Maxwell, Gavin (Coolfin Rectory, Coolfin Portlaw, County Waterford, IE)
Smith, Henry Joseph (8 Cashel Court, Cashel Road Clonmel, County Tipperary, IE)
| 1. | Apparatus for cutting an arcuate piece from a length of material comprising a circular saw characterised in that the apparatus comprises an arcuate guide rail mounted on a support structure and said circular saw is mounted for traversing said arcuate guide rail such that a blade of said circular saw is constrained to move along an arcuate path. |
| 2. | Cutting apparatus according to claim 1 further characterised in that the circular saw is mounted on the arcuate guide rail such that the arcuate path has a greater radius than the arcuate guide rail. |
| 3. | Cutting apparatus according to any preceding claim further characterised in that the circular saw comprises a cutting head having a pair of discs spaced apart by a predetermined distance and having the same rotational axis. |
| 4. | Cutting apparatus according to any preceding claim further characterised in that the circular saw comprises two cutting heads, the rotational axes of the cutting heads being spaced both horizontally and vertically. |
| 5. | Cutting apparatus according to claim 3 or any succeeding claim further characterised in that the cutting head enables two concentric arcuate paths to be cut simultaneously. |
| 6. | Cutting apparatus according to any preceding claim further characterised in that the circular saw comprises a disc with a toothed edge wherein the ratio of the width of the disc to the width of the cutting tooth is 0.75 or less. |
| 7. | A method of cutting an arcuate piece from a length of material using a cutting apparatus according to any preceding claim. |
| 8. | Apparatus for assembling components of a frame for an architectural opening comprising a pair of elongate support members for receiving side sections of a frame in a horizontal orientation characterised in that the apparatus comprises a transverse support member for receiving a transverse section of the frame and a circular saw mounted adjacent the transverse support member such that the position of a blade of said circular saw is adjustable relative to three orthogonal axes and one rotational axis. |
| 9. | Assembly apparatus according to claim 8 further characterised in that the elongate and/or transverse support members have an elongate channel formed in the upper surface thereof, the channel being profiled to correspond to the external profile of a corresponding frame side or transverse sections. |
| 10. | Assembly apparatus according to any preceding claim further characterised in that the assembly apparatus comprises a guide rail and the circular saw comprises a base member mounted on the guide rail so as to be movable in a transverse direction. |
| 11. | Assembly apparatus according to claim 10 further characterised in that the circular saw comprises an upright member mounted on the base member, the upright member being vertically adjustable relative to the base member. |
| 12. | Assembly apparatus according to claim 11 further characterised in that the circular saw comprises a swivel member mounted on the upright member, the swivel member being angularly adjustable relative to the upright member. |
| 13. | Assembly apparatus according to claim 12 further characterised in that the circular saw comprises a sliding member mounted on the swivel member, the sliding member being horizontally adjustable relative to the swivel member. |
| 14. | Assembly apparatus according to any preceding claim further characterised in that the assembly apparatus comprises one or more mortise mechanisms mounted adjacent one of the elongate support members for mortising the hinge locations of a door. |
| 15. | A method of assembling components of a frame for an architectural opening using an assembly apparatus according to any preceding claim. |
| 16. | Apparatus for producing an arcuate moulding from a length of arcuate material having a datum face, the apparatus comprising rotary cutting means for cutting an exposed face of the length of material to a predetermined profile characterised in that the apparatus comprises a surface having an arcuate formation for sliding engagement with a complementary arcuate formation along the datum face of the length of material such that the latter can be fed along the surface to follow an arcuate path by sliding engagement of the complementary formations. |
| 17. | A method of producing an arcuate moulding from a length of arcuate material having a datum face and an arcuate formation along the datum face, the method comprising using a rotary cutter to cut an exposed face of the length of material to a predetermined profile characterised in that the method comprises feeding the datum face along a surface having an arcuate formation complementary to the arcuate formation in the datum face such that the length of material follows an arcuate path by sliding engagement of the complementary formations. |
| 18. | Moulding apparatus according to claim 16 further characterised in that the rotary cutting means comprises a series of rotational cutting heads. |
| 19. | Moulding apparatus according to claim 18 further characterised in that the rotary cutting means comprises a series of six rotational cutting heads, a first such rotational cutting head being adapted to plane an under surface of the material and cut a guidance groove in the under surface, such guidance groove being the complementary arcuate formation along the datum face, a second such rotational cutting head being adapted to profile an outside edge of the material, a third such rotational cutting head being adapted to profile an inside edge of the material, a fourth such rotational cutting head being adapted to plane the upper surface of the material, a fifth such rotational cutting head being adapted to profile the upper surface of the material and a sixth such rotational cutting head being adapted to plane the under surface of the material. |
| 20. | 2 0. Moulding apparatus according to any preceding claim further characterised in that the surface having an arcuate formation comprises a table having an arcuate guidance rail embedded therein. |
The invention is particularly concerned with the complete industrial manufacture of an integrated frame assembly ready for installation rather than a series of components for site assembly. Thus, the invention relates particularly to methods and apparatus for use on an industrial scale, for example in a factory as opposed to by a craftsperson, and which provide frames usable in complete door or window systems requiring only unskilled or semi-skilled fitters on site.
Frames for architectural openings generally have square heads since such are relatively easy and cost effective to manufacture and assemble. However, from a design point of view frames with a curved head, such as the doorframe shown in figure 1, are generally more attractive and aesthetically pleasing. Such curved head frames have hitherto been expensive and laborious to produce and assemble since a skilled craftsman is required to cut the head to the desired curvature and then manually assemble the frame and architrave components on site. Thus, high quality curved head door and frame construction possesses an inherently slower and more expensive craft element than square head door and frame construction.
The present invention has been made from a consideration of the disadvantages associated with such known curved head frame manufacturing techniques and in order to provide improved apparatus and methods for the manufacture of frames, which may overcome one or more of the above-mentioned disadvantages. Thus, the invention seeks to provide apparatus and methods for facilitating the industrial scale production of frames, particularly with a curved head component, by allowing high speed, accurate, cost effective and high throughput, automated production of a curved head frame component, a curved profiled architrave component and off site assembly of a frame. This is sought to be provided in a factory setting as opposed to by a craftsperson or in a once-off manner.
According to a first aspect of the invention there is provided apparatus for cutting an arcuate piece from a length of material comprising a circular saw characterised in that the apparatus
comprises an arcuate guide rail mounted on a support structure and said circular saw is mounted for traversing said arcuate guide rail such that a blade of said circular saw is constrained to move along an arcuate path.
Preferably, the circular saw is mounted on the arcuate guide rail such that the arcuate path has a greater radius than the arcuate guide rail. Preferably, the circular saw is mounted on the arcuate guide rail by means of a housing which contains the saw drive mechanism. The circular saw may be of conventional type, being a power driven saw in the shape of a flat disc with a serrated edge or toothed blade. Preferably, the circular saw comprises a cutting head having a pair of discs spaced apart by a predetermined distance and having the same rotational axis. Preferably, the circular saw comprises two cutting heads, mounted on the arcuate guide rail by means of a single housing, the rotational axes of the cutting heads being spaced both horizontally and vertically, typically by a predetermined distance.
Preferably, the upper cutting head cuts an arcuate path in the upper surface of the material and the lower cutting head simultaneously cuts an arcuate path in the under surface of the material.
Preferably, the double disc cutting heads enable two concentric arcuate paths to be cut simultaneously. Preferably, the circular saw comprises a disc with a toothed edge wherein the ratio of the width of the disc to the width of the cutting tooth is 0.75 or less.
The invention further provides a method of cutting an arcuate piece from a length of material using a cutting apparatus of the invention.
According to a second aspect of the invention there is provided apparatus for assembling components of a frame for an architectural opening comprising a pair of elongate support members for receiving side sections of a frame in a horizontal orientation characterised in that the apparatus comprises a transverse support member for receiving a transverse section of the frame and a circular saw mounted adjacent the transverse support member such that the position of a blade of said circular saw is adjustable relative to three orthogonal axes and one rotational axis.
Preferably, the elongate and/or transverse support members have an elongate channel formed in the upper surface thereof. Preferably, the channel is profiled to correspond to the external
profile of the corresponding frame side or transverse sections. Preferably, at least one, typically both, of the elongate support members is laterally movable with respect to the other, thereby enabling the apparatus to be used in the assembly of frames of different width. In practice, both elongate support members are preferably laterally movable, as they can then be centred symmetrically about a centre datum line.
Preferably, a circular saw is mounted adjacent each end of the transverse support member.
Preferably, the assembly apparatus comprises a guide rail and the circular saw comprises a base member mounted on the guide rail so as to be movable in a transverse direction.
Preferably, the circular saw comprises an upright member mounted on the base member, the upright member being vertically adjustable relative to the base member. Preferably, the circular saw comprises a swivel member mounted on the upright member, the swivel member being angularly adjustable relative to the upright member. Preferably, the circular saw comprises a sliding member mounted on the swivel member, the sliding member being horizontally adjustable relative to the swivel member.
Preferably, the apparatus comprises one or more mortise mechanisms, typically three, mounted adjacent one of the elongate support members for mortising the hinge locations of a door. Preferably, each such mortise mechanism comprises a mortise bit the position of which is adjustable in two transverse directions and in a vertical direction.
The invention further provides a method of assembling components of a frame for an architectural opening using an assembly apparatus of the invention.
According to a third aspect of the invention there is provided apparatus for producing an arcuate moulding from a length of arcuate material having a datum face, the apparatus comprising rotary cutting means for cutting an exposed face of the length of material to a predetermined profile characterised in that the apparatus comprises a surface having an arcuate formation for sliding engagement with a complementary arcuate formation along the datum face of the length of material such that the latter can be fed along the surface to follow an arcuate path by sliding engagement of the complementary formations.
The invention further provides a method of producing an arcuate moulding from a length of arcuate material having a datum face and an arcuate formation along the datum face, the method comprising using a rotary cutter to cut an exposed face of the length of material to a predetermined profile characterised in that the method comprises feeding the datum face along a surface having an arcuate formation complementary to the arcuate formation in the datum face such that the length of material follows an arcuate path by sliding engagement of the complementary formations.
Preferably, the rotary cutting means comprises a series of, preferably six, rotational cutting heads. Preferably, one such rotational cutting head is adapted to plane an under surface of the material and cut a guidance groove in the under surface. Preferably, another such rotational cutting head is adapted to profile an outside edge of the material. Preferably, a further such rotational cutting head is adapted to profile an inside edge of the material. Preferably, a further such rotational cutting head is adapted to plane the upper surface of the material. Preferably, a still further such rotational cutting head is adapted to profile the upper surface of the material.
Preferably, a further such rotational cutting head is adapted to plane the under surface of the material.
Preferably, the surface having an arcuate formation comprises a table having an arcuate guidance rail embedded therein. Preferably, the complementary arcuate formation along the datum face comprises an elongate groove, preferably formed by a first cutting head of the rotary cutting means.
The invention further provides a method of producing an arcuate moulding from a length of arcuate material using a moulding apparatus of the invention.
The invention further provides a workstation for the manufacture of frames for architectural openings comprising a combination of apparatus according to different aspects of the invention. The invention also provides a method for the manufacture of frames for architectural openings comprising the combination of methods of the invention.
The invention will now be described further, by way of example only, with reference to the accompanying drawings, in which:
Fig. 1 is a schematic elevation of the upper part of a doorframe; Figs. 2a and 2b are cross-sections of the doorframe taken along the lines 2A-2A and 2B-2B respectively of figure 1 ; Fig. 3 is a perspective view of a cutting apparatus of the invention for cutting an arcuate piece from a length of material; Fig. 4 is an enlarged perspective view of the circular saw of the cutting apparatus of figure 3; Fig. 5 is a schematic view of the cutting of an arcuate piece by the circular saw of the cutting apparatus of figure 3; Figs. 6a and 6b are an angular section of a conventional circular saw blade and an edge view of a conventional circular saw blade respectively; Figs. 7a and 7b are an angular section of a circular saw blade and an edge view of a circular saw blade respectively of the circular saw of the cutting apparatus of figure 3; Fig. 8 is a schematic view showing the lead and lag effect of the inner and outer circular saw blades of the cutting apparatus of figure 3; Fig. 9 is a perspective view of an assembly apparatus of the invention for assembling components of a frame for an architectural opening; Fig. 10 is a detailed perspective view of a frame section located in the profiled elongate support member of the assembly apparatus of figure 9; Fig. 11 is a detailed perspective view of the multi-axis circular saw of the assembly apparatus of figure 9;
Fig. 12 is a schematic view showing the orientation of the frame section for cutting with the assembly apparatus of figure 9; Fig. 13 is a schematic perspective view showing the operation of the circular saw of the assembly apparatus of figure 9; Fig. 14 is a schematic view of the blade edge cutting path of the circular saw of the assembly apparatus of figure 9; Fig. 15 is a perspective view of the hinge mortise mechanism of the assembly apparatus of figure 9; Fig. 16 is a detailed side view of the operation of the mortise bit of the hinge mortise mechanism of figure 15; Fig. 17 is perspective view of an assembly apparatus of the invention with a multi mortise arrangement; Fig. 18 is a perspective view of a moulding apparatus of the invention for producing an arcuate moulding from a length of arcuate material; and Fig. 19 is a perspective view of an arcuate moulding produced using the moulding apparatus of figure 18.
Figures 1 and 2 illustrate the component parts of a curved head doorframe. The curved head doorframe comprises opposite upright jambs 20 and a transverse frame head 22 joining the jambs 20 at their upper ends. The frame also includes side and head architraves 12,14 respectively which extend laterally away from the door opening 10, against the wall 18, on each side of the frame, each architrave 12 or 14 being fixed by a tongue and groove joint along the respective edge of the jamb 20 or frame head 22. Each architrave 12,14 has a flat face against the wall 18 and a moulded or profiled external face 16, as shown in figures 2a and 2b. The frame further includes a door stop 24 mounted on the frame head 22 and on the upright jambs 20.
Referring to figure 3, a cutting apparatus 30 of the invention, for cutting an arcuate piece 32 from a length of material 34 to form a curved head for a doorframe, comprises an arcuate guide rail 36 mounted on a support structure 38 and a circular saw 40 mounted for traversing the arcuate guide rail 36 such that a blade of the circular saw 40 is constrained to move along an arcuate path 42. The track saw 40 is mounted for sliding movement along the guide rail 36 so that the blade thereof follows the arcuate path 42.
The saw 40 is mounted on the arcuate guide rail 36 such that the arcuate path 42 has a greater radius than the guide rail 36. The support structure 38 is substantially rectangular in construction and comprises four legs 44 interconnected by pairs of cross bars 46 to form opposing short sides 48 and a rear section 50. The guide rail 36 extends in an arc between the upper ends of the two front legs to form a suspended monorail. Typically, the guide rail is about 2.2m in length. The circular saw 40 comprises a housing 52 mounted on the guide rail 36. The housing 52 contains the saw drive mechanism. A set of stops or buffers and reversing switches are typically set at each end of the guide rail in order to limit the extent of travel of the circular saw 40 and in order to enable the latter to be returned for continuous cutting. Such buffers may be adjusted or located to suit the extent of travel required according to the desired length of the arcuate piece.
Referring to figure 4, the housing 52 supports two cutting heads 54, 56 each having a pair of saw discs 58, 60 and 62,64 respectively. The inside 58, 62 and outside 60,64 discs in each pair are spaced apart by a predetermined distance and having the same rotational axis 66,68.
The rotational axes 66,68 of the cutting heads 54, 56 are spaced by a predetermined distance both horizontally and vertically. The cutting heads 54, 56 are located in offset vertical planes.
Thus, the inside disc of one cutting head is located in a vertical plane which is offset relative to the vertical plane of the inside disc of the other cutting head and the outside disc of one cutting head is located in a vertical plane which is offset relative to the vertical plane of the inside disc of the other cutting head.
The upper cutting head 54 cuts an arcuate path 42 through the upper surface of the material while the lower cutting head 56 creates an offset undercut through the under surface of the material which precisely mirrors the upper cutting head. The double disc cutting heads enable
two concentric arcuate paths to be cut simultaneously, as shown in figure 5, thereby allowing a complete arcuate component 32 to be cut in a single pass.
Although two double disc cutting heads are shown in figures 3 and 4, it will be appreciated that the housing may support a single saw disc, a single cutting head having a pair of discs or two cutting heads each having a single or a pair of discs, as required.
In the multi-disc cutting head, the saw discs 58,60 ; 62,64 are typically mounted on a sleeve (not shown) whose internal bore is a sliding fit onto the main drive shaft 66,68, with the external size of the sleeve being a sliding fit in the saw discs. The sleeve typically has one stopped end which prevents the discs from sliding off. The sleeve locates the inside disc 58, 62 at the correct radius when the sleeve is positioned tight against a shoulder provided on the main shaft 66,68. The spacing between the inside 58,62 and outside 60,64 discs is determined by the desired width of the piece to be cut and spacers are located on the sleeve accordingly before locating the outside disc 60,64 and tightening the assembly with a lock nut. Typically, the thread of the lock nut runs counter to the direction of cut thereby ensuring that the assembly is self tightening in use.
The apparatus is adapted for cutting a length of substantially flat sheet material 34 and includes an automated feed table or platform 70 for supporting the length of material to be cut.
The platform 70 comprises a base structure 72 supporting a plurality of substantially parallel transverse rollers 74. The platform is separable from the support structure 38 and is engaged therewith in use. The material 34 is movable on the platform 70 substantially in its own plane and in a direction, indicated by arrow A, radially towards the arcuate path 42 intermittently towards the saw 40. Successive traverses of the saw blade along the arcuate path 42 cut successive arcuate pieces 32 from the material 34. The platform is provided with a pair of adjustable side fences 76 set to accommodate the length of material to be cut. The platform may be used to manually or automatically feed the material for cutting.
In conventional machine woodworking, jig saws rather than circular saws are generally used because of the short distance between the leading (cutting) edge and the trailing edge.
It is well known that a circular saw blade is restricted in its ability to cut in a curve by the lead edge and trailing edge or lag braking. Thus, as the lead edge of the blade cuts forward, the trailing edge is pressed against the radius of the arc path and causes the blade to rub and create friction on the exterior edge of the material being cut. Consequently, the blade width and lagging edge have been found to restrict safe cutting to materials of 2 to 4 mm depth before kick back takes effect and the material is thrown forward violently in the direction of the user due to the upwardly moving saw teeth on the trailing edge catching the material. The conventional saw blade was therefore redesigned to facilitate the exclusion of lead and lag friction.
Referring to figures 6a and 6b, a conventional saw blade comprises a disc 78 with a toothed edge 80. Referring to figures 7a and 7b, a preferred saw blade for use on the cutting apparatus of the invention comprises a disc 82 with a toothed edge 84 wherein the width of the disc is narrower than the width of the cutting tooth 86. Such a saw blade allows depths of material up to 40 mm to be cut safely. The disc 82 is thinner than normal and the cutting teeth 86 are wider than normal. Typically, in a conventional circular saw blade, the tooth is the same width or, at most, marginally wider than the disc so that the ratio of disc width to tooth width is close to 1. For example, the disc plate may be 2. 5mm thick and the tooth tip 3mm thick, giving a ratio of 0.83. In the preferred saw blade for the cutting apparatus of the invention, the tooth is relatively much wider than the disc. Typically, the ratio of disc width to tooth width is 0.75 or less, preferably 0.65 or less, more preferably 0.5 or less. In one example, with a chosen radius of curvature of 1200mm, a disc width of 1. 5mm and a tooth tip width of 4mm cut safely to a depth of up to 20mm. In a further example, with the same radius, a disc width of 2mm and a tooth tip width of 4mm was successfully used. Typically, the disc is thinner, typically by 0. 5mm or more, than a conventional disc and the tooth is wider, typically by lmm or more, than a conventional tooth. Preferably, the tooth width is at least lmm wider than the disc width, more preferably at least 2mm wider. Preferably, the disc width is half or less than half of the width of the tooth. The relative thickness of the teeth and disc is chosen to suit the radius of curvature required. In general, a high curvature cut benefits from a wider cutting tooth or lower disc to tooth width ratio than a low curvature cut.
Referring to figure 8, where arrow E indicates the direction of travel of the saw blades, to facilitate an arcuate cut with a circular saw, the distance between the inner leading tip A of the
tooth to the inner tip of the lagging tooth B and also the corresponding points on the outer lead C and lag D teeth must always form a straight line. With the preferred saw blade of the invention, the material being cut is retained on all successive terminating points of an arcuate path between the lead A, C and lag positions B, D. The required arcuate edges on a completed component when using two blades are therefore defined by the outer leading point of the inner saw blade and the inner leading point of the outer saw blade.
The respective straight lines that exist between the leading and lagging inner and outer edges of a tooth constitute two parallel straight lines which are tangential to the desired arc of the component being cut and constitute the inner and outer edges of the saw kerf being generated.
An alternative cutting apparatus may have a double disc upper cutting head and a single disc lower cutting head to simultaneously create an arcuate undergroove in the arcuate piece. Such an undergroove may be used as a locating groove for locating an architrave on the frame head in a tongue and grove arrangement as previously described with reference to figures 1 and 2.
Alternatively, the lower cutting head may comprise three discs located on a single shaft, the middle disc having a smaller diameter, less cutting teeth and greater spacing between the teeth for creating the undergroove. Typically, all three discs have wide cutting teeth, as described with reference to figure 7.
The ability to use multiple circular blades in the cutting apparatus of the invention typically allows the cutting of arcuate pieces with a width in the range of 20mm to 150mm. The cutting apparatus allows depths of material up to 40mm to be cut accurately and efficiently. The radius of curvature of the cut is generally fixed according to the specific design of cutting apparatus and the apparatus may be designed accordingly to give the desired radius. For example, a radius to the inside edge of the arcuate piece of 120cm has been used for doorframe heads.
Unlike conventional techniques, wherein the use of a circular saw is generally restricted to straight or linear cutting, the cutting apparatus and method of the invention allows the use of a circular high speed blade for accurate radiused cutting. Hitherto, the cutting of materials in a curved path has been limited generally to the use of band saws or jig saws. However, neither of these types of saw delivers the speed and accuracy associated with high speed circular
saws. By contrast, using the cutting apparatus of the invention allows a series of circular blades to deliver a perfectly tolerant curved component without the need for a skilled operator.
Typically, a lm curved component can be produced with the cutting apparatus of the invention in about 4 seconds.
The use of concentric circular saw blades on each cutting head and the opposing blade configurations provided by the spaced cutting heads enables the cutting apparatus of the invention to achieve a bi-directional cut without the degradation in performance which may be associated with single circular blades, thereby eliminating an idle reverse stroke.
It is known to manually cut a curved path in a thin sheet of material up to about 4mm thickness using a circular saw pivoted along the curve by a radial arm. However, such a technique is limited to cutting thin materials, gives inaccurate cuts and cannot be adapted to provide industrial scale output and speed.
In addition, the use of a pivoted circular saw to create a pair of arcuate cuts in a sheet, with the sheet being advanced between the successive cuts, would create a crescent shaped component.
This is because both cuts would have the same radius of curvature. By contrast, the cutting apparatus of the invention (see Fig. 8) enables a pair of arcuate cuts to be made, with each cut lying on an arc of a different but concentric circle. For this reason, the inner cut has a smaller radius of curvature (by an amount equal to the width of the piece being cut) than that of the outer cut. The width of the piece cut using the apparatus of the invention is therefore constant along its length. This could not be achieved using a circular saw on a pivoted arm, without adjusting the distance between the saw and pivot point after each cut.
As a result, the apparatus of the invention allows two or more conventional saw discs to sustain two or three cuts in close proximity and enables both sides of a curved wood component to be cut to an accuracy and depth which can generally only be achieved with linear cutting machines. In addition, a symmetrical component having both arcuate edges of the curved piece concentric so that the component has exactly the same width along its entire length is achieved with the cutting apparatus of the invention.
Referring to figure 9, an assembly apparatus or jig 100 of the invention for assembling components of a frame, typically a doorframe, comprises a pair of elongate support members 102 for receiving the side sections 104 of the frame in a horizontal orientation and a transverse support member 106 for receiving the transverse section 108 of the frame also in a horizontal orientation. The side frame sections 104 include jambs 20 and side architraves 12 and the transverse frame section 108 includes the frame head 22 and associated architraves 14, as illustrated in figure 2. In the embodiment of figure 9, the transverse support member 106 is arcuate for accommodating arcuate frame heads 108, but a straight support member for accommodating straight frame heads can equally be employed as required. The support members 102,106 are disposed relative to one another so as to allow the components 104, 108 of the frame to be fitted and joined to one another.
A circular saw 118, described in more detail with reference to figure 11, is mounted adjacent each end of the transverse support member 106 for providing a mitre cut through the corresponding side sections 104 and transverse section 108 of the frame. Thus, the circular saws 118 cut the jambs at an angle and cut the transverse section of the frame at a corresponding angle, whereby a mitred joint between the jambs and lintel, and the associated architraves and doorstops of the doorframe can be effected.
A mortise mechanism 120, described in more detail with reference to figures 15 and 16, is mounted adjacent one of the elongate support members 102 at a central region thereof for mortising the hinge locations of a door whilst the latter is in its final closed position within the assembled frame.
A chop saw 122 is provided adjacent each end of the elongate support members 102 remote from the transverse support member 106, for cutting the frame side sections 104 to the desired length.
In order to enable frames of different widths to be assembled, each of the elongate support members 102 is laterally movable. A toothed rack 124, located at the end of the elongate support members 102 adjacent the transverse support member 106, is used to locate the support members 102 at discrete intervals, for example, with 2.5 cm gaps between successive teeth of the rack. Although in conventional doorframe manufacture, it is known to use an
assembling jig which receives the doorframe components horizontally in the correct spaced relationship and holds them in position as they are first fitted and then joined together, such jigs are generally not adaptable for different widths of frames, that is, for varying distances between the jambs.
The jig 100 is used to assemble and secure together all of the frame components 12,14, 20 and 22 so as to form a complete pre-fabricated self-supporting door frame. Typically, a set of splitting saws (not shown) are provided, each splitting saw being movable along the longitudinal axis of one of the elongate support members 102 or the arcuate axis of the transverse support member 106. Such saws are used to cut the assembled door frame along the jambs 20 and frame head 22 substantially into two opposite halves, that is, the entire frame is divided on the plane X-X shown in figures 2a and 2b. Then, these two halves can be assembled into the door opening 10 from either side and joined together to form the final complete frame assembled in the door opening. This provides a more easily and rapidly assembled door frame.
Referring to figure 10, the elongate support members 102 are substantially rectangular in cross-section and have an elongate channel 110 formed in the upper surface thereof. The channel 110 is adapted to receive the side sections 104 of the frame therein so that such side sections are retained securely and accurately therein. Typically, the channel 110 is profiled to correspond to the external profile of the side sections 104 in order to ensure perfect alignment of the side sections. When the frame side section is located horizontally in the assembly apparatus, the base 112 and sidewalls 114 of the channel 110 correspond to and abut the external profile of the side section architrave 116 in use. The transverse support member 106 is similarly profiled to match the profile of the transverse frame section. Thus, the counter profile beds of the elongate and transverse support members accommodate the three- dimensional frame section and architrave moulding perfectly. It will be appreciated that the elongate and transverse support members 102,106 may be replaceable to enable alternative support members with different frame matching profiles to be used in the assembly apparatus to accommodate frame components of different external profiles.
Referring to figure 11, the circular saw 118 comprises a circular saw blade 126 vertically mounted for rotation on a drive shaft 128. The drive shaft 128 is fixed to first ends of a pair of
parallel rods 130. A stop 132 is fixed to the other end of the rods 130. The rods pass through and are slidable within a pair of sleeves 134 so that the saw blade 126 is horizontally movable, as indicated by arrow x, relative to the sleeves. The sleeves 134 are fixed to a plate 136 which is rotatable about a longitudinal axis, as indicated by arrow c. Thus, the vertical orientation of the saw blade 126 is adjustable in the direction indicated by arrow c. The plate 136 supporting the sleeves 134, drive shaft 128 and saw blade 126 is mounted on an upright member 138 which is vertically adjustable, as indicated by arrow z, relative to a base member 140. For example, the upright member 138 may be telescopically arranged relative to the base member 140. The base member 140 is mounted on the assembly structure, as shown in figure 9, so as to be movable in a transverse direction, as indicated by arrow y. Consequently, the saw blade 126 is adjustable horizontally, transversely, vertically and angularly about a vertical axis, as indicated by the arrows x, y, z and c, respectively. The base member 140 may be mounted on a straight transverse component or guide rail of the assembly structure for linear movement therealong. Alternatively, as shown in figure 9, the base member 140 may be mounted on an arcuate transverse component or guide rail 142 of the assembly structure so as to follow an arcuate path, particularly when the assembly apparatus is to be used for curved head frames.
Thus, the position of the blade of the circular saw is adjustable relative to three orthogonal axes and one rotational axis. The multi-axis mitre saw 118 enables large three-dimensional profiles to be cut. The rotational axis adjustment enables both true and found mitre angles to be obtained.
In order to sustain absolute accuracy and tolerance when simultaneously cutting mitred corners at the intersection of three, three-dimensional U-shaped sections, for example the head and both side sections of a door frame complete with architraves, it is essential that the three sections of the frame can be mitre cut whilst sustaining a perfect zero orientation in all three axes, that is along the x, y and z axes. Figure 12 shows the orientation of the three frame sections to be cut and assembled, where the datum zero in the x, y and z axis is nominated as datum A.
Referring to figure 13, the operation of the circular saw 118 of the assembly apparatus involves cutting the side 104 and top 108 frame sections to the correct angle. Referring to figure 14, the blade 126 edge cutting path through a three-dimensional frame section 104,108
passes from one lateral edge of the frame section cross-section to the other lateral edge in the direction of arrows A. Such operation is achieved by the design of the pair of multi-axis mitre saws 118 which work through four axes x, y, z and c. The saws 118 have the capacity to produce mitre cuts which can be true mitres, being exactly 45 degrees, or found mitres, being greater or less than 45 degrees. The ability to produce found mitres accurately is necessary in the manufacture of curved or segmental doorframes of varying width, in particular.
The x axis gives the ability to plunge cut in and out. The y axis gives the ability to move side to side, thereby facilitating different widths of doorframe. The z axis gives the ability to climb-cut, which facilitates the cutting of doorframes which are thicker than the diameter of the saw blade 126 used. The c axis enables the saw blade 126 to be swivelled to any false mitre setting and located automatically.
Referring to figures 15 and 16, the mortise mechanism 120 comprises an adjustable mortise bit 144 mounted on a support housing 146. The housing 146 is vertically slidable, as indicated by arrow zl, on vertical rods 148. The vertical rods 148 and housing 146 are mounted on an upright support 150 which is vertically adjustable, as indicated by arrow Z2, relative to a base member 152, the latter being secured to the assembly apparatus structure, as shown in figure 9. The housing 146 is horizontally adjustable in two directions, as indicated by arrows XI, Xz, by sliding on pairs of transverse rods 154, 156 respectively. Stops 158 are fixed to the free ends of the pairs of transverse rods 154,156.
The pairs of transverse rods 154,156 pass through and are slidable within corresponding pairs of sleeves 160 mounted on the upright support 150. Thus, the mortise bit 144 is movable in two transverse directions and is adapted for course and fine adjustment in the vertical direction.
In use, as shown in figure 16, when a door 162 and frame 164 have been located in the assembly apparatus 100, a standard mortise bit 144 is presented to a location between the door and frame in the closed position. The size of the mortise bit 144 is designed and calculated to accommodate the required air gap between the door 162 and frame 164 and the hinge plate depth for both the door and frame. Different size bits can be substituted to accommodate different sizes of air gap and hinge plate.
Conventional door and frame hinging is a two stage process normally executed by a craftsman at the time of hanging the door. Since the two halves of the hinge mortise are conventionally produced consecutively, this can lead to inaccurate alignment of the two halves for the hinge thereby creating misalignment of the door when hung. Such a manual process also leads to a risk of creating too deep a cut on either the door or the frame which causes the door to be misaligned with the frame or hinge bound. By contrast, the single action door and frame hinge mortise mechanism 120 enables both door and frame mortises to be produced in perfect alignment because the door and frame located in the assembly apparatus are guaranteed to be in perfect alignment.
Referring to figure 17, a preferred assembly apparatus 100 includes a series of mortise mechanisms 120, typically three or four, mounted along one of the elongate support members 102 for simultaneously mortising the hinge locations of a door. The series of mortise mechanisms may be interconnected by a connection rod or the like and may be adjustable longitudinally to the desired position along the elongate support member.
The assembly apparatus 100 of the invention may be used to assemble and secure together all of the frame components 12,14, 20 and 22 so as to form a complete pre-fabricated self- supporting frame. The apparatus may also be used to produce a complete frame with casings and door fitted, hinged and locked by virtue of the constant alignment of all components and machining processes, inclusive of the mortise mechanism 120 thereof.
The assembly apparatus of the invention has been designed to enable curved and straight components and sub-assemblies to be mitre cut and joined at optimum efficiency and with absolute accuracy. The assembly apparatus overcomes a range of problems and inefficiencies generally associated with the manufacture and installation of doors and frames in architectural openings. Thus, with the assembly apparatus of the invention, perfect orientation of all the assemblies and components can be maintained and all the mitred corners can be warranted as true and absolutely parallel to each other in all axes. The apparatus ensures repeatability and industrial scale output and de-skills the assembly process thereby saving cost at both the manufacture and the installation stage. In addition, the apparatus allows the reduction of material wastage.
The assembly apparatus enables a perfect physical orientation of the three-dimensional frame section to be obtained, since the use of a counter profile of the required frame section, whether straight and/or segmental, allows the consistent location of the frame sections in the absolute zero orientation. Because the architrave profile and the counter profile in the corresponding support member match perfectly, all three of the three-dimensional sections of the frame are disposed to sit in their correct aspect for cutting, thereby guaranteeing that the sections, which are to be mitred and joined, always rest in perfect alignment to blades used for cutting found mitres and true mitres.
It will be appreciated that the apparatus and method for assembling components of a frame for an architectural opening according to the invention may be used for square head or curved head frames as desired.
In conventional mitre joint cutting, it is standard practise to use one face of the blade as the reference cut and the other side as the waste cut. The saw is then re-configured to cut the required mating component section using the original reference face. Thus, the same face of the blade is used for both cuts. However, using such a technique the maintenance of accuracy is rarely achieved due to the dependency on a skilled operator. By contrast, the assembly apparatus of the invention uses both opposing faces of the blade, one for each side of the mitre cut. Thus, the reference face for the mitre cut of the frame head section is the waste face for the mitre cut of the abutting side section and vice-versa. This allows a true or square joint to be achieved irrespective of whether the cut is a degree or two off (about any axis), since this is automatically compensated for in the cut made in the complementary piece. The assembly apparatus therefore achieves a high level of accuracy in mitre cutting and jointing two sides of a three-dimensional frame section.
Conventional bench type saws, such as chop saws, bevel mitre saws, radial arm and crosscut saws, which incorporate a circular saw blade, can only cut large sections of material if the blade diameter is approximately three times larger than the maximum thickness of the material to be cut. Such conventional saws are therefore not suitable for cutting three- dimensional sub-assembled sections, which typically have an overall cut-through face of 8
inch (20cm) x 4 (lOcm) inch in the case of a standard 5 inch (12. 5cm) door frame with 4 inch (lOcm) x 1 inch (2. 5cm) architraves.
The cutting of mitres across any material increases the overall depth of material to be cut as the angle of the mitre increases, for example an 8 inch (20cm) x 4 (lOcm) inch doorframe section would require a blade of 22 inch (55cm) to achieve a 90 degree cut though the entire section. If the desired angle of cut is 45 degrees, as in a mitre joint, a 24 inch (60cm) blade size would be required.
The multi-axis circular saw of the assembly apparatus of the invention overcomes the limitations and potential inaccuracies of conventional mitre saws, band saws and jig saws, by enabling a three-dimensional doorframe section, which incorporates the stile and architrave components in a U-shaped section, to be cut and the mechanical and physical aspects of the blade movement give the multi-axis circular saw a large cutting capacity. The cutting portion of the blade is able to travel through an overall circumference which is greater than the circumference of the material to be cut. The motion of the cutting edge of the blade is able to travel through an accurately constrained vertical and horizontal path whilst maintaining absolute lateral rigidity. The whole of the sawing mechanism is also capable of radial travel to establish found mitre angles.
The ability of the assembly apparatus to allow simultaneous mortise of the hinge position, further enhances the efficiency and cost effectiveness of the total door and frame joining process. The accuracy created by the simultaneous placing of a frame and door together within the same jig creates a perfect alignment of the edge of the door and frame. This allows the hinge locations to be mortised whilst the door is in its final closed position within the frame.
Standard moulding machines have a profiling knife which cuts the desired profile as a rough section of material is passed along a table under the knife in a straight line. Such machines cannot be used for cutting curved sections such as the head architraves 14 shown in figure 1 because of the difficulty in accurately feeding a rough section along an arcuate path as it is cut by a profiling knife. Arcuate moulded sections are instead cut by hand by skilled craftsmen.
Referring to figure 18, a moulding apparatus 200 of the invention for producing an arcuate moulding 202, such as the profiled head architraves 14, from a length of arcuate material 204
having a datum face 206 comprises rotary cutting means in the form of a series of, typically six, high speed rotational cutters or cutting heads 208,210, 212,214, 216 and 218 of a type familiar to the skilled person.
The cutters are mounted above a platform (not shown), typically constructed from a cast iron base forged to a curved shape and engineered to accommodate a series of motors and gearing systems, which are installed within the body of the casting. The platform incorporates a cast iron table, which is engineered to receive an arcuate guidance rail embedded in the surface of the table. The arcuate guidance rail follows a specific radius and provides a raised strip or tongue which is received in use in a corresponding groove 220 machined into the bottom face of a curved component. Thus, the material 204 is constrained to follow the arcuate path of the guidance rail.
Each rotational cutting head 208,210, 212,214, 216 and 218 carries a blade for cutting, either planning or profiling, part of an exposed face of the length of material 204 so that as the material passes through the series of cutters, guided by the arcuate guidance rail, it is cut to a predetermined profile. As the datum face 206 of the timber passes along the table, in the direction of arrow F, it first meets the first cutting head 208 which planes the bottom datum face of the material and cuts the guidance groove 220, typically of dimension 4mm x 4mm, along the entire length of the component 204. The groove 220 is dimensioned to correspond to the rail on the table of the apparatus 200. The first cutting head 208 has a planar blade 222 for planning with a cutting tooth 224 projecting therefrom for cutting the groove 220.
The second cutting head 210 profiles an outside edge of the component to form the outer line or edge of the finished architrave. The third cutting head 212 profiles an inside edge of the component to form the inner line or edge of the finished architrave. The second and third cutting heads 210,212 may each carry a profiled or planar blade according to the finished outer and inner architrave edge profiles required. The fourth cutting head 214 carries a planar blade and planes the top face of the component thereby reducing the upper surface of the component to the desired thickness for profiling. The fifth cutting head 216 profiles the top surface of the planed component to form the decorative relief profile of the finished architrave, according to the profile 226 of its blade 228. The sixth cutting head 218 carries a planar blade and planes, cleans and finishes the bottom face of the component.
Thus, referring to figure 19, the arcuate moulding 202 produced using the moulding apparatus 200 comprises a profiled inner 230, outer 232 and upper 234 surface and a planed under surface 236 with a guide groove 220. It will be appreciated that the moulding apparatus cuts a profile which may be conventional in cross-section but which, because of the arcuate path followed by the length of material, is arcuate in its longitudinal extension.
The apparatus may be provided with means for applying a lubricant such as clear oil to the datum face, to assist in the passage of the datum face over the table and along the raised strip.
If necessary, a fine sander can be used after profiling to remove this oil, or the face can be cleaned by the final cutting head 218.
The first bottom profiling planar cutting head 208 has a planar blade 222 with a cutting tooth 224 projecting therefrom and creates a substantially uniform datum face with a groove 220 in a rough piece of timber. Immediately past the planar cutting head 208 in the direction of travel of the timber, right to left in figure 18, a table (not shown) having a raised arcuate rail of the desired curvature is provided. Although the cutting tooth 224 would normally tend to cut a linear groove in the timber, the groove 220 has only just started when it meets the raised arcuate rail on the table. Subsequent travel of the timber is constrained by the raised curved rail, and thus as the timber passes over the cutting tooth 224, an arcuate groove 220 is cut.
The profiling of the moulding apparatus is carried out in consecutive stages. This imparts the advantage that as the blades of each cutting head 208,210, 212, 214, 216 and 218 wear away, the position of the blades can be adjusted inwards or downwards as required to ensure that the dimensional accuracy of the finished piece remains constant, otherwise the dimension of the cut profiles increases over time as the cutting surface wears away.
As well as being adjustable in position in all three (x-y-z) dimensions, the angular attitude of the cutting heads 208,210, 212,214, 216 and 218 may be adjustable to accommodate various degrees of curvature, as determined by the raised arcuate strip on the table. In a further modification, each of the cutting heads 208,210, 212,214, 216 and 218 may be replaced by two or more saws which successively cut the wood towards the desired profile, i. e. a rough cut followed by a fine cut.
Curved cutting of wood generates a force known as back cutting where the piece to be moulded is forced to be re-cut when it exits the area of cutting. This generates a momentum which tries to destroy the wood surface and can cause the component to be fired backwards away from the cutting head. The rail and groove guidance system and the radius of travel past the cutting heads in the apparatus of the invention solves the problem of such radius back cutting and prevents the component travelling off line.
The process of sustaining the component through and past the cutting heads is supported by the use of a series of spring loaded rollers and pressure shoes. This ensures vertical pressure on the component as it is guided through the apparatus with its multiple planning and profiling heads. Thus, curved frame components, which have been cut accurately using the cutting apparatus of the invention, can be multi surface planed and profiled along the entire length of the component using the moulding apparatus of the invention to form a finished curved segmental architrave.
Conventional profile moulders are principally for moulding straight timber in a continuous linear fashion. Such conventional systems do not accommodate curved or segmental wood components where the top, side and bottom of the curved section is to be profiled or planed to meet a desired architectural design. A linear machine could not be modified to enable profiling of a curved component as is achieved with the moulding apparatus of the invention, which enables the entire length of the component to be held to a specific and arcuate path in order to guarantee the physical symmetry of the finished profile. Furthermore, conventional moulding technology for curved assemblies is only capable of single edge profiling by a skilled person, whereas the moulding apparatus of the invention allows high speed output with a high accuracy and curved sections of wood can be moulded on four faces simultaneously at feed rates equal to the most advanced straight moulders.
It will be appreciated that the present invention is not intended to be restricted to the details of the above embodiments, which are described by way of example only.
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