Abstract:
A transfer apparatus has a vertical guide rod, on which a vertical carriage slides, which is integrated with a horizontal carriage, both of which support a transfer bar and gripping members that are responsible for the automatic handling of stamped parts in process. The transfer apparatus has a shaft limiter, below which there is a right angle lever with a stop, and a horizontal guide rod where the horizontal carriage slides. The transfer apparatus has a drive lever to drive a connecting rod which is connected to the right angle lever and has an adjustable stop toward a fixed stop, which limits the travel of the horizontal carriage in the Y-axis direction. The transfer apparatus in question has a continuous operating cycle and is controlled by a central processing unit.

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from Brazilian Patent Application No. PI-0803973-9 filed Sep. 29, 2008, the entire contents of which are hereby incorporated by reference into this application. 
     TECHNICAL FIELD 
     The present invention generally relates to a transfer apparatus, such as the type commonly used to transfer stamped, molded or other processed parts between work stations. 
     BACKGROUND 
     It is known for systems to use part transference between sequential work stations in a manufacturing process, particularly in a stamping press. Other processes and equipment, sometimes referred to as transfer sets, may also be used for the transference of parts that are to be formed, molded and are installed inside or adjacent their work process, known as operations. These are usually installed in the equipment (presses) in order to process the parts in a sequence of operations to be manufactured. This parts transference can be made manually (e.g., average production of around 350 parts per hour), but due to the demand for higher productivity of equipment, there is an increased demand for automated systems that allow the press to work in a continuous cycle (e.g., average production of 1,000 to 1,500 parts/hour). The advantages to the cost of parts can be obvious and substantial, however, the parts transference between the various process stages while the press (or other machine) is working in a continuous cycle requires technology. 
     SUMMARY 
     According to one embodiment, there is provided a transfer apparatus for moving parts between work stations and for use in equipment such as transfers and the like. The transfer apparatus is characterized by having: a vertical guide rod which slides up and down; a vertical carriage; and a horizontal carriage with forward and back displacement where there is mounted a transfer bar and gripping elements. The transfer apparatus is provided with a shaft limiter, which is located below a right angle lever, this with a stop and a horizontal guide rod, in which slides forward and back the whole horizontal carriage. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred exemplary embodiments of the invention will hereinafter be described in conjunction with the appended drawings, wherein like designations denote like elements, and wherein: 
         FIG. 1  is an elevation view of an exemplary transfer apparatus, where the apparatus is shown in an open and non-elevated position; 
         FIG. 2  is an elevation view of the transfer apparatus of  FIG. 1 , wherein the apparatus is shown in a closed and non-elevated position; 
         FIG. 3  is an elevation view of the transfer apparatus of  FIG. 1 , wherein the apparatus is shown in a closed and elevated position; 
         FIG. 4  is another elevation view of the transfer apparatus in the closed and non-elevated position of  FIG. 2 ; 
         FIG. 5  is another elevation view of the transfer apparatus in the open and non-elevated position of  FIG. 1 ; 
         FIG. 6  is an enlarged elevation view of the transfer apparatus of  FIG. 1 ; 
         FIG. 7  is a side view of the transfer apparatus of  FIG. 1 ; 
         FIG. 8  is a plan view of the transfer apparatus of  FIG. 1 ; 
         FIG. 9  is another elevation view of the transfer apparatus of  FIG. 1 ; 
         FIG. 10  is a perspective view of the transfer apparatus of  FIG. 1 ; 
         FIG. 11  is an elevation view of the transfer apparatus of  FIG. 1 , wherein the apparatus is shown in a fully opened position; 
         FIG. 12  is an elevation view of the transfer apparatus of  FIG. 1 , wherein the apparatus is shown in a fully closed position; 
         FIG. 13  is an elevation view of the transfer apparatus of  FIG. 1 , wherein the apparatus is shown opposing an additional transfer apparatus; and 
         FIG. 14  is a schematic plan view of the transfer apparatus of  FIG. 1 , wherein the apparatus is shown—along with three other transfer apparatuses—being installed along a manufacturing line. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A transfer apparatus  20  is shown and described below that may be used to transfer parts or components between different work stations and, depending on the particular embodiment, may provide movement in an X-axis direction (horizontal), a Y-axis direction (horizontal) and/or a Z-axis direction (vertical). According to an exemplary two-axis embodiment, the transfer apparatus engages in movement in the X- and Y-axes; in an exemplary three-axis embodiment, the transfer apparatus engages in movement in the X-, Y- and Z-axes. In both cases, transfer apparatus  20  engages a transfer mechanism  32  and causes it to grasp and transfer parts from one work station to the next so that separate machines—such as stamping, molding and/or welding machines—can each work the parts as they cycle through. It should be appreciated that the transfer apparatus  20  and transfer mechanism  32  shown and described herein may be used with any combination of machines and equipment, and are not limited to the stamping, molding and/or welding machines mentioned above. Furthermore, the transfer apparatus  20  and the transfer mechanism  32  may be used to move, index or advance any type of part, component or work piece, and is not limited to any one particular type. 
     With reference to  FIG. 14 , a general overview of a manufacturing line  18  is shown, where the manufacturing line includes two pairs of opposing transfer apparatuses  20 ,  20 ′ and  21 ,  21 ′ that are mounted along a sequence of work stations  24 ,  26 ,  28 ,  30 , etc. Each of the work stations may include one or more types of suitable machines, such as the exemplary stamping, molding and/or welding machines mentioned above. The two pairs of opposing transfer apparatuses  20 ,  20 ′ and  21 ,  21 ′ work together to engage and operate a transfer mechanism  32 , which includes two longitudinal transfer bars  4  and a number of pairs of gripping members  14 . Each pair of gripping members  14  grasps and releases parts  22  so that they can be moved or advanced between work stations  24 ,  26 ,  28 ,  30 , etc. Generally speaking, transfer apparatuses  20 ,  20 ′ and  21 ,  21 ′ drive transfer mechanism  32  between open and closed positions (Y-axis movement) and between non-elevated and elevated positions (Z-axis movement), while a drive mechanism  19  moves the transfer mechanism  32  between work stations (X-axis movement). Those skilled in the art will appreciate that any number of different drive mechanisms  19  may be used with the transfer mechanism  32  described below, and that the transfer mechanism is not limited to any one particular drive mechanism. Each of the drive apparatuses  20 ,  20 ′ and  21 ,  21 ′ may be both modular and compact; that is, each drive apparatus may be an independent unit that can be combined with other apparatuses and easily rearranged or interchanged to form different systems, and is small and makes an efficient use of space. 
     In an open position (i.e., retracted away from a centerline CL that longitudinally extends down the length of manufacturing line  18 ), transfer mechanism  32  is opened up such that it does not engage the parts  22 . This allows each of the work stations  24 ,  26 ,  28 ,  30 , etc. to perform their designated task on their respective part  22 . In a closed position (i.e., advanced towards the centerline CL), transfer mechanism  32  is closed such that it engages or grasps the parts  22  and is ready to index or advance them to the next work station. When it is time to transfer or advance the parts to the next work station, the transfer apparatuses  20 ,  20 ′ and  21 ,  21 ′ are also in a closed position so that transfer mechanism  32  simultaneously engages all of the parts along the manufacturing line  18 , and drive mechanism  19  moves the entire transfer mechanism  32  along the X-axis so that all of the parts move together. The transfer apparatuses  20 ,  20 ′ and  21 ,  21 ′ then cause the transfer mechanism  32  to release the parts so that the transfer mechanism can be returned along the X-axis to its previous position. Although  FIG. 14  shows two pairs of transfer apparatuses (a first pair  20 ,  20 ′ and a second pair  21 ,  21 ′), it should be appreciated that a different number of transfer apparatuses may be used with manufacturing line  18 . For instance, shorter manufacturing lines having fewer work stations may have a single transfer apparatus pair; longer manufacturing lines having greater work stations may need three or more pairs of transfer apparatuses. The transfer apparatus  20  and transfer mechanism  32  described herein are not limited to any particular arrangement. 
     Turning now to  FIGS. 6-8 , there is shown an exemplary embodiment of transfer apparatus  20  (transfer apparatus  20 ′ may be a mirror image and is thus not separately described here). Transfer apparatus  20  may include one or more vertical guide rods  1 , a vertical carriage  2 , a horizontal carriage  3 , a shaft limiter  5 , a right angle lever  6 , one or more horizontal guide rods  7 , a drive member  8 , an adjustable stop  9 , a fixed stop  10 , a connecting rod  11 , a stop  12 , and a base  13 . An exemplary transfer mechanism  32 , shown best in  FIG. 14 , includes a pair of elongated transfer bars  4  that carry a number of pairs of gripping members  14  and are driven back and forth along an X-axis by drive mechanism  19 . The drive mechanism  19  is coupled to the transfer bars  4  by one or more flexible joints  33  that enable the transfer bars to be spread apart and brought together under the power of the transfer apparatuses  20 ,  20 ′ and  21 ,  21 ′ without being disconnected from the drive mechanism. Any number of different drive mechanism/flexible joint arrangements known in the art may be used. 
     The vertical guide rods  1  are aligned so that vertical carriage  2  can slide up and down in the Z-axis direction; as subsequently explained, this feature is optional as some embodiments may not require vertical or Z-axis movement. Similarly, horizontal guide rods  7  are aligned so that horizontal carriage  3  can move back and forth in the Y-axis direction. A single guide rod or multiple guide rods may be used for items  1  and  7 . Adjustable and fixed stops  9  and  10  may be used to limit or control the range of motion in the Y-axis direction. Right angle lever  6  is shown here having a generally L-shaped or right-angle configuration and is operably attached between connecting rod  11  and shaft limiter  5 . It is not necessary that right angle lever  6  be L-shaped, as other configurations and arrangements are certainly possible; but a 90° transfer of movement can result from 90° action points, and the “L” shape shown in the drawings is a simple and suitable shape for that. 
     Drive member  8  may be driven by a rotational drive mechanism (not shown) about a center shaft  34 , and is pivotally attached to one end of connecting rod  11 . As best shown in  FIG. 13 , a single drive member  8  may be connected to a first connecting rod  11  of a first transfer apparatus  20  and to a second connecting rod  11 ′ of a second transfer apparatus  20 ′, such that the two connecting rods move in unison in response to rotation of drive member  8  about shaft  34 . Base  13  acts as a foundation for transfer apparatus  20 , and may be securely fastened to the floor of the manufacturing facility or to some other pedestal or foundational component. Gripping members  14  are operably mounted to and carried by transfer bars  4  and are designed to grasp or clutch parts  22  so that they can be advanced from one work station to the next. The particular design and nature of the gripping members  14  may be dictated by the part or work piece that they are intended to move; not all of the gripping members  14  need to be the same, as a work piece may require different types of gripping members as it advances through the manufacturing line. For example, some gripping members may have soft rubbery pads for gently engaging a work piece, while others may be equipped with suction and/or magnetic elements, for example, for indexing sheet metal stock. Additional guide rods, carriages, transfer bars, shafts, stops, members, elements, and other components could also be used to provide additional freedoms of motion and capabilities to the exemplary transfer apparatus and transfer mechanism shown here. 
       FIGS. 1-5  illustrate an operating cycle for transfer apparatus  20 , where the machine transitions through the following sequence of positions: from an open and non-elevated position (position “A”) in  FIG. 1 , to a closed and non-elevated position (position “B”) in  FIG. 2 , to an optional closed and elevated position (position “C”) in  FIG. 3 , back to a closed and non-elevated position in  FIG. 4 , and back to an open and non-elevated position in  FIG. 5 . Movement between open and closed positions generally involves moving along the Y-axis, while movement between the non-elevated and elevated positions generally involves moving along the Z-axis. Transferring parts or components between operating stations typically involves moving along the X-axis, and is illustrated in  FIGS. 7 and 14 . Skilled artisans should appreciate that the transfer apparatus described herein is not limited to a three-axis embodiment, and that a two-axis embodiment that does not provide for movement in the Z-axis is also possible. 
     Beginning with  FIG. 1 , the exemplary transfer apparatus  20  is shown in a starting or open position (position “A”), where the transfer bars  4  and gripping members  14  are in an open position. This may occur in the operating cycle just after the point when the part is stamped, molded, or otherwise formed by the various work stations  26 ,  28 ,  28 ,  30 , etc. At the appropriate time, a command is generated that causes a rotational drive mechanism (e.g., one having pneumatic, hydraulic and/or electric drive means) to rotate drive member  8  in a clockwise direction (see arrows in  FIGS. 1-2 ) such that connecting rod  11  is pulled back towards the centerline CL. This, in turn, pulls horizontal carriage  3  along horizontal guide rods  7  towards the centerline CL so that the gripping members  14 , which are carried by transfer bars  4 , may contact and handle the part  22 . These actions result in the closed and non-elevated position of  FIG. 2  (position “B”). It should be appreciated that a concurrent and synchronized event also occurs with transfer apparatus  20 ′, which is located across the centerline CL from transfer apparatus  20 , so that part  22  is engaged by a pair of opposing gripping members  14 . 
     In a two-axis embodiment, the transfer apparatus  20  generally does not perform any vertical lifting or Z-axis movement. Therefore, the part  22  would be ready to be transferred to the next work station along the X-axis under the power of drive mechanism  19  without experiencing any vertical displacement. In a three-axis embodiment, however, an additional lifting step (Z-axis movement) may be performed before the part  22  is advanced to the next work station. Such a step may be helpful for properly evacuating or removing the part from the work station. This is shown as the closed and elevated position in  FIG. 3  (position “C”) and is an optional step. According to one embodiment, once the drive member  8  reaches the position illustrated in  FIG. 2  and stops  9  and  10  engage one another so that further Y-axis movement is prohibited, the pivotal connections at one or both ends of the connecting rod  11  lock (e.g., the pivotal connection between the inner end of connecting rod  11  and drive member  8  lock and/or the pivotal connection between the outer end of connecting rod  11  and the lower end of right angle lever  6  lock) such that additional clockwise rotation of the drive member  8  causes the right angle lever  6  to lift up in the vertical direction (Z-axis). This in turn causes the vertical carriage  2  to slide up the vertical guide rods  1  such that the transfer bars  4  and gripping members  14  lift up the various parts or components  22  before advancing them to the next work station. A corresponding and concurrent sequence of events may occur in the other transfer apparatus  20 ′ located across the centerline CL, such that transfer mechanism  32  and parts  22  are vertically lifted out of their respective work station (Z-axis movement) before being advanced or indexed to the next work station (X-axis movement). 
     Transfer mechanism  32  may grip and move the parts  22  along the X-axis according to one of a number of different techniques. In one embodiment, the X-axis movement is provided by drive mechanism  19  which pushes and pulls the transfer bars  4  in the X-axis direction (i.e., a direction parallel to the centerline CL) so that a keyed or male component  15  of the transfer bar  4  can slide within a complementary female component  16  of the vertical carriage  2  (see  FIG. 6 ). The embodiment shown in the drawings uses a dovetail-type arrangement, however, this is only one possibility as other arrangements are certainly possible. This X-axis movement occurs simultaneously at all of the work stations so that all of the parts in the system are indexed or advanced together. In the exemplary sequence of steps illustrated in  FIGS. 1-5 , this X-axis movement or advancement between work stations may occur between  FIGS. 3 and 4 . 
     Once the parts  22  have been properly advanced to the next work station, transfer apparatus  20  may be used to lower the parts into place for additional processing; closed and non-elevated position in  FIG. 4  (position “B”). At the end of the part transfer (X-axis movement) and the lowering of the parts (Z-axis movement), a reverse set of steps may be performed in order to return the transfer apparatus  20  and transfer mechanism  32  to their initial open and non-elevated position (position “A”). Drive member  8  can be rotated in the counter clockwise direction so that connecting rod  11  is pushed outward and the transfer apparatus returns to the open and non-elevated position of  FIG. 5  (position “A”). The drive mechanism  19  can then be used to return the different transfer apparatuses along the X-axis to their initial positions; thus, completing the cycle. This occurs simultaneously at all of the transfer apparatuses  20 ,  20 ′ and  21 ,  21 ′ so that both transfer bars  4  and all of the gripping members  14  are opened and closed together. Thus,  FIGS. 1-5  demonstrate an operating cycle that can be used in a continuous process, where the next operating cycle simply picks up where the preceding one left off. 
     According to an exemplary embodiment, the transfer apparatus  20  may be driven between the “fully open” and “fully closed” positions shown in  FIGS. 11-12 . Put differently, it is possible for drive member  8  to be driven through 180° of displacement so that a certain amount of mechanical acceleration and/or deceleration is experienced. This may be helpful, for example, when the drive member  8  is driven by a pneumatic or hydraulic cylinder in the rotational drive mechanism. The fully open position occurs when the gripping members  14  are pushed furthest away from the centerline CL; this is demonstrated in  FIG. 11 , where the connecting rod  11  is in a generally horizontal orientation. The fully closed position occurs when gripping members  14  are pulled closest to the centerline CL, and is demonstrated in  FIG. 12 . In the fully closed position, the horizontal carriage  3  is pulled as close as possible to the centerline CL so that adjustable stop  9  contacts fixed stop  10  and prevents the transfer apparatus from additional Y-axis movement towards the centerline CL. The movement inhibiting interaction between stops  9  and  10  can be seen in  FIG. 12 . 
     Skilled artisans will appreciate that any combination of known components, devices, features, etc. may be used with the exemplary transfer apparatus  20  described above. For example, an electric motor and/or a hydraulic or pneumatic cylinder may be used in any of the drive mechanisms in order to facilitate the various horizontal, vertical and/or rotational movements described above. Moreover, the description provided above in connection with the exemplary transfer apparatus  20  applies equally to transfer apparatuses  20 ′,  21 ,  21 ′, etc. 
     It is to be understood that the foregoing description is not a definition of the invention, but is a description of one or more preferred exemplary embodiments of the invention. The invention is not limited to the particular embodiment(s) disclosed herein, but rather is defined solely by the claims below. Furthermore, the statements contained in the foregoing description relate to particular embodiments and are not to be construed as limitations on the scope of the invention or on the definition of terms used in the claims, except where a term or phrase is expressly defined above. Various other embodiments and various changes and modifications to the disclosed embodiment(s) will become apparent to those skilled in the art. All such other embodiments, changes, and modifications are intended to come within the scope of the appended claims. 
     As used in this specification and claims, the terms “for example,” “e.g.,” “for instance,” “such as,” and “like,” and the verbs “comprising,” “having,” “including,” and their other verb forms, when used in conjunction with a listing of one or more components or other items, are each to be construed as open-ended, meaning that that the listing is not to be considered as excluding other, additional components or items. Other terms are to be construed using their broadest reasonable meaning unless they are used in a context that requires a different interpretation.