US2002666A - Abrading or polishing machine - Google Patents

Description

y 1935. c. JOHNSON ET m.

ABRADING OR POLISHING MACHINE Filed June 29, 1932 2 Sheets-Sheet 1 Patented May 28, 1935 h c 2,002,666

. UNITED STATES PATENT OFFICE,

i aooases. V v ABRADING on POLISHING MACHINE, Charles Johnson and Carl Lawrence Mattison, t

3 Rockford, Ill., assignors to MattisonxMachine wfork s, Rockford, 111., a corporation of Illinois a licat on June 29, 1e32, Serial No. 619,836

' 10 Claims. (01. 51-135) One of the objects -of the invention is' to vent buckling or warping of'the sheet due to provide'novel and improvedmeans for driving the heat generated therein by the abrading the abrading or polishing belt and=for pressing mechanism. I g 7 the belt against the work. r The endless abrasive belt I S'is supported upon 5 Another object is to provide novel and imtwo idler pulleys l6 which are suitably jour- 5 proved means for reciprocating the presser naled on the machine frame and the lower or carriage. j I 'activ'e run of this belt runs around rolls on 9. Another object is toproduce a novel machine carriage I] which is mounted on a horizontal in which the abrading or polishing operation rail l8 to reciprocate longitudinally of said belt.

10 maybe performed either throughthe medium 'This carriage I1 is ,ireciprocated-by means of 10 of the usual endless belt or directly by the an endless cable I 9, running over a pair of presser roll'which presses the \belt against the sheai'es 20 journaled on the machine frame, one work. of whichsheaves is driven alternately in oppo- A further object is to provide a presser carsite directions by reversible electric motor 2| riage of novel construction by which the posiand suitable reduction gearing 22. The car- 15 tion of the presser roll may be varied to accomriage has means to be presently described for modate work of different thicknesses. attaching it to thelower run of said cable 19.

In the accompanying drawings, Figure 1 is Means is provided for automatically reversa front eleyation with parts broken away showing the electric ,inotor 2|, which means in the ing'a -machin'embodying our invention. exemplary embodiment herein shown is actu- 20 Fig. 2 is an levational view illustrating the ated by the movement of the carriage ll. A remechanis m' 'for reciprocating the presser car-, versing switch 23 mounted on the machine has riage. I a pair of contacts 24 and a pivoted switch arm Fig. 3 is a vertical front-to-rear sectional 25 which contacts and arm are connected by 25 view through said carriage. wires 26 to the reversing fields of the motor 2li' Fig. 4 is a rear elevation of/ the carriage in a manner well known. The switch has a showing a modified form of means for driving Sp 27 a d to t arm 25 acting o hold the presser roll. the arm in engagement with either one of the The present invention is applicable to a m contacts 24, with the result that the motor will 30 chine of the general type disclosed in Patent be driven in one direction or the other depending No. 1,478,044, issued'December 18, 1923, to Carl 1113011 whi h one Of the contacts the arm en- Lawrence Mattison, but in the present applicaag A r d 8 slidably mounted in h ri tion we have shown only such parts of the 29 O the m h frame has a P Of p machine as are necessary to an understanding tiOnS embracing the Switch arm d t of the invention. I rod also carries a pair of collars 3| which are M It should be understood that the present adjustable along the rod and are secured thereinvention is susceptible of embodiment in varoby sui a l m ns s h s s t s w Th ious forms and alternative constructions. and Collars n DOSitiOHtO be engaged by a P that the illustration by way of example of one Oh the Carriage l in its reciprocation Q effect '40 preferred embodiment of the invention is not to alternate longitudinal movement of e od in 40 be taken as an intention to limit the invention Opposite directions and thereby swing the switch to th present disclosure, The scope of the arm 25 from one of the contacts 24 to the other. invention will be pointed out in the appended It w thus be seen that by setting he o lars l ims, 3| at different distances apart, the range of re- The machine comprises a air of pedestals" r i n of th r i m y be v ri d n 45 I0 connected at their upper ends by a support Controlledupon whi h th iou Operating mecha- The carriage comprises two sections, one of nlsms are carried. The pedestals also carry wh designated is q pped with a plutracks I! running from front to rear upon which rality of rollers 32 to run upon a guide rail I8.

60 the work supporting table I3 is mounted. A 'The other section ll of the carriage is mounted pair of spaced hold-down rollers I4 are jourfor vertical sliding movement upon the first naled in bearings on the pedestals inioverlymentioned section.

ing relation to the work table and act to press The means for connecting the carriage to the against the work table the piece of work A, reciprocating cable l9 may be of any suitable 65 which may be a sheet of steel, and thereby pre-' form, that herein shown comprising an arm 33 '(Fig. 3) projecting rearwardly from the carriage section II and having a finger 34 to engage between a pair of stops or collars 35 fixed on the cable 19.

The lower carriage section [1 is mounted on vertical guideways 36 on the upper section and is held by a vertical screw 31 rotatably mounted in the lower section and threaded in a lug 38 on the upper section,-which lug passes through a slot 39 'in the lower section. A collar4ll fixed on the screw 31 prevents endwise movement of the screw relative to the lower section so that by rotating the screw the lower carriage section may be adjusted vertically by the operator.

In the lower carriage section are mounted a pair of idler rolls 4| and a combined driving and belt pressing roll 42. The lower run of the abrasive belt l5 passes over the top of the two idler rolls and down underneath the driving and pressing roll 42. The belt is thus flexedsharply out of the plane of the lower run thereof to form a relatively small loop which accomplishes a two-fold purpose in that it insures driving traction between the presser roll 42 and the belt and it gives the belt a much more efficient cutting action. In passing around these carriage rolls, the belt is sharply flexed in alternately reversed directions which acts to loosen dust or foreign matter that alwaystends to pack in between the abrasive grains and which, if not removed, would eventually cause the belt to glaze with the result that its cutting action is impaired and more heat is generated. As the belt passes around the presser roll 42 the particles of abrasive are spread apart so that their cutting edges aremore effectively brought into action along the zone of contact with'the work. has been found that this greatly increases the efliciency of the abrading action and also permits worn particles of abrasive to free themselves and escape from the belt and thereby present fresh sharp particles into cutting engagement with the work. The length of life of the belt is thus increased.

The presser roll 42 is preferably made of or surfaced with a yielding or cushion material which compresses very slightly under the existing pressure to maintain a narrow zone of contact between the belt and the work a little wider thana mere line contact. It has been found that providing a contact zone about Y three-eighths of an inch in width gives the most eflicient cutting action.

The idler rolls 4| are mounted on the carriage in such position that the upper surfaces of said rolls lie substantially in the plane of the lowermostpoints on the periphery of belt supporting pulleys I6 so that the tension upon and deflection of the belt in its passage through'the carriage I! will remain constant in all positions of the carriage in-its reciprocation.

In prior machines of this type, the abrasive belt hasusually been driven by one of the pulleys I6. It has been found that driving the belt from the presser roll on the carriage greatly reduces the strain on the belt and the liability of danger of its tearing or breaking; also that the quality of the work is improved because the surface of the presser roll does not have a tendency to be roughened by the belt and there is less tendency to vibration or chattering at the point of contact of the belt with the work than is the case where the belt is driven from one of the pulleys l8.

of the present invention to mount on the carriage power means for driving the presser roll and, through said roll, the abrasive belt is. The arrangement of this power driving means may be varied to suit requirements. In the present instance we have shown in Figs. 3 and 4 two alternative constructions. Referring first to Fig. 3, the presser roll 42 is mounted on a shaft is journalled in the carriage and this shaft constitutes anextension of or is axially alined with and fixed torthe armature shaft of an electric motor 44 which is secured beneath a rearwardly projecting portion of the lower carriage section. It will be noted that the presser roll 42 is positioned between'the two hold-down rollers l4 and the electric motor 44 is located rearwardly of the rear one of said hold-down rollers, the shaft with the presser roll 42, and power is communi-' cated from the motor ;to said presser roll by a belt 45 running over sheaves 4B fixed respectively on the armature shaft and the shaft of said presser roll. By replacing the sheaves 4% with sheaves of relatively different diameters, the speed of the presser roll 42 may be varied at will.

It will be understood, of course, that suitable connections between the motors 2i and 44 to power lines and suitable controlling switches therefore are provided. It is not deemed necessary to illustrate this arrangement herein since it may be of conventional form and constitutes no part of the present invention.

If desired, the abrasive belt may be removed from the machine and an abrasive or polishing sheet fastened about the periphery of the presser roll 42, or instead the presser roll may be removed from the carriage and another roll having abrasive or polishing material on its periphery may be substituted therefor.

In operation the sheet of material A to be finished is laid upon the work table l3 while the table is in its foremost position. The table is then pushed rearwardly to carry the sheet beneath the hold-down rollers l4. Either the supporting rails H for the work table or the bearings for the hold-down rollers H or both may be made vertically adjustable to vary the space between said hold-down rollers and the upper surface of the work table for accommodation of work of different thicknesses. The construction of the carriage I! also permits, through manipulation of the screw 31, a micrometer adjustment of the height of the presser roll 42. To control the range of reciprocation of the carriage .to accord with the width of the work piece, the operator may adjust the stop collars 3| on the rod 28 so that the switch 22 will be reversed when the carriage has traveled a desired distance in either direction. When the proper relationship has been established, the motors 2| and 44 may be started and so long as the carriage is coupled to the cable IS the carriage will be reciprocated along its guide rail, with the abrasive belt I5 or the abrading or polishing surface of the roll 42, as the case may be, in contact with the work A. The work table is moved rearwardly either by hand or by power as the carriage reciprocates so that every point on the sheet. A will be treated. If desired, the arm 33 on the carriage may be disengaged from the driving cable I! and the position of the carriage may be then manually controlled so that the operator may give further or special treatment to any spots on the work which have not been finished to the desired degree.

We claim as our invention:

1. A machine of the character described having, in combination, an endless belt to operate on the work, a plurality of idler pulleys supporting said belt, and means for driving said belt and for pressing the belt against the work comprising a carriage mounted to reciprocate along said belt, a power-driven presser roll on said carriage friotionally engaging and driving said belt and pressing the belt against the work, and a pair of idler rolls located at opposite sides of and close to said presser roll and acting to hold said belt in contact with said presser roll and to cause alternate reverse flexing of the belt so as to free foreign matter and to spread the abrasive particles apart at the zone of en gagement with the work for better cutting action.

2. A machine of the character described having, in combination, an endless abrading or polishing belt, a plurality of pulleys supporting said belt, and means for driving said belt and for pressing the belt against the work comprising a carriage mounted to reciprocate parallel to the active run of the belt, a presser roll mounted on said carriage in driving engagement with the belt and arranged to press the belt against the work, a pair of idler rolls mounted on said carriage on opposite sides of and close to said presser roll and holding said belt against said presser roll, and a motor mounted on said carriage for driving said presser roll and thereby driving said belt.

3. A machine of the character described having, in combination, an endless abrading or polishing belt, a carriage mounted to reciprocate along the active run of said belt, a plurality of rolls mounted on said carriage over which rolls said active run ot'the belt passes, one of said rolls acting to press the belt against the work, and power means on said carriage for driving the last mentioned roll and thereby driving said belt.

4. A machine of the character described having, in combination, an abrading or polishing belt, means for supporting said belt, and means for driving said belt and for pressing the belt against the work comprising a carriage mounted to reciprocate along the active run of said belt, a pair of idler rolls on said carriage engaging said belt, a presser roll mounted on said carriage between and close to said idler rolls and engaging said belt to deflect a loop thereof sharply out of the plane of the remainder of the active run of the belt for engagement with the work, and a motor mounted on said carriage for driving said presser roll and thereby driving said belt.

5. A machine of the character described comprising, in combination, means for supporting a piece of work, work hold-down means overlying said work supporting means, abrading or polishing means including a carriage mounted to re ciprocate along the work, a presser roll on said carriage, and a driving motor on said carriage operatively connected to said roll. said roll and said motor being located at opposite sides of said hold-down means.

6. A machine of the character described having, in combination, a horizontal work table, a pair of hold-down rollers overlying said work table, abrading or polishing means above said work table including a carriage mounted for horizontal reciprocation parallel to said rollers, a presser roll on said carriage located between said hold-down rollers for pressing the abrading or polishing means against the work, and a driving motor mounted on said carriage and drivingly connected to said roll, said motor being located at the outer side of one of said holddown rollers relative to said presser roll.

'7. A machine of the character described having, in combination, an endless belt for operating on the work and having a plain and an abrasive side, a plurality of idler pulleys supporting said belt to provide a run with a straight portion, a power-driven presser roll frictionally engaging the plain side of said belt at the straight portion of the run to drive the belt, and a pair of idler rolls located at opposite sides of and close to said presser roll and engaging the abrasive side of said belt, said presser roll being offset relative to said idler rolls to deflect the belt into engagement with the work and to cause the belt to contact with a substantial portion of the periphery of said presser roll to insure proper driving traction between the latter and said belt.

8. A machine of the character described having, in combination, an endless belt for performing a working operation, a carriage mounted for reciprocation along a piece of work and longitudinally of said belt, a plurality of rolls mounted on said carriage over which said belt passes, one of said rolls acting to press a face of said belt against the work to perform a working operation, and power driven means on said carriage drivingly connected with one of said rolls for driving said belt.

9. A machine of the character described having, in combination an endless abrading or polishing belt, a carriage mounted to reciprocate along the active run of said belt, a roll mounted on said carriage over which the active run of the belt passes and by which the belt is pressed against the work, and power means on said carriage for driving the last mentioned roll and thereby driving said belt.

10. In a machine of the character described, the combination of a frame having a work supporting face, an endless belt having an active run extending substantially parallel to said face, a pair of hold-down rollers disposed adjacent to said face and located in substantial parallelism, one on each side of said active run, a reciprocating carriage mounted for movement longitudinally of said active run, and a driven roll mounted on said carriage and engaging said active run for driving said belt and for pressing it against the work between said hold-down g rollers.

CHARLES JOHNSON. CARL LAWRENCE MA'I'I'IBON.

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