US3908316A

US3908316A - Multi-station simultaneous dual-side sanding machine

Info

Publication number: US3908316A
Application number: US502920A
Authority: US
Inventors: Richard L Retteu
Original assignee: Lok Box Inc
Current assignee: Lok Box Inc
Priority date: 1974-09-04
Filing date: 1974-09-04
Publication date: 1975-09-30
Anticipated expiration: 1992-09-30

Abstract

An adjustable automatic belt sanding machine wherein rectangular box-shaped workpieces requiring finish sanding of the four peripheral sides thereof are continuously fed through subsequent sanding stations of the machine in a line of top-to-bottom abutting workpiece relationship by means of a set of compressively engaging drive belts at the feed end of the machine, and thereafter each workpiece is progressively advanced and sequentially subjected to simultaneous coarse sanding of the respective opposing vertically machine oriented side surfaces thereof by a set of transversely spaced vertical sanding belts, afterwhich there is simultaneous coarse sanding of the upper and lower machine oriented side surfaces thereof by transversely spaced horizontal sanding belts, thereafter followed by simultaneous fine sanding of the aforementioned vertically oriented side surfaces by a second set of transversely spaced vertical sanding belts, and lastly, fine sanding of the aforementioned upper and lower side surfaces thereof by a second set of transversely spaced horizontal sanding belts, all of which enables the four-side finish sanding of box-shaped workpieces by a single pass of the workpieces through the machine.

Description

United States Patent 1,1911

Rettew 1451 Sept. 30, 1975 1 1 MULTl-STATION SIMULTANEOUS DUAL-SIDE SANDING MACHINE Richard L. Rettew, Newmanstown Pa.

[73] Assignee: Lek-Box, lnc., York, Pa.

[22] Filed: Sept. 4, 1974 [21] Appl. No.: 502,920

[75] Inventor:

354L735 11/1970 Sehaller et 211....

3562.961 2/1971 Clayson et a1. 51/138 3.566546 3/1971 Lindmark 51/142 $845,588 11/1974 Huffman 51/140 Primary Examiner-Othcll M. Simpson Allorney. Agent. or FirmC Hercus Just; Samuel M. Learned, Jr.

[57] ABSTRACT An adjustable automatic belt sanding machine wherein rectangular box-shaped workpieces requiring finish sanding of the four peripheral sides thereof are continuously fed through subsequent sanding stations of the machine in a line of top-to-bottom abutting workpiece relationship by means of a set of compressively engaging drive belts at the feed end of the machine, and thereafter each workpiece is progressively advanced and sequentially subjected to simultaneous coarse sanding of the respective opposing vertically machine oriented side surfaces thereof by a set of transversely spaced vertical sanding belts, afterwhich there is simultaneous coarse sanding of the upper and lower machine oriented side surfaces thereof by transversely spaced horizontal sanding belts, thereafter followed by simultaneous fine sanding of the aforementioned vertically oriented side surfaces by a second set of transversely spaced vertical sanding belts, and lastly fine sanding of the aforementioned upper and lower side surfaces thereof by a second set of transversely spaced horizontal sanding belts all of which enables the four-side finish sanding of box-shaped workpieces by a single pass of the workpieces through the machine.

10 Claims, 4 Drawing Figures Sheet 1 of 3 3,908,316

f Sept 30,1975

US. Patent US. Patent Sept. 30,1975 Sheet 2 of3 3,908,316

I IL 'I] MULTI-STATION SIMULTANEOUS DUAL-SIDE SANDING MACHINE BACKGROUND OF THE INVENTION It has long been a marketing technique to package prestige products in correspondingly appropriate containers in order to carry through a theme and sense which gives the consumer an outward impression as to the quality of the product packaged within the container. In recent years, with the advent of an expanded male toiletry product market, one type of container which has come into popular and wide-spread use for packaging such products are various sizes and shapes of wooden boxes which are held together at the corners thereof by a plurality of glued mortice and tenon corner joints. In the construction of such boxes it has been found necessary to sand down any protruding tenon members or any other irregularities extending beyond both sides of all four corners of said boxes and thereby bring the respective peripheral sides of said boxes and the connective corner joint elements, i.e., extending tenon members, into a smooth flush relationship with the box sides.

Previously, the side-corner finishing operation as described supra has been accomplished by an individual operator standing at a horizontal or vertical belt sanding machine, picking up and hand-holding one or more boxes at a time with one side thereof in working contact with the operating horizontal or vertical sanding belt of said machine, and then in rotatable order, belt sanding each of the remaining three sides and extending corner elements of the box. The present invention relates to a machine designed to automatically accomplish the finishing operations heretofore described and done by a single side, single unit at a time handholding procedure.

Multiple station polishing and sanding machines have long been known, and, as is the case with the instant invention, such machines were primarily developed for accomplishing with greater speed, efficiency, and reduced material handling requirements which had formerly been done by less productive means. The disclosure in U.S. Pat. No. 908,977 to Dickson, dated Jan. 5, 1909, teaches an adjustable mechanical means whereby a workpiece manually inserted between a single set of transverse opposingly and inwardly rotating endless belts would enable the simultaneous polishing of two opposite sides of said workpiece. However, the disclosure requires that an operator hand-hold and manipulate the workpiece in order to employ the machine. No provisions are disclosed for conveyance of multiple workpieces through said machine, nor is there shown or claimed anything other than a single polishing station capability.

In U.S. Pat. No. 2,195,340 to Potash, dated Mar. 26, 1940, there is revealed the incorporation of reciprocating shoe members to backup a set of transverse opposingly rotating sanding belts thereby imparting additional abrading action upon the transverse sides of a .wooden slat workpiece positively driven through the sanding station by a set of feed rollers. However, again, only two sides of a workpiece are operated upon by a single sanding station during a single pass through the machine, and, the machine is primarily designed to finish wooden slat workpieces by sanding.

The employment of subsequent sanding stations in order to completely finish a workpiece with one pass LII through a machine is taught in U.S. Pat. No. 2,714,278 to Dostert, dated Aug. 2, 1955, which shows a transverse set of oppositely rotating sanding belts to finish the longitudinal end faces of solid rod shaped workpieces as said workpieces are rolled along a channel guide by drive belt means, thereafter followed by two nonopposing supplemental belt sanding stations respectively disposed at equally opposite angles, one to the other, whereby the periphery of each of the opposite end faces of said rod shaped workpieces are sequentially chamfered as said workpieces are rolled along said guide by said belt drive means. However, Dostert discloses a machine specifically designed and suited to a particular finishing operation upon a particular geometrically shaped workpiece, namely cylindrical rods or pins. Further, Dostert does not teach a sand-. ing station employing a set of transverse oppositely rotating horizontally disposed sanding belts.

In U.S. Pat. No. 3,178,860 to Clyne, dated Apr. 20, 1965, there is taught a multiple station sanding machine, however, disclosing single side sanding of a workpiece only as the machine side which is transverse to each respective sanding head is occupied by a conveyor belt member which is essential for transporting workpieces through said machine. Therefore, each side of a workpiece to be finished requires a separate pass through the machine.

Subsequently issued patents, such as the disclosures taught in U.S. Pat No. 3,269,065 to Nylund, dated Aug. 30, 1966, as well as in U.S. Pat. No. 3,541,735 to Schaller et al., dated Nov. 24, 1970, and U.S. Pat. No. 3,654,738 to Sternal, dated Apr. 11, 1972, each teach certain improvements and new and useful efficiency features in belt sanding machines not previously disclosed or claimed, but none of which show nor anticipate the instant invention, nor in combination would make the instant invention obvious to one having ordinary skill in the art at the time the instant invention was made. For example, Nylund teaches non-simultaneous transverse side sanding of a workpiece whereby roller means are employed in order to apply abrading medium pressure to a workpiece, as well as the art of partial cross-grain sanding of a workpiece along the longitudinal dimension thereof. Schaller et al teaches the employment of variable oscillating non-aligned transverse abrading heads, i.e., abrading heads which are transversely opposed by a backup roll and not by another abrading head, thereby also resulting in successive but not simultaneous abrasion of opposite sides of a workpiece. Sternal teaches high-speed transverse single pass sanding of the opposite sides of rough-sawn boards, employing also a partial cross-grain sanding technique as discussed in Nylund, but, however, by means wherein either the workpieces are fed through the machine at an angle to the longitudinal dimension of said workpieces, or the longitudinal axes of the sanding heads are set at an angle off the perpendicular to the longitudinal dimension of the workpiece. Sternal also teaches transverse reciprocation of the sanding belts as the sanding operation is beingperformed upon a workpiece.

The present invention is distinguishable from said earlier inventions in one or more ways in that the present invention has utility features and new and useful advantages, applications, and improvements in the art of belt sanding workpieces not heretofore disclosed, as set forth below.

SUMMARY OF THE INVENTION It is the principal object of the present invention to provide a multi-station belt sanding machine wherein a head-to-foot or top-to-bottom abutting line of mortice and tenon corner joint wooden or similar box-shaped workpieces are manually introduced to a horizontally disposed compressive feed belt conveyor by which said workpieces are engaged and positively impelled forward in longitudinal head-to-foot or top-to-bottom compression through said machine along guide members therein to subsequent laterally disposed vertical and horizontal dual-belt sanding stations through which said workpieces are moved and during transit therethrough respective rough and fine sanding of all four peripheral corners and sides of said workpieces are sequentially accomplished.

Another object of the present invention is to provide a multi-station belt sanding machine which will reduce workpiece handling requirements by performing the finish sanding of all four corners and sides of said workpieces during only a single pass of said workpieces through said machine and effective vacuum removal of sanding wastes is accomplished to provide efficiency and worker safety.

Still another object of the invention is to provide a multi-station belt sanding machine which is safe, relatively simple to adjust and operate, and may be set and run by an individual not possessed of special mechanical skills or training.

A further object of the present invention is to provide a multi-station belt sanding machine which is easily and readily adjustable in the horizontal and vertical direc tions in order to accommodate a wide range of different sizes of workpieces, which adjustments, once set, will retain dimensional stability throughout a production run.

Still another object of the invention is to provide a multi-station belt sanding machine which is designed to enable quick and easy changing of sanding belts when said belts become worn.

It is yet another object to provide a multi-station belt sanding machine wherein the belt tension at each sanding station is continuously maintained at a constant value by pneumatic means mechanically linked to belt tensioning members.

Details of the foregoing objects and of the invention as well as other objects thereof are described in the following specification and illustrated in the accompanying drawings comprising a part thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of the sanding machine embodying the principles and features of the present invention.

FIG. 2 is a sectional top plan view of the machine shown in FIG. 1, as seen on the line 22 thereof.

FIG. 3 is an end view ofa transverse vertical sanding belt unit per se as shown in FIG. 1, as seen on the line 3-3 thereof.

FIG. 4 is an end view of a transverse horizontal sanding belt unit per se as shown in FIG. 2, as seen on the line 4-4 thereof.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1, the present invention is shown which comprises a multi-station dual-side sanding machine 10 having a supporting frame structure 12 com prised of interconnected horizontally and vertically disposed structural support members, an infeed conveyor station 14 whereby workpieces are delivered into said machine 10 along guide rails 16 and sequentially impelled in head-to-foot or top-to-bottom abutment through a dual vertical belt, coarse sanding station 18,

then through a dual horizontal belt, coarse sanding station 20, afterwhich said workpieces are moved through a dual vertical belt, fine sanding station 22, and thereaf tcr through a dual horizontal belt, fine sanding station 24 to the delivery table 26.

Also referring to FIG. 1 to explain the details of adjustment and operation of the present invention, it will be seen that initially, depending upon the lateral side dimension of the box-shaped workpieces to be run, the adjustable flexible compressive feed belt 28 of the infeed conveyor station 14 is laterally moved in or out by rotating the feed belt adjustment screw 30, by means of the feed belt adjustment screw handle 32 attached thereto, so as to compressively engage and convey into the machine workpieces introduced into the infeed conveyor station 14 between said adjustable flexible compressive feed belt 28 and the stationary flexible compressive feed belt 34, said stationary flexible

compressive feed belts

28 and 34 being shown more particularly in FIG. 2.

In making the infeed conveyor station 14 operational, adjustment is made for accommodating the lateral dimension of said workpieces to be fed therethrough. It is important that the compressive pressure exerted upon said workpieces fed between

feed belts

28 and 32 within said infeed conveyor station 14 at any one time be sufficient to impel an abutting line of headto-foot workpieces through said machine 10 along guide rails 16 thereof to the delivery table 26 while

sanding belt stations

18, 20, 22, and 24 of said machine 10 are in operation, while at the same time not resulting in slippage of said

feed belts

28 and 34 across the compressively engaged surfaces of said workpieces, nor cause damage to or distortion of said workpieces as a result of excessive compressive pressure resulting from an insufficient dimensional adjustment to accommodate the lateral dimension of said workpieces.

In order to insure proper operational compressive feed-force adjustment upon said workpieces, in accordance with the foregoing criterion, the infeed conveyor station 14 is also provided with compressive drive rollers 36, as well as compressive idler rollers 38, and infeed conveyor backup plates 40, all of which function as backup members for flexible

compressive feed belts

28 and 34 so as to limit the compressive deflection of said flexible

compressive feed belts

28 and 34, thereby enabling operational compressive feed-force adjustment upon said workpieces. In order to further control the infeed conveyor station 14, a variable-speed pneumatic motor 42 imparts controllable rotary motion to feed

belts

28 and 34 drive rollers 36 by means of a chain drive 44 to sprocket 46 which, in turn, drives transmissions 48 through which rotary motion is imparted to drive rollers 36 by which said

feed belts

28 and 34 are driven. Following the operational adjustment of said infeed conveyor station 14, the

sanding belt stations

18, 20, 22, and 24 are dimensionally adjusted for workpieces to be run. Since the two vertical

belt sanding stations

18 and 22 are identical in all operational respects, excepting for the abrasive grades of sanding belts affixed thereto, as are also the two horizontal belt sanding stations and 24, only one of each type station, namely 18 and 20, will be described in detail, it being understood that the respective

corresponding sanding stations

22 and 24 are identical excepting only for the finer abrasive grade of the sanding belts affixed thereto.

Dimensional adjustment of the vertical

sanding belt stations

18 and 22 to accommodate the machine oriented lateral sides of workpieces to be fed therethrough, is accomplished by rotating the vertical belt sanding station adjustment handle 50, which moves the operator-side vertical sanding belt member 52, by means of the vertical belt adjustment screw 54, as well as the guide rail member 16 attached thereto, laterally in or out. It will be understood that dual vertical belt, fine sanding station 22 will be set at a dimensional adjustment slightly less than dual vertical belt coarse sanding station 18 as the majority of material to be removed from the lateral sides of said workpieces will have been accomplished during passage thereof through coarse sanding station 18.

Initial lateral adjustment of

belts

52 and 53 may be made in terms of dimension by measuring the lateral distance between the stationary vertical sanding belt member 53 and the adjustable operator-side sanding belt member 52 by means of the side guide belt and guide rail dimension indicator 56, see FIG. 2. However, final dimensional adjustment between

vertical belts

52 and 53 is made by the operator, and is primarily dependent upon the amount of material to be sandably removed from the workpieces, as well as any other operational factors and considerations to be taken into account. Additionally, vertical holddown guide 58 shown in FIG. 1 is set to retain said workpieces in stable position during transit through dual vertical

sanding belt stations

18 and 22.

Centering and control of

vertical belt members

52 and 53 upon the respective vertical belt drive rollers 60 and vertical idler rollers 62 is by means of a belt guide dog 64 whichis adjustable for purposes of centering

vertical belt members

52 and 53 by means of the belt tracking adjustment assembly 66 shown in FIG. 2. It should be understood that all adjustments and settings of

vertical belt members

52 and 53 are accomplished while said

belt members

52 and 53 are under tension, which tension is consequent from extension of an air cylinder piston rod 68 connectably linked to vertical belt idler rollers 62, whereby said idler rollers 62 are held in extension by said air cylinder 70, thereby providing means to maintain a constant belt tension. When

vertical belt members

52 and 53 are to be changed, said air cylinder piston rod 68 is retracted, thereby releasing belt tension, and enabling quick and easy removal of worn

vertical belt members

52 and 53 and replacement of new

vertical belt members

52 and 53, after which air cylinder piston rod 68 is extended, thereby regaining a constant tension on

vertical belt members

52 and 53. Additionally shown as elements of the dual vertical

belt sanding stations

18 and 22 are vertical belt drive motors 72 and vertical belt station vacuum system collectors 74 for sanding dust.

Dimensional adjustment of the horizontal

belt sanding stations

20 and 24, in order to accommodate the machine oriented upper and lower sides of workpieces to be fed therethrough, is accomplished by essentially the same methods, means, and technique as is used to adjust the vertical

belt sanding stations

18 and 22, namely, the horizontally adjustable sanding belt member 76 is raised or lowered in relation to the stationary horizontal sanding belt member 78 by means of rotating the horizontal belt sanding station adjustment handle 80, which in turn rotates the horizontal belt adjustment screw 82, whereby said horizontally adjustable sanding belt member 76 is elevated or depressed in order to accommodate the vertically machine-oriented dimension of workpieces to be fed therethrough. Initial setting of said horizontally adjustable belt member may be measured by means of the top guide belt and guide rail dimension indicator 84 shown in FIG. 1. However, as with the operational setting of the vertical belt members, final dimensional adjustment between

horizontal belts

76 and 78 is made by the operator in accordance with and dependent upon the operational factors to be considered in finishing a particular type, size, and run of workpieces.

Again, it will be understood that the dimensional setting on the fine horizontal sanding belt station 24 will be dimensionally slightly less than the setting at the coarse horizontal sanding belt station 20 as the majority of material to be removed from the upper and lower sides of workpieces will have been accomplished during passage thereof through coarse horizontal sanding station 20. Upon operational adjustment of horizontal

sanding belt members

76 and 78, as heretofore explained, which is also accomplished under tension from air cylinder 70, the horizontal side retaining guides 86 are adjusted to stabilize the workpieces as they are transported through horizontal

sanding belt stations

20 and 24.

As with the earlier described vertical

sanding belt stations

18 and 22, the horizontal

sanding belt stations

20 and 24 likewise have as component elements thereof horizontal belt drive rollers 88 connected to horizontal belt drive motors 90 and horizontal belt idler rollers 92 around which

rollers

88 and 92 the

horizontal belt members

76 and 78 rotate. Horizontal belt guide dogs 94, adjusted by means of horizontal belt tracking adjustment assembly 96, provide the means whereby horizontal

sanding belt members

76 and 78 are adjusted, centered, and maintained in position upon the horizontal belt drive rollers 88 and the idler rollers 92 during operation. Also, as with the vertical sanding

stations

18 and 22, horizontal sanding

stations

20 and 24 include belt tension means provided by extension of an air cylinder rod 68 connectably linked to horizontal belt idler rollers 92, whereby said idler rollers 92 are held in extension by aforementioned air cylinder 70, thereby providing means to maintain constant

horizontal belt

76 and 78 tension. Retraetion of said air cylinder piston rod 68 releases tension on

belts

76 and 78, whereby said

belts

76 and 78 may be removed and replaced by new belts or belts having different sanding properties. Upon the installation of new belts said piston rod 68 is extended and tension on said

belt members

76 and 78 is re-established. Additionally included as a component element of horizontal

belt sanding stations

20 and 24 are horizontal belt station vacuum system collectors 98 for sanding dust.

The multi-station dual-side sanding machine 10 thus far described is operationally set to run a particular lot of similar workpieces to which dimensional adjustment has been made in the machine. workpieces are thereafter aligned in an abutting head-to-foot or top-to-bottom configuration on the staging conveyor 100 which is driven by a belt 102 attached to a pulley 104 on the drive shaft of variable-speed pneumatic motor 42. It should be noted that all electrical functions of the machine are operated from control panel 106., whereas all pneumatic functions, such as those of variable-speed pneumatic motor 42 and air cylinders 70, are controlled by standard regulators and valves connected to the plant air supply, none of which are shown in the drawings included herewith since the same are of conventional nature.

The machine 10 as disclosed in FIG. 1 preferably is constructed of metal, but any other suitable materials or combinations thereof may be used.

Referring to FIG. 2, which is a sectional top view of the side elevation of the machine shown in FIG. 1 as seen along the line 2--2 thereof, there is shown more specifically the configuration of component elements of the machine as heretofore described. Principally shown in more particular detail is the plan relation and arrangement of infeed conveyor station 14 and the elements thereof.

In FIG. 3, an end view per se of the vertical sanding station 18 is shown as seen along the line 3-3 of FIG. 1. Additionally shown, however, is an exemplary workpiece 108 and the manner by which said workpiece 108 is supported in the sanding zone of sanding station 18 by guide rails 16. It will be noted that guide rails 16 have support lips which extend under the lower surfaces at opposite sides of said workpiece 108, thereby providing the necessary support to maintain said workpiece 108 in vertical alignment against the pushing effects of inwardly rotating vertical

sanding belt members

52 and 53. It should be noted, however, that the guide rail members are interrupted within the sanding zone, to accommodate the sanding belts thereby enabling the respective belt members to be flush with the opposing vertical sides of workpieces as said workpieces are sanded and transported through said sanding zone. Also shown to advantage in FIG. 3 are the vertical sanding belt backup plates 110 which provide lateral support to workpiece 108 shown within the sanding zone. Also shown, as heretofore described, is vertical holddown guide 58 which provides stabilizing support to said workpiece 108 in the vertical station 18 sanding zone by being slidably engaged by the workpieces 108.

Additionally shown in more detail are certain of the structural support elements for the vertical sanding station roller and belt assemblies. In particular, support rods 114 for the vertical belt adjustment means are shown, along which the frame which supports the adjustable vertical sanding belt member 52 is slidably guided and moved during a lateral increase or decrease of the transverse dimension of the sanding zone, and also by which said sanding belt member is held securely in position during sanding operations. Also shown are the lateral support arms 116 for the belt member backup plate, which not only provide the backup plate mounting means, but also include connection means 118 for pivotally attaching the air cylinders 70 which provide the tensioning means for

belt members

52 and 53 through pivotal engagement and movement of the belt tensioning lever arm 120 upon extension of the air cylinder piston rod 68. Support plate members 122 are the structural means in the vertical sanding belt station 18 by which the drive and idler rollers are securely supported for rotation about fixed axes to support belt 53 and relative to which the supporting means for belt 52, described above, are mounted for adjustment toward and from belt 53.

The entire vertical sanding belt station end view assembly, as shown in FIG. 3, is positioned within and securely affixed to and supported by the vertical frame member 126 and horizontal frame member 128 of the supporting frame structure shown in FIGS. 1 and 2,

which frame attachment and support members form mechanical enclaves within which said sanding station assemblies are enclosed, but however, for purposes of drawing clarity, said enclave assembly has not been shown in FIG. 3. All other elements seen in FIG. 3 are as heretofore described, except as seen in end view.

In FIG. 4 an end view per se of the horizontal sanding station 20 is shown as seen along the line 44 of FIG. 2. Also additionally shown, however, is an exemplary workpiece 108 as seen in FIG. 3, but revealing how said workpiece 108 is supported in said sanding station 20 sanding zone by horizontal guide rail sections 16. It will be noted that horizontal guide rails 16 have longitudinal support lips extending above and below the outboard lateral surface of the workpiece 108, thereby providing the necessary support to maintain said workpiece 108 in horizontal alignment against the pushing effects of outboard rotating horizontal

sanding belt members

76 and 78. Again, it should be noted that the guide rail members are interrupted within the sanding zone, thereby providing spaces to enable the respective belt members to be flush with the opposing horizontal sides of workpieces as said workpieces are sanded and transported through said sanding zone. Also additionally shown to advantage in FIG. 4 are horizontal sanding belt backup plates 112 which provide vertical support to workpieces 108 when within the sanding zone. Further shown, as heretofore described, is horizontal holddown guide 86 which provides stabilizing support to said workpiece 108 in the horizontal station 20 sanding zone.

Additionally shown in FIG. 4 are the support rods 124 for the horizontal belt adjustment means along which the frame which adjustably supports the horizontal sanding belt member 76 is slidably guided and moved during a vertical increase or decrease of the vertical dimension of the sanding zone of sanding station 20, and by which said sanding belt member also is held securely in position during sanding operations. Also shown, as heretofore described in the description of FIG. 3, are the horizontal support arms 116 for the belt member backup plate, as well as the pivotal connection. 118 for air cylinder and the tensioning lever arm 120, as well as the respective stationary and adjustable horizontal support plate assemblies 122 for sanding belt 76 which is vertically adjustable relative to belt 78 which is non-adjustable. As with the structure in FIG. 3, the supporting frame structure of said machine has not been shown for purposes of clarity of the drawing. It will, however, be understood that the descriptions of said frame structure heretofore given are equally applicable as regards mounting and support of the unit depicted and described by FIG. 4. All other elements seen in FIG. 4 are as heretofore described, except as seen in end view.

While the invention has been described and illustrated in its several preferred embodiments, it should be understood that the invention is not to be limited to the precise details herein illustrated and described since the same may be carried out in other ways falling within the scope of the invention as illustrated and described.

I claim:

1. A sanding machine having a supporting frame structure of interconnected vertical and horizontal frame members to support units thereof adapted to sand the four peripheral sides of a plurality of head-tofoot abutted rectangular shaped objects during a single pass of said objects through said machine comprising in combination, a laterally disposed compressive infeed conveyor means by which opposite sides of said objects are compressively engaged in abutting head-to-foot relationship one to the other and impelled unidirectionally from the feed end to the delivery end of said machine along an elongated series of guide members having horizontal supporting surfaces extending from the feed to the delivery ends of said machine to provide a path along which said objects are slidably supported in said head-to-foot abutting relationship to each other during movement through said machine, a first sanding unit comprising a pair of opposed endless sanding belts having parallel vertical courses disposed adjacent opposite sides of said guide members and operable simultaneously to sand opposite lateral faces of said objects, horizontal guide means laterally disposed below the lower surfaces of said abutted objects to resist downward deflective movement therof from the plane of said guide members, a second sanding unit comprising another pair of opposed endless sanding belts having vertically spaced parallel horizontal courses respectively above and below the other pair of opposed surfaces of said objects as moved along said guide members, said guide members being interrupted to accommodate said courses of said horizontal belts above and below said objects, perpendicular guide means adjacent one side of said guide members between said horizontal courses of said another pair of belts to permit said objects to resist lateral movement from said guide members in the direction of movement of said courses of said horizon tal belts, and supporting frame means supporting all of said conveyor means and guide members in association with said first and second sanding units.

2. The sanding machine according to claim 1, in which said supporting frame means is provided with adjustable means operable to effect adjustable spacing of the infeed conveyor means and sanding belts of said sanding units.

3. The sanding machine according to claim 1, in which the compressive infeed conveyor means comprises a pair of feed belts operable in vertical planes having parallel inwardly moving courses at opposite sides of the feed-end of said machine to impel said objects in feeding direction in succession to and through said sanding units.

4. The sanding machine according to claim 1, wherein each respective vertiical and horizontal sanding belt member of the respective vertical and horizontal pairs of sanding belts extend around pairs of spaced rollers supported by elongated parallel plate members, the first roller of which is a drive roller and the second roller is an idler roller, each axis of rotation of said idler roller being mechanically linked to a separate pneumatic cylinder means mechanically affixed to a separate supporting frame member of said machine, whereby pneumatic extension of a piston of each of said pneumatic cylinder means distends said idler roller and tensions each of said vertical and horizontal sanding belt members of said vertical and horizontal pairs of sanding belts.

5. The sanding machine according to claim 1, wherein each pair of vertical and horizontal belts extending around pairs of spaced drive and idler rollers respectively comprise a stationary belt member assembly and an adjustable belt member assembly, said adjustable belt member assembly being slidably mounted upon guide rods supported upon the frame of said machine, and means operable to move said adjustable belt member assembly upon said rods toward or away from said stationary belt member.

6. The sanding machine according to claim 1, wherein said adjustable vertical and horizontal sanding belt members of each sanding unit are substantially the same, said belts are mounted upon a support plate member transverse to the stationary sanding belt members, said support plate members are adjustable by screw means and mounted vertically for horizontal sanding belt adjustment and horizontally for vertical sanding belt adjustment.

7. The sanding machine according to claim 1, further provided with gauge means for both the adjustable vertical and horizontal sanding belt members to indicate the dimensional spacing of said adjustable vertical and horizontal sanding belt members from the respective stationary vertical and horizontal sanding belts members.

8. A sanding machine according to claim 1, adapted to sand the four peripheral sides of a plurality of headto-foot aligned and abutted rectangular shaped objects during a single pass of said objects through said machine and further including a geometrically configured sanding dust collection hopper positioned below each of the inward rotating vertical pair of sanding belts, and vacuum means attached to said hopper by which particulate matter abrasively removed from the peripheral vertical sides of the plurality of rectangular shaped objects during the sanding operation is captured and conveyed therefrom to collection means.

9. A sanding machine according to claim 1, adapted to sand the four peripheral sides of a plurality of headto-foot abutted rectangular shaped objects during a single pass of said objects through said machine and further including a geometrically configured sanding dust collection hopper vertically positioned at the end opposite the inward rotating direction of each of the horizontal pair of sanding belts and having a vertically disposed extension underlying the lower belt member thereof, and dual vacuum means connected thereto by which particulate matter abrasively removed from the peripheral horizontal sides of the plurality of rectangular shaped objects during the sanding operation is captured and conveyed therefrom to collection means.

10. A sanding machine according to claim 1, adapted to sand the four peripheral sides of a plurality of headto-foot abutted rectangular shaped objects during a single pass of said objects through said machine and wherein the guide members of said machine are I..- shaped in cross-section and are positioned to slidably support said objects against downward movement during transfer of said objects through pairs of vertical sanding belts and also laterally support said objects during transfer of said objects through pairs of horizontal sanding belts.

Claims

1. A sanding machine having a supporting frame structure of interconnected vertical and horizontal frame members to support units thereof adapted to sand the four peripheral sides of a plurality of head-to-foot abutted rectangular shaped objects during a single pass of said objects through said machine comprising in combination, a laterally disposed compressive infeed conveyor means by which opposite sides of said objects are compressively engaged in abutting head-to-foot relationship one to the other and impelled unidirectionally from the feed end to the delivery end of said machine along an elongated series of guide members having horizontal supporting surfaces extending from the feed to the delivery ends of said machine to provide a path along which said objects are slidably supported in said head-to-foot abutting relationship to each other during movement through said machine, a first sanding unit comprising a pair of opposed endless sanding belts having parallel vertical courses disposed adjacent opposite sides of said guide members and operable simultaneously to sand opposite lateral faces of said objects, horizontal guide means laterally disposed below the lower surfaces of said abutted objects to resist downward deflective movement therof from the plane of said guide members, a second sanding unit comprising another pair of opposed endless sanding belts having vertically spaced parallel horizontal courses respectively above and below the other pair of opposed surfaces of said objects as moved along said guide members, said guide members being interrupted to accommodate said courses of said horizontal belts above and below said objects, perpendicular guide means adjacent one side of said guide members between said horizontal courses of said another pair of belts to permit said objects to resist lateral movement from said guide members in the direction of movement of said courses of said horizontal belts, and supporting frame means supporting all of said conveyor means and guide members in association with said first and second sanding units.

8. A sanding machine according to claim 1, adapted to sand the four peripheral sides of a plurality of head-to-foot aligned and abutted rectangular shaped objects during a single pass of said objects through said machine and further including a geometrically configured sanding dust collection hopper positioned below each of the inward rotating vertical pair of sanding belts, and vacuum means attached to said hopper by which particulate matter abrasively removed from the peripheral vertical sides of the plurality of rectangular shaped objects during the sanding operation is captured and conveyed therefrom to collection means.

9. A sanding machine according to claim 1, adapted to sand the four peripheral sides of a plurality of head-to-foot abutted rectangular shaped objects during a single pass of said objects through said machine and further including a geometrically configured sanding dust collection hopper vertically positioned at the end opposite the inward rotating direction of each of the horizontal pair of sanding belts and having a vertically disposed extension underlying the lower belt member thereof, and dual vacuum means connected thereto by which particulate matter abrasively removed from the peripheral horizontal sides of the plurality of rectangular shaped objects during the sanding operation is captured and conveyed therefrom to collection means.

10. A sanding machine according to claim 1, adapted to sand the four peripheral sides of a plurality of head-to-foot abutted rectangular shaped objects during a single pass of said objects through said machine and wherein the guide members of said machine are L-shaped in cross-section and are positioned to slidably support said objects against downward movement during transfer of said objects through pairs of vertical sanding belts and also laterally support said objects during transfer of said objects through pairs of horizontal sanding belts.