GB2153507A - Heating apparatus for drying paint - Google Patents

Abstract

Heating apparatus suitable or drying paint, particularly on vehicles, comprising at least one heat lamp movably mounted upon a guide, drive means for moving the heat lamp along the guide, limiting means for limiting the extent of movement of the heat lamp in each direction along the guide and control means for controlling said guide means to cause the heat lamp to reciprocate between said limiting means. The apparatus is portable and and may readily be moved around a vehicle or from one vehicle to another. <IMAGE>

Description

SPECIFICATION Heating apparatus for drying paint This invention relates to heating apparatus suitable for drying paint and to its use in painting applicatons.

Coach painting of vehicle bodies and the like is generally conducted by spraying synthetic cellulose or acrylic enamels onto the surface of the body in a spray booth. In order to ensure an optimum finish it is normal practice to heat the surface to be painted before spraying and to bake the vehicle body after application of the paint to facilitate drying and curing of the paint coating. Spray booths may be designed as low bake ovens capable of reaching a temperature of about 80"C for accomplishing the necessary heating cycles.

Whilst the provision of such ovens is commercially viable in establishments which paint complete vehicles, the space, installation costs and cost of energy for heating the ovens is not viable in establishments where parts of vehicle bodies are to be painted, e.g. scratches, replacement panels or wings of a vehicle body. Establishments specialising in respraying portions of vehicle bodies generally employ infrared lamps which are statically mounted upon stands in order to supply the necessary heat to the specific parts of the vehicle body to be painted. A major disadvantage of using static infrared heat lamps of this type is that the lamps provide a fairly confined heating area and in order to heat a reasonable length of a vehicle body it is necessary to employ a large number of static lamps.It is not uncommon to respray a small area along a substantial length of a vehicle body which has been scratched or damaged in order to restore the body to its original condition.

The present invention provides apparatus for heating a surface which is suitable in paint drying applications in which the heat lamp is capable of controlled movement over the painted surface.

Therefore according to the present invention there is provided apparatus for heating a surface comprising at least one heat lamp movably mounted upon a guide, drive means for moving the heat lamp along the guide, limiting means for limiting the extent of movement of the heat lamp in each direction along the guide and control means for controlling said guide means to cause the heat lamp to reciprocate between said limiting means.

The heating apparatus of the invention is particularly suitable for coach painting of vehicles and the like. The apparatus generally comprises a vertical frame which extends at least the full length of the vehicle to be painted; a length of 14.5 feet (4.4 m) is sufficient for most cars and small vans although longer or shorter lengths may be used. The vertical extent of the frame is generally 4 feet (1.2 m) and provision may be made to adjust the height of the frame. The frame may be constructed with hinged or removable sections such that it may be folded or dismantled when not in use to facilitate storage.

At least one heat lamp is mounted for movement along the length of the frame. Preferably, the heat lamp is a sealed infrared heat lamp of the type commercially available for paint drying applications. However, any source of heat useful in the environment in which the apparatus is to be used may be mounted on the frame. In paint drying applications the heat source should be flameless in order to avoid a fire hazard. Heaters incorporating powerful high powered blowers are not desirable since a powerfui airflow should not impinge against a wet painted surface. Suitable heat lamps other than infrared lamps include thermoreactors utilising propane which emit radiant heat and gentle air convection. Examples of such heat lamps are commercially available under the trade name Sunkiss.Preferably, a battery of six to twelve heat lamps, more preferably infrared heat lamps, is mounted on the frame such that the complete battery of lamps moves on the frame as a single unit.

A drive means, for example a reversible electric motor, and associated control means is provided such that in use the lamp(s) will move backwards and forwards along the length of the frame. Preferably, adjustable limiting means are provided such that the lamp(s) may be controlled to reciprocate over any desired length of the frame. Means for varying the speed of the lamp(s) may be provided although in practice it has been found that a constant speed of 1 foot (0.3 m) per second is adequate for most applications.

In use, the apparatus is positioned adjacent the area of the vehicle to be painted and the limiting means are adjusted in order for the heat lamp(s) to traverse the area to be painted. In the case of a scratch along the length of the vehicle the limiting means will be positioned towards each end of the frame allowing the heat lamp(s) to traverse the full length of the vehicle. However, in other applications, for example painting a door panel, the limiting means will be adjusted such that the heat lamp(s) will traverse the shorter length of the door panel. After adjustment of the limiting means the apparatus is activated and the heat lamp(s) reciprocate along the area to be painted thereby heating the desired surface area. The apparatus may be left unattended after activation.When the surface to be painted has reached its desired temperature the apparatus may be switched off, and moved away if necessary, and a coat of paint applied to the desired area, for example by spraying. The heating apparatus is then repositioned and activated to facilitate drying and curing of the coated surface.

The painting/drying cycle may be repeated several times to achieve the desired finish.

It will readily be appreciated that the heat lamp(s) need not reciprocate along a horziontal axis and the apparatus may be designed for movement of the heat lamp(s) to take place in any desired direction, e.g. vertically or along an inclined guide. The frame of the apparatus need not extend vertically, for example the frame may be supported horizontally above the vehicle for spraying a vehicle roof. The apparatus may also be employed in other drying or painting applications by suitable adaption of the guide means and frame, e.g. paint spraying lorries, trains or aeroplanes and the like.

The apparatus of the invention may be movable, for example the guide means and frame may be mounted upon castors, in order to facilitate positioning of the heating apparatus relative to the surface to be painted. Such a construction is particularly suitable for use in small garages specialising in coach painting of damaged vehicles.

However, the guide means and frame may be permanently fixed, for example to a wall, or permanently mounted from the floor or ceiling and the object to be painted moved into the required position. This construction is applicable to larger establishments since it is readily possible to construct an oven-like environment employing several reciprocating batteries of lamps mounted upon suitably positioned frames.

The invention will now be described with reference to the accompanying drawings, in which: Figure 1 represents an isometric view of a heating apparatus in accordance with the invention, Figure 2 represents a side view of the heat lamps and drive means of the apparatus of Figure 1, Figure 3 represents an isometric view of a second embodiment of a heating apparatus in accordance with the invention, Figure 4 represents a side view of the heating apparatus of Figure 3, and Figure 5 represents an end view of the heating apparatus of Figure 3.

The drawings illustrate heating apparatus of the invention suitable for use in paint drying applications for cars and the like. The apparatus comprises a rectangular frame 2 having a length of 14.5 feet (4.4 m) and a height of 4 feet (1.2 m). The frame is vertically mounted upon feet 4 having castors 6. The frame may be mounted to the feet 4 in such a manner that the frame 2 is adjustable in height. A central rail 8 is mounted to the frame which acts as a guide means and a drive surface or a drive roller which will be described hereinafter. A battery 10 of lamps comprising eight infrared heat lamps 12, each bulb being for example 250 kW or more, secured to a support 14 is movably mounted upon a frame 2. The support 14 is mounted to the frame 2 by castor rollers 16 which allow smooth movement of the battery of heat lamps along the length of the frame.A reversible motor 18 is attached to the rear of the support 14. The motor 18 is connected to a drive roller 20 which bears against the driving surface of the central rail 8. The electric motor may be of variable speed although in practice it has been found that the drive roller may be geared to provide a linear speed of about 1 foot (0.3 m) per second to satisfy most applications. Power to the electric motor 18 and infrared lamps 12 is provided by an extensible power cable 22 connected to a control box 24. The control box 24 may be wired in order to switch on the compiete battery of infrared lamps or a selection of individual lamps.

Movable limiting means 26 in the form of sliding blocks are positioned upon the central rail 8 and a reversible switcn 28 is positioned upon the rear of the support 14 such that it may be activated upon contact with either limiting block 26. In use, the apparatus is activated causing the infrared lamps to emit radiation and the electric motor 18 to operate, thereby driving the support 14 bearing the battery of lamps in one direction along the frame. Movement of the battery of lamps will continue until the reversing switch 28 abuts the limiting block 26 which trips the reversing switch 28 causing tne electric motor to rotate in the opposite direction thereby moving the battery of lamps in the opposite direction along the frame. The battery of lamps will continue to reciprocate between the limiting blocks 26 until such time as the apparatus is switched off.

Figures 3 to 5 illustrate a further embodiment of the present invention in which identical parts of the apparatus with those in Figures 1 and 2 have been indicated with identical reference numerals.

The battery 10 of heat lamps 12 is vertically mounted as in the previous embodiment but is supported from below upon the frame 30. The frame 30 has end sections 32 which are pivotally mounted to a central section 34 thereby enabling the end sections 32 to be folded (see Figure 4) to facilitate storage, manoeuvrability and transport of the apparatus. The end sections 32 may be locked in the extended position by latch means 36, e.g.

toggle locks, bolts, etc. In a practical embodiment, the central section 34 may be 3 metres in length and the end sections 32 1 metre in length.

The frame 30 is provided with side tracks 38 which engage castor rollers 16 allowing smooth movement of the battery 10 along the length of the frame. The electric motor 18 drives a pair of drive rollers 20 in frictional engagement with the top surface of the frame 30. The battery 10 of lamps 12 may be mounted such that its height may be adjusted relative to the frame.

It will readily be appreciated that the 5 limiting blocks 26 may be adjusted to allow the lamps to traverse the full length of the vehicle or simply a short length, for example a door panel or wing.

The heat lamps may be adjusted to heat a broad band of the vehicle body or may heat a narrow band width.

It will readily be appreciated that the specific apparatus described above is simply one example of many constructions which may be made in accordance with the invention. For example, the lamps may be moved by hydraulic drive means, pneumatic drive 15 means, a sprocket-chain drive, rack and cog drive or a moving conveyor and the control of the movement and heating of the lamps may be regulated by a microprocessor.

The apparatus of the invention may be used in 20 many applications other than paint drying. For example, the apparatus may be used in greenhouses to reciprocate heat lamps and/or daylight bulbs in order to provide uniform heating conditions and/or lighting.

Claims (13)

1. Apparatus for heating a surface comprising at least one heat lamp movably mounted upon a guide, drive means for moving the heat lamp along the guide, limiting means for limiting the extent of movement of the heat lamp in each direction along the guide and control means for controlling said guide means to cause the heat lamp to reciprocate between said limiting means.

2. Apparatus as claimed in Claim 1, in which the heat lamp is supported by a frame.

3. Apparatus as claimed in Claim 1 or Claim 2, which comprises a plurality of infrared lamps mounted as a single unit which is movable along the guide.

4. Apparatus as claimed in any preceding claim, in which the limiting means are adjustable to vary the extent of movement of the lamp.

5. Apparatus as claimed in in any preceding claim, in which the drive means comprises an electric motor.

6. Apparatus as claimed in Claim 5, in which the limiting means cooperate with a reversible switch to reverse the motor.

7. Apparatus as claimed in any preceding claim, in which the guide means is substantially horizontal.

8. Apparatus as claimed in any one of Claims 1 to 6, in which the guide means is substantially vertical.

9. Apparatus as claimed in any preceding claim, which is mounted upon castors.

10. Apparatus as claimed in any preceding claim, in which the frame comprises one or more pivotally mounted sections which may be folded.

11. Apparatus as claimed Claim 1 substantially as herein described with reference to the drawings.

12. A method of heating a surface which comprises positioning the apparatus as claimed in any preceding claim adjacent said surface such that in use the heat lamp will irradiate said surface and activating the apparatus to cause the heat lamp to reciprocate between the limiting means and heat said surface.

13. A method as claimed in Claim 11, in which said heating is conducted immediately before and/ or after painting said surface.