Abstract:
A quick change, self-contained vacuum system includes a debris container with an input opening and a pressure head that is configured to receive a fluid under a high pressure and which includes a low pressure inlet and an exhaust port. A guide pin may be provided along with a body that is selectively engageable with the pressure head and the guide pin. The body includes a bore having a first port communicating with the exhaust port of the pressure head and a second port communicating with the input opening of the debris container. The vacuum system further includes a shutoff valve that is operable in response to movement of the guide pin. In operation, movement of the guide pin relative to the body in one direction establishes locking engagement of the pressure head and the body along with a response by the shutoff valve to establish fluid communication between the exhaust port of the pressure head and the input opening of the debris container. Movement of the guide pin relative to the body in another direction provides for separation of the pressure head and the body and response by the shutoff valve to prevent fluid communication between the first port of the bore and the input opening of the debris container.

Description:
GOVERNMENT RIGHTS 
     This invention was made with Government support under Contract F33657-96-C2059 awarded by the Air Force. The Government has certain rights in this invention. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to an apparatus for collecting debris and, more particularly, to a vacuum system that may have a debris container that may be self-contained to prevent spills and may be quickly changed and that may have an adjustable vacuum pressure level. 
     Portable vacuum tools and hand tools having vacuum tool attachments are well-known useful devices for collecting debris during fabrication, assembly and general clean up activities, e.g., in a factory. A typical vacuum tool is shown generally at  10  in FIG.  1 . The vacuum tool  10  has a body  12  connected via a connector  13  to a high-pressure line  14  providing air pressure at about 90-100 psi, a low pressure outlet  16  at which vacuum action is attained and an exhaust pipe  18 . A debris container or bag  20  is mounted by a retention wire  22  (dotted line) on the exhaust pipe  18 . The bag  20  includes an opening (not shown) at the bottom that may be closed by a clamp  24 . In operation, high-pressure air from high-pressure line  14  is introduced into the body  12  through an orifice (not shown) which is configured to channel air in the direction of arrow  26  and into bag  20 . In this way, a vacuum is created at the low pressure outlet  16  that, when placed in the proximity of, e.g., a hand tool (not shown) creating debris, such as drill chips and the like, causes the debris to pass into the bag  20 . 
     Typical use of vacuum tools in a factory requires the repeated emptying and, if necessary, the replacing of filled vacuum bags  20 . For example, assembly mechanics are required to stop working on a particular task, leave a work station carrying the tool, and either empty the bag or, if the bag is in bad shape such as being tainted with drill lubricant, clogged with dust, or losing vacuum performance, replace it with a new one. In order to do so, mechanics typically obtain additional tools such as pliers, a screw driver, a piece of metal retaining wire, cleaning solvent, rags and protective hand gloves. 
     Emptying a filled vacuum bag can be an unpleasant, messy job since the bags may contain, for example, drilled chips from drill motors, such as the Hi-Speed Drill Kit, which are sharp and which may cause injury. To make matters worse, the chips are often mixed with lubricant and therefore tend to stick to anything they come in contact with. The vacuum bag  20  may be emptied by removing a the clamp  24  so that the contents may fall out. The bag  20  may then be inspected, and if it is determined that a new bag is required, the bag must be turned inside out until the retention wire is exposed, which may cause any chips left inside the bag to fall out. Use of the pliers and/or the screw driver may be required to remove the retention wire  22  and separate the bag  20  from the vacuum tool  10 . The bag  20  may then be slid out of the vacuum tool  10  and be replaced with a new one. When installing a new bag, the new bag must be turned inside out and slid onto the exhaust pipe  18  of the vacuum tool  10 . A new retention wire  22  is used to wrap an upper portion of the bag  20  onto the exhaust pipe  18 . Pliers are needed to twist the two ends of the wire together until it wraps around tight enough to hold the bag  20  in place. Usually it is the case that during the process of removing the old bag, some remaining chip debris falls out requiring additional clean up. For applications where debris is dry, such as floor dust or composite dust, replacing a new bag may cause some of these debris to become airborne which may cause a safety and/or health hazard concern in a working environment. 
     After the old bag is replaced, testing of the tool with a new bag is usually carried out to insure it is functioning properly. In addition where the tool is attached to a portable hand tool, the whole tool is usually tested to be sure it functions properly before mechanics return to their work station. Also, mechanics&#39; hands may contact the oil-tainted chips and may need to be washed before they can go back to their work station to resume their tasks. 
     In confined areas, where access is limited and getting in or out is not easy, mechanics may tend to wait until the next break time to empty or replace a vacuum bag. In such a situation, the continuous use of a filled bag may lose up to 75% of the vacuum performance. 
     Accordingly, there is a need for an improved vacuum system that is self-contained to prevent spills and is quickly changed in order to increase the time available for performing more valuable tasks. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the present invention, a quick change, self-contained vacuum system comprises a debris container having an input opening and a pressure head that is configured to receive a fluid under a high pressure and may have a low pressure inlet and an exhaust port. A guide may be provided along with a body that is selectively engageable with the pressure head and the guide. The body comprises a bore having a first port communicating with the exhaust port of the pressure head and a second port communicating with the input opening of the debris container. The vacuum system further comprises a shutoff valve that is operable in response to movement of the guide. In operation, movement of the guide relative to the body in one direction establishes locking engagement of the pressure head and the body along with a response by the shutoff valve to establish fluid communication between the exhaust port of the pressure head and the input opening of the debris container. Movement of the guide relative to the body in another direction provides for separation of the pressure head and the body and response by the shutoff valve to prevent fluid communication between the first port of the body and the input opening of the debris container. 
     In another aspect of the invention, a quick change, self-contained vacuum system, is presented. The self-contained vacuum system may comprise a movable pressure head that is configured to receive a fluid under a high pressure and that comprises a low pressure inlet, an exhaust port and a guide pin extending away from the pressure head. An inner member that comprises a bore having a first opening that is in fluid communication with the exhaust port of the pressure head and a second opening that is in fluid communication with the first opening. The inner member may be operatively engageable with the guide pin of the pressure head. An outer member may be provided which is in slidable relationship with the inner member and the pressure head. The outer member may comprise a helical slot that is dimensioned and configured to receive the guide pin of the pressure head whereby the guide pin may move therewithin and the outer member may further comprise an aperture. A shutoff valve may also be provided that is operable in response to movement of the guide pin. In operation, selective movement of the guide pin relative to the outer member in one direction causes movement of the shutoff valve for establishing fluid communication from the exhaust port of the pressure head, through the first and second openings of the inner member and to the aperture of the outer member. Movement of the guide pin relative to the outer member in another direction causes movement of the shutoff valve for preventing fluid communication from the exhaust port, through the first and second openings of the inner member and to the aperture. 
     In a further aspect of the invention, a quick change, self-contained vacuum system having a debris bag, comprises a movable pressure head that is configured to receive a fluid under a high pressure and includes a low pressure inlet, an exhaust port and a guide pin extending away from the pressure head. The vacuum system also comprises an inner member that includes a sleeve having a bore that includes a first opening that is in fluid communication with the exhaust port of the pressure head and a second opening that is in fluid communication with the first opening. The inner member may be operatively engageable with the guide pin of the pressure head and the inner member also may comprise a mounting portion including radially spaced slots and an outer surface having an increasing diameter. The vacuum system also includes an outer member comprising a sleeve disposed in concentric relationship with the inner member and the outer member comprises a helical slot dimensioned and configured to receive the guide pin of the pressure head whereby the guide pin may move therewithin. The outer member further comprises an aperture, an end disposed within the input opening of the debris bag and an inner tapered surface disposed at an angle with respect to a central axis of the outer member which corresponds to that of the outer surface of the inner member. A shutoff valve that is operable in response to movement of the guide pin is also provided. In operation, selective movement of the guide pin relative to the outer member in one direction causes movement of the shutoff valve for establishing fluid communication from the exhaust port of the pressure head, through the first and second openings of the inner member and to the aperture of the outer member. Movement of the guide pin relative to the outer member in another direction causes movement of the shutoff valve for preventing fluid communication from the exhaust port, through the first and second openings of the inner member and to the aperture of the outer member. 
     These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagram showing a prior art vacuum tool; 
     FIG. 2 is an exploded view, in perspective, of a quick change, self contained vacuum system in accordance with one embodiment of the present invention; 
     FIG. 2 a  is a partial view, in perspective, of an optional sealing mechanism for the vacuum bag of FIG. 2; 
     FIG. 3 a  is an end view of a pressure head in accordance with the embodiment of FIG. 2; 
     FIG. 3 b  is a sectional view taken along line  3   b  of FIG. 3 a ; 
     FIG. 4 is a cross sectional view of the quick change, self-contained vacuum bag of FIG. 2 when assembled; 
     FIG. 5 is a perspective view, partially in phantom, of a pressure head, an inner member and an outer member in an open state in accordance with the embodiment of FIG. 2; 
     FIG. 5 a  is a sectional view taken along line  5   a  of FIG. 5; 
     FIG. 6 is a perspective view, partially in phantom, of a pressure head, an inner member and an outer member in a nearly closed state in accordance with the embodiment of FIG. 2; 
     FIG. 6 a  is a sectional view taken along line  6   a  of FIG. 6; 
     FIG. 6 b  is a top view of the pressure head and the inner member of FIG. 6; and 
     FIG. 7 is a series of diagrams showing various embodiments of a shut off valve usable in the practice of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following detailed description is of the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims. 
     An improved vacuum system is provided by the present invention that is self-contained to prevent spills and is quickly changed in order to increase the time available for performing more valuable tasks. The vacuum system may be employed in connection with a hand tool such that it may allow a mechanic to quickly empty and/or replace the bag without fear of spillage. In particular, rather than requiring movement of a hand tool with a debris container to a remote location, the vacuum system of the present invention allows quick release of the vacuum bag and containment during movement thereof. This is in order to prevent spills and to reduce loss of work time associated with prior art devices. 
     Referring to FIG. 2, a quick change, self-contained vacuum system is illustrated in an exploded state and is shown generally at  100 . The vacuum system  100  may comprise a pressure head  102 , a debris container  104 , and a body  106  that may comprise an inner member  108  and an outer member  110 . 
     As best seen in FIGS. 3 a  and  3   b  the pressure head  102  may be generally cylindrical in outer configuration and may be composed of any suitably strong and durable material such as a metallic substance. One suitable material may be aluminum for its well-known strength, durability and ease in manufacture. The pressure head  102  may comprise a cylindrical wall  111 , a high-pressure interface  112 , a low pressure inlet  114 , an exhaust port  116 , a central bore  117  and a guide or guide pin  118 . 
     The high-pressure interface  112  may comprise a high-pressure connector  120 , a control valve  122  (FIG. 3 b ) and a high-pressure outlet  124 . The high-pressure connector  120  is configured in a well-known manner to receive a fluid, such as air, at a high pressure, e.g., between approximately 90 and 100 psi. Typically, in a manufacturing environment, high pressure air is available on a network basis as “shop air” and is communicated by, e.g., a flexible hose with a connector (both not shown) which is capable of mating with the connector  120 . 
     The control valve  122  may be provided for varying the flow of fluid into the central bore  117  of the pressure head  102  and comprises a lever  126  (FIG. 3 a ). Movement of lever  126  allows a mechanic to vary the volume of air passing through high-pressure outlet  124  and, in turn, vary the pressure level provided at the inlet  114  where removal of debris from a work area, such as from drill bits, occurs. It has been found that a pressure level of between approximately three (3) and eight (8) inches of mercury is suitable for the vacuuming of drilled chips from most hand-held drill motors (not shown). Varying the pressure level at inlet  114  also allows a mechanic to accommodate for different chip sizes and thereby optimize tool performance versus air consumption. In particular, it will be appreciated that where the chip sizes tend to be relatively smaller, a mechanic may adjust the lever  126  to reduce the flow of air out of high-pressure outlet  124  and thereby “save” air. However, the pressure level at inlet  114  would be somewhat higher than that which would be required to move relatively larger chip sizes. 
     Also, it will be appreciated that additional appropriate structure may be provided so that the inlet  114  may communicate with the surrounding volume of a drill bit of a drill motor. Further details of such a structure are provided, for example, in U.S. Pat. No. 5,033,917 to McGlasson et al, the entire contents of which is incorporated herein by reference. 
     The high-pressure outlet  124  may be oriented so that the fluid escapes in the direction of exhaust port  116  thereby creating a low pressure at the low pressure inlet  114 . Preferably, a central axis  127  of the high-pressure outlet  124  is disposed at an angle which ranges between approximately 6 and 7 degrees with respect to a central axis  129  of the pressure head  102 . 
     The guide pin  118  may be composed of a strong and durable material such as a steel and is mounted in a recess  128  of the cylindrical wall  111 . The guide pin  118  is preferably dimensioned to extend radially outward a sufficient distance from the cylindrical wall  111  so that, when the pressure head  102  is assembled to the body  106  (described below), the guide pin  118 , and in turn the pressure head, may be slid or rotated by hand with respect to the body. 
     Referring again to FIG. 2, the debris container  104  may be preferably a debris bag  130 , however, it will be understood that other suitably configured debris containers may be employed in the practice of this invention. The debris bag  130  may be composed of, e.g., a cloth or woven material such as a woven nylon, or paper, and may function as a filter so that debris carried by the high-pressure fluid from the pressure head  102  will be screened from the high-pressure fluid. The debris bag  130  may be generally rectangular in outer configuration and may comprise an input opening  132  defined by a rim  133  and a sealable bottom portion  134 . The input opening  132  may be dimensioned to fit over the outer member  110  (described in more detail below), is preferably tubular in configuration and extends from the debris bag  130 . 
     The sealable bottom portion  134  may comprise an open end  136 , a tab portion  138  and a well-known hook and loop fastener  140  such as that sold under the mark VELCRO. The hook and loop fastener  140  may include a hooks portion (not separately numbered) mounted to the tab portion and loops portion (also not separately numbered) mounted to the bottom portion  134 . In order to close the debris bag  130 , the hooks portion and the loops portion are pressed together. 
     In an optional embodiment, as illustrated in FIG. 2 a , rather than using a tab portion and a hook and loop fastener, a tubular clamp  142  may be employed for sealing purposes. The tubular clamp  142  may be composed of any suitably strong material such as a plastic and may comprise a slot  144  defined by edges  145  which, when mounted to a debris bag  146 , clamps a lower end  148  together at about broken line  150 . The material thickness of the debris bag at broken line  150  may be less than that of a bottom edge  149  to thereby maintain a tight clamping action on the lower end  148 . Also, edges  145  may include a chamfered portion  151  that increases the size of the slot  144  at one end thereof (not numbered) for ease in assembly with the debris bag  146 . 
     As depicted in FIG. 2, the inner member  108  may be preferably tubular in configuration and, more preferably a sleeve, and may be composed of aluminum, similar to the composition of the pressure head  102  discussed above. The inner member  108  may include a central bore  152  communicating with an opening  154  at a first end  156 . The central bore  152  may have an inner diameter which is sufficiently large to receive at least a portion of the cylindrical wall  111  including the exhaust port  116  of the pressure head  102 . Also located at the first end  156  may be a mounting portion  158  comprising a first slot  160  along with second slots  162 . Referring now also to FIG. 6, the first slot  160  may be dimensioned such that the guide pin  118  may be received therein so that, when the inner member  108  is mated with the pressure head  102 , both may be fixed together for simultaneous movement. The second slots  162  may be dimensioned shorter in a width W than the first slot  160  but longer in a length L and may function to increase the flexibility or spring of the mounting portion  158  and thereby provide a gripping action when clamped, as discussed in more detail below, to the pressure head  102 . Referring now also to FIG. 4, the mounting portion  158  includes an outer surface  159  that may be of decreasing outer diameter in order to provide a clamping action with the outer member  110  as discussed below. The inner member  108  also may comprise a constant outer diametrical portion  164  for mating with the outer member  110  described below. 
     As shown in FIGS. 2 and 4, the outer member  110 , similar to the inner member  108 , also may be composed of aluminum, is preferably tubular in configuration and, more preferably, comprises a sleeve. The outer member  110  also may include a central bore  166 , a threaded portion  168 , an inner tapered portion  170 , a slot  172  and a helical slot  174 . The central bore  166  may include an inside diameter that may be dimensioned to receive the inner member  108  therewithin. The threaded portion  168  may be configured to receive a nut  176  that may be connected to the rim  133  of the debris container  104  to thereby retain the latter on the outer member  110 . In this way, the debris container  104  may be easily replaced by removal of nut  176 . 
     As best seen in FIG. 4, the inner tapered portion  170  may be tapered at an angle that corresponds to the angle of the tapered outer surface  159  of mounting portion  158 . The slot  172  communicates with the helical slot  174  and both may be dimensioned of a sufficient size to receive the guide pin  118  therewithin. 
     Referring to FIGS. 4,  5  and  6 , axial movement of the inner member  108  causes guide pin  118  to move into the slot  172  and then rotation of the inner member  108  with respect to outer member  110 , causes the guide pin to move within the helical slot  174 . Because of this rotation, a clamping force may be exerted by the outer member  110  via contact with the mounting portion  158  of the inner member  108  against the cylindrical wall  111  of the pressure head  102 . In particular, the inner tapered portion  170  may ride up and over the tapered outer surface  159  thereby pressing the latter adjacent the pressure head  102 . The inner member  108  and outer member  110  are thereby clamped to the pressure head  102 . 
     The vacuum system  100  may also comprise a shutoff valve  178  for preventing debris once collected in the debris container  104  from leaving the debris container when the inner member  108  and outer member  110  are separated from the pressure head  102 . In a first embodiment shown in FIGS. 2 and 4 the shutoff valve  178  may comprise an opening  180  located on the inner member  108  and an aperture  182  located on the outer member. In operation, the shutoff valve  178  may be open allowing air represented by arrows  179  to pass therethrough when the opening  180  is aligned with the aperture  182  as shown in FIGS. 4,  5  and  5   a . Referring now to FIGS. 6 and 6 a , the shutoff valve  178  may be closed when the opening  180  and the aperture  182  are not aligned after rotation of the inner member  108  with respect to the outer member  110  represented by arrow  184 . At this time, rotation in the direction of arrow  186  (FIG. 5) may cause the shutoff valve  178  to become open again. 
     Referring again to FIGS. 2,  5  and  6 , the debris bag  130  may be connected to or separated from the pressure head  102  by rotation of the outer member  110  relative to the pressure head  102  and guide pin  118 . During this relative rotation, the shutoff valve  178  functions to open or close such that it is open when the debris bag  130  is connected to the pressure head  102  and is closed when separated from the latter. In particular, FIGS. 5 and 6 show in phantom the pressure head  102  and linear movement relative to the inner member  108  and the outer member  110 . Accordingly, a mechanic or operator may, in this way, quickly separate the vacuum bag  130  without fear of spilling any of the contents thereof and bring the vacuum bag  130  to a remote location for emptying the contents. As illustrated in FIG. 2, if it is determined that the vacuum bag requires replacement, it may then be quickly removed from the outer member  110  by removal of nut  176 . 
     Referring now to FIG. 7, a series of views are presented which illustrate optional embodiments of the shutoff valve  178 . Box  188  illustrates an embodiment, similar to that described above, wherein the inner member  108  may include an opening  180  and the outer member  110  includes an aperture  182  and wherein there may be relative movement between the inner member  108  and the outer member  110  in the direction of arrow  190  in order to open or close the shutoff valve  178 . 
     In another embodiment illustrated in box  192 , a shutoff valve is illustrated generally at  194  and may comprise a flap  196  which may be mounted to the outer member  110  by a suitable spring loaded mounting bracket  198  which biases the flap in a closed position. In order to open or close the flap  196 , the inner member  108  may be moved along a central axis  200 . Optionally, the flap  196  may be composed of two flaps  202  each mounted by spring loaded mounting brackets (not numbered) as illustrated in box  204 . 
     Another embodiment of a shutoff valve  205  is illustrated in box  206 . There, a heart valve  208  is provided which may comprise a flexible material such as a flexible plastic/rubber composition that is configured to collapse and thereby close the inner member  108  based on the lack of fluid pressure. In order to do so, one end  210  may be mounted to the inner member  108  with the other end  212  remaining free. Accordingly, fluid pressure in the direction of arrow  213  causes opening of the heart valve  208 . 
     A further embodiment of a shutoff valve  214  is illustrated in box  216 . In this embodiment, the shutoff valve  214  may comprise a throttle valve  218  mounted within the inner member  108 . The throttle valve  218  may be centrally hinged at  220  such that it may rotate into alignment with a central axis  222  of the inner member  108  because of fluid pressure in the direction of arrow  223 . 
     As illustrated in box  224 , a shutoff valve  226  comprises a diaphragm including a plurality of hinged plates  228  which may be moved into a closed or open position in a known manner via an outer-positioned ring  230 . 
     It should be understood, of course, that the foregoing relates to preferred embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.