Patent Application
20070205207
Not Applicable
Not Applicable
1. Field of the Invention
The present invention relates to plugs for temporarily closing apertures in a manufactured article to prevent contaminates from entering the aperture during transportation and storage prior to use; and more particularly to such plugs that prevent paint from entering the apertures when the article is painted.
2. Description of the Related Art
Hydraulic systems are controlled by valves that are inserted into a manifold through which hydraulic fluid is routed to and from the valves. For example, the manifold has an inlet aperture to which a hose from a hydraulic pump is connected for supplying pressurized fluid to the valves. Passages through the manifold lead from the inlet aperture to other apertures in which the valves are inserted. Other passages lead from those valve apertures to workport apertures to which hydraulic actuators, such as cylinders and motors, are connected. Fluid returning from the hydraulic actuators enters the manifold at different workport apertures connected to a return passage to an outlet aperture that is connected to the fluid reservoir of the hydraulic system.
A typical manifold is cast from metal and then machined to form the various apertures. Thereafter fabrication of the manifold is completed by painting the exterior surfaces. The finished manifold is stored and then shipped to a manufacturer of machinery that utilizes it as part of a hydraulic system.
During painting, storage and shipping, the apertures of the manifold are closed by temporary plugs to prevent paint and debris from entering and subsequently contaminating the hydraulic system into which the manifold is assembled. Typically, the temporary plugs are made of plastic which are either pushed or threaded into the apertures to secure them in place. The plugs are removed upon assembly of the manifold into the hydraulic system.
When the customer receives the painted manifold, the plugs are removed and proper hydraulic fittings are installed. In the course of removing the plugs, paint shards are created as the plug pulls the paint away at the interface between the edge of the plug and the surface of the manifold. The paint shards often contaminate the work space at which the plugs are removed. Because this work space may also be the place at which the various hydraulic components are connected to the manifold, the shards can enter those hydraulic components, thus contaminating the hydraulic system being assembled.
Therefore, it is desirable to provide a device for closing the apertures of a manufactured article in a manner does generate paint shards upon removal of the plugs during subsequent assembly of the article with other components.
A plug is provided for closing an aperture of a manufactured article prior to use to protect against debris entering the aperture. The plug includes a first portion that is arranged to fit into the aperture and secure the plug therein. A second portion is attached to the end of the first portion and has an exterior perimeter that fits outside the manufactured article. A band is attached to and extends radially outward from the exterior perimeter of the second portion, and is adapted to tear away from the second portion.
The plug is inserted into the aperture prior to painting and serves as a paint mask by covering part of the exterior surface of the manufactured article around the aperture. After painting, the band is torn away from the remainder of the plug, preferably before the paint has completely dried. The article then can be stored and shipped to a customer. The customer can remove the remainder of the plug after the paint has completely dried without producing paint particles which could contaminate the workplace.
With reference to
The flange 26 has a circumferential perimeter around which a removable band 28 extends. A weakened area is provided at the interface between the band 28 and the perimeter of the cap 24 that allows the band to tear away from the cap, as will be described. Specifically, a first score line 30 in the form of a V-shaped groove extends in a circle around the perimeter of the cap on the bottom side of the band 28 that is proximate to the body 20 of the plug. A second score line 32 extends around the perimeter of the cap on the upper surface of the flange 26 on the side of the band 28 that is remote from the body 20. The two score lines 30 and 32 are directly opposite each another providing a relatively thin piece of material there between by which the band 28 is attached to the perimeter of the cap 24. The band 28 has a pull tab 34 that projects upward above the top surface of the cap.
The plugs 16 are used to close the apertures 14 following the metal forming operations on the manifold 10. Specifically, after the apertures 14 have been machined, a plastic plug 16 is screwed into each aperture so that the bottom surface of the flange 26 abuts the exterior surface 33 of the exterior manifold 10, as shown in
The manifold 10 then is sprayed with paint that forms a coating 38 on the exterior surface 33. The paint also covers at least part of the exposed surfaces of the plugs 16.
With continuing reference to
When the band has been fully removed from the cap 24, a small gap 40 exists between the paint and perimeter of the flange 26 of the plug 16, as seen in
In some cases, the manufacturer of the manifold 10 applies only a coat of primer paint. The purchaser of the manufactured article applies the finish coat of paint in the desired color. In this situation, the manufacturer of the manifold does not remove the bands 28 from the plugs 16, but ships the article to the purchaser with the bands in place. Once the purchaser has applied the finish coat of paint, the bands 28 can be removed before that outer finish coat of paint has completely dried. Because the finish coat of paint is relatively soft at that time, any particles of the primer coat will be removed integrally with the finish coat material that adheres to the plug band.
The foregoing description was primarily directed to a preferred embodiment of the invention. Although some attention was given to various alternatives within the scope of the invention, it is anticipated that one skilled in the art will likely realize additional alternatives that are now apparent from disclosure of embodiments of the invention. Accordingly, the scope of the invention should be determined from the following claims and not limited by the above disclosure.
