GB2114859A - High intensity heat application means - Google Patents

Abstract

High intensity heat application means or unit (1, 1') is provided consisting of a low power heat source such as a fifty watt lamp (2) in front of a concave mirror or reflector (3) for directing radiant heat through a convergent lens system (4) to a focal point (F). Such units (1, 1') are shown incorporated in apparatus for the localised high intensity application of heat to a workpiece such as a double glazing window unit (8) (Figs. 2-7, not shown) for heat sealing it, the apparatus providing roller support (70, 71, 60, 61) (Figs. 2-3, not shown), for feeding a unit (8) relative to the heat application units (1, 1'). At least some of the heat application units viz: the units (1') are movable relative to the window unit (8) in obtaining complete heat sealing about the latter. The apparatus is capable of low power operation e.g. from an electric mains supply outlet. <IMAGE>

Description

SPECIFICATION High intensity heat application means The primary object of this invention is to provide heat application means for providing localised high intensity heating from a low power heat source and for use in affecting heat sealing, e.g. of double glazing units or for other purposes such as cutting various metals.

A further object of this invention is to provide such means in an apparatus or machine fgr carrying out the heat sealing of double glazing window units or similar operations in an automatic manner. Practical advantages of the invention especially as regards economic operation will be apparent from the following disclosure.

Basically according to this invention high intensity heat application means comprises a low power heat source such as a lamp or heating element and an optical system for converging radiant heat therefrom to a focal point for localising high intensity heat application.

Further in accordance with the invention apparatus or a machine for carrying out the heat sealing or a workpiece such as a double glazing window unit or for similar operations comprises support structure carrying means for feeding a workpiece in relation to one or more of said high intensity heat application means and effecting their relative movement in the linear or similar applications of the localised high intensity heat point or points to a workpiece.

In practice the construction and arrangement of the high intensity heat application means and of the apparatus or machine may be as follows reference being had to the accompanying diagrammatic drawings in which~ FIGURE 1 is an axial plane section of the heat application means or head, FIGURE 2 is a side elevation of the machine, FIGURE 3 is a sectional plan view, and FIGURES 21 7 are diagrams showing a typical sequence of operation of the apparatus.

Referring to FIGURE 1 the high intensity heat applicator means or head 1 is shown consisting of a housing 10 containing a low power heat source such as an infra-red lamp 2 or electric heating element mounted in relation to an optical system for converging radiant heat from the lamp 2 or element to a focal point F.

For this purpose the lamp 2 is shown mounted in front of a concave mirror 3 or parabolic reflector for directing radiant heat therefrom to a convergent lens system 4 to the focal point F.

From a lower power lamp or element e.g.

operating of fifty watts input, high temperature localised heat can be obtained at the point F, e.g.

of the order of 80000 especially for sealing purposes or for other operations such as cutting various materials as referred to below.

Considerably higher localised heat temperatures are possible, e.g. 1 6000C or more. In order to avoid excess heat due to the lamp 2 or element within the housing 10, the latter is vented at 1 1 and may also contain a motor driven cooling fan 5 at the rear behind the mirror 3 or reflector, or other suitable cooling means may be provided.

The head 1 or each of a pair or more thereof has particular application in effecting heat sealing of double glazing window units in an automatic manner in apparatus or a machine for the purpose as shown in FIGURES 2 and 3.

The machine generally comprises a central section 6 carrying the heads 1, 1' for heat application with support frames or racks 7, 7' or similar structure at each side carrying horizontal and vertical guide rollers 70, 71 for feeding a double glazing window unit 8 into the centre section 6 and receiving it therefrom.

For sealing by the apparatus the double glazing unit 8 consists of a pair of panes 80 spaced apart by spacer bars 81 at their edges, which spacer bars 81 are pre-coated with sealing material such as butyl mastic.

The assembled unit 8 is positioned against the rollers 70, 71 in the left-hand support frame 7 and is fed into the centre section 6 by power driven operation of the horizontal rollers 70. The unit 8 is supported by horizontal rollers 60 and vertical rollers 61 in the centre section 6. The vertical rollers 61, 71 may be laterally adjustable such as by screw mechanism according to the thickness of the unit 8 and its required alignment for movement through the section 6.

The heat application heads carried by the centre section 6 comprise a fixed pair of opposed lower heads 1 and a vertically movable pair of opposed heads 1'. The double glazing unit 8 is first fed forwardly until the lower end of its forward vertical edge portion is aligned with the fixed pair of heads 1 , the latter are switched on for the localised high intensity application of heat to the base of the leading edge portion of the double glazing unit 8 and the unit is fed forwardly at a suitable slow rate so that the localised heat application is caused to travel linearly for a short distance along the base edge portion of the unit 8.

The linear application of the localised heat in this way by the fixed heads 1 progressively softens the mastic material on each side of the pre-coated base spacer bar 81 which, after passage of the applied heat sets to effectively seal the bar 81 to the panes 80.

When the unit 8 has travelled a short distance D in this way, i.e. equivalent to the distance between the focal points F of adjacent heads 1, 1', the fixed heads 1 are switched off and forward movement of the unit 8 stopped, i.e. with its forward vertical edge portion and vertical spacer bar 81 therein aligned with the movable heads 1' which are switched on (see FIGURE 4). The movable heads 1' are then caused to travel vertically upwardly (FIGURE 5), i.e. up guideways 62 in the centre section 6 so as to linearly apply the high intensity localised heat up the forward edge portion of the unit 8. This effects complete sealing of the forward vertical spacer bar 81 to the panes 80.

When the vertically movable heads 1' have reached the upper limit of their necessary movement, the lower fixed heads 1 are switched on again and the unit 8 advanced forwardly (FIGURE 6) at a suitable rate of movement for the entire remainder of its length or horizontal extent so that both the lower and upper edge portions are subject to the localised heat application by the heads 1, 1' for fully sealing the upper and lower horizontal edges.

The lower fixed heads 1 are then switched off and the movable heads 1 then caused to travel downwardly (FIGURE 7) to finally effect complete sealing of the rearvertical edge of the unit 8 after which the completely sealed unit passes fully on to the right hand support roller frame 7' for removal from the apparatus.

The rate of movement of the movable heads 1' and of the unit 8 may be controlled by heat sensors responsive to the local temperature of the edge portion of the unit so that an appropriate rate of movement of the heads 1' or unit 8 for obtaining required sealing is effected in an automatically controlled manner. Such control also automatically adapts the operation of the apparatus to different sizes of units 8.

The sequence of movement of the heads 1' and unit 8 a nd switchi ng on and off of the heads 1,1' can be effected by suitably programmed control means and such sequence of operation and arrangement of the heads can be varied from the example described above. Thus the movable heads 1' can precede the fixed heads 1 to intially effect upward sealing of the forward edge portion of the unit 8 with final short distance base edge sealing performed by the fixed heads 1.

Mechanical means for moving the movable heads 1' may be of any suitable form such as screw or rack and pinion mechanism or may have a push and/or pull action such as by chain and sprockets or similar mechanism. Alternatively the heads 1' may be fluid pressure operated such as by hydraulic or pneumatic ram operation.

The low power electrical operation of the heads 1, 1' and the arrangement of the apparatus enables double glazing window units 8 to be sealed as a continuous process and with a high degree of economy as regards electric power consumption which can be from a normal mains outlet source.

The above described apparatus is capable of simple construction for carrying out high volume production of sealed units 8, e.g. at the rate of one unit per half minute or thereabouts dependent on size. However, if desired, a larger number of fixed and movable heads 1, 1' may be employed for heat sealing each unit more rapidly, such as by sealing all four edges substantially simultaneously.

Whereas the apparatus has been herein described and shown in FIGURES 2 to 7 as operating in an upright position for economy of floor space, it may be horizontally or otherwise arranged,e.g. for horizontal feed of double glazing units between upper and lower heads 1, 1'.

In addition to heat sealing, one or more of the heads 1, 1 ' may be employed for other sealing purposes or for cutting or welding plastic materials and also for cutting other materials such as wood or even glass.

Claims (6)

1. High intensity heat application means comprising a low power heat source such as a lamp or heating element and an optical system for converging radiant heat therefrom to a focal point for localised high intensity heat application.

2. Apparatus or a machine for carrying out localised heat application e.g. for heat sealing to a workpiece such as a double glazing window unit or for similar operations comprising support structure carrying means for feeding a workpiece in relation to one or more high intensity heat application means e.g. according to claim 1 and for effecting their relative movement in the linear or similar application of localised high intensity heat point or points to a workpiece.

3. Apparatus or a machine according to claim 2 wherein one or more of the high intensity heat application means is movable relative to the workpiece for the linear or similar application of localised high intensity heat point or points thereto.

4. Apparatus or a machine according to claim 2 or 3 wherein the support structure provides roller support for a workpiece such as a double glazing window unit for facilitating feeding movement of the workpiece in relation to the or each high intensity heat application means and discharge therefrom.

5. High intensity heat application means substantially as herein described with reference to FIGURE 1 of the accompanying drawings.

6. Apparatus or a machine for carrying out localised heat application e.g. for heat sealing to a workpiece such as a double glazing window unit when substantially as herein described with reference to FIGURES 1 to 7 of the accompanying drawings.