Foldable Sandblasting Cabinet

Abstract

A collapsible sand blasting cabinet comprising a folding frame (10), the folding frame comprising a base (1000), a plurality of legs (1110) pivotally mounted to the base, a front frame (1200) pivotally mounted above the front of the base, a rear frame (1300) pivotally mounted above the rear of the base, a flexible enclosure (20) attached to the said folding frame in a way which allows internal access through the front frame, a perforated floor (3160) attached to the said base sandwiching the enclosure, and, a removable door adapted to seal said flexible enclosure at the front frame. The plurality of legs may comprise of two sets of legs that are hingedly mounted to the base. The front frame may comprise of a top section (1200b) and a bottom section (1200a), the top and bottom sections meeting at an angle of between 90 degrees and 180 degrees. The rear frame may comprise of an upper (1320) and a lower (1310) section, the sections being hingedly joined. The enclosure preferably includes a hopper (2200) and is composed of PVC.

Description

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a sandblasting cabinet assembly which is collapsible, lightweight and portable while still having a large working volume.

[0002] Sandblasting is a well known operation where a pressurized fluid medium, such as air or water, has an abrasive medium introduced into it and is directed at a work piece. The effect of this process is to abrasively clean the work piece.

[0003] Abrasive blasting can be performed in an open uncontained environment. In this operation there are several problems including the abrasive and waste dust creating a "dust storm" necessitating the need to wear protective clothing and the use of breathing apparatus, polluting the environment. Further in an open uncontained environment this is a total loss system meaning that the once abrasive is used it cannot be reused.

[0004] Because of these problems sealed cabinets have been used to contain the work piece. These cabinets are typically constructed from sheet materials and have an enclosure with an inbuilt hopper, a perforated or mesh floor to support the work piece, an access door, a viewing portal, a pair of apertures to which gloves are connected so the operator can handle the work piece, a connection for a dust extractor, a vent to relieve internal pressure (created by the dust extractor), a valve to remove spent abrasives and an abrasive blasting gun to carry out the operation.

[0005] Most available cabinets are made of sheet metal and are of a welded construction. They vary in size and cost, with the largest being many thousands of dollars and able to handle very large work pieces and the smallest bench top units costing several hundred dollars but having little useful work volume. Because of their size, larger more useful cabinets have been very expensive to buy as distribution costs become a major part of the cabinet's cost. Additionally, they occupy a significant amount of floor space and they are not easily moved between different sites. This is of particular concern in environments where sandblasting is not carried out on a continual basis.

[0006] Sandblasting cabinet assemblies have been proposed which can be non destructively disassembled or collapsed via a folding frame however they either take too long to disassemble or when collapsed are still relatively large.

[0007] It is an object of the present invention to overcome or ameliorate the problems seen in the prior art, or to at least provide an alternative.

[0008] The term "comprising" and its grammatical variations as used herein, is used in the inclusive sense of "having" or "including" and not in the exclusive sense of "consisting only of".

SUMMARY OF THE INVENTION

[0009] According to a first aspect of the invention, there is provided a collapsible sand blasting cabinet comprising a folding frame, the folding frame comprising a base, a plurality of legs pivotally mounted to the base, a front frame pivotally mounted above the front of the base, a rear frame pivotally mounted above the rear of the base, a flexible enclosure attached to the said folding frame in a way which allows internal access through the front frame, a perforated floor attached to the said base sandwiching the enclosure, and, a removable door adapted to seal said flexible enclosure at the front frame.

[0010] Preferably the plurality of legs comprises two sets of legs that are hingedly mounted to the base.

[0011] Preferably the front frame comprises a top section and a bottom section, the top and bottom sections meeting at an angle of between 90 degrees and 180 degrees.

[0012] Preferably the rear frame comprises an upper and a lower section, the sections being hingedly joined.

[0013] The enclosure is preferably includes a hopper and is composed of PVC.

[0014] Preferably the door is fastened to the front frame using fastening means, including retaining strips.

[0015] Preferably the door includes a viewing portal and two apertures, the apertures being adapted to have gloves inserted therethrough. The gloves are preferably composed of abrasion resistant material.

BRIEF DESCRIPTION OF DRAWINGS

[0016] FIG. 1 shows a perspective view of a sandblasting cabinet in accordance with the preferred embodiment.

[0017] FIG. 2 shows an exploded view of a sandblasting cabinet in accordance with the preferred embodiment.

BEST MODE OF CARRYING OUT THE INVENTION

[0018] The preferred embodiment of the sandblasting cabinet assembly of the present invention can be seen by referring to the drawings FIG. 1 & FIG. 2.

[0019] By reference to FIGS. 1 and 2 the folding frame 10 has a base frame 1000, left and right legs 1110L & 1110R, front frame 1200 and rear frame 1300. Base frame 1000 is composed of a rectangular or square metal sectioned tube 1115 which is bent to form the required frame shape as shown then welded to close the loop. Other parts will be attached to the base frame to perform other functions and details of these will be described in their relevant sections.

[0020] Attached to each side of the base frame 1000 are left and right legs 1110L and 1110R. These are also formed from rectangular or square metal tube to the required shape as shown. Legs 1110L and 1110R also incorporate a cross bar 1112, which acts to increase the leg stability. Crossbar 1112 is positioned so it also has the additional function of providing a pivotal stop for leg brace 1130 when the legs are folded up. Legs 1110L and 1110R are pivotally connected to the base frame 1000. Hinges 1010 are fixed to the inner vertical face of the legs and frame. The pivot point of the hinges 1010 is located so that the effect of pivoting the legs 1110L and 1110R is to move them away from the base frame 1000 to provide clearance between said legs 1110L and 1110R and base frame 1000. This clearance improves the nesting of the legs 1110L and 1110R when they are folded.

[0021] Leg brace 1130 comprises a pair of supports 1131 which on one end are pivotally connected to the legs 1110L & 1110R using pins or fasteners 1140. The other end of the leg brace 1130 has slots which are engaged into threaded studs 1030 secured in the base frame 1000 which are then secured with nuts or wing nuts (not illustrated) to hold the legs 1110L & 1110R in the open position. Leg brace 1130 is also cross-braced to increase stability. The leg braces 1130 are placed to clear the hopper portion of the enclosure assembly.

[0022] Attached above the front of the base frame 1000 is the front frame 1200. This is also formed from rectangular or square metal tube and is formed into two substantially `U` shaped sections 1200a (lower) and 1200b (upper), which are welded to form a bend 1205 of between 90 and 180 degrees approximately in the center of the front frame 1200. The purpose of the bend 1205 is to change the angle of the viewing portal 4200 so the operator's line of sight is directed towards the work piece (not illustrated). The front frame 1200 is pivotally connected to the base frame 1000 using hinges 1040. The hinge 1040 is connected to the front vertical face of the base frame 1000. The hinge 1040 is also fastened to the bottom of the front frame 1200. This connection sandwiches the front edge of the enclosure, the front lower enclosure retaining strip 1211 and the door lower retaining bracket 1230. Front frame 1200 is held in the opened position by front frame stays 1280.

[0023] Attached above the rear of the base frame 1000 is the rear frame assembly 1300. This is also formed from rectangular or square metal tube formed into two substantially `U` shaped sections 1310 (lower rear frame) and 1320 (upper rear frame), which are pivotally connected approximately in the center of the rear frame assembly 1300. The pivot between frames 1310 and 1320 is a pin with a loop formed on one end 1330. Lower rear frame 1310 is pivotally connected to the base frame 1000 using hinges 1050. The hinge 1050 is connected to the rear of the base frame 1000 and connected to the bottom of the rear lower frame 1310. Rear frame assembly 1300 tensions the enclosure system and final tensioning is achieved using tensioning stays 1340 which are located approximately halfway up the upper rear frame 1320. After the front frame 1200 has been locked into position with front frame stays 1280, the rear frame assembly 1300, the enclosure 20 and the tensioning stays 1340 work in unison to tension the enclosure.

[0024] The structural combination of the legs 1110L & 1110R with the base frame 1000, the front frame 1200 with the base frame 1000 and the lower rear frame 1310 with the base frame 1000 increase the strength and stability of the frame assembly 10 by doubling up the material section strength on each edge of the base frame's edges resulting in a frame assembly 10 that is strong, lightweight and simple to manufacture.

[0025] The enclosure assembly 20 in conjunction with the frame 10 and door 40 forms a sealed volume so the operator can perform the sandblasting task while keeping the dust and contaminants within the enclosure assembly 20. As illustrated the assembly 20 contains an almost rectangular working upper volume 2100 defined by the extents of the front frame 1200 and rear frame 1300 above the base frame 1000. The enclosure assembly 20 also contains a funnel shaped hopper 2200, which hangs below the base frame 1000 for the purpose of collecting and recycling the blast media. Below the hopper 2200 there is a pocket 2300, which has an opening flap 2310, which is used to remove the blast media from the enclosure assembly 20. The enclosure assembly 20 is fixed to the edges of the front frame 1200 using retaining strips 1211 and 1221 and the edge of the upper rear frame 1320 using retaining strips 1350. It is also attached to perimeter of the base frame 1000 by being sandwiched in between the base frame 1000 and the floor frame 40.

[0026] The upper section 2100 comprises a back wall 2101, left side wall 2102, right sidewall 2103 and a top wall 2104. A vacuum port 2107 is provided in one or more of the upper wall sections so a dust extractor can be attached to the enclosure. Port 2107 is composed of a flexible sheet with a central aperture secured to one of the walls. It can be seen that the flexibility will allow different sized vacuum nozzles to be inserted into the enclosure assembly 20. Enclosure tensioner lugs 2105 are incorporated on side walls of 2100 and a tensioning cord 2400 is fastened to each of these through the loops of the pins 1330 in the rear frame 1300. The tensioner ensures the rear frame 1300 and enclosure 20 collapses inwards when tensioning stays 1340 are released and enclosure side walls 2100 remain in tension and do not get caught in tensioning stays 1340 or rear frame 1300 as the frame is folding.

[0027] The lower section 2200 is an inverted pyramid shaped funnel. Attached to the bottom of the lower part of the funnel is a tubular pocket 2300 which can be closed off at its end for removal of blast media and waste.

[0028] The enclosure 20 is composed from a material which is lightweight, flexible, abrasion resistant and easily repairable, such as PVC.

[0029] A vent hole 2106 is disposed in the upper section 2100. The vent hole 2106 will also be provided with a chute 2108 leading to it to minimize dust seeping out the vent 2106.

[0030] The floor assembly 30 consists of a frame 3100, which follows the shape of the base frame 1000 and has a mesh floor 3160 attached to the top of the frame. Depending on the size of the frame it may have cross supports to increase the stiffness of the mesh 3160. An opening 3105 is included in the assembly so the blast media feed pipe (not illustrated) can be inserted into the blast media (not illustrated) in the hopper 2200 and to retrieve small objects, which may fall through the mesh. The opening 3105 could optionally have a closing door. Introduction of compressed air into the sandblasting cabinet 1 is via fittings 3210 fastened to the frame 3100 in one of the corners however this connection could be made directly into any part of the enclosure 20 or the door assembly 40. The floor assembly 30 is fastened to the base frame 1000 with enclosure 20 sandwiched in-between these two parts.

[0031] The cabinet is closed off by the door assembly 40, which is secured in an openable fashion to the front frame 1200. The door assembly is secured by putting the lower edge of the door assembly 40 into the door retaining brackets 1230 and locking the door closed with toggle catch 1240 however other forms of fastening or variations in design such as hinging the door or using toggle catches around the perimeter could be used.

[0032] The door 40 follows the shape of the front frame 1200 with a flange that follows the external edge of the front frame 20. A seal 1250 is attached to the edge of the front frame 1200 and provides a seal between the door 40 and frame 10 and enclosure assembly 20 so dust is kept within the unit. The upper portion of the door 40 is supplied with an aperture 4201 which carries a viewing window 4200 and the lower portion of the door 40 includes a pair of apertures 4202 which have flanges 4203 around them to which are attached the abrasion resistant gloves 4410 and glove extensions 4420. The gloves are composed of thick rubber or other abrasion resistant material. The viewing window 4200 is supplied so the operator can view the article being abraded and the gloves 4410 are provided so the operator can manipulate the article. The bent shape in the door 40 is provided so the operator's line of sight is directed down towards the area where the article will be held. The glove extensions 4420 are supplied as an extension of the gloves 4410 to allow the operator to reach all areas of the cabinet 1. The glove extensions 4420 are made of a filter fabric so that internal pressure will be relieved when a vacuum is applied to extract the dust.

[0033] While the above detailed description generally describes the preferred embodiment of the invention it should be noted that variations of detail design, material selections, manufacturing methods and configuration are possible within the spirit of the invention.

[0034] It is envisaged that other methods could be employed to hold the legs in an opened position. For example, folding table stays or other methods could be used to fasten the top brace 1130 to the base 1000.

[0035] The legs could be individual removable legs or a separate removable assembly.

[0036] The frame components of the base frame 1000, legs 1110L and 1110R, front frame 1200 and rear frame parts 1310 & 1320 could also be made with welded corner joints rather than bends or all parts could be molded from some type of plastic.

[0037] The flexible port 2107 could be replaced with fixed sized nozzles (not illustrated) constructed from solid materials with appropriate adapters to achieve the same result.

[0038] The top wall of 2100 or the entire enclosure could be made of a transparent material so that the interior of the enclosure would be well lit so an internal light would not be necessary. In an alternate embodiment of the invention parts of the fabric enclosure could be made from a breathable filter fabric to relieve internal pressures due to the use of a dust collecting vacuum. It should be noted that this invention should not be restricted to the venting methods described rather to the need to vent the enclosure while minimizing dust escaping.

Claims

1. A collapsible sand blasting cabinet comprising: a folding frame, the folding frame comprising a base, a plurality of legs pivotally mounted to the base, a front frame pivotally mounted above the front of the base, a rear frame pivotally mounted above the rear of the base, a flexible enclosure, the enclosure is attached to the perimeter of the front frame, to the rear frame and to the perimeter of the base. a removable door adapted to seal said flexible enclosure at the front frame. a perforated floor attached to the base frame inside the flexible enclosure.

2. A collapsible sand blasting cabinet as defined in claim 1, wherein the plurality of legs comprises two sets of legs that are hingedly mounted to the base.

3. A collapsible sand blasting cabinet as defined in claim 1, wherein the front frame comprises a top section and a bottom section, the top and bottom sections meeting at an angle of between 90 degrees and 180 degrees.

4. A collapsible sand blasting cabinet as defined in claim 1, wherein the rear frame comprises an upper and a lower section, the sections being hingedly joined.

5. A collapsible sand blasting cabinet as defined in claim 1, wherein the enclosure includes a hopper.

6. A collapsible sand blasting cabinet as defined in claim 5, wherein the enclosure is composed of PVC.

7. A collapsible sand blasting cabinet as defined in claim 1, wherein the door is fastened to the front frame using fastening means, including retaining strips (1211).

8. A collapsible sand blasting cabinet as defined in claim 7, wherein the door includes a viewing portal.

9. A collapsible sand blasting cabinet as defined in claim 8, wherein the door includes two apertures, the apertures being adapted to have gloves inserted therethrough.

10. A collapsible sand blasting cabinet as defined in claim 9, wherein the gloves are composed of abrasion resistant material.

11. A collapsible sand blasting cabinet according to claim 1 wherein the front frame and the rear frame are foldable onto the top surface of the base along the respective pivotal mountings on the base, the flexible enclosure being foldable as well by the rear and front frames' collapse; and the plurality of legs are foldable onto the bottom surface of the base.

12. Any one or combination of the parts of a collapsible sand blasting cabinet according to claim 1 in assembled or unassembled configuration.