FR2462200A1 - Spray gun paint container connection - uses locking ring on container with locking faces for lugs inside cover - Google Patents

Abstract

The catch for locking a paint spray gun (1) on top of a container (3) for the paint, uses an intermediate flanged metal ring (5) mounted on the rim of the vessel, inside a flanged cover (3) which supports the gun and encloses the dip tube (4). The cover has lugs (7) which project inwards and lock frictionally under locking strips (6) projecting from the metal ring. Each locking strip slopes upwards at an acute angle to the horizontal, and has an entry portion (6a) which slopes at a steeper angle at one end. Further along is a blocking face.

Description

Spray guns for spraying paint with pneumatic spraying frequently use buckets containing the paint to be sprayed; these buckets are detachably fixed under the spray gun, and a tube, connected to the paint supply opening of the spray gun and through which the paint is sucked to reach the spray nozzle, plunges until their background.

 The attachment of the bucket to the pistol must be secure, perfectly watertight, and easy and quick to handle.

 To this end, this fixing is done by means of a cover, which is itself fixed to the gun and comprises a tube capable of plunging to the bottom of the bucket when the latter is removably fixed to its cover.

The bucket can be fixed to the cover by screwing; the seal is obtained by an interposed seal, which allows the use of a thread which is not very small but nevertheless such that it is necessary to make at least one full turn; with a bucket full of paint, and a cover connected to the compressed air hose, the operations of screwing and unscrewing the bucket on the cover are not easy.

 This fixing can also be obtained by means of a stirrup, mounted on the cover, cooperating with pins provided on the cup, so as to lift the latter and press the edge of its neck against the bottom of the cover; the operation is easy but the construction complicated.

 It has also been proposed to make this attachment by means of ramps provided internally on the cover, or externally on the bucket, cooperating with pins provided externally on the bucket or internally on the cover. The embodiments known hitherto have the disadvantage of a small inclination of the ramps, necessary to obtain the desired seal, causing only a small axial displacement of the bucket which must cause the edge of the bucket to block against a seal of the cover bottom; therefore the tolerances on the thickness of the seal, on the position of the pins relative to the edge of the cup or of the seal, depending on whether they are provided on the cup or on its cover, and on the position of the ramps relative to the seal or at the edge of the cup, depending on whether they are provided on the cover or on the seal, are very weak to ensure a good seal; more the blocking of the bucket against the bottom of the cover depends on the screwing force.

 The subject of the present invention is a bucket for a paint spray gun, the attachment of which is of the latter type but arranged so as to avoid the aforementioned drawbacks.

To this end, the ramps of this attachment, cooperating with pins, comprise an input part with a strong inclination ensuring a significant axial movement between the bucket and its cover, an engagement part with a slight inclination preparing for blocking, and a part blocking with intermediate inclination and opposite direction, ensuring the blocking of the stud between it and a stop.

According to a preferred embodiment of the invention, these ramps are provided 6Ur a metal ring crimped inside the neck of the cup, and the corresponding pins are provided on the inner face of the cover.

 The seal between the edge of the cup neck and the bottom of the cover must simultaneously provide the desired seal and have an elastic action pushing the cup axially outwards, so as to maintain the blocking of the nipples between the blocking part of the ramp and the corresponding stop.

For this purpose, this seal can consist of a cylindrical part fitting onto the edge of the bucket and a C or S-shaped part ensuring the elastic force necessary for operation; it can be made of any plastic material resistant to paint solvents and having the desired elasticity, in polyamide for example.

Attachment is quick and secure; the seal is well ensured between the cup and its cover, whatever the inclination given to the gun, for spraying into a vertical direction.

The accompanying drawing shows by way of example an embodiment of the present invention
Figure 1 is an elevational view of the cup mounted on a gun, the cover-only being shown in section.

 Figure 2 is a sectional view, partial and on a larger scale, of the edge of the neck of the bucket attached to its cover.

 Figure 3 is a similar view of a variant.

 Figure 4 is a perspective view of a ramp.

Figure 5 is a developed view of this ramp.

 At the bottom of a conventional paint spray gun 1 is fixed the cover 2 of a cup 3, to the bottom of which plunges the paint suction tube LI, integral with said cover 2.

 On the edge of the cup 3 is externally crimped a metal ring 5, comprising at least two ramps 6, regularly distributed, cooperating with an equal number of pins 7 provided on the inner surface of the skirt of the cover 2.

 The ramps include an inlet part 6a, the inclination of which can be of the order of 300, an interlocking part 6b, the inclination of which can be of the order of 40, and a locking part 6c, whose inclination, in the opposite direction, can be of the order of 120, which keeps the corresponding stud 7 blocked between it and the stop 6d.

The seal 8 comprises a cylindrical part 8a, fitted with hard friction in the neck of the bucket 3, and extended upwards by a part 8b forming a spring, of section in the form of
S in one direction in Figure 2, and in the opposite direction in Figure 3; this latter solution is preferable if pneumatic pressure must prevail in well 3, above the paint level.

 A knurling 3a is provided at the lower part of the bucket 3 to ensure better grip.

 It is understood that the embodiment of the invention which has been described above with reference to the attached drawing has been given for information only and is in no way limitative and that numerous modifications can be made without departing from the scope. for this the scope of the present invention; thus, in particular, as indicated above, that the ramps 6 could be integral with the cover 2 and the pins 7 of the bucket 3.

Claims (4)

1. Bucket for paint spray gun in which the removable attachment of the bucket to the cover is obtained by means of ramps provided internally on the cover, or externally on the bucket, cooperating with pins provided externally on the bucket or internally on the cover , to cause by rotation of the bucket an axial displacement of the bucket in the direction of its cover until crushing of a joint between the edge of the neck of the bucket and the bottom of the cover characterized in that the ramps comprise an inlet part 6a with a strong inclination ensuring a large axial displacement between the bucket 3 and its cover 2, a latching part -6b with a small inclination preparing for blocking, -and a blocking part 6c with intermediate inclination and of opposite direction, ensuring the blocking of the nipple 7 between it and a stop 6d. 2. Bucket according to claim 1 characterized in that these ramps6 are provided on a metal ring 5 crimped outside the neck of the bucket 3, and the corresponding pins 7 are provided on the inner face of the cover 2. 3. Bucket according to any one of claims 1 or 2 characterized in that the seal 8 between the edge of the neck of the bucket 3 and the bottom of the cover2 breaks up with a cylindrical part 8a, fitted with hard friction in the neck of the bucket 3, and extended upwards by a part 8b forming a spring.  4. Bucket according to claim 3 characterized in that the part 8b of the spring-forming seal is S-shaped;