Abstract:
A clamp squeeze apparatus and method for squeezing a pair of handles of a hand clamp to open a jaw of the hand clamp, is provided. The clamp squeeze apparatus includes a body, a handle, a pair of squeeze jaws and a fluid pressure device. The handle is connected to the body. The pair of squeeze jaws are slidably mounted on the body and slidable in a closing direction and an opening direction. The closing direction advances the jaws together and the opening direction retracts the jaws apart. The fluid pressure device is connected to a fluid pressure supply and is operable to slide the pair of squeeze jaws in the closing direction so as to squeeze a pair of handles of the hand clamp and open the jaws of the hand clamp. The clamp squeeze apparatus and method eliminates the risk of hand and wrist injuries by automating clamping processes.

Description:
FIELD OF THE INVENTION 
     The present invention is related to the field of clamping processes and, more particularly, to automated clamp opening devices for opening and deploying of hand operated spring clamps. 
     BACKGROUND OF THE INVENTION 
     Many manufacturing processes use spring clamps that must be deployed manually in various operations, such as the gluing together of the parts of an assembly. For instance, during construction of aircraft interiors in the aerospace industry it is not uncommon to need fifteen or thirty hand clamps spaced every couple of inches on an assembly to hold the assembly together during a gluing operation. Once the glue is spread, all of the spring clamps must be placed on the assembly within a couple of minutes due to the short time period required for the glue to dry. A large percentage of workers do not have the hand strength or stamina to install fifteen or thirty hand clamps in rapid succession and with satisfactory results. Clamp removal must also be done quickly and is almost as rigorous a task as clamp placement. 
     The rigors of the clamping task pose a risk for cumulative trauma injuries to the hand and wrist. Tendinitis of the hand, wrist or forearm may occur, which is an inflammation of the tendons and tendon sheaths. Carpal tunnel syndrome may also occur, which is an inflammation of the flexor tendons of the fingers which pass through a channel on the palmer side of the wrist formed by the carpal bones and the transverse carpal ligament. These flexor tendons become inflamed with repetitive overuse and place pressure on the nearby median nerve. Pressure on the median nerve causes numbness and/or pain in the lower arm. Carpal tunnel syndrome may even result in permanent dysfunction of the hand and wrist. 
     Despite the drawbacks of manual deployment of hand clamps, there are a lack of alternatives that have the same flexibility and effectiveness as manual clamping processes. Lighter-duty spring clamps are easier to open, but often do not have sufficient force to secure assemblies together during gluing. Dedicated jigs can be used, but are complicated and expensive because the jigs must typically be customized to the different assembly shapes and sizes. 
     Therefore, it would be advantageous to have a method and apparatus for opening spring clamps while avoiding possible trauma to the hand and wrist. In addition, it would be advantageous to have a method and apparatus for opening spring clamps that does not require modification of the spring clamps or the manufacture of customized clamping. It would also be advantageous if the clamps could still be quickly deployed in time-sensitive operations, such as the gluing together of assemblies. 
     SUMMARY OF THE INVENTION 
     The present invention includes a clamp squeeze apparatus for squeezing a pair of handles of a hand clamp to open a jaw of the hand clamp. The clamp squeeze apparatus includes a pair of fluid pressure driven squeeze jaws for holding and squeezing the handles of a variety of hand clamps. The pair of squeeze jaws are driven by fluid pressure so that operation of the clamp squeeze apparatus does not require significant manual exertion. 
     In one embodiment, the clamp squeeze apparatus includes a body, a handle, a pair of squeeze jaws and a fluid pressure device. The handle is connected to the body. The pair of squeeze jaws are slidably mounted on the body and slidable in a closing direction and an opening direction. The closing direction advances the jaws together and the opening direction retracts the jaws apart. The fluid pressure device is connected to a fluid pressure supply and is operable to slide the pair of squeeze jaws in the closing direction so as to squeeze a pair of handles of the hand clamp and open the jaws of the hand clamp. 
     A first one of the pair of squeeze jaws may include a large pocket and a small pocket. The first one of the pair of squeeze jaws is adjustable to move the large and small pockets alternatively into a position facing a second one of said pair of squeeze jaws so that the handles of large and small hand clamps, respectively, fit between the pair of squeeze jaws. 
     In yet another embodiment, the clamp body includes a slide channel along which a first one of the pair ofjaws is slidable in the opening and closing directions. The fluid pressure device may include a chain and a cylinder. The chain has a first end connected to the first one of the pair ofjaws and a second end connected to the cylinder. The cylinder is actuated by the fluid pressure supply. The chain is slidable along a second channel defined by the body in response to actuation of the cylinder so that the first one of the pair ofjaws slides in the closing direction. In another aspect, a spring urges the pair ofjaws to slide in the opening direction. 
     The present invention has several advantages. The risk of cumulative hand and wrist trauma from manual deployment of hand clamps is eliminated as the clamp squeeze apparatus can be operated with the pull of a trigger. The squeeze jaws are easily adjustable to allow for the opening of a range of clamp sizes. Thus, the hand clamps do not have to be modified or custom manufactured to be opened by the clamp squeeze apparatus. The hand clamps can also be quickly inserted and removed from the squeeze jaws for rapid deployment during time-sensitive operations, such as the gluing of assemblies. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: 
     FIG. 1 is a perspective view of one embodiment of a clamp squeeze apparatus of the present invention having a pair of squeeze jaws in a closed position to hold open a jaw of a conventional hand clamp; 
     FIG. 2 is a partial cut-away view of the clamp squeeze apparatus of FIG. 1 with the pair of squeeze jaws in an open position; 
     FIG. 3 is a partial cut-away view of the clamp squeeze apparatus of FIG. 1 with the pair of squeeze jaws in a closed position; and 
     FIG. 4 is a partial cut-away view of the clamp squeeze apparatus of FIG. 1 with one of the squeeze jaws configured to open hand clamps having small handles. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. 
     A clamp squeeze apparatus  10  of the present invention is shown in FIGS. 1 through 4. The clamp squeeze apparatus includes a body  11 , a handle  12 , a fixed squeeze jaw  13 , a moving squeeze jaw  14  and a cylinder  19 . The handle  12  is attached to one side of the body  11  and the squeeze jaws  13 ,  14  are spaced from the handle  12  on an opposing side of the body  11 . The moving squeeze jaw  14  attached to the chain  20  and is slidably mounted to a slide channel  50  defined by the body  11 . The chain extends through a second channel  21  defined by the body  11  and the other end of the chain is attached to a chain pawl  31  which is in turn attached through a piston rod  81  to a piston  39  of the cylinder  19 . The cylinder itself is contained within the body  11  and forms part of the handle  12 . 
     During operation, a pair of handles  38  of a hand clamp  36  are inserted between the squeeze jaws  13 ,  14  when the squeeze jaws are open, as shown in FIG. 2. A worker grips the handle  12  in one hand and pulls a trigger  16  on the handle which opens a pneumatic valve  15  and supplies air pressure to the cylinder  19 . Supplying air pressure to the cylinder causes the piston  39  to move from the position shown in FIG. 2 to the position shown in FIG.  3 . Movement of the piston  39  is coupled with the movement of the moving squeeze jaw  14  by the chain  20 . As the piston of the cylinder  19  is driven open by air pressure, the chain  20  drives the moving squeeze jaw  14  closer to the fixed jaw  13  in a closing direction. This movement squeezes closed the pair of handles  38  of the hand clamp  36  and opens a pair ofjaws  37  of the hand clamp allowing the hand clamp to be deployed in a clamping process, as shown in FIG.  1 . Release of the trigger  16  shuts off the air supply and releases air within the cylinder  19  allowing a slide compression spring  28  to drive the moving squeeze jaw  14  in an opposite, opening direction away from the fixed jaw  13 . 
     The pneumatic cylinder  19  is preferably housed partially in, and forming part of, the handle  12  and partially in the body  11  of the clamp squeeze apparatus  10  to minimize the bulk of the apparatus. The pneumatic cylinder  19  is supplied air from an internal supply line  29  that is in turn supplied with air from the fluid pressure supply line  18 . The air supply to the internal supply line  29  is controlled by the pneumatic valve  15  which is a three-way valve that is opened and closed by a toggle switch  17 . Movement of the toggle switch is controlled by movement of the trigger  16 . Pulling the trigger flips the toggle switch  17  and opens the pneumatic valve  15  releasing the pneumatic pressure through the internal supply line  29  and into a chamber of the cylinder  19  behind the piston  39 . Release of the trigger  16  returns the toggle switch  17  to its original position, which cuts off the air pressure from the supply line  29  and releases pressure from the cylinder  19  to the outside atmosphere. 
     The movement of the moving jaw  14  could also be powered by a range of fluid pressure devices, such as hydraulic cylinders or servo-hydraulic cylinders. In addition, the present invention should not be considered limited to the use of a cylinder to transfer fluid pressure into mechanical power. In other embodiments, the cylinder  19  could be replaced with other fluid pressure devices, such as a rotor or a turbine. 
     The pneumatic cylinder  19  is sized to provide a comfortable grip diameter as well as sufficient force to open most commonly used hand clamps. Some examples of the hand clamps that can be opened using the present invention include, but are not limited to, Stanley Model  83-262  requiring 28 pounds of force to open, Stanley Model  83-263  requiring up to 48 pounds of force to open, Brink &amp; Cotton No. 1 and Wilton Model 634 requiring from 18 to 22 pounds to open. The cylinder is selected to provide a force equal to approximately 90% of the available air line pressure. 
     The clamp squeeze apparatus  10  is essentially a pressure sensitive device i.e., the amount of pressure in the cylinder  19 , not the air flow into the cylinder, controls the force developed by the clamp squeeze. However, high air flow may result in an excessive jaw closing speed. Jaw closing speed is regulated by the slide compression spring  28  and the relatively small internal diameter of the internal air pressure supply line  29 . The small diameter of the internal air pressure supply line  29  reduces the flow-rate of the air supplied from the supply line  18 . The slide compression spring  28  is housed in a receptacle  40  defined by the body  11 . The slide compression spring  28  has a fixed end and an opposing end, the opposing end is in contact with the moving squeeze jaw  14 . As the moving squeeze jaw is moved in the closing direction toward the fixed jaw  13 , the force in the compression spring  28  increases, urging the moving squeeze jaw  14  in the opposite, opening direction. The counterbalance of compression spring  28  force and air pressure force serves to decelerate the movement of the moving squeeze jaw  14 . Note also, that in the absence of air pressure, the compression spring  28  will bias the jaws  13 ,  14  into a normally open position to readily receive another hand clamp  36 . 
     The majority of the hand clamps in use, such as the Stanley Model  83-262 , require about 1.5 inches of stroke in the cylinder  19 . The clamp squeeze apparatus  10  can also be fitted with a 2 inch stroke cylinder  19  and wider jaws to accommodate larger clamps, such as the Stanley Model  83-263 . In an alternative embodiment, additional space savings could be had if the pneumatic valve  15  and the cylinder  19  were incorporated in a single unit. 
     Movement of the cylinder piston  39  is coupled with movement of the moving jaw  14  via the chain  20  which rides in the second channel  21 . The second channel  21  of the illustrated embodiment has an inverted U-shape with a first arm  32  in proximity to the piston of the cylinder  19  and a second arm  33  in proximity to the moving jaw  14 . The moving jaw has a pawl  30  that slides in the first arm  32  of the second channel  21  and the piston  39  of the cylinder  19  has a pawl  31  that slides in the second arm  33  of the second channel  21 . The chain  20  connects the two pawls  30 ,  31  so that air pressure on the piston of the cylinder  19  is transmitted as tension along the chain that urges the moving jaw  14  along the slide channel  50  in the direction of the fixed jaw  13 . The chain  20  and piston  39  can be connected in other ways so as to couple of movement of the piston to the chain. 
     The pawl  31  is similar to a piston, sliding in a cavity  80  and has teeth machined on one side for attachment of the chain. The cavity  80  is machined into the body  11  and the handle  12  to provide space for pawl  31  which is threaded onto the end of the rod of the cylinder  39 . The chain  20  is not pulled along the axis of the cylinder  39 , but rather on an offset defined by one half of the width of the pawl  31  to decrease the top-to-bottom length of the apparatus  10 . Alternatively, the chain  20  could be attached in a different manner, such as directly to the end of the rod of the cylinder  39 . 
     The fixed jaw  13  has a pair of pockets, a small pocket  23  and a large pocket  22  that can be positioned to allow opening of smaller or larger clamps, respectively. As shown in FIG. 2, the fixed jaw  13  is positioned so that the large pocket  22  is facing the moving jaw  14 , so as to readily receive larger pairs of clamp handles. As shown in FIG. 4, the fixed jaw  13  is repositioned more closely to the moving jaw  14  and with the small pocket  23  facing the moving jaw, so as to easily receive smaller pairs of clamp handles. The fixed jaw  13  can be alternated between the two positions by gripping a finger pull  26  which retracts a spring-biased locator pin  24  out of either a top locator hole  34  or bottom locator hole  35 , depending upon the initial configuration. Retracting the locator pin  24  allows the worker to slide the fixed jaw  13  off of the body  11  and reposition the fixed jaw  13 . With the locator pin  24  retracted, the fixed jaw  13  can be slid off of the body  11 , along the channel  50 . The fixed jaw can then be flipped over to position the opposing pocket to face the moving jaw  14  and slid back on the channel  50  until the locator pin  24  seats into the desired locator hole  34  or  35 . The clamp squeeze  10  is configured for larger clamps when the locator pin  24  is in the top locator hole  34 , as shown in FIGS. 1,  2  and  3 , and for smaller clamps when in the bottom locator hole  35 , as shown in FIG.  4 . The pockets  22 ,  23  can be constructed in a range of sizes and shapes to match up with various clamp handle designs. 
     The slide channel  50  is defined by the body  11 , more specifically, is a machined aluminum channel that is attached to the rest of the body which is comprised of plastic. However, the body  11  and channel  50  could also be integrally constructed of a range of different materials. 
     Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.