US 3864876 A
This invention relates to a fixture for a blast cleaning machine. The fixture is portable and adapted to be positioned on a metallic surface and secured thereto by electromagnets. A blast cleaning device is attached to the fixture, on a movable carriage, for movement along the fixture under control of a motor operated hoist. When cleaning is finished, the fixture is released and moved to the next segment of the surface to be cleaned. A linkage assembly assures that the blast cleaning device is maintained in intimate contact with the surface to be cleaned, and a set of opposed rollers assures that the blast cleaning device moves only in the intended direction.
Description (OCR text may contain errors)
1111 3,864,876 1451 Feb. 11, 1975 FIXTURE FOR A BLAST CLEANING MACHINE  Inventor: Philip H. Diehn, Mishawaka, Ind.
 Assignee: Wheelabrator-Frye,lnc.,
' Mishawaka, 1nd.
221 Filed: Apr. 15,1974
] App]. No.: 461,030
521 US. Cl. 51/9 M, 114/222 51 1m. 01. B240 3/06  Field of Search.'.'.... 51/8 R, 9 M; 114/222, 224; 118/207, 208, 305; 248/14, 206 173/32,
3,034,262 5/1962 Pawlson 51/9 3,396,423 8/1968 Hope 114/222 X 3,396,492 8/1968 Schenck 51/8 R 3,566,543 3/1971 Fogle 51/9 3,788,010 l/l974 Goff 51/9 Primary Examiner-Donald G. Kelly  ABSTRACT This invention relates to a fixture for a blast cleaning machine. The fixture is portable and adapted to be positioned on a metallic surface and secured thereto by electromagnets. A blast cleaning device is attached to the fixture, on a movable carriage, for movement along the fixture under control of a motor operated hoist. When cleaning is finished, the fixture is released and moved to the next segment of the surface to be cleaned. A linkage assembly assures that the blast cleaning device is maintained in intimate contact with the surface to be cleaned, and a set of opposed rollers assures that the blast cleaning device moves only in the intended direction.
11 Claims, 2 Drawing Figures PATENIEDFEB' 1 5 I H I LuL LLuJ:
HHHHW n MZ M ///////fl /////AA//////// FIXTURE FOR A BLAST CLEANING MACHINE BACKGROUND OF THE INVENTION This invention relates to a fixture for supporting surface finishing machines which utilize particulate material for cleaning or resurfacing. By causing the particulate material to strike the surface to be treated at sufficiently high velocities and in sufficient numbers, metal and other surfaces which require periodic maintainance can be cleaned or otherwise treated.
A particularly desirable form of apparatus for performing this task is one which is portable so that it may be utilized in circumstances where it would not be feasible to bring the surface to the machine for treatment. A specific use for such a portable apparatus is the cleaning of a vertical or other non-horizontal surface such as a wall, a platform or the like. Portable machines capable of performing abrasive blasting operations on such non-horizontal surfaces are known, for example, U.S. Pat. No. 3,034,262 to Pawlson, and my copending application, Ser. No. 443,389.
In the past, it was necessary to hoist such devices from a crane or from a'fixed catwalk and to move them along the surface to be cleaned. Such techniques are inconvenient and difficult to perform.
It is accordingly an object of'the present invention to provide a fixture which is itself portable, and which is easily and quickly affixed to the surface to be cleaned.
It is another object of the invention to provide a fixture which is easily disassembled and may be carried from one work site to another.
It is another objectof the present invention to provide a fixture which offers safe but quick adhesion to the surface to be cleaned.
It is another object of the present invention to provide a fixture for a ferromagnetic surface which is adapted to engage the surface by means of electromagnetic force.
It is yet another object of the present invention to provide a fixture which will assure intimate engagement of the cleaning device with the surface to be cleaned to prevent loss of abrasive or hazard to operating personnel.
It is a further object of the present invention to provide a fixture which will maintain the blast cleaning device parallel to the treated surface in the presence of surface irregularities.
It is a further object of the present invention to provide a fixture which is capable of moving the blast machine over the surface to be cleaned at an adjustable rate to optimize efficiency of the blast machine.
It is yet another object of the present invention to provide a fixture which is easily positioned along a desired location ofthe surface to be cleaned and which can be repositioned to a new area to be cleaned in a quick and efficient manner.
These and other objects and advantages of the invention will appear more fully in the concluding portion of this specification.
BRIEF DESCRIPTION OF THE DRAWINGS Fl. 1 is a front view of the fixture according to the present invention having a blast machine mounted thereon; and
FIG. 2 is an enlarged front view of the fixture of FIG. 1.
g 2 DETAILED DESCRIPTION Referring now to the figures, a fixture 10, according to the present invention is shown. The fixture includes a frame composed of two longitudinal members 12. The members 12 are preferably hollow and have a rectangular cross section. Such members are desirably 20 to 30 or more feet in length. Connecting the longitudinal members 12 at their ends I4, are a pair of transverse members not shown. The frame thus constituted by the longitudinal and transverse members forms a rectangular frame wherein the longitudinal members are desirably of a greater length than the transverse members.
Attached at each of the ends 14 is a leg 16 on which is mounted an electromagnet 18. The four electromagnets, one at each corner of the rectangular frame, are adapted to be energized by passing an electric current therethrough, in a manner well known by means of a wiring harness not shown. Energizing the electromagnets is effective for securing the rectangular framework to a ferromagnetic surface such as a wall, deck or other surface 20. Due to the intimate contact of the electromagnets against the surface, the fixture is rigidly secured in place when the electromagnets are energized.
Mounted for movement along the longitudinal merri bers is a carriage structure 22. The specific shape of the carriage will depend upon the type of blasting machine which is to be mounted thereto and the carriage illustrated in the drawings is exemplary only. The carriage 22 is mounted to the frame for linear movement, i.e., vertical movement in the figure along the length of the longitudinal members 12. As best shown in FIG. 2, movement of the carriage in any other direction is prevented by a plurality of opposed rollers. The rollers are mounted to the carriage but on different sides of the longitudinal member 12. For example, rollers 26 and 28 are mounted on the side opposite the roller 30. Likewise, rollers 32 and 34 are mounted on the side opposite the roller 36. Since all of the rollers are adapted for vertical movement, the carriage can be moved up and down but cannot be moved sideways or angularly.
A parallelogram swing linkage assembly is provided for mounting a blasting machine to the carriage 22. The linkage assembly includes a pair of forward links 40 and a pair of rear links 42. As best shown in FIG. 2, the upper end of the forward link 40 is connected to the carriage 22 while the lower end of the link 40 is at tached to the blasting machine housing 44.As indicated in the above referenced copending application, the blasting machine shown is of the type manufactured by Wheelabrator-Frye, Inc. of Mishawaka, Indiana. These devices are airless centrifugal blasting wheels and include a throwing wheel contained within a housing, such as housing 44. The wheel is driven by a motor 46 at high velocity for projecting particulate material fed through a controlled rate valve 48 onto a surface. The material fed through the valve 48 is supplied from a feed hopper 49.
In a similar manner, the rear links 42 are connected to the carriage at their upper ends while their lower ends are connected to the feed hopper 49. Connecting the blasting machine to the carriage through this linkage permits small movements normal to the direction of travel, i.e., perpendicular to the surface being treated. This move nent is desirable in order to permit the blast machine to follow surface irregularities or imperfections without catching thereon.
The blast machine utilizes a protective seal 50 adapted to intimately engage the surface for preventing the abrasive blast from escaping outside the blast area, causing a loss of particulate and danger to personnel. Because of the necessity for keeping the seal in intimate contact with the wall, and at the same time providing for some give," it is desirable to provide means for urging and maintaining the blast cleaning device against the surface 20. For this purpose, a pair of linear actuators 52 mounted to the carriage are provided. Typically these actuators are hydraulic or pneumatic cylinders effective for pushing the swing linkage towards the surface to be cleaned. When the seals of the blast device strike an irregularity or the seam in a metal surface, the machine is pushed slightly backward, and this is permitted by the linkage assembly. Once the irregularity has been passed, the actuators are effective for restoring the blast machine into firm contact with the surface.
In order to move the carriage and the blast machine attached thereto along the longitudinal members 12, a powered hoist is provided on the fixturing device. The hoist includes a motor 60 and a speed reducing gearbox 62 driving a sprocket wheel 64. A corresponding sprocket wheel 66 is disposed at the other end of the longitudinal member 12. Entrained about the sprocket wheels 64 and 66 is a roller chain 68 adapted to mate with the sprockets on the sprocket wheels. The ends of the roller chain are connected to the carriage by connectors 70 and 72. As will be apparent, operation of the motor is effective for propelling the carriage up or down the longitudinal frame members 12.
OPERATION From the preceding description it is believed that the operation and use of the device is apparent. However, for clarity, a brief operating description of the fixture in combination with the blast cleaning device will be provided. Prior to use, the blast cleaning device is mounted to the carriage of the fixture by attachment to the front and rear links. The fixture is then lifted by a crane, forklift truck or other device and positioned against the surface to be cleaned. When the fixture is in the approximate position desired, preferably with the members 12 vertical, the electromagnets are energized, causing the fixturing device to grip the surface 20 to securely hold itself and the blast cleaning device thereon.
The power hoist mounted on the fixturing device is then utilized to position the carriage at the top or bottom of its travel path and the blast cleaning device is switched on. The hoist is then utilized for moving the carriage mounted blast cleaning device along the length of the longitudinal members 12. The rate of movement of the blast cleaning device is controlled by the speed of the motor, and this rate is optimized to obtain the desired cleaning characteristics for the particular surface being treated. The linear actuators 52 and the linkage maintain a constant pressure on the blast machine to keep the seal parallel and in intimate contact with the surface 20. The linkage assures that the seal face remains parallel and in contact with the treated surface even when passing across surface irregularities such as seam welds.
After the carriage has traveled the full length of the longitudinal members, the blast machine will have cleaned a vertical path on the treated surface. The fixture is again supported by the forklift truck, crane or other device and the electromagnets are deenergized. The fixture device is repositioned to an adjacent area of the surface 20 and the sequence is repeated until the entire surface has been cleaned.
While I have shown and described embodiments of this invention in some detail, it will be understood that this description and illustrations are offered merely by way of example, and that the invention is to be limited in scope only by the appended claims.
1. A portable device for movably securing a blast cleaning machine to a ferromagnetic surface comprising:
a. a rectangular frame;
b. electromagnetic means on said frame for releasably securing said frame to said surface;
c. a carriage movable on said frame; and
(1. means for linking said blast cleaning machine to said carriage for movement therewith and for maintaining said machine in intimate contact with said surface.
2. A portable device according to claim 1 wherein said means for linking includes:
a. a swing linkage adapted to permit small movements of said blast cleaning device relative to said carriage in a direction normal to the direction of carriage movement; and
b. actuator means for urging and maintaining the blast cleaning machine in contact with said surface.
3. The device according to claim 1 wherein said frame includes:
a. two longitudinal members; and
b. two transverse members connecting said longitudinal members at their ends.
4. The device according to claim 3 wherein said electromagnetic means are mounted on legs attached to said frame at the ends of the longitudinal members.
5. The device according to claim 1 wherein said carriage includes a plurality of rollers adapted to engage said frame to permit linear movement along its length but to restrict movement in any other direction.
6. The device according to claim 3 wherein said carriage includes a plurality of rollers adapted to engage said frame to permit linear movement only in a direction parallel to the longitudinal members.
7. The device according to claim 2 wherein said actuator means are hydraulic cylinders.
8. The device according to claim 1 further including a motor driven hoist connected to said carriage for selectively moving said carriage on said frame.
9. The device according to claim 6 further including a motor driven hoist connected to said carriage for selectively moving said carriage on said frame.
10. A portable device for movably securing a blast cleaning machine to a ferromagnetic surface comprisa. a rectangular frame comprising two longitudinal members and two transverse members connecting said longitudinal members at their ends;
b. electromagnetic means mounted on legs attached to said frame at the ends of the longitudinal members for releasably securing said frame to said surface;
c. a carriage movable on said frame and including a plurality of rollers adapted to engage said frame to linkage means includes a swing linkage adapted to permit smallmovements of said blast cleaning device in a direction normal to the direction of carriage movement and actuator means for urging and maintaining the blast cleaning machine in contact with said surface.