Patent Publication Number: US-2010124476-A1

Title: Cylinder cart having a retention hook

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to provisional U.S. patent application Ser. No. 61/114,664, filed Nov. 14, 2008, the contents of which are incorporated herein by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a cylinder cart, particularly a cylinder cart that includes a retention hook. 
     BACKGROUND 
     Manual carts for carrying cylinders such as dewars or other liquid or gas cylinders are well known in many industries. Typical cylinders can contain liquefied Oxygen, Nitrogen, Argon or other gases or gas mixtures. Typical handling of cylinders such as liquefied gas cylinders, tanks, and dewars has been achieved by manually capturing the cylinder onto a cart, manually retaining it in the cart (e.g., using a retention hook), and then manually propelling the cart. 
     Manually pushing or pulling a cart containing a heavy or unwieldy cylinder can lead to leg, back and shoulder injuries. The exposure to such injuries is compounded when the cart is pushed or pulled along a graded surface. In addition, manual carts require the user to manually manipulate a retention hook that retains the cylinder. However, the high weights of some cylinders (e.g., dewars) exposes the user&#39;s hands and fingers to serious injuries such as crushing or amputation. 
     It is desirable to develop a cylinder cart that has improved performance compared to the designs in the prior art. 
     SUMMARY 
     A cart for carrying a cylinder containing a liquid or gas is disclosed, the cylinder having an anchor location, the cart including a frame including a body and a handle, wheels coupled to the frame for carrying the frame and the cylinder, a hook capable of engaging the anchor location of the cylinder to capture and retain the cylinder on the frame, an automatic actuator configured to move the hook into and out of engagement with the anchor location, and first and second safety switches that are configured to be engaged respectively by left and right hands of a user, the safety switches disabling the actuator if not engaged by both hands of the user. 
     A cart for carrying a cylinder containing a liquid or gas is disclosed, the cylinder having an anchor location, the cart including a frame including a body and a handle, wheels coupled to the frame for carrying the frame and the cylinder, a motor for driving the wheels, a hook capable of engaging the anchor location of the cylinder to capture and retain the cylinder on the frame, and a belly bar configured to directly contact the throttle when the belly bar is contacted, thereby reversing the of direction operation of the motor. 
     The cart can include a motor for driving the wheels. The cart can include a battery for powering the motor. The actuator can be an electro-mechanical actuator. The actuator can be one of a pneumatic cylinder or a hydraulic cylinder. The actuator can be linear such that the hook moves linearly upon actuation. The frame can include a lower platform extending from the body and capable of supporting an underside of the cylinder. 
     These and various other advantages and features are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying descriptive matter, in which there are illustrated and described preferred embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a side perspective view of a cylinder cart and cylinder illustrating aspects of the invention; 
         FIG. 1B  is a rear perspective view of the cylinder cart and cylinder depicted in  FIG. 1A ; 
         FIG. 2A  is a perspective view of the cylinder cart depicted in  FIG. 1A ; 
         FIG. 2B  is a side view of the cylinder cart depicted in  FIG. 2A ; 
         FIG. 3A  is a perspective view of a retention hook system included in the cylinder cart depicted in  FIG. 2A ; and 
         FIG. 3B  is a perspective view of a control system included in the cylinder cart depicted in  FIG. 2A . 
     
    
    
     DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
     Referring to  FIGS. 1A and 1B , an exemplary cylinder cart  10  is configured to carry a cylinder  11 . The cylinder  11  includes a cylindrical body  12 , a halo ring  13  mounted onto the upper end of the cylindrical body  12 , and a plurality of connecting members  14  that connect the halo ring  13  to the cylindrical body  12 . Each connecting member  14  includes an anchor slot  15 . 
     The cylinder cart  10  preferably is configured to capture, retain, and move the cylinder  11 , which can contain liquefied Oxygen, Nitrogen, Argon, or any other combinations of liquid or gas mixtures. For instance, the cylinder  11  can contain approximately 140 to 260 liters of a liquid that would be in a gas state at ambient temperature (e.g., 70° F.). The cylinder  11  can be of any size and shape as desired, such as approximately 20-26 inches in diameter, approximately 60 inches in height, and a weight of over 1,000 pounds in accordance with one embodiment. 
     The halo ring  13  can be a round structure disposed above the top surface of the cylindrical body  12 . The halo ring  13  can substantially follow the outer perimeter of the cylindrical body  12  and can have substantially the same diameter as the cylindrical body  12 . The halo ring  13  can also have a diameter smaller or greater than the outer perimeter of the cylindrical body  12 . The halo ring  13  can share a common central axis with the cylindrical body  12 . The halo ring  13  can also define a different central axis than the cylindrical body  12 . The halo ring  13  can provide protection for various valves and fittings at the top of the cylinder  11 . The halo ring  13  can provide a surface for a user to grab, so that the user can manually position the cylinder  11  by leaning or rolling the cylinder  11 . 
     The halo ring  13  can be coupled to the cylinder  11  by one or more connecting members  14 . As shown in  FIG. 1B , each connecting member  14  can be welded or otherwise attached to the top of the cylinder  11  and the bottom of the halo ring  13 . Each connecting member  14  can be provided as a vertical plate defining an anchor slot  15 . Each anchor slot  15  can be configured to accommodate a conventional hook from a conventional manual cylinder cart. 
     Referring now to  FIGS. 2A and 2B , the cylinder cart  10  includes a frame  20 , a retention hook system  30 , a propulsion system  40 , and a control system  50 . The frame  20  includes cylinder support members (or frame body)  21 , a hook support member  22 , a motor support member  23 , rear caster brackets  24 , front wheel brackets  25 , and handles  26 . The hook support member  22  includes a hook actuator bracket  27  and adjustment holes  28  (shown in  FIG. 3A ). The retention hook system  30  includes a hook  31 , a hook bracket  32 , and a hook actuator  33 . The hook bracket  32  includes positioning holes  34  (shown in  FIG. 3A ). The propulsion system  40  includes a motor  41 , a drive wheel axle  42 , drive wheels  43 , rear wheels  44  (preferably rotatably mounted on the rear caster brackets  24  as caster wheels), front wheels  45 , and a battery  46 . The control system  50  includes a throttle  51 , a hook control switch  52 , handle tapes  53  (shown in  FIG. 3B ), a belly bar  54 . The belly bar  54  includes a throttle contact portion  55  (shown in  FIG. 3B ). 
     The frame  20  can be made from steel or any other material known in the art that can support the weight of a typical cylinder  11 . As shown in  FIG. 2A , the cylinder support members  21  (and the hook  31 ) are configured to support the weight of a cylinder  11 . The length and configuration of the cylinder support members  21  can be chosen to support a cylinder  11  of a desired range of sizes and diameters. In some embodiments (not shown), the frame  20  can include a lower platform (e.g., two toes or forks, a solid plate, or a plate of toes or forks) extending from the cylinder support members (or frame body)  21  and configured to support an underside of the cylinder  11 . In some embodiments (not shown), the frame  20  can include one or more straps coupled to the cylinder support members  21  and configured to be placed around the outer perimeter of the cylindrical body  12  of the cylinder  11  such that the straps can help capture and/or retain the cylinder  11  against the frame  20 . 
     The propulsion system  40  preferably assists a user in moving the cylinder cart  10  and the cylinder  11  forward and backward and on graded or ungraded surfaces. The propulsion system  40  can provide dynamic braking (not shown), which can allow a braking force to be applied to the drive wheels  43  when the forward or backward speed of the cylinder cart  10  exceeds a predetermined maximum safe speed. The propulsion system  40  can include an automatic parking brake (not shown) that can lock the drive wheels  43  when the motor  41  is not turning the drive wheels  43  (e.g., if the throttle  51  is at a zero-speed setting or if the motor  41  is not receiving power from the battery  46 ). The automatic parking brake feature can help prevent the cylinder cart  10  from unexpectedly rolling away from or towards the user. The battery  46  can provide energy to the motor  41 . The battery  46  is preferably a 12-volt DC battery, but any battery, combination of batteries, or other power source for the motor  41  (and/or the hook actuator  33 ) can be used. 
     Referring now to  FIG. 3A , the retention hook system  30  can allow a user to capture a cylinder, such as the cylinder  11 , by automatically positioning the hook  31  into the anchor slot  15  or around a portion of the halo ring  13  and automatically raising the hook  31  upward in a direction D 1  until the cylinder  11  is positioned on the cylinder cart  10 . Although  FIG. 1B  shows the hook  31  positioned into the anchor slot  15 , the hook  31  can also capture and retain the cylinder  11  by being positioned around a portion of the halo ring  13  or by being positioned into or around any structure known in the art that can allow the hook  31  to stably capture the cylinder  11  and retain the cylinder  11  against the cylinder cart  10 . It can thus be appreciated that one or more surfaces defining the anchor slot  15 , a portion of the halo ring  13 , or any other suitable structure that is known in the art can serve as an anchor location for the hook  31  to capture and retain the cylinder  11 . Anchor locations of any size, shape, and location that are coupled to the cylindrical body  12  are contemplated in the invention. Although the embodiment shown in the figures includes a motor  41  and a retention hook system  30 , in other embodiments (not shown), the retention hook system  30  can be included in a cylinder cart  10  without a motor  41  (e.g., with a manual propulsion system). 
     As shown in  FIG. 3A , the hook  31  preferably is removably coupled to the hook bracket  32 . In some embodiments, the hook  31  can be integrally formed with the hook bracket  32 . The hook  31  preferably is upward-pointing, such that the hook  31  can exert an upward force on the cylinder  11  when it is positioned in the anchor slot  15  or around a portion of the halo ring  13 , thereby holding the cylinder  11  in position on the cylinder cart  10  while the cylinder  11  is being transported. 
     In embodiments where the hook  31  is removably coupled to the hook bracket  32 , different hooks  31  having different lengths, shapes, or thicknesses can be coupled to the hook bracket  32 , depending on the diameter of the cylinder  11 , the weight of the cylinder  11 , or the location or configuration of the anchor slot  15  or the halo ring  13 . For example, the hook  31  can extend approximately two inches further from the hook support member  22  towards the cylinder  11  when a 26-inch diameter cylinder  11  is carried on the cylinder cart  10 , compared to when a 20-inch diameter cylinder  11  is carried. 
     The hook actuator (or automatic actuator)  33  preferably is removably coupled to the hook bracket  32  and the actuator bracket  27  using, for example, ⅜-inch diameter pins (not shown). In some embodiments, the hook actuator  33  can be permanently attached or integrally formed with the hook bracket  32  and/or the actuator bracket  27 , or any size pins or removable coupling mechanism can be used to couple the hook actuator  33  to the hook bracket  32  and the actuator bracket  27 . 
     In embodiments where the hook actuator  33  is removable from the hook bracket  32  and the actuator bracket  27 , when the hook actuator  33  is removed, the hook  31  can be manually positioned in the anchor slot  15  or around a portion of the halo ring  13 , for example, as a back-up measure if the hook actuator  33  becomes inoperable. In such embodiments, as shown in  FIG. 3A , the hook support member  22  includes a plurality of adjustment holes  28 , and the hook bracket  32  includes positioning holes  34 . Once the hook  31  is manually positioned in the anchor slot  15  or around a portion of the halo ring  13 , a user can insert a pin through a pair of adjustment holes  28  and positioning holes  34  to fix the location of the hook bracket  32  in a particular desired position along the hook support member  22 . In other embodiments, any locking mechanism that is known in the art can be used to fix the location of the hook bracket  32  in a particular desired position along the hook support member  22 . 
     The adjustment holes  28  and the positioning holes  34  preferably are configured to accommodate a ⅜-inch pin, such that a single ⅜-inch pin can pass through a pair of adjustment holes  28  and positioning holes  34  to fix the location of the hook bracket  32  in a particular desired position along the hook support member  22 . The adjustment holes  28  preferably are spaced at 1-inch intervals along the hook support member  22 , although any size interval can be used. The positioning holes  34  preferably are spaced at ½-inch intervals along the hook bracket  32 , although any size interval can be used. 
     As shown in  FIG. 3A , the hook actuator (or automatic actuator)  33  preferably is an electromechanical screw-type device that is configured to slide the hook bracket  32  along the hook support member  22  in either an upward linear direction D 1  or a downward linear direction D 2 . In other embodiments (not shown), the hook actuator  33  can be any positioning device that is known in the art, including, for example, an electromechanical actuator, a manual or automatic hydraulic cylinder, a manual or automatic pneumatic cylinder, a manual or motorized winch, a manual or motorized rack and pinion, or any other motorized or manual gearing or sprocket arrangement. 
     Although in  FIG. 3A , the hook  31  and/or the hook bracket  32  is configured to move in a linear direction D 1  or D 2  along the linear hook support member  22 , in other embodiments (not shown) the hook  31  can be configured to move in a non-linear direction along a non-linear hook support member  22 . In some embodiments, for example, the hook  31  can move in an arcuate path towards and/or away from the anchor slot  15  or a portion of the halo ring  13 . 
     In the embodiment shown in  FIG. 3A , the hook actuator  33  receives energy from the battery  46 . However, in other embodiments (not shown), any battery or other power source for the hook actuator  33  can be used. In some embodiments where the hook actuator  33  is mechanical, pneumatic, or hydraulic (not shown), the hook actuator  33  may not need to use a battery  46  or other power source. 
     Referring now to  FIGS. 3A and 3B , the control system  50  allows a user to capture the cylinder  11  by automatically positioning the hook  31  without the user placing his hands on or near the retention hook system  30 , particularly without the user placing his hands on or near the hook  31 . 
     For instance, a user can control the propulsion system  40  by actuating the throttle  51 , which can be located near the handles  26  such that the user can actuate the throttle  51  with a thumb while not removing either hand from the handles  26 . The throttle  51  preferably provides an automatic safety feature that biases the throttle to return to the zero-speed position if the user&#39;s thumb or other finger is removed from the throttle  51 . 
     As shown in  FIG. 3B , the belly bar  54  preferably can protect a user by forcing the throttle  51  into a forward position if the belly bar  54  is contacted, for example, by the torso of a user who may be trapped between the belly bar  54  and a wall or other obstacle (not shown). If a user inadvertently moves the cylinder cart  10  backward towards a wall or other obstacle, thereby pinning the user between the handles  26  and the wall, the trapped portion of the user&#39;s body (e.g., the torso) can contact and actuate the belly bar  54 . Upon actuation of the belly bar  54 , the throttle contact portion  55  of the belly bar  54  pushes the throttle  51  into a forward position, which can cause the propulsion system  40  to move the cylinder cart  10  forward, away from the user and away from the wall or other obstacle. Although the throttle contact portion  55  is shown in  FIG. 3B  as integrally formed with the belly bar  54 , in other embodiments (not shown), the throttle contact portion  55  can be separated from the belly bar  54 , and the throttle contact portion  55  can instead be mechanically linked to the belly bar  54 . 
     The control system  50  preferably includes two handle tapes (or safety switches)  53 , each handle tape  53  preferably located on a respective handle  26 . Each handle tape  53  can be a contact sensor or any other safety switch that is known in the art, such that the hook  31  and/or the drive wheels  43  can only move (via actuation of the hook control switch  52  and/or the throttle  51 , respectively) when both hands are contacting the respective handle tape  53 . In some embodiments, the handle tapes  53  can serve as a safety feature to ensure that the user can only operate the retention hook system  30  and the propulsion system  40  when the user&#39;s hands are safely positioned on the handles  26 , thereby protecting the user&#39;s hands from injury. In some embodiments, the handle tapes  53  can disable the hook actuator  33  if both handle tapes  53  are not each engaged by respective left and right hands of a user. 
     A user preferably can control the retention hook system  30  by actuating the hook control switch  52 , which preferably is located near the handles  26  such that the user can actuate the control switch  52  with a thumb while not removing either hand from the handles  26 . For example, in some embodiments, the hook control switch  52  can be configured such that a user can slide the hook  31  in an upward direction D 1  along the hook support member  22  by toggling or actuating the hook control switch  52  in an upward direction, and a user can slide the hook  31  in a downward direction D 2  along the hook support member  22  by toggling or actuating the hook control switch  52  in a downward direction. 
     As shown in  FIG. 3B , the hook control switch  52  preferably is located remotely from the retention hook system  30 . This remote location of the hook control switch  52  relative to the retention hook system  30  can allow a user to capture and release a cylinder  11  without having to manually hold and position the hook  31 . The automatic retention hook system  30  can be controlled by a user with the user&#39;s hands and fingers located remote from the hook  31  and the engagement area of the hook  31  and the anchor slot  15 , which can eliminate or reduce the risk of injury to the user&#39;s hands during operation of the cylinder cart  10 . 
     In the embodiment shown in  FIG. 3B , the hook control switch  52  can be a mechanical toggle switch that is configured to send an electric signal to actuate the hook actuator  33 . However, in other embodiments (not shown), the hook control switch  52  can be any switch, lever, crank, winch, pulley system, or any other mechanism that is known in the art that can move the hook  31  up and down, preferably without the user having to manually hold and position the retention hook system  30 , particularly without the user having to manually hold and position the hook  31 . The hook  31  preferably is positioned indirectly and/or remotely by the user actuating the hook control switch  52 , not by grasping the hook  31  with the user&#39;s hands. 
     To capture a cylinder  11 , a user can push the cylinder cart  10  toward a cylinder  11  to be captured. When the user can observe the approximate position of the anchor slot  15  and/or the halo ring  13 , the user can actuate the control switch  52  to move the hook  31  to an approximately aligned position with the anchor slot  15 , for example. When the cylinder cart  10  is proximate to the cylinder  11 , the user can rotate the cylinder cart  10  about the drive wheels  43  by pushing up on the handles  26  until the front wheels  45  contact the ground. While keeping both hands on the handles  26 , the user can guide the hook  31  into the anchor slot  15 . Once the hook  31  has been inserted into the anchor slot  15 , the user can toggle the control switch  52  to move the hook  31  in an upward direction D 1 , preferably continuing to move the hook  31  in the upward direction D 1  until the hook  31  has tightly engaged the anchor slot  15 , thereby capturing the cylinder  11 . Alternatively, a sensor (not shown) can be provided that causes the hook  31  to stop moving in the upward direction D 1  when the hook  31  has tightly engaged the anchor slot  15 , for example, such that the hook  31  has reached a predetermined location, is bearing a predetermined amount of weight, or has satisfied any other indication that identifies that the hook  31  has reached a location sufficient to capture and/or retain the cylinder  11 . Once the cylinder  11  has been captured, the user can rotate the cylinder cart  10  about the drive wheels  43  by easing the handles  26  down until the rear wheels  44  contact the ground. 
     To release a cylinder  11 , a user can rotate the cylinder cart  10  about the drive wheels  43  by pushing up on the handles  26  until the front wheels  45  contact the ground, and the user can continue to tilt the cylinder  11  forward until it is vertically oriented on the ground. While keeping both hands on the handles  26 , the user can toggle the control switch  52  to move the hook  31  in a downward direction D 2 , until the hook  31  begins to disengage from the anchor slot  15 . As the hook  31  disengages from the anchor slot  15 , the user can rotate the cylinder cart  10  about the drive wheels  43  by easing the handles  26  down. Once the hook  31  is fully disengaged from the anchor slot  15 , the user can continue to rotate the cylinder cart  10  about the drive wheels  43  until the rear wheels  44  contact the ground. 
     The foregoing description is provided for the purpose of explanation and is not to be construed as limiting the invention. While the invention has been described with reference to preferred embodiments or preferred methods, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Furthermore, although the invention has been described herein with reference to particular structure, methods, and embodiments, the invention is not intended to be limited to the particulars disclosed herein, as the invention extends to all structures, methods and uses that are within the scope of the appended claims. The disclosed cylinder cart may address some or all of the problems previously described. A particular embodiment need not address all of the problems described, and the claimed cylinder cart should not be limited to embodiments comprising solutions to all of these problems. Further, several advantages have been described that flow from the structure and methods; the present invention is not limited to structure and methods that encompass any or all of these advantages. Those skilled in the relevant art, having the benefit of the teachings of this specification, may effect numerous modifications to the invention as described herein, and changes can be made without departing from the scope and spirit of the invention as defined by the appended claims. Furthermore, any features of one described embodiment can be applicable to the other embodiments described herein.