Convertible spray gun

Abstract: A spray gun (10) is easily convertible between a number of configurations. A removable fluid insert (14) may be placed in interchangeable (airspray and HVLP) spray heads (12) with the fluid insert being either a pressure fed device which depends downwardly from the front end of the gun into a pressurised cup or via a connection to a pressurised fluid source or may have an upwardly directed insert which will take fluid from a gravity cup. A simple air swivel (22) also adds ergonomic benefits.

Description: Air spray and HVLP (high volume low pressure) spray guns have been a popular way to apply paint and other coatings over the years. While conversion between various configurations has been possible with some models, such conversion has typically been expensive, difficult and/or performance compromising. A spray gun comprising the features of the prior art portion of claim 1 is known from WO 95/22409. The present invention will now be described, by way of example only. It is therefore an object of this invention to provide a spray gun which is easily converted between airspray and HVLP configurations as well as between pressure and gravity fed configurations. This object is achieved by a spray gun according to claim 1. A spray gun which may be either a conventional air spray gun or the HVLP variant of an air spray gun is designed with a number of features to enhance its ergonomics and general ease of use. As part of this ease of use issue a number of features contribute towards it success. First of all the gun is easily convertible between a number of configurations. A removable fluid insert may be placed in interchangeable spray heads with the fluid insert being either a pressure fed device which depends downwardly from the front end of the gun into a pressurised cup or via a connection to a pressurised fluid source or may have an upwardly directed insert which will take fluid from a gravity cup. The interchangeable spray head assemblies may be used for conventional air spray or HVLP with the HVLP spray head having restricted air passages to assure that the proper restricted air pressure is present at the front end of the spray gun in order to meet HVLP standards. This interchangeability and reconfiguration ability is easily accomplished in that the fluid insert slides into the spray head which is then inserted through the depending annular member on the front of the gun body and threaded into place with a nut. These and other objects and advantages of the invention will appear more fully from the following description made in conjunction with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the several views. Embodiments of the present invention will now be described by way of further example only and with reference to the accompanying drawings, in which: Figure 1 is a cross-sectional view of the spray gun of the instant invention for use with a pressurised cup. Figure 2 is a cross-sectional view of the spray gun of the instant invention for use with a gravity feed cup. Figure 3 is a cross-sectional view of the spray head of the instant invention. Figure 4 is an end view of the spray head of the instant invention. Figure 5 is a perspective view of the pressurised cup fluid insert of the instant invention. Figure 6 is another perspective view of the pressurised cup fluid insert of the instant invention. Figure 7 is a cross-sectional view of the pressurised cup fluid insert of the instant invention taken along line 7-7 of Figure 5. Figure 8 is a cross-sectional view of the pressurised cup fluid insert of the instant invention taken along line 8-8 of Figure 5. Figure 9 is a perspective view of the gravity feed fluid insert of the instant invention. Figure 10 is another perspective view of the gravity feed fluid insert of the instant invention. Figure 11 is a side plan view of the gravity feed fluid insert of the instant invention. A spray gun 10 which may be either a conventional air spray gun or the HVLP variant of an air spray gun is shown generally in Figures 1 and 2. As part of this ease of use issue a number of features contribute towards it success. First of all the gun is easily convertible between a number of configurations. A removable fluid insert 14 may be placed in interchangeable spray heads 12 with the fluid insert 14 being either a pressure fed device 14a which depends downwardly from the front end of the gun into a pressurised cup or via connection to a pressurised fluid source (Figure 1) or may have an upwardly directed insert 14b which will take fluid from a gravity cup (Figure 2). The interchangeable spray head assemblies 12 may be used for conventional air spray or HVLP with the HVLP sprayhead having restricted air passages 12a to assure that the proper restricted air pressure is present at the front end of the spray gun in order to meet HVLP standards. This interchangeability and reconfiguration ability is easily accomplished in that the fluid insert 14 radially slides into the spray head 12 guided by flange 14c (see Figures 5 to 11) which is then inserted through the depending annular member 16 on the front of the gun body 18 and threaded into place with a nut 20. Spray head 12 is merely rotated 180° and secured depending on which insert is desired for spraying. It is contemplated that various changes and modifications may be made to the spray gun without departing from the scope of the invention as defined by the following claims.

Claims: An air atomising fluid spray gun designed for interchangeable use between gravity feed and pressure feed, said spray gun comprising: a trigger; a body comprising a boss having first and second sides, said boss first side facing said trigger; a needle, said needle being controlled by said trigger and extending through said boss; and a spray head (12), which is attachable to said boss; characterised by a fluid insert (14), which is radially insertable into said spray head (12); said spray head (12) being rotatable between first and second generally diametrically opposed positions. The fluid spray gun of claim 1, further comprising a plurality of said fluid inserts (14). The fluid spray gun of claim 1, wherein said spray head (12) comprises air passages. The fluid spray gun of claim 3, wherein said spray head (12) air passages are restricted to make said spray gun an HVLP gun.

Inventors: ANDERSON RICHARD D, FLOER KEN C, SIMONDS JOHN R, ANDERSON, RICHARD D., FLOER, KEN C., SIMONDS, JOHN R.
Applicants: GRACO INC, GRACO INC.
Application year: 1998
Main classification: B05B7
IPC codes: B05B7, F16L27