflecti on of the projecting end of the shaft and elimihates the whipping action and consequent vibration, which in previousmachines resultedalso is the provision of a vibrationless and smoothly operated oscillating drive. Both improvements contribute toward considerable improvement in the grade of the work produced by the machine. They also are factors in prolonging the life of the bearings'for the drum shafts and in this way reduce operating costs and give generally better efiiciency. The provision of eccentrics as separate pieces assembled on the shaft 32 enable cheap and easier replacements. he takeup bolts on the split strap ends of the links 48 permit compensating for. wear so that a close'working fit for the links on the eccentrics 50 can be maintained at all times.

Referring for the present more particularly to Fig. 3, it will be noted that the housing 36 of the motor 21 has the bell ends and 56 providing spaced armature shaft bearings. The bell end 55 is bolted to thebearing 35 as indicated at 57. A cap 58 bolted on the bearing 35 positions an outer ball race member 59 between the hollow neck 60 thereof, and a similar hollow neck 61-on the bell end 55 of. the motor housing. The race member 59 and the. necks 60 and .61 are all received snugly within the bore 62 of the bearing 35, and the race member 59 is held stationary between the necks 60 and 61 in an obvious manner. Anti-friction balls 63 operate between the outer race 59 and an inner race 64. The race 64: is of elongated collar form and has a sleeve 65 slidable therein. Thesleeve 65 is fixed, as by means of a pin 66. against rotation relative to the shaft 33, the pin 66 being received in a notch 67 provided at the end of the'sleeve 65 where the sleeve comes in contact with a shoulder 68,.pr0vided by an enlargement in the diameter of the shaft 33. It will appear that the rotation of the sha t 33 with the sleeve 65 and the inner race. member 64: is permitted and is rendered almost frictionless by the provision of the balls 63. At the same time, the telescoping relation of the sleeve 65 in the inner race 64 permits the oscillation of the shaft 33 with the abrading drum as previously described. This feature is covered in my copending application Serial No. 416,523 filed December 26. 1929. The lubrication of the sliding jointbetween the sleeve and the race is induced by rings 69 dipping in the oil in the bottom of the chamber provided about the shaft within the hollow necks 60 and 61.

The lubricant is retained in the chamber referred to by packing provided at 7 O in the cap 58 and bell piece 55.

The armature core, the end of which appears at 71, is suitably splined on the shaft- 33 and rests in engagement with a shoulder afforded by an enlargement of the diameter;

of the shaft 33. A spacing sleeve 7 3 abuts against the end of the armaturecore 71 at one end and at its other end abuts against the adjacent end of the bearing sleeve 65, thereby keeping the sleeve 65 in proper re lation to its ball bearing in an obvionsman The sleeve 7 3 is preferably of the samediameter and of the same length as the sleeve ROI.

65 to be interchangeable therewith. For this reason, it is also provided with a notch 67 in one end thereof to receive the pin 66 when the sleeve 7 3 is substituted for the sleeve 65. The purpose in this provision is to obviate having to shut the machine down for an extended period in the event the sleeve 65 be-' comes worn to any appreciable degree. With the spacing, sleeve substituted for the bearing sleeve and the bearing sleeve 'in turn performingthe function of the spacingsleeve, the machine may be keptnn serv ce and necessary replacement sleeves ordered from the manufacturer of he machine or otherwisemade to have in readiness when another replacement is necessary.- This feaf ture'is also covered' 1n the copending appl1-' cation mentioned above. The stepping n the diameter of the shaft toward the outer end affording the shoulders at 68 and'4'2, etc. enables the removal of the parts and ea-sy 'replacement thereof. i i l t The outer end f the shaft 33 is received in a bearing held in thebellend 56 of the motor housing 36. A. capZ l is bolted to the ,bell' end 56, as shown, clamps an outer race 75 in placeQ The anti-friction bearing balls 76 operate between vthe outer race 7 5 and. an inner race 77. The latter similarly to the race 6a is extended in the form of. a collar and arranged to slide freely on a bearing sleeve 7 8 which, like the sleeves 65 and 73, is renewable. The sleeve 7 8 is held in engagement at one end with a shoulder 79, providod by an enlargementin the diameter of the shaft 33, by means of a disc at its other end bolted, as at 81, to the free end of the shaft 33. This also forms part of the subject matter of the copending application above mentioned. he loose'rings'82 serve.'in'thisinstance the same function as the rings 69; to feed lubricating oil onto the sliding joint between the sleeve 78 and the race 77. It is apparent that the arrangement provides for the compound movement of the shaft 33 by the sliding of the sleeve 78 in the race 7'? and the rotation of the innerrace' relative to the outer race.

Referring now to l, it will be seen that the oppositeend of the shaft 33 from the end previously under consideration has similar provisions in the bearing 34 for permitting simultaneous rotation and reciprocation of the shaft in anti-friction bearings. A pair of caps 83 are bolted to the opposite sides of the'bearing 34 and clamp the outer race 8; between them inan obvious manner. The bearing balls 85 are held between the outer race -84 and an inner race 86 sliding on the bearing sleeve 87. This sleeve is held in engagement with the shoulder 88 by aspacing slteve 89. The latter is in turn held in place by the inner race 90 of an anti-friction bearing within the thrust collar 38'. The sleeves 89 and 87 are interchangeable in like manner to the sleeves and 73, as covered in the copending application. The inner race 90 is held in place by a collar 91, secured as by means of a tapered pin 92 to the free end of the shaft 33. The outer race 93 for the balls 94 is held within the thrust collar 38 behind a cap 95 which bolts on the end of the collar 38. It will thus be seen that the provision of anti-friction bearings is extended throughout the machine so far as practicable with a saving in operating costs and an increase in general efiiciency.

I claim:

1. A machine as set forth in claim 5 wherein the shaft bearing supports on the machine frame members are vertically adjustable whereby to adjust the drum with its shaft according to the work to be handled, said counterbalancing means for said rocker arm being practically unaffected by such vertical adj stment of said shaft with its bearings by reason of the fact that the adjustment is slight.

2. A machine as set forth in claim 6 wherein the shaft bearing supports on the machine frame members are vertically adj ustable whereby to adjust the drum with its shaft according to the work to be handled, said pivotal mounting for the rocker arm with the yielding counterbalancing means therefor being arranged to be practically unaffected by the vertical adjustment of said shaft by reason of the fact that the adjustment is slight.

3. A machine as set forth. in claim 7 wherein the drum shaft bearings are vertically adjustable relative to the frame elements to correspondingly adjust the drum relative to the work, the counterbalancing means in connection with said link pivotally connected with the rocker arm being arranged to be practically unaffected by the endwise movement of said arm required in the vertical adjustment of said shaft by reason of the fact that the adjustment is slight.

4. In a machine of the character described, the combination of a pair of spaced frame elements, a shaft received in bearings in said elements and carrying a rotating abrading drum operating between said elements, a

the other of said links having means for com-' municating a thrust thereto to rock said arm on its pivotal mounting whereby to communicate endwise oscillation to said shaft through the thrust collar thereon, and means in connection with one of said links for counterbalancing the weight of said rocker arm whereby to eliminate the weight thereof from the thrust collar and hence from said shaft, both of said links being arranged by slight oscillation to permit straight line motion of the end of said arm pivotally connected with the thrust collar, said drum shaft being vertically adjustable with its bearings relative to the machine frame whereby to correspondingly adjust the drum relative to the work, and said counterbalancing means being arranged to be practically unaffected by the accompanying endwise movement of said arm by reason of the fact that the adjust ment is slight. v

5. In a machine of the character described, the combination of frame members, a shaftsupported by the latter and carrying an abrading drum for rotation between the frame members, a thrust collar on one end of said shaft, a rocker arm having a pivotal connection with said collar at its upper end, a link providing a floating pivotal connection for said arm with the one frame member to permit straight line motion of the upper end of said arm, another link having connection" with'said arm for rocking the same to communicate reciprocatory movement to said shaft, and means cooperating with one of said links to cause the frame to assume the weight of said arm whereby to keep the Weight thereof off the thrust collar.

6. In a machine of the character described, the combination of frame members, a shaft supported thereby and carrying an abra-ding drum for rotation between the frame members, a thrust collar on one end of said shaft,

a rocker arm having a pivotal connection with said collar at its upper end, a link providing a floating pivotal connection for said arm with one of said frame members whereby to permit straight line motion of the upper end of said rocker arm, another link hav ing connection with the lower end of said rocker arm for rocking the same so as to communicate reciprocatory movement to said shaft, and a spring reaching from a suitable support to one of said links to yiel-dingly assume the weight of said arm and thus keep this weight off the thrust collar.

7. In a machine of the character described, the combination ofv frame members, a shaftsupported thereby and carrying an abrading drum for rotation between the frame members, a thrust collar on one end of said shaft which projects beyond one of the frame members, a vertically disposed rocker arm having the upper end thereof pivotally connected with said collar, a link pivoted at one end on the last mentioned frame member and at the other end on said rocker arm intermediate the ends of the latter, providing a floating pivotal mounting for said arm to permit straight line motion of the upper end thereof, spring means associated with said link for counterbalancing said rocker arm to relieve the weight thereof from the thrust collar, a second link having pivotal connection with the lower end of said rocker arm for communicating rocking motion to said arm and thereby reciprocatory movement to said shaft, and means for communicating reciplrgocatory movement to the last mentioned lin 8. A machine as set forth in claim 7 including a bracket on the frame member having the first mentioned link pivoted with respect thereto, the rocker arm counterbalancacting between said bracket and the lower side of said link.

9. In a sanding machine comprising a pair of frame members, and a shaft supported thereon and carrying an abrading drum for simultaneous rotation and reciprocation between the frame members; a thrust collar on one end of said shaft for transmitting reciprocatory movement thereto, a rocker arm pivotally suspended from said collar, means for pivoting the rocker arm relative to the frame for rocking movement, the said means permitting a certain amount of up and down movement of the rocker arm in the rocking thereof to provide for straight line motion of the upper end thereof with the thrust collar, means for assuming the support of the rocker arm whereby to relieve the thrust collar of this weight and thereby provide for smooth operation of the shaft, and means for rocking the rocker arm, the means for assuming the weight of the rocker arm comprising spring means acting between the arm and the frame, the same being yieldable to permit the up and down movement of the rocker arm.

In witness of the foregoing I aflix my signature.

PETER A. SOLEM.

mg means comprising a compression spring e

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