DUST CONTROL SYSTEM
United States Patent 3800890
The system comprises an enclosure for enveloping a portion of drill rod used with an earth drilling machine the enclosure having only one side opening formed therein for coupling to a source of suction. The enclosure has axially aligned holes formed in the top and bottom thereof for admitting drill rod therethrough for address to the earth; and at least one "floating" type seal disposed about the drill rod for tracking radial excursions of the drill rod during drilling. A baffle plate fixed to the enclosure prevents the travel of large earth cuttings to the source of suction. Further, a flexible hood is carried about the enclosure, and is movably mounted for elevation from the ground area and for lowering thereto to prevent an escape of earth cuttings dust.
US Patent References:
Dust remover for drills and the like
Baumeister et al. - May 1936 - 2041689
Hood for rock drills
Smith - February 1938 - 2107552
Apparatus for trapping dust arising in bore holes
Hunter - February 1938 - 2107864
Method of rock drilling and dust removal therefor
Kelley - January 1939 - 2144586
Drilling well head
Redman - July 1955 - 2712921
Dust remover for drills and the like
Baumeister et al. - May 1936 - 2041689
Hood for rock drills
Smith - February 1938 - 2107552
Apparatus for trapping dust arising in bore holes
Hunter - February 1938 - 2107864
Method of rock drilling and dust removal therefor
Kelley - January 1939 - 2144586
Drilling well head
Redman - July 1955 - 2712921
Inventors:
Gyongyosi, Laszlo (Clarksburg, WV)
Gregory, David A. (Lost Creek, WV)
Gregory, David A. (Lost Creek, WV)
Application Number:
05/332686
Publication Date:
04/02/1974
Filing Date:
02/15/1973
View Patent Images:
Export Citation:
Assignee:
Ingersoll-Rand Company (Woodcliff Lake, NJ)
Primary Class:
Other Classes:
175/213
International Classes:
E21B21/015; E21B21/00; E21B7/02
Field of Search:
175/207,209,210,211,213,214,215,71
US Patent References:
Primary Examiner:
Brown, David H.
Attorney, Agent or Firm:
Murphy, Bernard Tibbott David J. W.
Claims:
We claim
1. A dust control system, for an earth drilling machine, comprising:
2. A system, according to claim 1, further including:
3. A system, according to claim 1, wherein:
4. A system, according to claim 3, wherein:
5. A system, according to claim 4, wherein;
6. A system, according to claim 1, wherein:
7. A system, according to claim 6, wherein:
8. A system, according to claim 7, wherein:
9. A system, according to claim 8, wherein:
10. A system, according to claim 9, wherein:
11. A dust control system, for a earth drilling machine, comprising:
1. A dust control system, for an earth drilling machine, comprising:
2. A system, according to claim 1, further including:
3. A system, according to claim 1, wherein:
4. A system, according to claim 3, wherein:
5. A system, according to claim 4, wherein;
6. A system, according to claim 1, wherein:
7. A system, according to claim 6, wherein:
8. A system, according to claim 7, wherein:
9. A system, according to claim 8, wherein:
10. A system, according to claim 9, wherein:
11. A dust control system, for a earth drilling machine, comprising:
Description:
This invention pertains to dust control apparatus and in particular to an improved dust control system especially useful in connection with earth drilling machines.
Dust control systems known in the prior art, and especially those used in connection with earth drilling machines, comprise a platform for mounting a centralizer therein through which drilling rod is passed for engaging the earth. Typically, a vacuum pump is coupled to or through the platform, by means of ducting disposed substantially co-axial or parallel with the axis of the drill rod, to draw dust and cuttings therethrough from the ground area.
In an effort to prevent an escape of earth cutting dust into the atmosphere, it is known in the prior art, typically from U.S. Pat. No. 2,730,333, issued January 10, 1956, to W. E. Lenhart, Jr., et al., for a "Dust Deflector", to seal off the earth drilling ground area with a base plate and earth-engaging walls. Such an arrangement can be satisfactory, if the ground is substantially level and if drilling to only a limited depth is undertaken. However, if the ground is quite uneven, some difficulty is encountered in building "earthworks" up against the walls --to seal off the area therewithin. More importantly, if considerable depths are to be drilled, a great quantity of cuttings and rubble will be deposited within and fill the base plate/walled enclosure finally to throttle the ground-located terminus of the annular, "flushing-fluid" passage (obtaining between the wall of the earth borehole and the outer surface of the drill rod).
Flexible boots have been used about drill rods, as exemplified by U.S. Pat. No. 2,145,939, issued Feb. 7, 1939, to James H. Markley, for a "Dust Hood". Initially these can be quite effective toward containing dust. But with continued use, and with "fatique" of the boot webs, joining slits open up to release clouds of dust into the atmosphere. Also, almost invariably, a web portion will become positioned between the ground level and the drill bit, and become torn and cut up --requiring replacement or a sufferance of dust release therefrom as a result thereof.
It is a purpose of this invention to teach an improved dust control system, especially adaptable for earth drilling machinery, which avoids the problems known from prior art. An object of this invention is to set forth a dust control system for an earth drilling machine comprising an enclosure defined by spaced-apart top and bottom members having side walls interpositioned therebetween; said enclosure having only one side opening formed therein for communicating said side opening with a source of suction; said members each having a hole formed therein, said holes having a common center for admitting drill rod therethrough, axially, in penetration of said enclosure; wherein one of said members comprises a seal for substantially sealingly engaging drill rod; hood means coupled to and in envelopment of said enclosure for effecting a substantially sealing engagement with an area of the ground; and baffle means coupled to said enclosure, in immediate adjacency to said side opening, for preventing travel of large earth cuttings to said source of suction.
A feature of this invention comprises the use of an enclosure for enveloping a portion of drill rod used with an earth drilling machine the enclosure having only one side opening formed therein for coupling to a source of suction. The enclosure has axially aligned holes formed in the top and bottom thereof for admitting drill rod therethrough for address to the earth; and at least one "floating" type seal disposed about the drill rod for tracking radial excursions of the drill rod during drilling. A baffle plate fixed to the enclosure prevents the travel of large earth cuttings to the source of suction. Further, a flexible hood is carried about the enclosure, and is movably mounted for elevation from the ground area and for lowering thereto to prevent an escape of earth cuttings dust.
Further objects and features of this invention will become more apparent by reference to the following description taken in connection with the accompanying figures, in which:
FIG. 1 is a combination schematic and sectional view, taken in cross-section, of an embodiment of a dust control system, according to the invention;
FIG. 2 is a underneath or "grounds-eye" view of a portion of the embodiment, according to FIG. 1, taken along section 2--2 of FIG. 1;
FIG. 3 is a cross-sectional view taken along section 3--3 of FIG. 2;
FIG. 4 is a view, in elevation, of a portion of the dust hood of FIG. 1;
FIGS. 5 and 6 are cross-sectional and plan views, respectively, of the hood, taken along sections 5--5 and 6--6 of FIG. 4; and
FIGS. 7 through 10 are schematic depictions of alternate configerations of flexible dust hoods, according to the invention.
As shown in FIG. 1 a first embodiment of the novel system 10 described herein comprises an enclosure 12 which is carried from a platform 14, the enclosure 12 having walls 16, 18 and 20 on three sides with a lateral opening 22 therein which communicates with a source of suction "S". The source of suction "S" which would comprise a vacuum pump and dust collection bags, and the like, is shown only in phantom.
The platform 14 has depending paneling 24 thereabout which carries a flexible hood 26 for engagement with a ground area "A". The enclosure 12, in this first embodiment, carries pulleys 28 thereon through which ropes or cables 30 are threaded, having ends fastened to a weldment 32 (or the like) carried by the earth drilling machine. Intermediate portions of the cables 30 are fed about other pulleys 28 coupled to frame lift rings of the hood 26. Other ends of the cables are rotatably mounted on a drum 34 driven by means (not shwn) so that the hood 26 may be raised for transit or lowered for operational use.
The drill rod 36, as is typical in this art, is hollow so that compressed air, or like fluid, can be conducted therethrough so as to blow cuttings: dust, earth, rock chips and like rubble, out of the hole, up alongside drill rod 36 to the source "S" for collection. The cuttings rise toward a drill rod centralizer 38, carried by platform 14. Now then, according to the invention, the lower portion of the enclosure 12 comprises a novel seal 40. Seal 40, of which more is explained subsequently, if free to follow radial excursions of the drill rod 36.
Tbe suction introduced by the source "S" causes the cuttings to move in the direction shown by the solid arrows in FIG. 1, so that fine dust is carried to the lateral opening 22 provided in the enclosure 12. That component of cuttings or dust which migrates through the seal 40, with a tendency to loft upward to the centralizer 28 is overcome by the side draft, or relative vacuum, and moved away from the centralizer 38, as depicted by the dashed arrows, in the lateral direction.
A baffle plate 42 is disposed between the lateral opening opening 22 and an aperture 44 formed in the paneling 24 depending from the platform 14. This plate 42 prevents the travel of large earth cuttings through to the source "S". Large cuttings, fragments of rock, and the like, are caused to impinge against the baffle plate 42 and then fall to the earth. An opening 46 formed in one end of the plate 42, adjacent to aperture 44, permits fine dust to rise therethrough for travel to source "S".
The enclosure 12 comprises the three side walls 16, 18, and 20 which are fastened by welding to the platform 14. At the four corners of the enclosure, short stub shafts or dowels 48 are welded to a base plate 50 which, in turn, is welded to the enclosure walls. Dowels 48 carry a pair of seals 52 and 52' thereupon. A second retainer plate 54 is emplaced over the seals and is held in place by rods 56 which are passed through holes 58 in the dowels. The seals 52 and 52' are a pair of compliant plastic sheets. Each is bored through, having a hole 60 formed therein to accomodate the drill rod 36 therethrough, and each has a plurality of radial slits 62 formed therein so that the rock cutter bit 64 is admissable therethrough. To insure that dust is not freely passed through the slits 62 one of the seals is rotated axially, so that the slits of the one are not in line with the other.
The seals 52 and 52' having mounting holes 66 at four corners thereof which are of greater diameter than required for mounting purposes, considering the diameter of the mounting dowels 48. The purpose for this is to allow the seals to float cylically about the dowels 48, in response to radial excursions of the drill rod 36 about its axis. Accordingly, the seals 52 and 52' constantly maintain an optimum sealing about the drill rod 36 and, in that they migrate, cyclically, with the rod, they are less subject to wear and abrading.
Hood 26, in this embodiment, as shown in FIGS. 1, and 4-6, is formed of plastic, and defines an annular sleeve which is freely flexible, axially, so that a portion thereof which may engage a ground prominence will collapse to conform to the ground configuration --to maintain a seal with the ground fully thereabout. Hood 26 comprises a pair of annular panels 68 and 69 which are fixed to a frame 80 by means of plastic straps 82. Straps 82 are looped about frame 80 and secured to the panels 68 (or 69) by means of hardware 84. Other hardware (not shown) secures the uppermost edge of panel 69 to paneling 24. Frame 80 has a plurality of lift rings 86 (only one of which is shown) extending therefrom, the rings being equally spaced apart about the periphery therof. Pulleys 28 (FIG. 1) are coupled to the lift rings (by any means well known in the art) to enable a raising and lowering of the hood from and to the ground.
According to the invention, it is essential to the formation of an efficient hood to define panel 68 with an axial taper, i.e., as a truncated cone, with the smaller diameter thereof disposed for ground engagement. This provides an excellent ground seal which, with any accumulation of cuttings against the inner wall of panel 68, becomes more and more secured against the ground.
Panel 69 is also axially tapered, to facilitate its flexible "fold-up", as illustrated in FIG. 1 in dashed outline, with panel 68 thereunder. Optional configurations of flexible dust hoods are shown in FIGS. 7-10 where, in each case, a lowermost panel 68 defines an inwardly-tapering skirt. Panels thereabove, 69a through 69h, are all tapered to allow a controlled, accordion-fold, or the like, of the hoods defined thereby, as shown in the dashed-line illustrations. In each of the embodiments, frames 80 serve to shape the hoods, and provide solid means for attachment of lifting pulleys and the like. Coincidentally, while a rotatable drum 34 (FIG. 1) and a weldment 32 are shown, as instrumental in raising and lowering the hood 26, other arrangements are capable of practice. Clearly, for instance, the hood 26 could be raised and lowered manually, by means of chain and hooks. So also, it can be done by means of power cylinders. These are matters of choice which proceed from the teachings of this disclosure.
The baffle plate 42 obviates any requirement for a pre-cleaner or "skimmer", those sub-units necessary in prior art apparatus of this type to separate large cuttings from dust. Pre-cleaners (or "skimmers") typically are centrifuges of some sort which whirl the cuttings and dust to separate out the larger particulate matter from that which is finer and dust-like, so as to not overburden the vacuum-operated dust collection devices further upstream. In accord with the instant invention, plate 42 defines means for obstructing a free passage of large particulate matter for travel to source "S", in cooperation with seal 40, and further includes a deflector 70 which depends, vertically, in immediate adjacency to the opening 46, as a type of insurance against a movement of larger cuttings into opening 46. Hood 26 defines a primary suction area, annularly disposed about the enclosure 12, and therebelow as well, and baffle plate 42 sub-divides this area in one lateral location, to intrude on a otherwise direct flow path to source "S". For purposes of defining a distinction, the area about the drill rod 36 which is bounded by the enclosure 12, may be considered a secondary suction area.
Retainer plate 54 is provided to lend some strength to the undermost face of the enclosure 12, and more, it supports the peripheral areas of seals 52 and 52' against a fatigue-induced sagging thereof. Plate 54 is apertured in the center, at 72, to expose only the central portions of seals 52 and 52' --particularly to expose the portions thereof that have the slits 62 therein. The slits 62 are shown to be spaced apart substantially 120° of arc. Optionally, they could be four in number, 90° apart, or two in number, 180° apart. What is essential to a practice of the invention is the deployment of two seals (52 and 52'), rather than one, with the slits 62 rotated in misalignment (from one to the other).
While the invention has been described in connection with specific embodiments thereof, it is to be clearly understood that this is done only by way of example, and not as a limitation to the scope of the invention as set forth in the objects thereof and in the appended claims.
Dust control systems known in the prior art, and especially those used in connection with earth drilling machines, comprise a platform for mounting a centralizer therein through which drilling rod is passed for engaging the earth. Typically, a vacuum pump is coupled to or through the platform, by means of ducting disposed substantially co-axial or parallel with the axis of the drill rod, to draw dust and cuttings therethrough from the ground area.
In an effort to prevent an escape of earth cutting dust into the atmosphere, it is known in the prior art, typically from U.S. Pat. No. 2,730,333, issued January 10, 1956, to W. E. Lenhart, Jr., et al., for a "Dust Deflector", to seal off the earth drilling ground area with a base plate and earth-engaging walls. Such an arrangement can be satisfactory, if the ground is substantially level and if drilling to only a limited depth is undertaken. However, if the ground is quite uneven, some difficulty is encountered in building "earthworks" up against the walls --to seal off the area therewithin. More importantly, if considerable depths are to be drilled, a great quantity of cuttings and rubble will be deposited within and fill the base plate/walled enclosure finally to throttle the ground-located terminus of the annular, "flushing-fluid" passage (obtaining between the wall of the earth borehole and the outer surface of the drill rod).
Flexible boots have been used about drill rods, as exemplified by U.S. Pat. No. 2,145,939, issued Feb. 7, 1939, to James H. Markley, for a "Dust Hood". Initially these can be quite effective toward containing dust. But with continued use, and with "fatique" of the boot webs, joining slits open up to release clouds of dust into the atmosphere. Also, almost invariably, a web portion will become positioned between the ground level and the drill bit, and become torn and cut up --requiring replacement or a sufferance of dust release therefrom as a result thereof.
It is a purpose of this invention to teach an improved dust control system, especially adaptable for earth drilling machinery, which avoids the problems known from prior art. An object of this invention is to set forth a dust control system for an earth drilling machine comprising an enclosure defined by spaced-apart top and bottom members having side walls interpositioned therebetween; said enclosure having only one side opening formed therein for communicating said side opening with a source of suction; said members each having a hole formed therein, said holes having a common center for admitting drill rod therethrough, axially, in penetration of said enclosure; wherein one of said members comprises a seal for substantially sealingly engaging drill rod; hood means coupled to and in envelopment of said enclosure for effecting a substantially sealing engagement with an area of the ground; and baffle means coupled to said enclosure, in immediate adjacency to said side opening, for preventing travel of large earth cuttings to said source of suction.
A feature of this invention comprises the use of an enclosure for enveloping a portion of drill rod used with an earth drilling machine the enclosure having only one side opening formed therein for coupling to a source of suction. The enclosure has axially aligned holes formed in the top and bottom thereof for admitting drill rod therethrough for address to the earth; and at least one "floating" type seal disposed about the drill rod for tracking radial excursions of the drill rod during drilling. A baffle plate fixed to the enclosure prevents the travel of large earth cuttings to the source of suction. Further, a flexible hood is carried about the enclosure, and is movably mounted for elevation from the ground area and for lowering thereto to prevent an escape of earth cuttings dust.
Further objects and features of this invention will become more apparent by reference to the following description taken in connection with the accompanying figures, in which:
FIG. 1 is a combination schematic and sectional view, taken in cross-section, of an embodiment of a dust control system, according to the invention;
FIG. 2 is a underneath or "grounds-eye" view of a portion of the embodiment, according to FIG. 1, taken along section 2--2 of FIG. 1;
FIG. 3 is a cross-sectional view taken along section 3--3 of FIG. 2;
FIG. 4 is a view, in elevation, of a portion of the dust hood of FIG. 1;
FIGS. 5 and 6 are cross-sectional and plan views, respectively, of the hood, taken along sections 5--5 and 6--6 of FIG. 4; and
FIGS. 7 through 10 are schematic depictions of alternate configerations of flexible dust hoods, according to the invention.
As shown in FIG. 1 a first embodiment of the novel system 10 described herein comprises an enclosure 12 which is carried from a platform 14, the enclosure 12 having walls 16, 18 and 20 on three sides with a lateral opening 22 therein which communicates with a source of suction "S". The source of suction "S" which would comprise a vacuum pump and dust collection bags, and the like, is shown only in phantom.
The platform 14 has depending paneling 24 thereabout which carries a flexible hood 26 for engagement with a ground area "A". The enclosure 12, in this first embodiment, carries pulleys 28 thereon through which ropes or cables 30 are threaded, having ends fastened to a weldment 32 (or the like) carried by the earth drilling machine. Intermediate portions of the cables 30 are fed about other pulleys 28 coupled to frame lift rings of the hood 26. Other ends of the cables are rotatably mounted on a drum 34 driven by means (not shwn) so that the hood 26 may be raised for transit or lowered for operational use.
The drill rod 36, as is typical in this art, is hollow so that compressed air, or like fluid, can be conducted therethrough so as to blow cuttings: dust, earth, rock chips and like rubble, out of the hole, up alongside drill rod 36 to the source "S" for collection. The cuttings rise toward a drill rod centralizer 38, carried by platform 14. Now then, according to the invention, the lower portion of the enclosure 12 comprises a novel seal 40. Seal 40, of which more is explained subsequently, if free to follow radial excursions of the drill rod 36.
Tbe suction introduced by the source "S" causes the cuttings to move in the direction shown by the solid arrows in FIG. 1, so that fine dust is carried to the lateral opening 22 provided in the enclosure 12. That component of cuttings or dust which migrates through the seal 40, with a tendency to loft upward to the centralizer 28 is overcome by the side draft, or relative vacuum, and moved away from the centralizer 38, as depicted by the dashed arrows, in the lateral direction.
A baffle plate 42 is disposed between the lateral opening opening 22 and an aperture 44 formed in the paneling 24 depending from the platform 14. This plate 42 prevents the travel of large earth cuttings through to the source "S". Large cuttings, fragments of rock, and the like, are caused to impinge against the baffle plate 42 and then fall to the earth. An opening 46 formed in one end of the plate 42, adjacent to aperture 44, permits fine dust to rise therethrough for travel to source "S".
The enclosure 12 comprises the three side walls 16, 18, and 20 which are fastened by welding to the platform 14. At the four corners of the enclosure, short stub shafts or dowels 48 are welded to a base plate 50 which, in turn, is welded to the enclosure walls. Dowels 48 carry a pair of seals 52 and 52' thereupon. A second retainer plate 54 is emplaced over the seals and is held in place by rods 56 which are passed through holes 58 in the dowels. The seals 52 and 52' are a pair of compliant plastic sheets. Each is bored through, having a hole 60 formed therein to accomodate the drill rod 36 therethrough, and each has a plurality of radial slits 62 formed therein so that the rock cutter bit 64 is admissable therethrough. To insure that dust is not freely passed through the slits 62 one of the seals is rotated axially, so that the slits of the one are not in line with the other.
The seals 52 and 52' having mounting holes 66 at four corners thereof which are of greater diameter than required for mounting purposes, considering the diameter of the mounting dowels 48. The purpose for this is to allow the seals to float cylically about the dowels 48, in response to radial excursions of the drill rod 36 about its axis. Accordingly, the seals 52 and 52' constantly maintain an optimum sealing about the drill rod 36 and, in that they migrate, cyclically, with the rod, they are less subject to wear and abrading.
Hood 26, in this embodiment, as shown in FIGS. 1, and 4-6, is formed of plastic, and defines an annular sleeve which is freely flexible, axially, so that a portion thereof which may engage a ground prominence will collapse to conform to the ground configuration --to maintain a seal with the ground fully thereabout. Hood 26 comprises a pair of annular panels 68 and 69 which are fixed to a frame 80 by means of plastic straps 82. Straps 82 are looped about frame 80 and secured to the panels 68 (or 69) by means of hardware 84. Other hardware (not shown) secures the uppermost edge of panel 69 to paneling 24. Frame 80 has a plurality of lift rings 86 (only one of which is shown) extending therefrom, the rings being equally spaced apart about the periphery therof. Pulleys 28 (FIG. 1) are coupled to the lift rings (by any means well known in the art) to enable a raising and lowering of the hood from and to the ground.
According to the invention, it is essential to the formation of an efficient hood to define panel 68 with an axial taper, i.e., as a truncated cone, with the smaller diameter thereof disposed for ground engagement. This provides an excellent ground seal which, with any accumulation of cuttings against the inner wall of panel 68, becomes more and more secured against the ground.
Panel 69 is also axially tapered, to facilitate its flexible "fold-up", as illustrated in FIG. 1 in dashed outline, with panel 68 thereunder. Optional configurations of flexible dust hoods are shown in FIGS. 7-10 where, in each case, a lowermost panel 68 defines an inwardly-tapering skirt. Panels thereabove, 69a through 69h, are all tapered to allow a controlled, accordion-fold, or the like, of the hoods defined thereby, as shown in the dashed-line illustrations. In each of the embodiments, frames 80 serve to shape the hoods, and provide solid means for attachment of lifting pulleys and the like. Coincidentally, while a rotatable drum 34 (FIG. 1) and a weldment 32 are shown, as instrumental in raising and lowering the hood 26, other arrangements are capable of practice. Clearly, for instance, the hood 26 could be raised and lowered manually, by means of chain and hooks. So also, it can be done by means of power cylinders. These are matters of choice which proceed from the teachings of this disclosure.
The baffle plate 42 obviates any requirement for a pre-cleaner or "skimmer", those sub-units necessary in prior art apparatus of this type to separate large cuttings from dust. Pre-cleaners (or "skimmers") typically are centrifuges of some sort which whirl the cuttings and dust to separate out the larger particulate matter from that which is finer and dust-like, so as to not overburden the vacuum-operated dust collection devices further upstream. In accord with the instant invention, plate 42 defines means for obstructing a free passage of large particulate matter for travel to source "S", in cooperation with seal 40, and further includes a deflector 70 which depends, vertically, in immediate adjacency to the opening 46, as a type of insurance against a movement of larger cuttings into opening 46. Hood 26 defines a primary suction area, annularly disposed about the enclosure 12, and therebelow as well, and baffle plate 42 sub-divides this area in one lateral location, to intrude on a otherwise direct flow path to source "S". For purposes of defining a distinction, the area about the drill rod 36 which is bounded by the enclosure 12, may be considered a secondary suction area.
Retainer plate 54 is provided to lend some strength to the undermost face of the enclosure 12, and more, it supports the peripheral areas of seals 52 and 52' against a fatigue-induced sagging thereof. Plate 54 is apertured in the center, at 72, to expose only the central portions of seals 52 and 52' --particularly to expose the portions thereof that have the slits 62 therein. The slits 62 are shown to be spaced apart substantially 120° of arc. Optionally, they could be four in number, 90° apart, or two in number, 180° apart. What is essential to a practice of the invention is the deployment of two seals (52 and 52'), rather than one, with the slits 62 rotated in misalignment (from one to the other).
While the invention has been described in connection with specific embodiments thereof, it is to be clearly understood that this is done only by way of example, and not as a limitation to the scope of the invention as set forth in the objects thereof and in the appended claims.