Patent Publication Number: US-6662926-B1

Title: Transfer apparatus

Description:
This is a divisional application of co-pending application Ser. No. 09/839,196 entitled “Transfer Apparatus”, filed Apr. 19, 2001. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to transfer apparatus for transferring an article laterally off of a conveyor system. 
     2. Description of the Prior Art 
     In the design of conveyor systems such as those utilized in manufacturing operations and warehousing and shipping operations, roller type conveyors are often utilized. 
     A roller conveyor has a plurality of regularly spaced cylindrical rollers upon which the articles, typically boxes, roll as the articles move along the length of the conveyor. 
     The rollers are powered in order to drive the articles along the conveyor, and power can be provided to the rollers in many different ways. 
     One conventional type of driven roller conveyor system is that generally known as a belt driven live roller system. A belt driven live roller system utilizes an endless drive belt that runs along the center of the conveyor with the upper side of the drive belt engaging lower surfaces of the drive rollers so that the drive rollers are driven by the drive belt. A series of idler rollers are located on the opposite side of the drive belt from the drive rollers in order to create the appropriate frictional engagement of the drive belt with the drive rollers. 
     Another conventional type of driven roller conveyor system is that known as a line shaft drive conveyor. A line shaft drive conveyor has a drive shaft located below the rollers and typically oriented adjacent the edge of one side of the conveyor. Each of the drive rollers is connected to the drive shaft by a flexible belt oriented in somewhat of a figure-8 shape so as to transfer the rotation of the drive shaft to rotation of the drive rollers. 
     Other types of driven roller conveyor systems include a “DC roller” system wherein some of the rollers have electric motors built into them, and each motor driven roller is connected to several other non-powered rollers with flexible drive belts. One DC powered roller will drive four or five adjacent rollers. 
     With any conveyor system there is a need for a transfer apparatus to move selected articles laterally off of the main conveyor. 
     With some of the above noted standard forms of driven roller conveyors, such as for example, the line shaft drive conveyor, transfer mechanisms have been constructed which utilize a plurality of transfer drive belts carried on a transfer frame. When it is desired to move an article laterally off of the conveyor, the transfer frame raises up so that the transfer drive belts extend up above the top of the rollers to lift an article off of the rollers. The drive belts are oriented parallel to the rollers and thus, the drive belts will move the article laterally when it engages the article. 
     With other types of driven roller conveyor systems, however, such as for example, the belt driven live roller conveyor, such a transfer mechanism has never been possible because the main conveyor drive belt is located along the center line of the conveyor and thus would interfere with the placement of such a transfer device. Accordingly, the transfer devices used to date with belt driven live roller systems have consisted of a pusher mechanism located at an elevation above the main conveyor rollers, which simply engages the article and shoves it laterally off of the main conveyor. As will be appreciated by those skilled in the art, such a pusher type transfer device does not provide precise control of the articles which are being moved laterally. 
     Accordingly, there is a continuing need for improved transfer devices, and particularly for improved transfer devices for use with a belt driven live roller conveyor system. 
     SUMMARY OF THE INVENTION 
     In a first embodiment the present invention provides a transfer device for transferring articles laterally off of a conveyor such as a belt driven live roller conveyor. The apparatus includes at least one, and preferably a plurality of transfer drive belts. Each of the drive belts is mounted upon a transfer frame with a plurality of belt guides, preferably roller pulleys. Each drive belt is mounted upon its respective belt guides so as to define a serpentine belt path having first and second uppermost belt portions for engaging the article to be transferred, and a lower belt portion located between the first and second uppermost belt portions. This provides a U-shape path for the upper portion of the transfer drive belt, with the bottom of the U being sufficiently deep that a conventional main conveyor drive belt of a belt driven live conveyor system can be received within the U. Thus the first and second uppermost belt portions will rise up through the rollers of the conveyor system on either side of the main conveyor drive belt to engage the article and move it laterally off of the main conveyor. A lifting mechanism is operably associated with the transfer frame and moved between a retracted position wherein the drive belt is located below the articles on the conveyor, and a raised position wherein the first and second uppermost belt portions of each transfer drive belt engage the article to be transferred. 
     Preferably the transfer drive belt is a toothed belt and it is driven from a toothed drive sprocket driven by a drive motor. The motor preferably has a brake so that very precise position control can be provided to the article being transferred. 
     The lifting mechanism preferably includes an actuating ram having an axis oriented parallel to the rollers and thus parallel to the width of the main conveyor system. 
     The apparatus preferably includes a stop abutment attached to the transfer frame and extending upwardly on an upstream side of the transfer apparatus so that when the lifting mechanism is in its raised position, the stop abutment extends above the main roller conveyor. 
     Certain aspects of the invention such as the toothed drive belts with associated toothed sprocket and motor with a motor brake, the lifting mechanism having the actuating ram oriented parallel to the width of the main conveyor, and the use of the stop abutment are also applicable to other types of conveyor systems other than the belt driven live roller conveyor system. For example, these features may be utilized with a line shaft drive conveyor system. 
     Accordingly, it is an object of the present invention to provide an improved transfer mechanism for use with conveyor systems. 
     Another object of the present invention is the provision of a transfer mechanism which may be utilized with a belt driven live roller conveyor system. 
     And another object of the present invention is the provision of a transfer mechanism utilizing toothed belts, particularly with a toothed drive sprocket driven by a motor having a motor brake so as to provide precise lateral position control. 
     And another object of the present invention is the provision of transfer mechanisms utilizing a stop abutment to prevent interference by a following article with an article being laterally transferred. 
     And another object of the present invention is the provision of an improved lifting mechanism for use with a transfer apparatus. 
     And another object of the present invention is the provision of a transfer mechanism which can easily be removed from the main conveyor system by simply unbolting a support frame from the frame of the main conveyor system and dropping the transfer mechanism out from between the rollers of the main conveyor system. 
     Other and further objects, features and advantages of the present invention will be readily apparent to those skilled in the art upon a reading of the following disclosure when taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view of the transfer apparatus of the present invention installed on a belt driven live roller conveyor system. 
     FIG. 2 is a side elevation view of the apparatus of FIG.  1 . 
     FIG. 3 is an end elevation view of the apparatus of FIG. 1 showing the transfer drive belts in their raised position. 
     FIG. 4 is an end elevation view of the apparatus of FIG. 1 showing the transfer drive belts in their lowered position. 
     FIG. 5 is a plan view similar to FIG. 1 but showing only the transfer assembly without the belt driven live roller conveyor. 
     FIG. 6 is a side elevation view of the apparatus of FIG.  5 . 
     FIG. 7 is an end elevation view of the apparatus of FIG. 5 showing the transfer drive belts in their raised position. 
     FIG. 8 is a plan view similar to FIG. 5, but showing only the fixed support frame portion of the transfer mechanism. 
     FIG. 9 is a side elevation view of the support frame of FIG.  8 . 
     FIG. 10 is an end elevation view of the support frame of FIG.  8 . 
     FIG. 11 is a plan view similar to FIG. 5, but showing only the transfer frame and lifting mechanism of the transfer apparatus of FIG.  5 . 
     FIG. 12 is a side elevation view of the transfer frame and lifting mechanism of FIG.  11 . 
     FIG. 13 is an end elevation view of the transfer frame and lifting mechanism of FIG. 11 showing the same in its raised position. 
     FIG. 14 is an end elevation view of the transfer frame and lifting mechanism of FIG. 11 showing the same in its lowered position. 
     FIG. 15 is a plan view of an alternative embodiment of the transfer apparatus of the present invention as installed on a line shaft drive conveyor system. 
     FIG. 16 is a side elevation view of the apparatus of FIG.  15 . 
     FIG. 17 is an end elevation view of the apparatus of FIG. 15 showing the transfer drive belts in their raised position. 
     FIG. 18 is an end elevation view of the apparatus of FIG. 15 showing the transfer drive belts in their lowered position. 
     FIG. 19 is a schematic view of a toothed belt and sprocket. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now the drawings, and particularly to FIGS. 1-4, the transfer apparatus of the present invention is shown and generally designated by the numeral  10 . The transfer apparatus  10  is shown assembled in combination with a belt driven live roller conveyor system  12 . 
     The belt driven live roller conveyor system  12  which may be generally referred to as the main conveyor  12 , includes a frame made of first and second spaced channels  14  and  16  with a plurality of regularly spaced cylindrical rollers  18  spanning the width of the conveyor  12  between the channels  14  and  16 . 
     The main conveyor  12  includes a main conveyor drive belt  20  which is an endless drive belt having an upper portion  20 A and a lower portion  20 B as seen in FIG.  2 . 
     At regular intervals between adjacent rollers  18  there is an idler roller  22  which is adjustable to apply an upward pressure to the upper run  20 A of the drive belt  20  in order to maintain an appropriate frictional engagement between the drive belt  20  and the lower surface of the rollers  18  so that the rollers  18  are driven by the drive belt  20 . Articles carried on the conveyor  12  are driven along the length of the conveyor  12  by the rollers  18 . 
     The transfer apparatus  10  includes a support frame  24  which spans the width of the main conveyor  12  and which is bolted to the lower flanges of the channels  14  and  16  of main conveyor  12 . The details of construction of the support frame  24  may best be seen in the isolated view of FIGS. 8-10. 
     The transfer apparatus  10  further includes a transfer frame  26  and a lifting mechanism  28 . The details of construction of transfer frame  26  and lifting mechanism  28  are best seen in the isolated views of FIGS. 11-14. The transfer frame  26  includes first and second vertical frame plates  30  and  32 . Each frame plate such as frame plate  30  is supported on two pivot pins  34  and  36  which are attached to the lifting mechanism  28 . 
     The lifting mechanism  28  includes an actuating ram  38 , one end of which is bolted to support beam  40  of support frame  24 . A piston  42  extends from ram  38  and is connected to a lever arm  44  which is fixed to a pivotable actuating bar  46  so that the actuating bar  46  can be rotated back and forth through a small arc by the extension and retraction of the piston  42  of ram  38 . The actuating bar  46  is rotatably mounted to the support frame  44  by bearing blocks  64  and  66 , which are best seen in FIG.  8 . 
     The actuating ram  38  and its piston  42  have a central axis  43  (see FIG. 1) oriented parallel to a width of the conveyor  12 . 
     Near either end of the actuating bar  46  adjacent the vertical frame plates  30  and  32  are actuating linkages  48  and  50 , respectively. The actuating linkage  48  is connected to the first vertical frame plate  30  by pivot pin  34 , and the actuating linkage  50  is similarly connected to the second vertical frame plate  32 . 
     The linkages  48  and  50  are also pivotally connected to transverse connector links  52  and  54 , respectively, which are in turn connected to follower links  56  and  58  which are in turn pivotally connected to the other ends of the vertical frame plates  30  and  32  by pivot pins  36  and  62 . 
     The follower links  56  and  58  pivot about a shaft  68  which is carried in bearing blocks  70  and  72  which are mounted on the support frame  24 . 
     Thus, the vertical plates  30  and  32  can be moved between their raised positions shown in FIG.  13  and their lowered positions shown in FIG. 14 by the extension or retraction, respectively, of the piston  42  of actuating ram  38 . 
     As best seen in FIG. 13, each of the plates  30  and  32  has a U-shape opening  31  in its upper side. Gap bars  33  and  35 , best seen in FIG. 5, span the openings  31  at an elevation level with the top edge  37  of the plates  30  and  32 . The gap bars  33  and  35  are attached with cap screws, and are put in place after the transfer device  10  is assembled with the main conveyor  12 . The gap bars will be located above the main conveyor drive belt  20 . 
     A plurality of belt guides  74 A- 74 H, which may also be referred to as roller pulleys  74 , and a toothed drive sprocket  76  are supported from the first vertical frame plate  26  and have a first transfer drive belt  78  mounted thereon. As can best be seen in FIG. 3, the transfer drive belt  78  as mounted upon the roller pulleys  74  and drive sprocket  76  defines a serpentine belt path having first and second uppermost belt portions  78 A and  78 B, and a lowered or dropdown belt portion  78 C located between the first and second uppermost belt portion  78 A and  78 B. 
     The uppermost belt portions  78 A and  78 B when in their raised position as seen in FIG. 3, extend above a top surface  80  of the rollers  16  so as to engage in an article such as a box moving down the length of the conveyor  12 . The lowered belt portion  78 C, at all times is located below the return run  20 B of the main conveyor drive belt  20  so there is no interference therebetween. 
     As seen in FIG. 4, when the lifting mechanism  28  is in its retracted position, the uppermost portions  78 A and  78 B of the transfer drive belt  78  are located below the top surface  80  of roller  16  so as not to engage any article moving down the length of the conveyor  12 . 
     A second similarly constructed transfer drive belt  82  is mounted upon the second vertical frame plate  32 . 
     As can best be seen in FIG. 1, the first and second transfer drive belts  78  and  82  are each located between two adjacent ones of the regularly spaced rollers  18  so that none of the regularly spaced rollers  18  of the main conveyor  12  have been removed to accommodate the placement of the transfer apparatus  10 . 
     A drive motor  84  drives through a transfer case  86  to turn a drive shaft  88  which has the drive sprocket  76  attached to one end thereof and a second drive sprocket  90  attached to the other end thereof to drive the belts  78  and  82 . The transfer case  86  is bolted to a support plate  87  (see FIG.  5 ), which is part of the transfer frame  26 . 
     The drive sprockets  76  and  90  are toothed drive sprockets and they engage the drive belts  78  and  82 , which are toothed drive belts in a positive non-slip manner. The drive belts  78  and  90  are toothed drive belts constructed similar to a timing belt of an automobile engine. FIG. 19 schematically shows toothed belt  78  engaging toothed sprocket  76 . 
     The transfer case  86  and the shaft  88  and sprockets  76  and  90  may be described as a transfer drive train between the drive motor  84  and the first and second drive belts  78  and  82 . 
     Additionally, the motor  84  may include an internal motor brake. The combination of the drive motor with motor brake and the positive toothed engagement between the drive sprockets and the drive belts allows precise lateral position control of an article being transferred laterally with the transfer apparatus  10 . 
     With the construction just described, the transfer apparatus  10  can be very easily assembled with or removed from the belt driven live roller conveyor  12  in the following manner. 
     If the transfer apparatus  10  and main conveyor  12  are already assembled as shown in FIGS. 1-4, the transfer apparatus  10  may be removed by merely unbolting the support frame  24  from its bolted engagement with the channels  14  and  16  of main conveyor  12 , and removing the gap bars  31  and  33  and the stop piece  92 , and lowering the lifting apparatus downward. 
     The transfer apparatus  10  can similarly be easily installed by simply inserting the same from below into position and bolting the support frame  24  to the channels  14  and  16  of the main conveyor  12 , and then hooking up the various hydraulic and/or electrical power connections to the same. Thus, neither the main conveyor drive belt  20  nor the transfer drive belts  78  or  82  need to be removed to assemble the transfer apparatus  10  with the main conveyor  12  or to disassemble the same. 
     As best seen in FIG. 2, the transfer apparatus  10  may include a stop abutment  92  attached to the transfer frame  24  and extending upwardly on an upstream side of the transfer apparatus  10 . As viewed in FIG. 2, articles such as boxes  300  and  302  are moving down the length of the conveyor from left to right. Thus, the left end of transfer apparatus  10  as seen in FIG. 2 is the upstream end or upstream side, and the right end of the apparatus shown in FIG. 2 is the downstream end or downstream side. 
     The stop abutment  92  is comprised of a cross bar  94  carried by first and second L-shaped brackets  96  and  98 . 
     As can best be seen in FIG. 2, when the transfer apparatus  10  is in its raised position where the first and second transfer belts  78  and  82  extend upward above the rollers  18 , the stop abutment  92  also extends above the rollers  18 . Thus, while the transfer apparatus  10  is in its raised position, a box  302  moving downstream toward the transfer apparatus  10  will engage stop abutment  92  and thus cannot interfere with another box  300  which is being raised and transferred by the transfer apparatus  10 . 
     The transfer apparatus  10  works in the following manner. As previously noted, conventional articles such as cardboard boxes  300  and  302  are moving down the conveyor  12  from left to right as viewed in FIGS. 1 and 2. The position of the various articles on the conveyor  12  can be sensed by various position detectors in a known manner. 
     When an article  300  is selected to be transferred laterally off of the main conveyor  12 , which will be accomplished through the use of the conventional position detectors, the transfer apparatus  10  will be raised from its lowered position shown in FIG. 4 to its raised position shown in FIG. 3, and will come up under the selected article and lift the selected article off of the rollers  18 . Then, the transfer belts  78  and  82  will move the article laterally to either side as controlled by the motion of the drive motor  84 . 
     Also, the transfer apparatus  10  allows an article to be transferred onto the main conveyor  12  from a laterally offset position. When transferring articles onto the main conveyor  12 , the braking mechanism of the drive motor  84  is utilized to accurately position the article on the main conveyor. Since the drive motor  84  includes a braking mechanism, the lateral position of the article by the drive belts  78  and  82  can be precisely controlled. 
     When the apparatus  10  is in its raised position to laterally transfer an article, any other articles upstream of the apparatus  10  will be prevented from moving into a position above the apparatus  10  and interfering with the transfer, due to the stop abutment  92  which will engage any such upstream articles. 
     The article being transferred will be engaged in at least four positions, namely the two uppermost portions of each of the serpentine drive belts  78  and  82 . Two of the four locations are on either side of the main conveyor drive belt  20 . 
     ALTERNATIVE EMBODIMENT OF FIGS.  15 - 18   
     Referring now to FIGS. 15-18, an alternative transfer apparatus  200  is thereshown assembled in combination with a line shaft drive main conveyor system  202 . 
     The line shaft drive conveyor system  202  includes first and second spaced channels  204  and  206  having a plurality of rollers  210  spanning therebetween. 
     A line shaft  212  extends parallel to the length of the conveyor  202  adjacent the side thereof defined by channel  206 . As will be understood by those skilled in the art, the line shaft  212  is a powered shaft which is rotating to provide power to the rollers  210 . 
     As best seen in FIG. 16, rotational motion is transferred from the line shaft  212  to each of the rollers  210  through a take off belt  214  received about a pulley  216  on the line shaft  212  and received within a drive groove  218  (see FIG. 15) in each of the rollers  210 . The take off belt  214  is arranged in somewhat of a figure-8 shape. 
     Since the line drive conveyor system  202  does not have a drive belt down the center thereof, the transfer apparatus  200  can utilize first and second transfer drive belts  220  and  222  which extend substantially all the way across the width of the conveyor  202 . Thus, the transfer apparatus  200  does not need to utilize the serpentine arrangement of the transfer drive belts of transfer apparatus  10  previously discussed. 
     Other aspects of the transfer apparatus  10 , however, are embodied in the transfer apparatus  200 . 
     One of the features carried over to the transfer apparatus  200  is the lifting mechanism  28  which is constructed in substantially identical fashion to the lifting mechanism  28  previously described. 
     Another feature carried over from the transfer apparatus  10  is the use of toothed drive sprockets such as  224  and the use of a toothed design for the belts  220  and  222 . 
     Although not illustrated in FIGS. 14-18, the concept of the stop abutment  92  may also be added to the transfer apparatus  200 . 
     The transfer apparatus  200  may similarly be easily installed and removed from the conveyor system  202  by unbolting the support frame of the same from the lower flanges of the channels  204  and  206  and lowering the same out of engagement with the main conveyor  202 . 
     Thus, it is seen that the apparatus and methods of the present invention readily achieve the ends and advantages mentioned as well as those inherent therein. While certain preferred embodiments of the invention have been illustrated and described for purposes of the present disclosure, numerous changes in the arrangement and construction of parts and steps may be made by those skilled in the art, which changes are encompassed within the scope and spirit of the present invention as defined by the appended claims.