Wide belt sanding machine with improved dust collector

Claim 2

In an abrading machine having a substantially vertically oriented abrading head that has a power driven endless abrasive belt with upwardly and downwardly traveling stretches, held against work fed through the machine by a backup member located at the bottom of the abrading head, improved dust collecting means for removing the dust and products of abrasion incident to operation of the machine, and which comprises the combination of: A. a vertically oriented air supply duct adjacent to the upwardly traveling stretch of the abrasive belt, the inlet to said air supply duct being at its top and the outlet at its bottom; B. means at the outlet of the air supply duct to cause the air issuing therefrom to impinge upon the abrasive belt in a zone located a short distance above the bottom of the upwardly traveling stretch of the belt; C. a suction duct connectable with a source of suction and having its mouth contiguous to the outlet of the air supply duct to draw air, dust and the products of abrasion from said zone; and D. closure means coacting with the abrasive belt to restrict access to said zone and thereby minimize the possibility of air entering said zone except through the air supply duct.

Claim 3

In an abrading machine, the invention defined by claim 1, wherein tHe outlet of the air supply duct is a narrow slot with parallel upstream and downstream edges that extend across the width of the abrasive belt, the upstream edge being spaced from but sufficiently close to the upwardly traveling stretch of the abrasive belt to enable said edge to effect removal of dust and products of abrasion carried along by the belt and to cause the same to be entrained by the air issuing from the outlet of the air supply duct; and wherein the mouth of said suction duct is directly below the outlet of the air supply duct and extends across the width of the abrasive belt and communicates with said zone through the space between the mouth of the suction duct and the abrasive belt.

Claim 4

In an abrading machine, the invention defined by claim 2, wherein the downstream edge of the outlet of the air supply duct coacts with the abrasive belt to define the size of the space communicating said zone with the mouth of the suction duct.

Claim 5

In an abrading machine, the invention defined by claim 3, wherein the means at the outlet of the air supply duct that causes the air issuing therefrom to impinge upon the abrasive belt is a substantially rectangular wall with opposite top and bottom edges and opposite end edges, the bottom edge of said substantially rectangular wall being the downstream edge of the outlet of the air supply duct.

Claim 6

In an abrading machine, the invention defined by claim 4, wherein the bottom edge of said substantially rectangular wall is defined by a smooth convexly curved surface.

Claim 7

In an abrading machine, the invention defined by claim 4, wherein the size of the mouth of the suction duct is determined by the distance the bottom edge of said substantially rectangular wall is from the abrasive belt; and further characterized by hinge means at an elevation above that of the upstream edge of the outlet of the air supply duct connected with the top edge of said substantially rectangular wall to mount said wall for swinging motion between a wide open position in which its bottom edge is close to the abrasive belt and the mouth of the suction duct is of maximum size and a closed position in which said bottom edge is remote from the abrasive belt and the mouth of the suction duct is essentially closed.

Claim 8

In an abrading machine having an abrading head with a power driven endless abrasive belt and a backup member engaging the back of the belt to hold the same against the surface of a workpiece being abraded, and also having a suction duct to carry off dust and products of abrasion incident to operation of the machine, said machine being characterized by: A. means mounting said suction duct with its mouth closely adjacent to the backup member and hence at the source of the dust and products of abrasion; B. an air supply duct having its inlet remote from the back-up member and its outlet adjacent to the inlet of the suction duct; C. a door at the mouth of the suction duct that is movable between a first position directing the air issuing from the outlet of the air supply duct against the adjacent surface of the abrasive belt and a second position essentially closing the mouth of the suction duct to prevent entry into the suction duct of extraneous matter capable of causing serious consequences if permitted to enter the suction duct; and D. means for moving said door from one to the other of said positions.

Claim 9

In an abrading machine having an abrading head with a power driven endless abrasive belt and a backup member engaging the back of the belt to hold the same against the surface of a workpiece being abraded, and also having a suction duct to carry off dust and products of abrasion incident to operation of the machine, said machine being characterized by: A. means mounting said suction duct with its mouth closely adjacent to the backup member and hence at the source of the dust and products of abrasion; B. an air supply duct having its inlet remote from the back-up member and its outlet adjacent to the inlet of the suction duct; C. a door at the mouth of the suction duct that is movable between a first position directing the air issuing from the outlet of the air supply duct against the adjacent surface of the abrasive belt and a second position essentially closing the mouth of the suction duct to prevent entry into the suction duct of extraneous matter capable of causing serious consequences if permitted to enter the suction duct; and D. means for moving said door from one to the other of said positions.

Claim 10

The abrading machine of claim 7, wherein the means for moving said door is manually operable.

Claim 11

The abrading machine of claim 7, wherein the means for moving said door to its second position is controlled by sensing means responsive to the occurrence of any one of a number of events, such as breakage of the abrasive belt or any other malfunctioning of the abrading head, and manual shut-down of the machine, and wherein the detection of such an event by the sensing means automatically effects movement of the door to its second position.

Claim 12

In an abrading machine having a vertically oriented abrading head with a power driven endless abrasive belt trained over a belt tensioning roll at the top of the head and held against the work being abraded by a backup member at the bottom of the head, so that the belt has upwardly and downwardly traveling stretches, improved dust collecting means for removing the dust and products of abrasion incident to operation of the machine, comprising: A. a suction duct connectable with a source of suction and having a mouth in juxtaposition to the backup member to suck the air-entrained dust and products of abrasion from the zone in which they are produced; B. an air supply duct having its inlet adjacent to the belt tensioning roll and its outlet directly above the mouth of the suction duct and facing the upwardly traveling stretch of the abrasive belt; C. a movable door adjacent to the outlet of the air supply duct and the mouth of the suction duct operable in one position thereof to direct the air issuing from the outlet of the air supply duct against the adjacent surface of the abrasive belt and in another position to close said mouth and thereby prevent entry into the suction duct of extraneous matter capable of causing objectionable consequences if permitted to enter the suction duct; and D. means for moving said door from one to the other of said positions.

Claim 13

In an abrading machine having a vertically oriented abrading head with a power driven endless abrasive belt trained over a belt tensioning roll at the top of the head and held against the work being abraded by a backup member at the bottom of the head, so that the belt has upwardly and downwardly traveling stretches, improved dust collecting means for removing the dust and products of abrasion incident to operation of the machine, comprising: A. a suction duct connectable with a source of suction and having a mouth in juxtaposition to the backup member to suck the air-entrained dust and products of abrasion from the zone in which they are produced; B. an air supply duct having its inlet adjacent to the belt tensioning roll and its outlet directly above the mouth of the suction duct and facing the upwardly traveling stretch of the abrasive belt; C. a movable door adjacent to the outlet of the air supply duct and the mouth of the suction duct operable in one position thereof to direct the air issuing from the outlet of the air supply duct against the adjacent surface of the abrasive belt and in another position to close said mouth and thereby prevent entry into the suction duct of extraneous matter capable of causing objectionable consequences if permitted to enter the suction duct; and D. means for moving said door from one to the other of said positions.

Claim 14

The abrading machine of claim 10, wherein said movable door has a hingedly mounted edge and a free edge, the latter coacting with the abrasive belt to define a constricted throat that communicates the air supply duct with the suction duct.

Claim 15

The abrading machine of claim 10, further characterized by: means including said movable door to cause the air debouching from the air supply duct to forcibly impinge upon the upwardly traveling stretch of the abrasive belt.

Claim 16

In an abrading machine having a vertically oriented abrading head with a power driven endless abrasive belt trained over a belt tensioning roll at the top of the head and held against the work being abraded by a backup member at the bottom of the head, so that the belt has upwardly and downwardly traveling stretches, improved dust collecting means for removing the dust and products of abrasion incident to operation of the machine, comprising: A. a suction duct connectable with a source of suction and having a mouth in juxtaposition to the backup member to suck the air-entrained dust and products of abrasion from the zone in which they are produced; B. an air supply duct through which air is brought to said zone, said air supply duct having an outlet directly above the mouth of the suction duct; and C. air directing means at the outlet of the air supply duct to cause the air entering said zone to impinge upon the upwardly traveling stretch of the abrasive belt as the belt leaves the backup member at an angle of between 38* and 45* to the upwardly traveling stretch of the belt.

Claim 17

In an abrading machine having a vertically oriented abrading head with a power driven endless abrasive belt trained over a belt tensioning roll at the top of the head and held against the work being abraded by a backup member at the bottom of the head, so that the belt has upwardly and downwardly traveling stretches, improved dust collecting means for removing the dust and products of abrasion incident to operation of the machine, comprising: A. a suction duct connectable with a source of suction and having a mouth in juxtaposition to the backup member to suck the air-entrained dust and products of abrasion from the zone in which they are produced; B. an air supply duct through which air is brought to said zone, said air supply duct having an outlet directly above the mouth of the suction duct; and C. air directing means at the outlet of the air supply duct to cause the air entering said zone to impinge upon the upwardly traveling stretch of the abrasive belt as the belt leaves the backup member at an angle of between 38* and 45* to the upwardly traveling stretch of the belt.

Claim 18

The abrading machine in claim 13, wherein the backup member is a contact drum, and wherein the air directing means causes the air to impinge upon the abrasive belt directly above the line of tangency between the upwardly traveling stretch of the belt and the contact drum.

Claim 19

In an abrading machine having a vertically oriented abrading head with a power driven endless abrasive belt trained over a belt tensioning roll at the top of the head and held against the work being abraded by a backup member at the bottom of the head, so that the belt has upwardly and downwardly traveling stretches, improved dust collecting means for removing the dust and products of abrasion incident to operation of the machine, comprising: A. an air supply duct having inlet and outlet ends, and opposite inner and outer walls, at least the former of said walls being substantially coextensive in size and shape with the upwardly traveling stretch of the abrasive belt; B. a curved air inlet duct having an entrancE and an exit; C. a suction duct having an outlet connectable with a source of suction and a mouth through which air-entrained dust and products of abrasion are drawn into the suction duct when the machine is in operation; D. means joining said ducts into a unitary structure with the exit of the curved air inlet duct opening into the inlet end of the air supply duct and with the suction duct overlying said outer wall of the air supply duct and its mouth contiguous to the outlet end of the air supply duct; and E. means mounting said unitary structure in an operative position adjacent to the abrading head, in which position said inner wall of the air supply duct overlies and is closely adjacent to the upwardly traveling stretch of the abrasive belt, the curved air inlet duct embraces the belt tensioning roll and the entrance thereof is positioned to receive air from the space surrounding the belt tensioning roll and also receive air-entrained dust and products of abrasion leaving the passing abrasive belt, and the outlet end of the air supply duct and the mouth of the suction duct are contiguous to the backup member at the bottom of the abrading head, so that the same air moving through the ducts carries away dust and products of abrasion from both the zone of action where the abrasion takes place and from the zone at the top of the abrading head.

Claim 20

In an abrading machine having a vertically oriented abrading head with a power driven endless abrasive belt trained over a belt tensioning roll at the top of the head and held against the work being abraded by a backup member at the bottom of the head, so that the belt has upwardly and downwardly traveling stretches, improved dust collecting means for removing the dust and products of abrasion incident to operation of the machine, comprising: A. an air supply duct having inlet and outlet ends, and opposite inner and outer walls, at least the former of said walls being substantially coextensive in size and shape with the upwardly traveling stretch of the abrasive belt; B. a curved air inlet duct having an entrancE and an exit; C. a suction duct having an outlet connectable with a source of suction and a mouth through which air-entrained dust and products of abrasion are drawn into the suction duct when the machine is in operation; D. means joining said ducts into a unitary structure with the exit of the curved air inlet duct opening into the inlet end of the air supply duct and with the suction duct overlying said outer wall of the air supply duct and its mouth contiguous to the outlet end of the air supply duct; and E. means mounting said unitary structure in an operative position adjacent to the abrading head, in which position said inner wall of the air supply duct overlies and is closely adjacent to the upwardly traveling stretch of the abrasive belt, the curved air inlet duct embraces the belt tensioning roll and the entrance thereof is positioned to receive air from the space surrounding the belt tensioning roll and also receive air-entrained dust and products of abrasion leaving the passing abrasive belt, and the outlet end of the air supply duct and the mouth of the suction duct are contiguous to the backup member at the bottom of the abrading head, so that the same air moving through the ducts carries away dust and products of abrasion from both the zone of action where the abrasion takes place and from the zone at the top of the abrading head.

Claim 21

The abrading machine of claim 15, wherein said means mounting said unitary structure provides for bodily movement thereof from its defined operative position to a retracted position to facilitate access to the abrading head, and further characterized by means for effecting such bodily movement of said unitary structure from and back to its defined operative position.

Claim 22

In an abrading machine having an abrading head with a power driven endless abrasive belt trained over a belt tensioning roll and held against the work being abraded by a backup member engaging the back of the belt, improved dust collecting means for carrying off dust and products of abrasion incident to operation of the machine, said dust collecting means comprising: A. an air supply duct overlying a stretch of the abrasive belt and having its inlet adjacent to the belt tensioning roll and its outlet opening to a zone adjacent to the backup member; B. a suction duct connectable with a source of suction and having its mouth contiguous to the outlet of the air supply duct to draw air, dust and products of abrasion from said zone; and C. closure means coacting with the abrasive belt to restrict access to said zone and thereby minimize the possibility of air entering said zone except through the air supply duct.

Claim 23

In an abrading machine having an abrading head with a power driven endless abrasive belt trained over a belt tensioning roll and held against the work being abraded by a backup member engaging the back of the belt, improved dust collecting means for carrying off dust and products of abrasion incident to operation of the machine, said dust collecting means comprising: A. an air supply duct overlying a stretch of the abrasive belt and having its inlet adjacent to the belt tensioning roll and its outlet opening to a zone adjacent to the backup member; B. a suction duct connectable with a source of suction and having its mouth contiguous to the outlet of the air supply duct to draw air, dust and products of abrasion from said zone; and C. closure means coacting with the abrasive belt to restrict access to said zone and thereby minimize the possibility of air entering said zone except through the air supply duct.

Claim 24

the invention defined in claim 17, further characterized by: structure connected with the inlet of the air supply duct arranged to direct dust and products of abrasion that reach the zone in which the belt tensioning roll is located into the air stream entering the inlet of the air supply duct.

Claim 25

The invention defined in claim 18, wherein the abrading head is vertically oriented with its belt tensioning roll at the top and its backup member at the bottom, so that the abrasive belt has upwardly and downwardly traveling stretches, and wherein the air supply duct has opposite walls, one of which is uniformly closely spaced from and substantially coextensive in size and shape with the upwardly traveling stretch of the abrasive belt, so that the air supply duct coacts with the upwardly traveling stretch of the abrasive belt to form a passage through which dust and products of abrasion that are carried along by the upwardly traveling stretch of the belt reach the zone in which the belt tensioning roll is located.

Claim 26

The invention defined in claim 18, wherein the abrading head is vertically oriented with its belt tensioning roll at the top and its backup member at the bottom, so that the abrasive belt has upwardly and downwardly traveling stretches, wherein the Air supply duct is upright and overlies the upwardly traveling stretch of the abrasive belt, wherein the inlet of the air supply duct is at a fixed level near the line of tangency between the upwardly traveling stretch of the abrasive belt and the belt tensioning roll, said inlet having a narrow oblong shape, the long margins of which are generally parallel to the axis of the belt tensioning roll and extend for substantially the width of the abrasive belt, one of said long margins being farther from the belt than the other, and wherein said structure connected with the inlet of the air supply duct comprises a hood embracing the top of the belt tensioning roll, said hood having an inlet and an outlet and being defined in part by a top wall which is joined to said long margin that is farthest from the belt.

Claim 27

The abrading machine of claim 20, wherein the hood has top and bottom curved walls connected by opposite side walls to form a curved extension of the upright air supply duct, the hood having an inlet remote from its connection with said upright air supply duct, and the bottom curved wall of the hood being relatively close to the cylindrical surface of the belt tensioning roll.

Claim 28

The abrading machine of claim 21, wherein the hood has a hinged connection with the top of said upright duct, the axis of that hinged connection being substantially parallel to the axis of the belt tensioning roll, and the hood being free to rock about the axis of its hinged connection with the upright duct, and further characterized by support means at the top of the abrading head and fixed with respect to the axis of the belt tensioning roll, and means on the hood seated upon said support means to positionally orient the hood with respect to the belt tensioning roll despite variations in the elevation thereof.

Claim 29

The abrading machine of claim 21, further characterized by deflector means at the inlet to the hood in close juxtaposition to the adjacent surface of the abrasive belt, to intercept dust and products of abrasion traveling with the belt and direct the same into the hood.

Claim 30

The abrading machine of claim 22, further characterized by deflector means at the inlet to the hood in close juxtaposition to the adjacent surface of the abrasive belt, to intercept dust and products of abrasion traveling with the belt and direct the same into the hood.