Abstract:
A pallet changer is rotatable around a pin which releasably engages a shop floor. A pneumatic load module assembly creates a cushion of air which supports the pallet changer for manual rotation. The pin can be released from the floor to allow linear horizontal movement of the pallet changer or the cushion of air when it is necessary to repair, refurbish or replace equipment adjacent the pallet changer.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to a device for feeding a supply of materials to a working station. More particularly, the present invention relates to a rotatable stock feeding mechanism which can be manually rotated to present a new supply of materials to a working station.  
         BACKGROUND OF THE INVENTION  
         [0002]    Manufacturing facilities typically supply components in bulk to a working station. The working station can be a machining center, an assembly line or any other type of working station. The components that need to be machined or assembled are supplied in a box, a bin, a pallet or in any other form of bulk supply. The worker at the working station works through the components that have been supplied and when all components in the box, bin, pallet or in any other form of bulk supply have been machined or used, it becomes necessary to restock the work station with additional components.  
           [0003]    In order to improve the efficiency of supplying and removing components from a working station, pallet changers have been developed. Pallet changers typically include a pallet support which is rotatable between the work station and a pallet supply station. The pallet supply station is where the finished components or empty pallets are removed and a new pallet filled with unfinished components or a new supply of components are supplied. A pallet or other container, on which components to be finished or assembled are stacked, is transferred from the pallet supply station to the working station. After the components are finished or assembled, the pallet or container, which has been finished or emptied, is transferred from the working station to the pallet supply station by rotation of the pallet changer. The rotation of the pallet changer moves the finished components or empty container to the pallet supply station while simultaneously moving a pallet or container of unfinished or unassembled components from the pallet supply station to the working station. Once, the finished components or empty containers arrive at the pallet supply station they can be exchanged for a pallet or container of unfinished or unassembled components and the cycle continues. Thus, the pallet changers ensure a continuous supply of materials to the working station.  
           [0004]    The incorporation of these pallet changers has improved the operating efficiency of the machining tool or the assembly process, but, the automatic pallet changers are expensive and difficult to maintain. In addition, the pallet changers require additional floor space for installation of the corresponding hydraulic pneumatic and/or electrical power units. Therefore, in a manufacturing plant, it may become difficult to install the pallet changer with its associated power unit once the machine tool and/or assembly line has been installed. Once the pallet changer has been installed, further problems may occur during maintenance/repair of the machine tool on the assembly line. In order to properly service the machine tool on the assembly line, it may be necessary to partially dismantle the pallet changer in order to gain access to the machine tool or the assembly line.  
           [0005]    Continued development of these pallet chambers has been directed towards systems that are less complicated, lower cost and systems which can easily be moved in order to provide access to the respective machine tool or assembly line.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention provides the art with a dual rotating stock system which includes a pair of tilt master positioning devices disposed at opposite ends of a rotatable turntable. The system incorporates a pair of aero-casters which lift the system in order to allow for the rotation between its two positions. The system rotates around a detent pin which engages a hole in the shop floor. The detent pin is retractable to allow for the horizontal movement of the system using the air springs when it is necessary to provide access to the manufacturing tool and/or assembly line.  
           [0007]    Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0009]    [0009]FIG. 1 is a perspective view of the dual rotating stock system in accordance with the present invention;  
         [0010]    [0010]FIG. 2 is an exploded perspective view of the dual rotating stock system shown in FIG. 1;  
         [0011]    [0011]FIG. 3 is a front elevational view of the dual rotating stock system shown in FIGS. 1 and 2;  
         [0012]    [0012]FIG. 4 is an end elevational view of the dual rotating stock system shown in FIGS.  1 - 3 ; and  
         [0013]    [0013]FIG. 5 is an exploded perspective view of the detent pin assembly for the dual rotating stock system of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0014]    The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.  
         [0015]    Referring now to the drawings in which like reference numerals designate like or corresponding parts throughout the several views, there is shown in FIGS.  1 - 4 , a dual rotating stock system in accordance with the present invention and which is designated generally by the reference numeral  10 . Dual rotating stock system  10  comprises a rotating base assembly  12 , a first stock supporting device in the form of a first tilting deck assembly  14 , a second stock supporting device in the form of a second tilting deck assembly  16  and a control system  18 .  
         [0016]    Rotating base assembly  12  comprises a generally rectangular frame  20 , a centrally located detent pin assembly  22  and a plurality of pneumatic load module assemblies  24 . Rectangular frame  20  is adapted at one end for mounting first tilting deck assembly  14  and it is adapted at the other end for mounting second tilting deck assembly  16 . Detent pin assembly  22  is mounted to the center of rectangular frame  20  and it is adapted to engage a hole  26  formed into the mounting floor  28  to which dual rotating stock system  10  is associated. Detent pin assembly  22  extends into hole  26  to provide a generally vertical axis around which generally rectangular frame  20  rotates. Detent pin assembly  22  is retractable as detailed below.  
         [0017]    The plurality of pneumatic load module assemblies  24  are disposed between frame  20  and floor  28 . Pneumatic load module assemblies  24  are manufactured by AeroGo Inc. and are well know in the art. Given a smooth surface such as floor  28  and a supply of air at the right pressure and volume, pneumatic load module assemblies  24  will lift dual rotating stock system  10  to enable a manual rotation of stock system  10  around detent pin assembly  22  as detailed below.  
         [0018]    First tilting deck assembly  14  is attached to one end of frame  20  of rotating base assembly  12 . Tilting deck assembly  14  comprises a stationary frame  30 , a pivoting deck  32  and a pressure cylinder  34 . Stationary frame  30  is secured to frame  20  of rotating base assembly  12  and it provides mounting locates for both pivoting deck  32  and pressure cylinder  34 . Pivoting deck  32  is pivotably secured to stationary frame  30  such that it is pivotable between a lower position as shown in FIGS. 3 and 4 and an upper position as also shown in FIGS. 3 and 4. In its lower position, pivoting deck  32  can easily be loaded with components that need to be processed or assembled, and it can easily be unloaded with components that have already been processed or empty containers whose parts have already been assembled. In its upper position, or at any position between its lower and upper position pivoting deck  32  can present the unprocessed or unassembled components to an operation at a convenient height or position to eliminate or reduce fatigue of the operator. Pressure cylinder  34  extends between frame  30  and pivoting deck  32 . Pressure cylinder  34  operates to move pivoting deck  32  between its lower position, its upper position and any position between its lower and upper position to present unprocessed or unassembled components to the operator. Pressure cylinder  34  can be powered by pressurized air or pressurized hydraulic fluid depending on what pressurized source is available and what load needs to be pivoted.  
         [0019]    Second tilting deck assembly  16  is attached to the other end of frame  20  of rotating base assembly  12 . Tilting deck assembly  16  also comprises a stationary frame  30 , a pivoting deck  32  and a pressure cylinder  34 . Stationary frame  30  is secured to frame  20  of rotating base assembly  12  and it provides mounting locates for both pivoting deck  32  and pressure cylinder  34 . Pivoting deck  32  is pivotably secured to stationary frame  30  such that it is pivotable between a lower position as shown in FIGS. 3 and 4 and an upper position as also shown in FIGS. 3 and 4. In its lower position, pivoting deck  32  can easily be loaded with components that need to be processed or assembled, and it can easily be unloaded with components that have already been processed or empty containers whose parts have already been assembled. In its upper position, or at any position between its lower and upper position pivoting deck  32  can present the unprocessed or unassembled components to an operation at a convenient height or position to eliminate or reduce fatigue of the operator. Pressure cylinder  34  extends between frame  30  and pivoting deck  32 . Pressure cylinder  34  operates to move pivoting deck  32  between its lower position, its upper position and any position between its lower and upper position to present unprocessed or unassembled components to the operator. Pressure cylinder  34  can be powered by pressurized air or pressurized hydraulic fluid depending on what pressurized source is available and what load needs to be pivoted.  
         [0020]    Control system  18  comprises an input system  40 , a first control box  42 , a second control box  44  and a removable handle  46 . Input system  40  receives pressurized gas and/or pressurized hydraulic fluid from an external source and routes these pressurized fluids to the plurality of pneumatic load module assemblies  24 , first tilting deck assembly  14  and second tilting deck assembly  16 . The supply and release of the pressurized fluids is controlled by first and second control boxes  42  and  44 . Control boxes  42  and  44  each include three buttons  50 ,  52  and  54 . Each button  50 ,  52  and  54  on each control box  42  and  44  perform the same function. Each button  50  on control boxes  42  and  44  controls the supply of pressurized air to the plurality of pneumatic load module assemblies  24 . Each button  52  controls the supply of pressurized fluid to first tilting deck assembly  14  to raise and lower its deck  32  using its pressure cylinder  34 . Each button  54  controls the supply of pressurized fluid to second tilting deck assembly  16  to raise and lower its deck  32  using its pressure cylinder  34 .  
         [0021]    The description of the operation for dual rotating stock system  10  will begin with first tilting deck assembly  14  being loaded with unprocessed or unassembled components and being located adjacent the working station and second tilting deck assembly  16  being loaded with processed components or holding an empty container. In this position, the operator at the work station takes components from deck assembly  14  for processing and assembly. The ability of pivoting deck  32  to tilt allows for the convenient positioning of the supply of components initially, as well as the repositioning of the components as the operator works through the supply of components loaded onto deck assembly  14 . While the operator is working through the supply of components loaded onto deck assembly  14 , the supply of processed components or the empty container on deck assembly  16  can be replaced by another supply of unprocessed or unassembled components. The individual responsible for this resupply of unprocessed or unassembled components will have sufficient time for the component exchange for deck assembly  16  while the operator at the work station works through the components on deck assembly  14 .  
         [0022]    When the operator at the working station has exhausted the supply of components in deck assembly  14  and a new supply of components have been placed on deck assembly  16 , the operator actuates the plurality of pneumatic load module assemblies  24  using one of the buttons  50  on box  42  or box  44  to raise stock system  10  above floor  28 . In this position, stock system  10  is supported by a cushion of air. Handle  46  can then be used to rotate base assembly  12  around detent pin assembly  22  to position deck assembly  16  adjacent the working station and position deck assembly  14  opposite to the working station. Handle  46  is removable from a pair of brackets  60  located on opposing sides of base assembly  12  to allow convenient positioning for handle  46 . Rotating base assembly may be provided with one or more detent systems which lock rotating base assembly in the two positions where deck assembly  14  and deck assembly  16  are positioned adjacent the working station if desired. If a detent system is incorporated, it must be released manually or automatically prior to the rotation of base assembly  12 . Pivoting deck  32  of deck assembly  14  can be returned to its lower position either before or after the rotation of base assembly  12  using one of buttons  52  on one of control boxes  42  or  44 . In a similar manner, pivoting of deck  32  of deck assembly  16  can be raised from its lower position either before or after the rotation of base assembly  12  using one of buttons  54  on one of control boxes  42  or  44 .  
         [0023]    When the rotation of base assembly  12  is complete and deck assembly  16  is adjacent the working station, the plurality of pneumatic load module assemblies  24  are deactivated and stock system  10  comes to a stationary position on floor  28 . The operator at the working station continues operating the working station using components from deck assembly  16  while the processed components or empty container is removed from deck assembly  14  and deck assembly  14  is resupplied with unprocessed or unassembled components. When the supply of components in deck assembly  16  becomes exhausted, the resupply process of rotating stock system  10  as described above is performed to now place deck assembly  14  adjacent the working station.  
         [0024]    At times it may be necessary to replace, repair and/or refurbish the manufacturing equipment at the working station. Detent pin assembly  22  is designed to simplify this process. Referring now to FIG. 5, detent pin assembly  22  comprises an outer housing  70 , a pin  72  and a biasing spring  74 . Outer housing  70  is a tubular housing secured to frame  20  and it defines a lower stop  76  and an upper stop  78 . Pin  72  is slidingly received within outer housing  70  with biasing spring  74  being located between a shoulder  80  defined by pin  72  and a stop (not shown) defined by housing  70  such that pin  72  is biased in a downward direction or towards the bottom of frame  20 . A stop  82  extends through pin  72  and is designed to rest within either of lower stop  76  or upper stop  78 . A handle  84  extends through pin  72  to facilitate the movement of pin  72  between a first position where stop  82  engages lower stop  76  and a second position where stop  82  engages upper stop  78 .  
         [0025]    Pin  72  is typically located in its lower position with stop  82  engaging lower stop  76 . In this position, pin  72  extends below the lower surface of frame  20  and engages hole  26  formed into floor  28 . In this position, stock system  10  is rotatable around an axis defined by pin  72  due to the engagement of pin  72  with hole  26 . This rotation of stock system  10  is described above in relation to positioning deck assembly  14  or deck assembly  16  adjacent the working station.  
         [0026]    When it is advantageous to move stock system  10  linearly horizontally along floor  28 , pin  72  can be disengaged from hole  26 . The operator grasps handle  84  and pulls pin  72  upward against the force of biasing spring  74 . Once stop  82  is located above housing  70 , pin  72  can be rotated to align stop  82  with upper stop  78  and handle  84  can be released to engage stop  82  with upper stop  74 . In this position, the end of pin  78  is located above or even with the lower surface of frame  20  and therefore no longer defines a vertical axis for rotation. The operator activates the plurality of pneumatic load module assemblies  24  using one of the buttons  50  on box  42  and box  44  to raise stock system  10  above floor  28 . In this position, stock system  10  is supported by a cushion of air. Handle  46  can then be used to move stock system  10  horizontally along floor  28  to provide access to the machining equipment at the working station. The amount of horizontal movement of stock system  10  will be determined by the length of flexible lines providing the pressurized fluid and the availability of open space around stock system  10 . Once stock system  10  has been moved, the pressurized air is removed from the plurality of pneumatic load module assemblies  24  and stock system  10  will come to rest at its new location.  
         [0027]    When it is desired to move stock system back to its original position, pressurized air is provided to the plurality of pneumatic load module assemblies  24 , stock system  10  is moved to align pin  72  with hole  26 , pin  72  is returned to its lower position and the pressurized air is removed from the plurality of pneumatic load module assemblies  24 .  
         [0028]    The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.