Abstract:
The prevention from hardening upon storage of paste-like material by use of a lid having an inlet port, an outlet port, and a plastic bag attached to the inlet port. By expelling the air in contact with the paste-like material, the material can be prevented from hardening during storage. A similar lid is used in a pre-cleaning device situated between a dust-producing tool and a wet/dry vacuum. Dust-laden air enters the device through an inlet port and is discharged over a water filter. The pre-cleaned air is vacuumed to a wet/dry vacuum. The pre-cleaning process lengthens the useful life of the wet/dry vacuum. A hand-held sander is disclosed which provides for rapid change of sandpaper. The sander has a hollow upper handle component and a lower surface component which are held together with a latch. Depressing of a quick-release button allows separation of the two parts.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the filing date of applicant&#39;s provisional application, Ser. No. 60/999,779, having an effective filing date of Jul. 1, 2008, which is incorporated herein by reference. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    (Not applicable) 
       REFERENCE TO SEQUENTIAL LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISC 
       [0003]    (Not applicable) 
       BACKGROUND OF THE INVENTION 
       [0004]    1) Field of the Invention 
         [0005]    This invention is directed to container lids which have multiple utilities and to processes for using these lids. One disclosed utility is keeping paste-like and liquid compositions from becoming hard during storage. Another disclosed utility is pre-cleaning air from an industrial tool prior to entrance into a wet/dry vacuum cleaner. This invention is also directed to a hand-held sander which has a fast and simple release of the sandpaper which may be used in combination with the lid. 
         [0006]    2) Description of the Related Art 
         [0007]    In the prior art, a user obtained a can of paste-like or liquid material such as joint compound, glazier&#39;s putty, or paint, removed the lid, used a portion of the material, reapplied the lid, and stored the can until the next use. Over a period of time the material reacted with air in the can and the reaction caused the material to harden. One partial solution was to place a wet cloth into the can of paste-like material to slow down the hardening process. With or without the use of this partial solution, the material at least partially dried out. The user had to discard the partially used can or remove as much of the dried material as possible and attempt to mix the material to get a smooth consistency. Any remaining dry lumps mixed into the material creating an inconsistent texture which created an annoyance to the user when the material was applied to a surface. Dried material created gouges or streaks in the applied material and the dried lumps had to be removed by hand. It is easy to see that the prior art containers and methods used to store paste-like materials and liquids caused a waste of material and time. 
         [0008]    A more recent solution to this problem is disclosed in Published Application US 2003/0019539. In this document, a paint can contains a lid having an opening. An inflatable bladder can be inserted between the surface of the paint and the lid, the bladder may be pressurized so as to substantially fill the space between the paint and the lid, a tube connecting the bladder with the exterior of the can may be closed with a valve, and air trapped between the can and the expanded bladder may be released by means of pressure valve. This innovation substantially decreases the amount of air coming in contact with the paint and decreases the formation of a crust due to contact of paint with air. However, the air remaining within the can between the paint and the lid is under a pressure at least as high as ambient pressure and the “amount” of air (P×V) may be appreciable and may not entirely prevent the formation of the crust and its associated problems. 
         [0009]    U.S. Pat. No. 7,246,406 issued Jul. 24, 2007 to Yarbrough et al discloses a device for cleaning dust from air which comes from an industrial operation, such as cutting concrete with a saw. Over time, the filter media of this device and conventional wet/dry vacuum cleaners becomes clogged, the airflow slows, and the dust collection becomes less efficient. 
         [0010]    Hand-held sanders are known in the art. Changing the sandpaper on conventional sanders can be cumbersome and time consuming. The user must use a screw driver or clip down a fastener that attaches from the top side of either end of the sanding device. 
       BRIEF SUMMARY OF THE INVENTION 
       [0011]    One embodiment of this invention is directed to lids for cans of paste-like and liquid compositions wherein the lids contain air inlet and outlet ports. An airtight flexible bag is attached to an inlet port. In one alternative, with the lid in place vacuum is applied to the outlet port, resulting in air passing out of the space between the bag and the material in the container. As a result, ambient air passes into the bag and the bag assumes the contour of the paste-like material and presses against the material. Since the pressure of the air between the lid and the material is below ambient pressure, only a very limited “amount” (P×V) of air is in contact with the paste-like or liquid material and the material retains its desired consistency. The present invention uses a can lid of predetermined size to fit over containers of paste-like or liquid material. Conventional examples are one-gallon and five-gallon containers. 
         [0012]    In another alternative, a flexible air-tight bag is fitted into an inlet port and secured in place. With the use of a built-in, hand-operated air pump, air in container is forced out and ambient air is drawn into the bag. The air expands the bag, forcing the bag to assume the contour of the paste-like material, thus keeping air from contacting the paste-like material and the original consistency of the material is maintained. With repeated pumping, the pressure of the air within the container may made to be lower than ambient pressure so that the “amount” (P×V) of air available to react with the material is less than that which would be available had the bladder been filled using high pressure. 
         [0013]    The second embodiment of the present invention discloses a device for pre-cleaning air to be filtered by any conventional wet/dry vacuum. The multipurpose lid of the present invention contains an inlet port and an outlet port. The inlet port is connected to a source of dirty air via an intake tube. The outlet port is attached to a device for cleaning dirty air, such as a conventional wet/dry vacuum cleaner. The lid is attached to a conventional pail or other container which is partially filled with water. Dirty air is discharged from an inlet tube above the level of the water, proceeds into the water where most of the dust is captured, and is pulled out of the container by a vacuum unit which is part of the final cleaning system. By use of the above device, the air coming from the source of dirty air is substantially cleaned, thus prolonging the life of the final cleaning apparatus. 
         [0014]    The sander of the present invention may be used as the source of dirty air in the above embodiment. The sander contains a button on the top of the handle. When the button is depressed, the bottom surface component of the sander is disengaged and swings open. Used sandpaper is removed from the sander. Ends of sandpaper strips are fitted into front and rear slots and the bottom surface component is fitted back into place. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0015]      FIG. 1  is a cut-away side elevational view of one device used in the first embodiment of the present invention. 
           [0016]      FIG. 2  is a cut-away side elevational view of another device used in the first embodiment of the present invention. 
           [0017]      FIG. 3  is a cut-away side elevational view of a pre-cleaning device used in the second embodiment of the present invention. 
           [0018]      FIG. 4  is an elevational perspective view of a sander of this invention suitable for use with the pre-cleaning device of the second embodiment of this invention. The sander is in the closed condition. 
           [0019]      FIG. 5  is an elevational perspective view of the sander of  FIG. 4  in the open condition. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    The first embodiment of this invention is directed to keeping paste-like materials or liquids  2  in containers  4  such as pails or cans in a fresh condition during storage. Such material  2  is basically any material that is stored in the container  4  and has a tendency to dry out due to contact with air during storage. The container  4  is made of metal or plastic and is of conventional size of containers used in the art, such as one gallon or five gallon cans or pails. To accomplish this goal the invention uses a pre-sized lid  6 , usually of plastic, which snaps onto the top edge  8  of the container  4 . 
         [0021]    In a first alternative of the first embodiment, shown in  FIG. 1 , the lid  6  for a container  4  has an inlet port  10  and an outlet port  12 . A strong, flexible bag  14 , conveniently a plastic bag, is fit through a first, inlet, port  10  so that the mouth  16  of the bag  14  will be toward the outside  18  of the container  4  when the lid  6  and the container  4  are joined. The bag  14  and the port  10  may be securely fastened by simple friction fit using an internal ring  20  to hold the bag  14  in place. A first closure component  22  may be used. This component  22  fits into the ring  20  to provide an air-tight seal for use during storage. This component  22  preferably has a one-way valve (not shown) to allow air into the bag  14  but will prevent air from exiting the bag  14 . The outlet port  12  contains an inwardly extending tube  24  having a plurality of openings  26 . The second, outlet, port  12  fits snugly by friction fit onto a hose  28  connected to a vacuum device (not shown). A second closure component (not shown) may be used. This component fits into the outlet port  12  to provide an air-tight seal during storage. 
         [0022]    In a second alternative of the first embodiment, shown in  FIG. 2 , the lid  6  contains an inlet port  10  connected to a bag  14  by means of an internal ring  20  as in the first alternative. The inlet port  10  contains a one-way inlet valve (not shown) as in the first alternative for allowing ambient air to pass from outside the container  4  into the bag  14  but preventing escape of the air from the bag  14 . The lid  6  is equipped with an outlet port  30  having a one-way valve (not shown) such that air may leave the container  4  but may not enter the container  4 . In this alternative, the lid  6  is designed in such a way that it will operate as a diaphragm pump  32  which allows air to leave the container  4  when the pump  32  is depressed and prohibits air from reentering the container  4  when the pump  32  is released. In this alternative the lid  6  has a domical configuration within its structure that will allow the user to compress and decompress the structure multiple times to remove air from the container  4 . The inlet and outlet diaphragm valves operate in an opposing method. When the lid  6  is compressed the outlet valve allows air to freely pass out of the container  4  while the inlet valve does not. When the lid  6  moves into a decompression mode the inlet valve opens and the outlet valve closes. With the inlet valve open, ambient air passes into the flexible bag  14 . With enough compressions substantially all of the air between the flexible bag  14  and the container  4 /composition  2  is forced out through the outlet valve and flexible bag  14  is inflated with drawn-in ambient air. This air pump serves to evacuate air from the container  4  and, unlike the first alternative, does not require a separate vacuum source. The lower resulting pressure in the space between the material  2  and the lid  6  means that a lower amount of air is available to react with the material  2  than if the bag  14  has been inflated using positive pressure. 
         [0023]    In carrying out the process of the first embodiment, the user obtains a container  4  of material  2  which is subject to hardening when exposed to air during storage. Such material  2  may be joint compound, glazier&#39;s putty, paint, and the like. The container  4  may have an original, conventional lid or it may have the lid  6  of the present invention. The original lid, if present, is removed, the material  2  in the container  4  is partially used, the lid  6  of the present invention is applied, air is evacuated from the space between the bag  14  and the material  2 , and the container  4  is stored. By using this process the material  2  is not subject to reaction with air and is maintained in a paste-like or liquid condition. 
         [0024]    The second embodiment of this invention is described with reference to  FIG. 3 . This embodiment provides a device  34  for pre-filtering dirty air before it comes in contact with the conventional filter within a wet/dry vacuum device (not shown). The device  34  of this invention provides longer useful operation time of the wet/dry vacuum device without clogging the filter medium. This device  34  has a container  36  such as a pail and a lid  38 . The device  34  is based on the function of forcing dirty air into water  40  that is placed in the bottom  42  of the device  34 . A conventional wet/dry vacuum attached to the device  34  by an outlet tube  44  is used to create a vacuum which is used to bring the dirty air into the container  36  by way of an intake tube  46 . The origin of the dirty air may be an industrial tool  48  such as a sander or circular saw. The tool  48  is connected by means of an intake tube  46  having an appropriate inlet fitting  50  to the inlet port  52  of the pre-cleaning device  34 . An inlet tube  54  is connected to the inlet fitting  50  and ends slightly above the surface of the water  40  with a water level indicator  56  on the surface of the filtration water  40 . The outlet port  58  contains an outlet fitting  60  having vertical openings  62  around it. These openings  62  help prevent the transfer of water  40  into the outlet fitting  60  by causing the air to flow over a greater surface and by pulling air in from only a horizontally diffused direction. The outlet port  58  is attached by the outlet fitting  60  to an outlet tube  44 , which carries the pre-cleaned air to a wet/dry vacuum for further cleaning. 
         [0025]    In operation, the inlet tube  54  having the water level indicator  56  is attached to the inlet fitting  50  on the inlet port  52  of the lid  38 . The lid  38  is placed on the container  36  and water  40  is introduced into the container  36  until the user can see through the outlet port  58  that the water  40  is at the proper level. The intake tube  46  is attached to the inlet fitting  50  and to the tool  48 . The outlet tube  44  is attached to the outlet port  58  and to the inlet port of a wet/dry vacuum. The vacuum pump of the wet/dry vacuum is turned on and dirty air from the industrial tool  48  is drawn into the pre-cleaning device  36  of the invention. Most of the dust in the dirty air is trapped in the water  40 . Water  40  is prevented from exiting the pre-cleaning device by the vertical openings  62  in the outlet fitting  60 . In this manner, much less dust than originally present in the dirty air comes in contact with the filter of the wet/dry vacuum and the wet/dry vacuum exhibits a longer useful lifespan. 
         [0026]    A third embodiment of the present invention will be described with reference to  FIGS. 4 and 5 . The third embodiment is a hand sander  64  of such construction as to provide a quick and efficient way to replace the sandpaper  66 . A disengagement button  68  at the top  70  of the handle component  72  is operatively connected with a hook-like latch  74  which engages and disengages the handle component  72  and the bottom surface component  76  of the sander  64 . Upon depression of the button  68 , the bottom surface component  76  of the sander  64  is disengaged and swings open about a pivot point  78  at the rear of the sander  64 . Alternatively, the sander  64  may be configured with a removable bottom surface component  76  that may be attached to the handle component  72  with any form of fastener. In either alternative, the bottom surface component  76  is constructed with horizontal slots  80  at both ends  82 ,  84 . These slots  80  are for the purpose of accepting and holding the ends  86  of the sandpaper  66 . As the bottom surface component  76  is fastened back into the handle component  72 , the frictional force of attachment holds the sandpaper  66  in place. The handle component  72  is hollow and contains a connection for a vacuum hose  46  which may be connected to the pre-cleaning device  36  of the second embodiment. 
         [0027]    In practice, when a new strip of sandpaper  66  is desired, the user depresses the disengagement button  68  at the top  70  of the handle component  72 . The latch  74  is disengaged, allowing the handle component  72  to separate from the bottom surface component  76 . The used strip of sandpaper  66  is removed, the new strip of sandpaper  66  is inserted into the horizontal slots  80  at the front  82  and rear  84  ends, and the device  64  is snapped shut causing the sandpaper  66  to be held by friction between the handle component  72  and the bottom surface component  76 . Closing the device  64  causes the latch  74  to engage, thereby locking the handle component  72  and the bottom surface component  76  together. The sander  64  contains a fitting  88  for attachment to a vacuum hose as shown in  FIG. 3 . Thus the sander  64  is designed to be used in conjunction with the pre-cleaning device  34  described with reference to  FIG. 3 . 
         [0028]    Although the invention has been described and illustrated in detail, it is to be clearly understood that the same is by way of illustration and example, and is not to be taken by way of limitation. The spirit and scope of the present invention are to be limited only by the terms of the appended claims.