CA2202731A1 - Cutting jig for collapsible cylindrical products - Google Patents
Cutting jig for collapsible cylindrical productsInfo
- Publication number
- CA2202731A1 CA2202731A1 CA 2202731 CA2202731A CA2202731A1 CA 2202731 A1 CA2202731 A1 CA 2202731A1 CA 2202731 CA2202731 CA 2202731 CA 2202731 A CA2202731 A CA 2202731A CA 2202731 A1 CA2202731 A1 CA 2202731A1
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- CA
- Canada
- Prior art keywords
- channel
- cutting
- insert
- support
- product
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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- Thermal Insulation (AREA)
Abstract
A cutting jig for collapsible cylindrical product, such as foam insulation tube. The jig comprises a channel which may have parallel side surfaces for supporting the tube and also inclined tube support surfaces extending downwardly and inwardly from the side surfaces. The inclined support surfaces increase the positions of support contact with the tube around its lower regions to hold the tube firmly towards its cylindrical condition during cutting. Support of the lower regions of tube tends to stiffen the tube upper regions to hold the whole tube toward or into a cylindrical condition with insignificant collapse during cutting. The channel may provide a support channel for an insert channel for nesting insertion inside the support channel. The insert channel also has side and inclined support surfaces for supporting a tube of smaller diameter during cutting. A further and smaller insert channel is also provided similar in construction to the insert channel. The smaller insert channel is nestable within the insert channel for supporting a yet smaller diameter tube during cutting. Alternatively, each channel may have a concave tube support surface which is preferably semicylindrical. Also included is a kit of cutting jigs each of which has tube support surfaces according to either of the alternatives discussed above.
Description
CA 02202731 1997-04-1~
~u~ G JIG FOR COLLAPSIBLE CYLINDRICAL PRODUCTS
This invention relates to cutting jigs for collapsible cylindrical products.
Various cylindrical products require cutting to desired 5 lengths or to have their ends cut at desired bias or mitre angles to suit their particular requirements. To provide these results, cutting problems do not normally arise unless a cylindrical product is radially collapsible under a cutting blade or is already collapsed inwardly out of its cylindrical 10 configuration before cutting commences. One example of such a collapsible product is foam insulation tube as may be used for fitting around fluid flow pipes, e.g. water pipes, for thermal insulation purposes.
Foam insulation tube may collapse radially inwards and 15 may even crease away from its true cylindrical shape. To provide satisfactory results which not only appeal to the eye by providing the look of a professionally fitted thermal insulation around flow pipes, but also provide a fully efficient thermal insulation construction, it is essential for 20 successive lengths of foam insulation tube to be abutted cleanly with no gaps. When the path taken by a fluid flow pipe is substantially straight, successive foam insulation tube lengths need to have planar cut end surfaces which are normal to the axial direction of the lengths. Alternatively, 25 when flow pipes join at 45 degrees or 90 degrees, each cut length of foam insulation tube requires to have respectively, a 22.5 degree or a 45 degree mitre. In addition, to this, other cuts may be necessary to provide a snug fit for foam insulation tube. In one particular construction at a "T"
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junction, a "V"-shaped notch is required to be cut into the side of the tube providing the head of the junction. A
corresponding symmetrically tapered cut end is required for the tube forming the leg of the "T" junction so as to fit 5 properly into the notch. In another example, a three sided notch forming three sides of a rectangle is required in the insulation to receive one edge of a structural member where a flow pipe is secured to the member. Because foam insulation tube is readily collapsible under pressure of a cutting blade 10 or may have already assumed a collapsed state before cutting commences, it may be extremely difficult or even impossible to provide properly executed cuts in the forms discussed above. As a result, satisfactory abutting together of foam insulation tube lengths may be difficult to obtain without 15 leaving gaps which detract from the heat exchange efficiency of the total insulation. Indeed, unsatisfactorily abutted insulation tubes may even result in wastage of tubing.
It is essential to realise that foam insulation tube may be usefully employed around flow pipes for cold fluids as well 20 as for warm or hot fluids. Flow pipes for transporting cold fluids present cold outer surfaces upon which condensation forms in humid atmospheres. Not only does such condensation tend to drip onto floors and articles beneath, which can be destructive, but it encourages growth of mold and fungus upon 25 condensate-contacted surfaces. In such environments, foam insulation tube effectively acts as a vapour barrier around such flow pipes. However, condensation may still form upon exposed surfaces of flow pipes for containing cold fluids CA 02202731 1997-04-1~
when foam insulation tube lengths do not abut properly but leave gaps.
The present invention seeks to provide a cutting jig for collapsible cylindrical products and which may be used to 5 minimize or avoid the above problems.
According to one aspect, the present invention provides a cutting jig for a collapsible cylindrical product comprising a channel for accommodating the product, the channel having an inner surface profile provided at least partly by a 10 plurality of at least four product support surfaces comprising opposed side surfaces, and inclined surfaces extending downwardly and inwardly of the side surfaces, respectively, the channel provided with a pair of aligned guide surfaces for guiding a cutting tool on cutting strokes with the tool 15 extending across the channel.
As may be seen, a cutting jig according to the invention not only has side surfaces but also has inclined surfaces which extend from the side surfaces. Thus the cylindrical product which is to be cut is supported in more positions 20 around its lower periphery, and in locations which are more closely positioned together than would be the case if either a conventional mitre block or Vee block were used. The jig does therefore tend to maintain the product in, or restore it to, its cylindrical form around its lower regions and as a 25 result tends to stiffen the upper regions through which the cutting blade will initially pass.
For the product to be supported around its lower periphery in a truly cylindrical configuration, the product support surfaces should preferably all form tangents to a CA 02202731 1997-04-1~
common circle equal to the diameter of the outer periphery of the cylindrical product. In a preferred embodiment of the invention, the inner surface profile of the channel has a single inclined surface extending between each side surface 5 and a base surface and with this structure, the profile provides five support surfaces the base surface and inclined surfaces of which provide part of an octagonal shape.
Alternatively, two or more inclined surfaces are provided between each side surface and the base surface with each of 10 the inclined surfaces also forming tangents to the common circle. It follows that the support positions for the lower regions of the product increase as the number of inclined surfaces increase and, correspondingly, the distances between these support positions decrease.
A single inclined surface may be provided by a single jig element extending along the jig and between each base surface and a side surface. Alternatively, a plurality of coplanar inclined surfaces may be provided between each side surface and the base surface, these coplanar surfaces provided by a 20 plurality of spaced apart corner members with certain of the corner members located specifically to provide support for the product adjacent to the pair of guide surfaces.
A plurality of pairs of aligned guide surfaces may be provided to provide a variety of alternative mitre angles at 25 the ends of insulation tube and/or to provide different shapes for these ends. In such a particular structure, the plurality of corner members are located adjacent to each cutting position so as to hold the product in a substantially cylindrical condition for any particular cutting action.
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Where corner members are used for providing the guide surfaces, in a practical construction the channel has two side walls extending downwards to, and secured to, a base. The side walls and the base provide, respectively, the side 5 surfaces and base surface of the inside surface profile.
In a particularly preferred arrangement, the channel of the jig, as discussed above, also provides a support channel for an insert channel providing a part of the jig. The insert channel is insertable in nesting relationship within the 10 support channel for accommodating a collapsible cylindrical product which is smaller in diameter than the product to be accommodated by the support channel. The insert channel also has an inner surface profile provided at least partly by a plurality of support surfaces for the smaller diameter 15 product. These support surfaces include opposed insert side surfaces, an insert base surface and an insert inclined surfaces depending one from each side surface. The insert also has aligned guide surfaces which, when the insert channel is inserted into the support channel, are aligned with the 20 guide surfaces of the support channel for guiding the cutting blade on its cutting strokes. A registration means may be provided for insertion of the insert channel into the support channel so as to locate the insert channel only in one position of orientation and longitudinal location along the 25 support channel. Preferably, the cross-sectional shape of the smaller insert channel is similar to that of the first insert channel.
In a further preferred construction, another and smaller insert channel is provided which is insertable in nesting CA 02202731 1997-04-1~
relationship within the insert channel referred to above. The smaller insert channel is to be used for cutting collapsible cylindrical product which is smaller in diameter than the product to be accommodated and cut within the larger insert 5 channel.
According to a further aspect, the present invention provides a cutting jig for a collapsible cylindrical product comprising a channel for accommodating the product, the channel having an inner surface profile provided at least 10 partly by a concave support surface, the channel provided with a pair of aligned guide surfaces for guiding a cutting tool on cutting strokes with the tool extending across the channel.
The cutting jig according to the above further aspect has similar advantages to the cutting jig defined according to the 15 invention of the first aspect, as above.
The invention also includes a kit of cutting jigs. In one arrangement of the kit, each cutting jig comprises a channel having an inner surface profile provided at least partly by a plurality of at least four product support surfaces 20 comprising opposed side surfaces and inclined surfaces extending downwardly and inwardly of the inclined surfaces.
In another arrangement of the kit, each cutting jig comprises a channel having an inner surface profile, provided at least partly by a concave support surface. In both kit 25 arrangements, each channel is provided with a pair of aligned guide surfaces for guiding a cutting tool on cutting strokes with the tool extending across the channel.
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Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which :-Figures la to le are perspective views showing different 5 types of joints required of foam insulation tubing and as maybe provided using a cutting jig of any of the embodiments;
Figure 2 is an exploded isometric view of a cutting jig of a first embodiment;
Figure 3 is an end view of the exploded cutting jig of 10 the first embodiment;
Figure 4 is a plan view of a part of the jig of the first embodiment;
Figures 5 and 6 are views similar to Figure 4 of other parts of the jig of the first embodiment;
Figure 7 is a side view of a channel forming the largest part of the jig of the first embodiment and showing foam insulation tube accommodated in the channel and ready for cutting;
Figure 8 is a cross-sectional view through the channel 20 of Figure 7 taken along line 'VIII-VIII' in Figure 7;
Figure 9 is an isometric view on one side of the channel of Figure 7 and showing use of the channel for providing cut ends for the tube length structure of Figure la;
Figures 10 and 11 are views similar to Figure 9 and 25 showing use of the channel for providing cut ends for the tube length structures, respectively, of Figures lb and lc;
Figures 12, 13 and 14 are each similar to Figure 9, the Figures showing stages in providing cut surfaces for the tube length structure of Figure ld;
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Figures 15, 16 and 17 are views similar to Figure 9, the Figures showing stages in providing a cut notch for the tube length structure of Figure le;
Figure 18 is a perspective view showing a type of joint 5 required of foam insulation tubing and similar to the cut notch structure of Figure le;
Figure 19 is a view similar to Figure 9 and showing use of the channel of Figure 7 for cutting the cut notch structure of Figure 18;
Figures 20 and 21 are views similar to Figures 7 and 8, respectively, and showing an assembly of the largest part of the jig of the first embodiment with an insert channel in position and carrying foam insulation tube of smaller diameter;
Figure 22 is an end view of an exploded cutting jig of a second embodiment; and Figures 23 and 24 are end views of cutting jigs forming kits of cutting jigs according to third and fourth embodiments.
A cutting jig of the first embodiment to be described may be used to form any of the joints or abutting end configurations for foam insulation tube as shown in any of Figures la to le.
As shown in Figure la, a fluid flow pipe in the form of 25 a water pipe 10 is surrounded by foam insulation comprising lengths 12 of foam insulation tube which are abutted end to end. Ends of the tube lengths 12 are cut normal to the lengths of the tubes with adjacent ends 14 abutted close CA 02202731 1997-04-1~
together in intimate contact without formation of noticeable gaps between these ends.
In other Figures lb to le, the abutting ends of lengths 12 of insulation also have no gaps formed between them through 5 which heat could be transferred to or from the water pipes shown in those Figures. Avoidance of gaps also prevents formation of condensation with its attendant mold, fungal and other problems caused by damp.
In Figure lb, a right hand junction is formed between two 10 water pipes 14 and 16 which necessitates two tube lengths 12 having ends 18 cut at a mitred angle of 45 degrees to the axes of their respective lengths. In Figure lc two water pipes 19 extend one from the other at an obtuse angle of 135 degrees.
This necessitates the abutting tube lengths 12 having abutting 15 ends 20 at the bent position, each end 20 being cut at 22.5 degrees to the longitudinal axis of its length 12.
As shown in Figure ld, a "T" joint is provided between a water pipe 21 forming the head of the "T" and water pipe 22 extending downward from it. In this arrangement a length 23 20 of foam insulation tube requires a "V" shaped notch formed into it with tapering sides 24 generating a right angle at the junction between them. A length 26 of foam tube for location around the pipe 22 is required to be formed with a tapered end having sides 28 complementary in angle to the sides 24 for 25 abutting purposes.
Finally, in Figure le a water pipe 30 extends beneath a structure comprising beams 32, which might be wood or metal, (one only being shown) to which the pipe is secured by suitable brackets. Foam insulation tube lengths 33 CA 02202731 1997-04-1~
surrounding the pipe 30 need to pass beneath each of the beams 32 and in doing so require to be cut at the one side with a three sided notch 34 for accommodating the beam. The fit of the beam 32 within the notch avoids any undesirable gaps which 5 may allow for heat transfer to or from the water pipe 30.
In the embodiment as shown particularly in Figures 2 and 3, a cutting jig 40 is provided for cutting the various end shapes to foam insulation tube lengths 12 shown in Figure la to le. The jig 40 comprises a channel 42 which provides a 10 support channel for a first insert channel 44. The channel 44 is the larger of two insert channels, the smaller insert channel being channel 46.
The support channel 42 comprises two side walls 48 and a base 50 secured between the side walls with the side walls 15 extending upwardly from the base in spaced apart relationship.
The channel 42 is provided with a product support surface profile, i.e. for supporting foam insulation tube lengths.
This profile comprises two side surfaces 51 provided by the side walls 48 and a base surface 52 which faces upwardly 20 between the side walls. The distance between the side surfaces 51 corresponds to the outside diameter of a foam tube length 12, 23 or 26 (Figures lc and ld), so that the tube length will fit snugly between the side walls while supported upon the base surface 52. The support surface profile also 25 includes inclined surfaces 54 between the base surface and the side surfaces. These inclined surfaces 54 are provided upon corner members 56 which are of suitable triangular shape to fit into the corner formed between and a corresponding side wall 48 and the base 50 of the channel 42. The corner members CA 02202731 1997-04-1~
56 may be formed integrally with the channel 42, perhaps as a unitary molding.
As shown particularly by Figure 2, the corner members 56 and thus the surfaces 54 between each side wall and the base 5 are spaced apart longitudinally of the channel with the surfaces 54 lying in a single inclined plane. Thus, effectively, a single inclined surface extends between each side wall and the base. The inclined surfaces 54 together with the base surface 52 and the side surfaces 51 form 10 tangents to a common circle substantially equal in diameter to that of a length 12, 23 or 26 of foam insulation tube which is to be accommodated in the channel thereby supporting the lower part of the tube in its substantially cylindrical condition. As an alternative to the individual corner 15 members 56, single fillet members (not shown), having a triangular section, may extend from end to end of the channel 42, one between each side wall 48 and the base 50 so as to provide a continuous inclined support surface throughout the length of the channel.
As shown in Figures 2 and 4, the channel 42 has its side walls 48 formed with pairs of aligned guide surfaces for guiding a cutting blade on cutting strokes to be performed upon a length of foam insulation tube. A first pair of aligned guide surfaces is provided by aligned slots 60 which 25 extend downwardly into the side walls 48, the slots 60 being joined together by a slot 62 which is formed into the surface 52 of the base member. The slots 60 and 62 are formed at a mitre angle of 45 degrees to a longitudinal axis of the channel 42. Similarly a second pair of guide slots 66 in the CA 02202731 1997-04-1~
side walls 48 and inclined at a mitre angle of 67.5 degrees to the longitudinal axis of the channel are joined together by a further slot 68 in the base surface 52 so as to provide straight line cutting guides at that required angle.
In addition, as shown by Figure 2, but more particularly by Figure 7, laterally aligned "V" notches 70 are provided in the side walls 48, towards one end of the channel 42. Each notch has downwardly inclined sides 72 which meet at a right angle, as shown by Figure 7. The junction point 74 of the 10 sides 72 lies substantially at the same vertical height from the base surface 52 as the longitudinal axis 76 for lengths of foam tubing which are to be cut in the channel 42. At the other end of the channel 42, the two side walls have aligned notches 78 which follow a rectangular configuration which is 15 open at that end of the channel. Each notch 78 is provided by a downward edge surface 80 in each side wall 48 and a horizontal edge surface 82. The two edge surfaces 82 coincide in height from the base surface 52 to the uppermost extremity of the inner peripheral surface of a length of foam insulation 20 tube which is to be cut within the channel 42.
As will be noticed, particularly from Figure 4, the corner members 56 are spaced apart as already stated above, but are located in positions such as to support foam insulation tube lengths in locations close to any cutting 25 operation which may be performed using any of the guide surfaces provided by the channel 42.
The channel 42 may be used alone without either of the inserts 44, 46 for cutting foam insulation tube lengths of a specific diameter.
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As shown in Figures 7 and 8 with a tube length 12 disposed in cylindrical form within the channel 42, the side, base and inclined surfaces 51, 52 and 54 engage and support the outer peripheral surface of the tube length around its 5 lower regions.
During any cutting action which is to follow, the support provided around lower regions of the tube length to hold it in cylindrical shape stiffens these lower regions and, in consequence, tends to hold and stiffen the upper regions which 10 are not so supported. Thus resistance to collapse of the upper regions is provided thereby enabling, with a careful cutting action of a sharp blade, the provision of a precisely cut end shape to the tube length.
The cutting blade (not shown), which may be a sharp 15 knife or a saw, may be used to cut downwards along the guide surface line 83 offered by the end 84 of the channel (see Figure 9) to provide a cut end 14 for abutting length ends as shown in Figure la. Cutting downwards with a knife inserted as shown in Figures 10 and 11, respectively, into slots 60 or 20 66 and continuing down along cutting lines 85 and 87 into the grooves 62 or 68 respectively, will provide cut ends 18 and 20 for use in the type of abutting relationship of the lengths 12 shown in Figures lb and lc respectively.
Alternatively, where a "V" notch with sides 24 is to be 25 provided as shown in Figure ld, the cutting blade is cut downwardly into the tube length 23 while being guided by the pair of guide surfaces 72 (see Figure 12). The tube length 23 is of conventional construction in that it has a longitudinal slit 88 to enable it to be opened for positioning CA 02202731 1997-04-1~
around the pipe 21. For the cutting of the notch with sides 24, the tube length 23 is placed in the channel 42 with the longitudinal slit upwards so that the notch is cut downwards into the tube length from both sides of the slit. The bottom 5 of the notch corresponds to the junction positions 74 and which are thus disposed at opposite ends of the tube diameter.
The tube length 23 is then removed and the tube length 26 placed into the channel. The tube length 26 is then trimmed at its end to provide the tapered end with sides 28 by first 10 cutting down into the slot 60 along cutting line 85 as discussed above to provide a planar end surface 18 mitred at 45 degrees on the tube length. The tube length is then rotated by 180 degrees at the same longitudinal position in the channel and the cutting process is repeated. The repeat 15 cutting process will only cut through part 86 of the end region of tube (Figure 14) to provide the required tapered end with surfaces 28. The intersection point between the grooves 62 and 68 lies upon the median plane of the channel. After the tube length 26 has been rotated, and prior to the repeat 20 in the cutting process as shown by Figure 114, the correct position of the tube length 26 for the repeat cutting process is when the end surface 18 crosses the intersection point between the grooves 62 and 68.
When it is required to cut a three sided notch 34 (Figure 25 le) a tube length 33 is cut radially. For this, two cuts 90, spaced apart and corresponding to the width of the beam 32, are made using the guide surface 80 (Figure 15). The blade is then urged downwards in inclined fashion (for instance as shown by the curved direction arrow in Figure 16) to the guide CA 02202731 1997-04-1~
surfaces 82. The blade then cuts along the tube using the guide surfaces 82 for blade positioning. This provides a partially finished base surface 88 for the notch 34, the surface having an upwardly inclined end as shown by Figure 16.
5 The cutting blade is then guided in the opposite direction, i.e. towards the right in Figure 17, along guide surfaces 82 until the blade reaches the guide surfaces 80. This action removes the upwardly inclined end of the base surface 88 to give a completely planar base surface 88, thereby completing 10 the notch 34.
Should a notch be required which is longer than the lengths of the guide surfaces 82, then this may be accommodated by the channel 42. This may occur, for instance, when a building has a wider beam 32a such as provided by three 15 beams 32 nailed together side-by-side (Figure 18). A
sufficiently long notch 34a must be formed to correspond to the width of the beam 32a. For this long notch formation, the notch 34 as discussed above is made longer. This is easily performed (Figure 19) by placing the cutting blade 91 upon the 20 base surface 88 with the tube 33 retained in the channel 42.
The tube 33 is then moved longitudinally along the channel while using the blade 91, supported upon the guide surfaces 82, to cut along the tube so as to increase the length of the base surface 88. When the blade has travelled the required 25 distance to provide the correct length of the base surface for the notch 34a, the tube 33 is reversed longitudinally in position within the channel 42 and the blade is cut down into the tube to the end of the cut 93 for the base surface while being guided by the guide surfaces 80. The base of the notch CA 02202731 1997-04-1~
34a will then be coplanar with a tangent to the top of water pipe 30 and will fit comfortably against the beam 32.
As a result of the use of the channel 42, all cutting operations performed on foam insulation tube lengths are 5 performed with each length held in substantially cylindrical manner. Thus the cut edges are as desired with little or no resultant tendency for gaps to be formed between abutting surfaces of adjacent tube lengths after installation.
The first, larger insert channel 44 is for supporting 10 foam insulation tube lengths of smaller diameter than lengths to be cut in channel 42. As shown by Figures 2 and 21, the channel 44 has a product support surface profile provided by opposing side surfaces 92, a base surface 94 and an inclined surface 96 extending between each side surface and the base 15 surface (see also Figure 5). These surfaces are provided respectively upon side walls 98, base 100 and inclined side walls 102. The channel 44 is provided to nest snugly within the channel 42 with side walls 98 slidably engaging the side walls 48 as the insert channel 44 is slid down into the 20 nesting position in which the base 100 is supported by the base surface 52. Upper end surfaces 104 of side walls 98 do not extend up to the level of guide surfaces 82 but rather to the junction position 74 of guide surfaces 72. However, the base 100 may be of suitable thickness to locate the 25 longitudinal axis of foam insulation tube length of the smaller diameter at the level of the longitudinal axis position 76 for tube lengths to be cut in the channel 42 as described above. Hence, a "V" shaped notch cut into the smaller diameter tube and similar to the notch with sides 24 CA 02202731 1997-04-1~
(Figure ld) will have the junction position of its sides at opposite ends of the diameter of the tube length.
Registration means is provided to assemble the channels 42 and 44 together. This registration means comprises a 5 plurality (normally two) of registration pins 106 (Figure 2) provided in channel 44 for insertion within complementary bores 108 of the base surface 52. As shown particularly by Figure 4, bores 108 (and thus the pins 106) are disposed on the longitudinal centre line 110 of the assembly. However to 10 ensure correct relative angular orientation and longitudinal positioning of the channels, the bores 108 and pins 106 may be disposed offset to one side of the centre line 110 as shown in chain dotted outline for the bores 108. Alternatively, one of the bores 108 and the corresponding pin 106 from the one 15 end of the channel may be different from the spacing of the other bore 108 and its pin 106 from the other end.
The channel 44 has a pair of aligned guide surfaces for a cutting blade. These are provided by guide slots 112 in side wall 98, and when channels 42 and 44 are assembled the 20 slots 112 are aligned with slots 60 in channel 42 to provide a 45 degree mitre. The slots 112 are connected by groove 114 in the base surface 94. Similarly, slots 116 interconnected by groove 118 in the base surface 94 are aligned with the slots 66 in channel 42 with the channels assembled together 25 for forming a 22.5 degree mitre.
As shown in Figures 20 and 21, with channels 42 and 44 assembled, a foam insulation tube length 120 of smaller diameter than a tube length 12, is snugly accommodated within the channel 44 with its lower regions supported by surfaces CA 02202731 1997-04-1~
92, 94 and 96 to retain the tube length 120 in cylindrical condition during cutting. The tube length 120 may then be provided with either of the mitred cut ends, a " V" shaped notch, or a rectangular cut out similar to those described in 5 use of the channel 42.
For the cutting operation as shown by Figures 20 and 21, the axis of the tube length 120 is coincident in position to that of a tube length 12 when carried by channel 42.
In the event that an even smaller diameter foam 10 insulation tube length (not shown) should require cutting in the manner described for tube lengths 12 and 120, the second and smaller insert 46 is used (Figures 2 and 6). This channel is identical to the channel 42 in design (except that it is smaller) and has side walls 122, a base 124, and inclined side 15 walls 126 which provide a product support surface profile in the form of opposing side surfaces 128, base surface 130, and inclined surfaces 132. Registration means, comprising registration pins 134 in the base 124, register within registration bores 136 formed into the base surface 94. The 20 pins 134 and bores 136 are displaced relative to the corresponding pins 106 and bores 108.
The channel 46 is nestable within the channel 44 with the base 124 supported upon the base surface 94. Cutting blade guide slots 138 and 140 in side walls 122 and 126 become 25 aligned, respectively, to the guide slots 112 and 116 in the channel 44 for cutting purposes. Slots 138 are interconnected by a groove 142 formed in the base surface 130 while slots 140 are interconnected by groove 144 in the base surface. For reasons similar to those associated with the channel 44, the CA 02202731 1997-04-1~
base 124 of channel 46 is sufficiently thick to locate the longitudinal axis of a tube length to be cut at the level of the longitudinal axis position 76 for a tube length 12 when this is accommodated in the channel 42.
As mentioned above, the base 100 may be of suitable thickness to locate the longitudinal axis of a tube length of smaller diameter at the level of the axis position 76 for tube lengths to be cut in the channel 42. However, the smaller diameter tube length cannot extend up to the correct position 10 for a notch 34 to be cut using the guide surfaces 82 while locating the base of the notch coplanar with a tangent to the top of a water pipe to be contained within the tube length.
For certain differences in diameter, the compressibility of the foam will accommodate the difference between the positions 15 of the base of the notch and this tangent. Hence, if the channel 42 is used for cutting a 0.75 inch diameter tube length and the channel 44 is provided for cutting a 0.5 inch diameter tube length, then the discussed difference is 0.125 inches and is acceptable. However, for the even smaller 20 diameter tube length to be cut in the channel 46, the difference between the two positions increases and may not be acceptable. In this situation, for cutting a notch 34, by way of compromise, the channel 44 is dimensioned to place its surfaces 104 at the height corresponding to the plane of the 25 tangent of the tube to be fitted within the channel. This then may allow for an acceptable difference between the two positions for each of the largest and smallest diameter tube lengths.
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It should be appreciated that the greater the number of support surfaces, the better will be the support for the tube.
Although the above-described embodiment has five support surfaces, namely two side surfaces, two inclined surfaces and 5 a base surface, it is envisaged that more or fewer could be provided, though a minimum of four is believed to be required for adequate support.
In a second embodiment shown by Figure 22, a cutting jig lS0 has a channel 152 which provides a support for a first 10 insert channel 154 which, in turn, provides a support for a smaller insert channel 156. The channels 152, 154 and 156 have some of the same basic features, respectively, as channels 42, 44 and 46 of the first embodiment and of these same features, like reference numerals are used in the second 15 embodiment.
The second embodiment differs fundamentally from the first embodiment, however, in the shapes of the product support surfaces and the shapes of the channels to support those surfaces. In the case of the channel 152, a base 158 20 and sidewalls 160 between them define a smoothly contoured product support surface profile. This is formed by vertical planar surfaces 162 defined by each sidewall, the surfaces 162 extending tangentially into a semicylindrical base surface 164. The radius of the base surface 164 corresponds to the 25 outside diameter of a foam tube length to be cut. The first and larger insert channel 154 is semicircular in end view with another surface 168 complementary to the base surface 164 to enable the channel 154 to be supported within the channel 152 when cutting a tube length supported within the channel 154.
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The radius of the inner surface 170 corresponds to that for the tube length to be cut within the channel 154. The second and smaller insert channel 156 is also semicircular to fit snugly within the insert channel 154. The channel 156 has an 5 inner surface 172 corresponding in radius to the radius of a tube length (not shown) to be supported by channel 156 during cutting. Because of the semicircular profile of the support surfaces of the three channels, the tube lengths to be cut are supported around their entire lower peripheries during 10 cutting. This is shown by the position of tube length 174 within the channel 152 during cutting. Hence the jig of the second embodiment has the same advantages obtained in use of the jig of the first embodiment while offering better support for tube lengths during cutting.
In third and fourth embodiments now to be described, different size but otherwise similar jigs form a kit for use in cutting tubes of different diameters.
In the third embodiment (Figure 23) three jigs in the form of channels 176, 178 and 180 are each of exactly the 20 structure of channel 42 and provide a kit of cutting jigs.
The jigs have similar features, as shown by the same reference numerals as in the first embodiment. These channels 176, 178 and 180 are, of course, each intended to be used separately from the other channels and indeed its shape prohibits it from 25 being used with the other channels. Each channel is of the correct inside profile shape to support in substantially undistorted manner a tube length of specific diameter during cutting.
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In a fourth embodiment (Figure 24), three jigs provide a kit in the form of channels 182, 184 and 186. Each channel is basically of the structure of each of jigs 176, 178 and 180 except that the product support surface 188 of each jig of the 5 fourth embodiment has the profile of base and side wall surfaces 162 and 164 of the channel 152.
Although embodiments of the invention have been described and illustrated in detail, it is to be clearly understood that the same are by way of illustration and example only and not 10 to be taken by way of the limitation, the spirit and scope of the present invention being limited only by the appended claims.
~u~ G JIG FOR COLLAPSIBLE CYLINDRICAL PRODUCTS
This invention relates to cutting jigs for collapsible cylindrical products.
Various cylindrical products require cutting to desired 5 lengths or to have their ends cut at desired bias or mitre angles to suit their particular requirements. To provide these results, cutting problems do not normally arise unless a cylindrical product is radially collapsible under a cutting blade or is already collapsed inwardly out of its cylindrical 10 configuration before cutting commences. One example of such a collapsible product is foam insulation tube as may be used for fitting around fluid flow pipes, e.g. water pipes, for thermal insulation purposes.
Foam insulation tube may collapse radially inwards and 15 may even crease away from its true cylindrical shape. To provide satisfactory results which not only appeal to the eye by providing the look of a professionally fitted thermal insulation around flow pipes, but also provide a fully efficient thermal insulation construction, it is essential for 20 successive lengths of foam insulation tube to be abutted cleanly with no gaps. When the path taken by a fluid flow pipe is substantially straight, successive foam insulation tube lengths need to have planar cut end surfaces which are normal to the axial direction of the lengths. Alternatively, 25 when flow pipes join at 45 degrees or 90 degrees, each cut length of foam insulation tube requires to have respectively, a 22.5 degree or a 45 degree mitre. In addition, to this, other cuts may be necessary to provide a snug fit for foam insulation tube. In one particular construction at a "T"
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junction, a "V"-shaped notch is required to be cut into the side of the tube providing the head of the junction. A
corresponding symmetrically tapered cut end is required for the tube forming the leg of the "T" junction so as to fit 5 properly into the notch. In another example, a three sided notch forming three sides of a rectangle is required in the insulation to receive one edge of a structural member where a flow pipe is secured to the member. Because foam insulation tube is readily collapsible under pressure of a cutting blade 10 or may have already assumed a collapsed state before cutting commences, it may be extremely difficult or even impossible to provide properly executed cuts in the forms discussed above. As a result, satisfactory abutting together of foam insulation tube lengths may be difficult to obtain without 15 leaving gaps which detract from the heat exchange efficiency of the total insulation. Indeed, unsatisfactorily abutted insulation tubes may even result in wastage of tubing.
It is essential to realise that foam insulation tube may be usefully employed around flow pipes for cold fluids as well 20 as for warm or hot fluids. Flow pipes for transporting cold fluids present cold outer surfaces upon which condensation forms in humid atmospheres. Not only does such condensation tend to drip onto floors and articles beneath, which can be destructive, but it encourages growth of mold and fungus upon 25 condensate-contacted surfaces. In such environments, foam insulation tube effectively acts as a vapour barrier around such flow pipes. However, condensation may still form upon exposed surfaces of flow pipes for containing cold fluids CA 02202731 1997-04-1~
when foam insulation tube lengths do not abut properly but leave gaps.
The present invention seeks to provide a cutting jig for collapsible cylindrical products and which may be used to 5 minimize or avoid the above problems.
According to one aspect, the present invention provides a cutting jig for a collapsible cylindrical product comprising a channel for accommodating the product, the channel having an inner surface profile provided at least partly by a 10 plurality of at least four product support surfaces comprising opposed side surfaces, and inclined surfaces extending downwardly and inwardly of the side surfaces, respectively, the channel provided with a pair of aligned guide surfaces for guiding a cutting tool on cutting strokes with the tool 15 extending across the channel.
As may be seen, a cutting jig according to the invention not only has side surfaces but also has inclined surfaces which extend from the side surfaces. Thus the cylindrical product which is to be cut is supported in more positions 20 around its lower periphery, and in locations which are more closely positioned together than would be the case if either a conventional mitre block or Vee block were used. The jig does therefore tend to maintain the product in, or restore it to, its cylindrical form around its lower regions and as a 25 result tends to stiffen the upper regions through which the cutting blade will initially pass.
For the product to be supported around its lower periphery in a truly cylindrical configuration, the product support surfaces should preferably all form tangents to a CA 02202731 1997-04-1~
common circle equal to the diameter of the outer periphery of the cylindrical product. In a preferred embodiment of the invention, the inner surface profile of the channel has a single inclined surface extending between each side surface 5 and a base surface and with this structure, the profile provides five support surfaces the base surface and inclined surfaces of which provide part of an octagonal shape.
Alternatively, two or more inclined surfaces are provided between each side surface and the base surface with each of 10 the inclined surfaces also forming tangents to the common circle. It follows that the support positions for the lower regions of the product increase as the number of inclined surfaces increase and, correspondingly, the distances between these support positions decrease.
A single inclined surface may be provided by a single jig element extending along the jig and between each base surface and a side surface. Alternatively, a plurality of coplanar inclined surfaces may be provided between each side surface and the base surface, these coplanar surfaces provided by a 20 plurality of spaced apart corner members with certain of the corner members located specifically to provide support for the product adjacent to the pair of guide surfaces.
A plurality of pairs of aligned guide surfaces may be provided to provide a variety of alternative mitre angles at 25 the ends of insulation tube and/or to provide different shapes for these ends. In such a particular structure, the plurality of corner members are located adjacent to each cutting position so as to hold the product in a substantially cylindrical condition for any particular cutting action.
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Where corner members are used for providing the guide surfaces, in a practical construction the channel has two side walls extending downwards to, and secured to, a base. The side walls and the base provide, respectively, the side 5 surfaces and base surface of the inside surface profile.
In a particularly preferred arrangement, the channel of the jig, as discussed above, also provides a support channel for an insert channel providing a part of the jig. The insert channel is insertable in nesting relationship within the 10 support channel for accommodating a collapsible cylindrical product which is smaller in diameter than the product to be accommodated by the support channel. The insert channel also has an inner surface profile provided at least partly by a plurality of support surfaces for the smaller diameter 15 product. These support surfaces include opposed insert side surfaces, an insert base surface and an insert inclined surfaces depending one from each side surface. The insert also has aligned guide surfaces which, when the insert channel is inserted into the support channel, are aligned with the 20 guide surfaces of the support channel for guiding the cutting blade on its cutting strokes. A registration means may be provided for insertion of the insert channel into the support channel so as to locate the insert channel only in one position of orientation and longitudinal location along the 25 support channel. Preferably, the cross-sectional shape of the smaller insert channel is similar to that of the first insert channel.
In a further preferred construction, another and smaller insert channel is provided which is insertable in nesting CA 02202731 1997-04-1~
relationship within the insert channel referred to above. The smaller insert channel is to be used for cutting collapsible cylindrical product which is smaller in diameter than the product to be accommodated and cut within the larger insert 5 channel.
According to a further aspect, the present invention provides a cutting jig for a collapsible cylindrical product comprising a channel for accommodating the product, the channel having an inner surface profile provided at least 10 partly by a concave support surface, the channel provided with a pair of aligned guide surfaces for guiding a cutting tool on cutting strokes with the tool extending across the channel.
The cutting jig according to the above further aspect has similar advantages to the cutting jig defined according to the 15 invention of the first aspect, as above.
The invention also includes a kit of cutting jigs. In one arrangement of the kit, each cutting jig comprises a channel having an inner surface profile provided at least partly by a plurality of at least four product support surfaces 20 comprising opposed side surfaces and inclined surfaces extending downwardly and inwardly of the inclined surfaces.
In another arrangement of the kit, each cutting jig comprises a channel having an inner surface profile, provided at least partly by a concave support surface. In both kit 25 arrangements, each channel is provided with a pair of aligned guide surfaces for guiding a cutting tool on cutting strokes with the tool extending across the channel.
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Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which :-Figures la to le are perspective views showing different 5 types of joints required of foam insulation tubing and as maybe provided using a cutting jig of any of the embodiments;
Figure 2 is an exploded isometric view of a cutting jig of a first embodiment;
Figure 3 is an end view of the exploded cutting jig of 10 the first embodiment;
Figure 4 is a plan view of a part of the jig of the first embodiment;
Figures 5 and 6 are views similar to Figure 4 of other parts of the jig of the first embodiment;
Figure 7 is a side view of a channel forming the largest part of the jig of the first embodiment and showing foam insulation tube accommodated in the channel and ready for cutting;
Figure 8 is a cross-sectional view through the channel 20 of Figure 7 taken along line 'VIII-VIII' in Figure 7;
Figure 9 is an isometric view on one side of the channel of Figure 7 and showing use of the channel for providing cut ends for the tube length structure of Figure la;
Figures 10 and 11 are views similar to Figure 9 and 25 showing use of the channel for providing cut ends for the tube length structures, respectively, of Figures lb and lc;
Figures 12, 13 and 14 are each similar to Figure 9, the Figures showing stages in providing cut surfaces for the tube length structure of Figure ld;
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Figures 15, 16 and 17 are views similar to Figure 9, the Figures showing stages in providing a cut notch for the tube length structure of Figure le;
Figure 18 is a perspective view showing a type of joint 5 required of foam insulation tubing and similar to the cut notch structure of Figure le;
Figure 19 is a view similar to Figure 9 and showing use of the channel of Figure 7 for cutting the cut notch structure of Figure 18;
Figures 20 and 21 are views similar to Figures 7 and 8, respectively, and showing an assembly of the largest part of the jig of the first embodiment with an insert channel in position and carrying foam insulation tube of smaller diameter;
Figure 22 is an end view of an exploded cutting jig of a second embodiment; and Figures 23 and 24 are end views of cutting jigs forming kits of cutting jigs according to third and fourth embodiments.
A cutting jig of the first embodiment to be described may be used to form any of the joints or abutting end configurations for foam insulation tube as shown in any of Figures la to le.
As shown in Figure la, a fluid flow pipe in the form of 25 a water pipe 10 is surrounded by foam insulation comprising lengths 12 of foam insulation tube which are abutted end to end. Ends of the tube lengths 12 are cut normal to the lengths of the tubes with adjacent ends 14 abutted close CA 02202731 1997-04-1~
together in intimate contact without formation of noticeable gaps between these ends.
In other Figures lb to le, the abutting ends of lengths 12 of insulation also have no gaps formed between them through 5 which heat could be transferred to or from the water pipes shown in those Figures. Avoidance of gaps also prevents formation of condensation with its attendant mold, fungal and other problems caused by damp.
In Figure lb, a right hand junction is formed between two 10 water pipes 14 and 16 which necessitates two tube lengths 12 having ends 18 cut at a mitred angle of 45 degrees to the axes of their respective lengths. In Figure lc two water pipes 19 extend one from the other at an obtuse angle of 135 degrees.
This necessitates the abutting tube lengths 12 having abutting 15 ends 20 at the bent position, each end 20 being cut at 22.5 degrees to the longitudinal axis of its length 12.
As shown in Figure ld, a "T" joint is provided between a water pipe 21 forming the head of the "T" and water pipe 22 extending downward from it. In this arrangement a length 23 20 of foam insulation tube requires a "V" shaped notch formed into it with tapering sides 24 generating a right angle at the junction between them. A length 26 of foam tube for location around the pipe 22 is required to be formed with a tapered end having sides 28 complementary in angle to the sides 24 for 25 abutting purposes.
Finally, in Figure le a water pipe 30 extends beneath a structure comprising beams 32, which might be wood or metal, (one only being shown) to which the pipe is secured by suitable brackets. Foam insulation tube lengths 33 CA 02202731 1997-04-1~
surrounding the pipe 30 need to pass beneath each of the beams 32 and in doing so require to be cut at the one side with a three sided notch 34 for accommodating the beam. The fit of the beam 32 within the notch avoids any undesirable gaps which 5 may allow for heat transfer to or from the water pipe 30.
In the embodiment as shown particularly in Figures 2 and 3, a cutting jig 40 is provided for cutting the various end shapes to foam insulation tube lengths 12 shown in Figure la to le. The jig 40 comprises a channel 42 which provides a 10 support channel for a first insert channel 44. The channel 44 is the larger of two insert channels, the smaller insert channel being channel 46.
The support channel 42 comprises two side walls 48 and a base 50 secured between the side walls with the side walls 15 extending upwardly from the base in spaced apart relationship.
The channel 42 is provided with a product support surface profile, i.e. for supporting foam insulation tube lengths.
This profile comprises two side surfaces 51 provided by the side walls 48 and a base surface 52 which faces upwardly 20 between the side walls. The distance between the side surfaces 51 corresponds to the outside diameter of a foam tube length 12, 23 or 26 (Figures lc and ld), so that the tube length will fit snugly between the side walls while supported upon the base surface 52. The support surface profile also 25 includes inclined surfaces 54 between the base surface and the side surfaces. These inclined surfaces 54 are provided upon corner members 56 which are of suitable triangular shape to fit into the corner formed between and a corresponding side wall 48 and the base 50 of the channel 42. The corner members CA 02202731 1997-04-1~
56 may be formed integrally with the channel 42, perhaps as a unitary molding.
As shown particularly by Figure 2, the corner members 56 and thus the surfaces 54 between each side wall and the base 5 are spaced apart longitudinally of the channel with the surfaces 54 lying in a single inclined plane. Thus, effectively, a single inclined surface extends between each side wall and the base. The inclined surfaces 54 together with the base surface 52 and the side surfaces 51 form 10 tangents to a common circle substantially equal in diameter to that of a length 12, 23 or 26 of foam insulation tube which is to be accommodated in the channel thereby supporting the lower part of the tube in its substantially cylindrical condition. As an alternative to the individual corner 15 members 56, single fillet members (not shown), having a triangular section, may extend from end to end of the channel 42, one between each side wall 48 and the base 50 so as to provide a continuous inclined support surface throughout the length of the channel.
As shown in Figures 2 and 4, the channel 42 has its side walls 48 formed with pairs of aligned guide surfaces for guiding a cutting blade on cutting strokes to be performed upon a length of foam insulation tube. A first pair of aligned guide surfaces is provided by aligned slots 60 which 25 extend downwardly into the side walls 48, the slots 60 being joined together by a slot 62 which is formed into the surface 52 of the base member. The slots 60 and 62 are formed at a mitre angle of 45 degrees to a longitudinal axis of the channel 42. Similarly a second pair of guide slots 66 in the CA 02202731 1997-04-1~
side walls 48 and inclined at a mitre angle of 67.5 degrees to the longitudinal axis of the channel are joined together by a further slot 68 in the base surface 52 so as to provide straight line cutting guides at that required angle.
In addition, as shown by Figure 2, but more particularly by Figure 7, laterally aligned "V" notches 70 are provided in the side walls 48, towards one end of the channel 42. Each notch has downwardly inclined sides 72 which meet at a right angle, as shown by Figure 7. The junction point 74 of the 10 sides 72 lies substantially at the same vertical height from the base surface 52 as the longitudinal axis 76 for lengths of foam tubing which are to be cut in the channel 42. At the other end of the channel 42, the two side walls have aligned notches 78 which follow a rectangular configuration which is 15 open at that end of the channel. Each notch 78 is provided by a downward edge surface 80 in each side wall 48 and a horizontal edge surface 82. The two edge surfaces 82 coincide in height from the base surface 52 to the uppermost extremity of the inner peripheral surface of a length of foam insulation 20 tube which is to be cut within the channel 42.
As will be noticed, particularly from Figure 4, the corner members 56 are spaced apart as already stated above, but are located in positions such as to support foam insulation tube lengths in locations close to any cutting 25 operation which may be performed using any of the guide surfaces provided by the channel 42.
The channel 42 may be used alone without either of the inserts 44, 46 for cutting foam insulation tube lengths of a specific diameter.
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As shown in Figures 7 and 8 with a tube length 12 disposed in cylindrical form within the channel 42, the side, base and inclined surfaces 51, 52 and 54 engage and support the outer peripheral surface of the tube length around its 5 lower regions.
During any cutting action which is to follow, the support provided around lower regions of the tube length to hold it in cylindrical shape stiffens these lower regions and, in consequence, tends to hold and stiffen the upper regions which 10 are not so supported. Thus resistance to collapse of the upper regions is provided thereby enabling, with a careful cutting action of a sharp blade, the provision of a precisely cut end shape to the tube length.
The cutting blade (not shown), which may be a sharp 15 knife or a saw, may be used to cut downwards along the guide surface line 83 offered by the end 84 of the channel (see Figure 9) to provide a cut end 14 for abutting length ends as shown in Figure la. Cutting downwards with a knife inserted as shown in Figures 10 and 11, respectively, into slots 60 or 20 66 and continuing down along cutting lines 85 and 87 into the grooves 62 or 68 respectively, will provide cut ends 18 and 20 for use in the type of abutting relationship of the lengths 12 shown in Figures lb and lc respectively.
Alternatively, where a "V" notch with sides 24 is to be 25 provided as shown in Figure ld, the cutting blade is cut downwardly into the tube length 23 while being guided by the pair of guide surfaces 72 (see Figure 12). The tube length 23 is of conventional construction in that it has a longitudinal slit 88 to enable it to be opened for positioning CA 02202731 1997-04-1~
around the pipe 21. For the cutting of the notch with sides 24, the tube length 23 is placed in the channel 42 with the longitudinal slit upwards so that the notch is cut downwards into the tube length from both sides of the slit. The bottom 5 of the notch corresponds to the junction positions 74 and which are thus disposed at opposite ends of the tube diameter.
The tube length 23 is then removed and the tube length 26 placed into the channel. The tube length 26 is then trimmed at its end to provide the tapered end with sides 28 by first 10 cutting down into the slot 60 along cutting line 85 as discussed above to provide a planar end surface 18 mitred at 45 degrees on the tube length. The tube length is then rotated by 180 degrees at the same longitudinal position in the channel and the cutting process is repeated. The repeat 15 cutting process will only cut through part 86 of the end region of tube (Figure 14) to provide the required tapered end with surfaces 28. The intersection point between the grooves 62 and 68 lies upon the median plane of the channel. After the tube length 26 has been rotated, and prior to the repeat 20 in the cutting process as shown by Figure 114, the correct position of the tube length 26 for the repeat cutting process is when the end surface 18 crosses the intersection point between the grooves 62 and 68.
When it is required to cut a three sided notch 34 (Figure 25 le) a tube length 33 is cut radially. For this, two cuts 90, spaced apart and corresponding to the width of the beam 32, are made using the guide surface 80 (Figure 15). The blade is then urged downwards in inclined fashion (for instance as shown by the curved direction arrow in Figure 16) to the guide CA 02202731 1997-04-1~
surfaces 82. The blade then cuts along the tube using the guide surfaces 82 for blade positioning. This provides a partially finished base surface 88 for the notch 34, the surface having an upwardly inclined end as shown by Figure 16.
5 The cutting blade is then guided in the opposite direction, i.e. towards the right in Figure 17, along guide surfaces 82 until the blade reaches the guide surfaces 80. This action removes the upwardly inclined end of the base surface 88 to give a completely planar base surface 88, thereby completing 10 the notch 34.
Should a notch be required which is longer than the lengths of the guide surfaces 82, then this may be accommodated by the channel 42. This may occur, for instance, when a building has a wider beam 32a such as provided by three 15 beams 32 nailed together side-by-side (Figure 18). A
sufficiently long notch 34a must be formed to correspond to the width of the beam 32a. For this long notch formation, the notch 34 as discussed above is made longer. This is easily performed (Figure 19) by placing the cutting blade 91 upon the 20 base surface 88 with the tube 33 retained in the channel 42.
The tube 33 is then moved longitudinally along the channel while using the blade 91, supported upon the guide surfaces 82, to cut along the tube so as to increase the length of the base surface 88. When the blade has travelled the required 25 distance to provide the correct length of the base surface for the notch 34a, the tube 33 is reversed longitudinally in position within the channel 42 and the blade is cut down into the tube to the end of the cut 93 for the base surface while being guided by the guide surfaces 80. The base of the notch CA 02202731 1997-04-1~
34a will then be coplanar with a tangent to the top of water pipe 30 and will fit comfortably against the beam 32.
As a result of the use of the channel 42, all cutting operations performed on foam insulation tube lengths are 5 performed with each length held in substantially cylindrical manner. Thus the cut edges are as desired with little or no resultant tendency for gaps to be formed between abutting surfaces of adjacent tube lengths after installation.
The first, larger insert channel 44 is for supporting 10 foam insulation tube lengths of smaller diameter than lengths to be cut in channel 42. As shown by Figures 2 and 21, the channel 44 has a product support surface profile provided by opposing side surfaces 92, a base surface 94 and an inclined surface 96 extending between each side surface and the base 15 surface (see also Figure 5). These surfaces are provided respectively upon side walls 98, base 100 and inclined side walls 102. The channel 44 is provided to nest snugly within the channel 42 with side walls 98 slidably engaging the side walls 48 as the insert channel 44 is slid down into the 20 nesting position in which the base 100 is supported by the base surface 52. Upper end surfaces 104 of side walls 98 do not extend up to the level of guide surfaces 82 but rather to the junction position 74 of guide surfaces 72. However, the base 100 may be of suitable thickness to locate the 25 longitudinal axis of foam insulation tube length of the smaller diameter at the level of the longitudinal axis position 76 for tube lengths to be cut in the channel 42 as described above. Hence, a "V" shaped notch cut into the smaller diameter tube and similar to the notch with sides 24 CA 02202731 1997-04-1~
(Figure ld) will have the junction position of its sides at opposite ends of the diameter of the tube length.
Registration means is provided to assemble the channels 42 and 44 together. This registration means comprises a 5 plurality (normally two) of registration pins 106 (Figure 2) provided in channel 44 for insertion within complementary bores 108 of the base surface 52. As shown particularly by Figure 4, bores 108 (and thus the pins 106) are disposed on the longitudinal centre line 110 of the assembly. However to 10 ensure correct relative angular orientation and longitudinal positioning of the channels, the bores 108 and pins 106 may be disposed offset to one side of the centre line 110 as shown in chain dotted outline for the bores 108. Alternatively, one of the bores 108 and the corresponding pin 106 from the one 15 end of the channel may be different from the spacing of the other bore 108 and its pin 106 from the other end.
The channel 44 has a pair of aligned guide surfaces for a cutting blade. These are provided by guide slots 112 in side wall 98, and when channels 42 and 44 are assembled the 20 slots 112 are aligned with slots 60 in channel 42 to provide a 45 degree mitre. The slots 112 are connected by groove 114 in the base surface 94. Similarly, slots 116 interconnected by groove 118 in the base surface 94 are aligned with the slots 66 in channel 42 with the channels assembled together 25 for forming a 22.5 degree mitre.
As shown in Figures 20 and 21, with channels 42 and 44 assembled, a foam insulation tube length 120 of smaller diameter than a tube length 12, is snugly accommodated within the channel 44 with its lower regions supported by surfaces CA 02202731 1997-04-1~
92, 94 and 96 to retain the tube length 120 in cylindrical condition during cutting. The tube length 120 may then be provided with either of the mitred cut ends, a " V" shaped notch, or a rectangular cut out similar to those described in 5 use of the channel 42.
For the cutting operation as shown by Figures 20 and 21, the axis of the tube length 120 is coincident in position to that of a tube length 12 when carried by channel 42.
In the event that an even smaller diameter foam 10 insulation tube length (not shown) should require cutting in the manner described for tube lengths 12 and 120, the second and smaller insert 46 is used (Figures 2 and 6). This channel is identical to the channel 42 in design (except that it is smaller) and has side walls 122, a base 124, and inclined side 15 walls 126 which provide a product support surface profile in the form of opposing side surfaces 128, base surface 130, and inclined surfaces 132. Registration means, comprising registration pins 134 in the base 124, register within registration bores 136 formed into the base surface 94. The 20 pins 134 and bores 136 are displaced relative to the corresponding pins 106 and bores 108.
The channel 46 is nestable within the channel 44 with the base 124 supported upon the base surface 94. Cutting blade guide slots 138 and 140 in side walls 122 and 126 become 25 aligned, respectively, to the guide slots 112 and 116 in the channel 44 for cutting purposes. Slots 138 are interconnected by a groove 142 formed in the base surface 130 while slots 140 are interconnected by groove 144 in the base surface. For reasons similar to those associated with the channel 44, the CA 02202731 1997-04-1~
base 124 of channel 46 is sufficiently thick to locate the longitudinal axis of a tube length to be cut at the level of the longitudinal axis position 76 for a tube length 12 when this is accommodated in the channel 42.
As mentioned above, the base 100 may be of suitable thickness to locate the longitudinal axis of a tube length of smaller diameter at the level of the axis position 76 for tube lengths to be cut in the channel 42. However, the smaller diameter tube length cannot extend up to the correct position 10 for a notch 34 to be cut using the guide surfaces 82 while locating the base of the notch coplanar with a tangent to the top of a water pipe to be contained within the tube length.
For certain differences in diameter, the compressibility of the foam will accommodate the difference between the positions 15 of the base of the notch and this tangent. Hence, if the channel 42 is used for cutting a 0.75 inch diameter tube length and the channel 44 is provided for cutting a 0.5 inch diameter tube length, then the discussed difference is 0.125 inches and is acceptable. However, for the even smaller 20 diameter tube length to be cut in the channel 46, the difference between the two positions increases and may not be acceptable. In this situation, for cutting a notch 34, by way of compromise, the channel 44 is dimensioned to place its surfaces 104 at the height corresponding to the plane of the 25 tangent of the tube to be fitted within the channel. This then may allow for an acceptable difference between the two positions for each of the largest and smallest diameter tube lengths.
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It should be appreciated that the greater the number of support surfaces, the better will be the support for the tube.
Although the above-described embodiment has five support surfaces, namely two side surfaces, two inclined surfaces and 5 a base surface, it is envisaged that more or fewer could be provided, though a minimum of four is believed to be required for adequate support.
In a second embodiment shown by Figure 22, a cutting jig lS0 has a channel 152 which provides a support for a first 10 insert channel 154 which, in turn, provides a support for a smaller insert channel 156. The channels 152, 154 and 156 have some of the same basic features, respectively, as channels 42, 44 and 46 of the first embodiment and of these same features, like reference numerals are used in the second 15 embodiment.
The second embodiment differs fundamentally from the first embodiment, however, in the shapes of the product support surfaces and the shapes of the channels to support those surfaces. In the case of the channel 152, a base 158 20 and sidewalls 160 between them define a smoothly contoured product support surface profile. This is formed by vertical planar surfaces 162 defined by each sidewall, the surfaces 162 extending tangentially into a semicylindrical base surface 164. The radius of the base surface 164 corresponds to the 25 outside diameter of a foam tube length to be cut. The first and larger insert channel 154 is semicircular in end view with another surface 168 complementary to the base surface 164 to enable the channel 154 to be supported within the channel 152 when cutting a tube length supported within the channel 154.
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The radius of the inner surface 170 corresponds to that for the tube length to be cut within the channel 154. The second and smaller insert channel 156 is also semicircular to fit snugly within the insert channel 154. The channel 156 has an 5 inner surface 172 corresponding in radius to the radius of a tube length (not shown) to be supported by channel 156 during cutting. Because of the semicircular profile of the support surfaces of the three channels, the tube lengths to be cut are supported around their entire lower peripheries during 10 cutting. This is shown by the position of tube length 174 within the channel 152 during cutting. Hence the jig of the second embodiment has the same advantages obtained in use of the jig of the first embodiment while offering better support for tube lengths during cutting.
In third and fourth embodiments now to be described, different size but otherwise similar jigs form a kit for use in cutting tubes of different diameters.
In the third embodiment (Figure 23) three jigs in the form of channels 176, 178 and 180 are each of exactly the 20 structure of channel 42 and provide a kit of cutting jigs.
The jigs have similar features, as shown by the same reference numerals as in the first embodiment. These channels 176, 178 and 180 are, of course, each intended to be used separately from the other channels and indeed its shape prohibits it from 25 being used with the other channels. Each channel is of the correct inside profile shape to support in substantially undistorted manner a tube length of specific diameter during cutting.
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In a fourth embodiment (Figure 24), three jigs provide a kit in the form of channels 182, 184 and 186. Each channel is basically of the structure of each of jigs 176, 178 and 180 except that the product support surface 188 of each jig of the 5 fourth embodiment has the profile of base and side wall surfaces 162 and 164 of the channel 152.
Although embodiments of the invention have been described and illustrated in detail, it is to be clearly understood that the same are by way of illustration and example only and not 10 to be taken by way of the limitation, the spirit and scope of the present invention being limited only by the appended claims.
Claims (21)
1. A cutting jig for a collapsible cylindrical product comprising a channel for accommodating the product, the channel having an inner surface profile provided at least partly by a plurality of at least four product support surfaces comprising opposed side surfaces, and inclined surfaces extending downwardly and inwardly of the side surfaces, the channel provided with a pair of aligned guide surfaces for guiding a cutting tool on cutting strokes with the tool extending across the channel.
2. A cutting jig according to claim 1, wherein the product support surfaces form tangents to a common circle.
3. A cutting jig according to claim 1, comprising opposing side walls and wherein the side surfaces are provided upon the side walls, the jig also comprising a base providing a base surface, and the side walls extend down to and are secured to the base, the inclined surfaces being provided by corner members extending between the side walls and the base.
4. A cutting jig according to claim 3, wherein in respect of each side wall, a plurality of spaced apart corner members are provided, each corner member comprising an inclined product support surface.
5. A cutting jig according to claim 4, wherein a plurality of pairs of aligned guide surfaces are provided for guiding a cutting tool, the guide surfaces provided at spaced locations along the channel and the corner members associated with each side wall are located to support the product for a cutting operation at each of the pairs of guide surfaces.
6. A cutting jig according to claim 1, wherein the product support surfaces provide a profile which is part of an octagon.
7. A cutting jig according to claim 1, wherein the channel provides a support channel and an insert channel is provided which is insertable in nesting configuration within the support channel, the insert channel provided for accommodating a collapsible cylindrical product smaller in diameter than the product to be accommodated by the support channel, the insert channel having an inner surface profile provided at least partly by a plurality of support surfaces for supporting the smaller diameter product, said support surfaces of the insert channel comprising opposed insert side surfaces, and insert inclined surfaces extending downwardly and inwardly of the side surfaces, and the insert channel provided with a pair of aligned guide surfaces which, with the insert channel inserted into the support channel, are aligned with the guide surfaces of the support channel for guiding the cutting tool on cutting strokes.
8. A cutting jig according to claim 7, wherein the insert channel has an outer surface profile complementary to the inside surface profile of the support channel.
9. A cutting jig according to claim 7, wherein registration means is provided for the support channel and insert channel to permit nesting insertion of the insert channel in the support channel only in one position of orientation and longitudinal location along the support channel.
10. A cutting jig according to claim 9, wherein the registration means comprises at least one projection in the insert channel and a cooperating recess in the support channel.
11. A cutting jig according to claim 7, wherein the insert channel is a larger insert channel and a smaller insert channel is provided which is insertable in nesting configuration within the larger insert channel, the smaller insert channel provided for accommodating a collapsible cylindrical product which is smaller in diameter then the product to be accommodated by the larger insert channel, the smaller insert channel having an inner surface profile provided at least partly by a plurality of support surfaces for supporting the product which is smaller than the product to be accommodated in the larger insert channel, the support surfaces of the smaller insert channel comprising opposed insert side surfaces, and insert inclined surfaces extending downwardly and inwardly of side surfaces, and the smaller insert channel provided with a pair of aligned guide surfaces which, with the insert channel inserted in the larger insert channel are aligned with the guide surfaces of the larger insert channel for guiding the cutting tool on a cutting stroke.
12. A cutting jig according to claim 11, wherein the smaller insert channel is provided with an outer surface profile complementary to the insert surface profile of the larger insert channel.
13. A cutting jig according to claim 11, wherein registration means is provided for the larger and smaller insert channels to permit nesting insertion of the smaller insert channel within the larger insert channel in only one position of orientation and longitudinal location along the larger insert channel.
14. A cutting jig according to claim 13, wherein the registration means for registering the smaller insert channel within the larger insert channel comprises at least one projection in the smaller insert channel and a cooperating recess in the larger insert channel.
15. A cutting jig for a collapsible cylindrical product comprising a channel for accommodating the product, the channel having an inner surface profile provided at least partly by a concave support surface, the channel provided with a pair of aligned guide surfaces for guiding a cutting tool on cutting strokes with the tool extending across the channel.
16. A cutting jig according to claim 15, wherein the concave support surface is semicylindrical.
17. A cutting jig according to claim 16, wherein the inner surface profile includes opposed planar support surfaces extending tangentially away from the two ends of the concave support surface.
18. A kit of cutting jigs for collapsible cylindrical products of different outside diameters, each cutting jig comprising a channel for accommodating its respective product, each channel having an inner surface profile provided at least partly by a plurality of at least four product support surfaces comprising opposed side surfaces, and inclined surfaces extending downwardly and inwardly of the side surfaces, the channel provided with a pair of aligned guide surfaces for guiding a cutting tool on cutting strokes with the tool extending across the channel.
19. A kit according to claim 18, wherein the product support surfaces of each channel form tangents to a common circle.
20. A kit of cutting jigs for collapsible cylindrical products of different outside diameters, each cutting jig comprising a channel for accommodating its respective product, each channel having an inner surface profile provided at least partly by a concave support surface, the channel provided with a pair of aligned guide surfaces for guiding a cutting tool on cutting strokes with the tool extending across the channel.
21. A kit according to claim 20, wherein, in respect of each channel, the concave support surface is semicylindrical.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2202731 CA2202731A1 (en) | 1996-04-19 | 1997-04-15 | Cutting jig for collapsible cylindrical products |
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA2,174,576 | 1996-04-19 | ||
| CA 2174576 CA2174576A1 (en) | 1996-04-19 | 1996-04-19 | Cutting jig |
| US71198196A | 1996-09-10 | 1996-09-10 | |
| US08/711,981 | 1996-09-10 | ||
| CA 2202731 CA2202731A1 (en) | 1996-04-19 | 1997-04-15 | Cutting jig for collapsible cylindrical products |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2202731A1 true CA2202731A1 (en) | 1997-10-19 |
Family
ID=27170141
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2202731 Abandoned CA2202731A1 (en) | 1996-04-19 | 1997-04-15 | Cutting jig for collapsible cylindrical products |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2202731A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2542760A (en) * | 2015-09-02 | 2017-04-05 | Gordon Harnett Tyronne | Tool |
| GB2612939A (en) * | 2021-11-17 | 2023-05-24 | Mark White Richard | Mitre box with removable saw guide slot sections |
-
1997
- 1997-04-15 CA CA 2202731 patent/CA2202731A1/en not_active Abandoned
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2542760A (en) * | 2015-09-02 | 2017-04-05 | Gordon Harnett Tyronne | Tool |
| GB2542760B (en) * | 2015-09-02 | 2021-07-28 | Plumbpal Innovations Ltd | Tool |
| GB2612939A (en) * | 2021-11-17 | 2023-05-24 | Mark White Richard | Mitre box with removable saw guide slot sections |
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| Date | Code | Title | Description |
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| FZDE | Dead |