Abstract:
There is provided a carrier puck for movement on a conveying circuit comprising at least one conveyor having lateral guides including at least two vertically spaced and distinct lateral guide plates adapted to slidably engage a distinct portions of said carrier puck to temporarily prevent rotation of said carrier puck while advancing on said conveying circuit. The carrier puck preferably comprises a rounded main body suitable for bulk conveying. Preferably, the carrier puck is manufactured by injection molding of separate parts, later assembled.

Description:
TITLE OF THE INVENTION 
     Steerable Carrier Puck 
     FIELD OF THE INVENTION 
     The present invention pertains to carrier pucks for receiving and supporting objects to be moved onto conveyors along a production line. More specifically, the present invention is concerned with a carrier puck that can be positioned and maintained in predetermined rotational orientations on conveyors along a production line. 
     BACKGROUND OF THE INVENTION 
     Carrier pucks are well known in the manufacturing and packaging industries. Their primary use is to support and stablize objects while moving along a production line. Carrier pucks are also very useful to protect fragile objects from collision during conveying. 
     A convenient way to convey carrier pucks is to move them in bulk between the stations of the assembly line. The main reason to convey puck in bulk is to allow the pucks to accumulate between each station. In doing this, the line can be kept running even though one or more stations are down because of jamming, repairs, or the like. 
     Bulk conveying is preferably done using round pucks. A round causes minimal surface contact to other similar pucks, minimizing friction and allowing bulk conveying while preventing jamming along the production line. 
     U.S. Pat. No. 4,664,248, entitled “Device and Method for Conveying and Orienting Randomized Circular Product-Carrying Pucks”, issued to Goodman, Jr. et al. on May 12, 1987, discloses a generally round carrier puck. The round puck has two distinct outer contacting surfaces. A first surface which is round and toothed and a second slide surface which is cut flat in an arc of circumference. As the puck travels on the conveying surface it will encounter a toothed side guide which engages the toothed round portion of the puck thus imparting rotation of the puck until it reaches the flat surface which will stop rotation and cause the puck to slide forward in the direction of travel of the conveyor. A drawback of this arrangement is that the puyck can only be oriented in one preferred direction (or at 180° from the preferred direction). Another drawback is that a pucks according to that invention cannot easily be spaced apart from one another. 
     U.S. Pat. No. 5,479,762, issued on Jan. 2nd of 1996 to Bliss and entitled “Carrier Puck”, discloses a rectangular carrier puck having lateral ears which fit recesses in the conveyor belt. The ears-recesses system restrains the puck movement allowing the pucks to be correctly oriented and equally spaced along the conveyor. However, a major drawback of such arrangement is that it is unsuitable for bulk conveying. 
     U.S. Pat. No. 5,484,052, issued to Pawloski et al. on Jan. 16, 1996 and also entitled “Carrier Puck”, describes a carrier puck having a rectangular base and a cylindrical top. The puck is shaped to receive either a first or a second article having different dimensions and shape. The rectangular base allows the puck to be oriented in four quadrants (90° increments) by sliding on conveyor lateral guides. However, since the base in rectangular, it is not possible to know in which quadrant the puck is oriented with additional data. Such data is obtained by four recesses with one recess located in each quadrant of the cyclindrical sides of the puck allowing mechanical sensors mounted to a conveyor to sense when the puck is properly oriented to receive either the first or the second articles. An important drawback is the lack of control over the quadrant orientation of the puck. Once the puck is in a given orientation, it will continue that way. 
     OBJECTS OF THE INVENTION 
     An object of the present invention is therefore to provide a steerable carrier puck which is suitable for bulk conveying and which avoids the drawbacks of the prior art. 
     A further object of the present invention is to provide a carrier puck manufactured to a precise weight tolerances so as to provide exact weight readings on the load of a loaded carrier puck by weighing the loaded carrier puck and subtracting the known weight of the empty carrier puck. 
     A further object of the present invention is to provide a carrier puck of a diameter similar to the size of the object being conveyed. 
     A further object of the present invention is provide a two-piece assembled carrier puck with interchangeable top and interchangeable bottom portions. 
     SUMMARY OF THE INVENTION 
     More specifically, in accordance with the present invention, there is provided a carrier puck for movement on a conveying circuit comprising at least one conveyor having lateral guides including at least two vertically spaced and distant lateral guide plates adapted to slidably engage a distinct portion of said carrier puck to temporarily prevent rotation of said carrier puck while advancing on said conveying circuit; 
     said carrier puck comprising a main body having a rotational axis, said main body comprising: 
     an open top for receiving at least one object to be conveyed, 
     a conveyor-contacting bottom portion, 
     a round peripheral rim centered about said rotational axis, and 
     an outer wall surface comprising the round peripheral rim and extending between the top and bottom portions of said carrier puck, said outer wall having at least two guide-contacting portions configured and sized to selectively and slidably engage at least one of said lateral guide plates on said conveying circuit; each said guide-contacting portions defining a specific angle about said rotational axis; 
     whereby when said carrier puck is in rotation about said rotational axis, said carrier puck is oriented and maintained in a desired position when a given guide-contacting portion slidably engages the guide plate configured and sized to slidably engage the given guide-contacting portion. 
     Other objects, advantages and features of the present invention will become more apparent upon reading of the following non restrictive description of preferred embodiments thereof, given by way of example only with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the appended drawings: 
     FIG. 1 is a perspective view of the carrier puck of the present invention; 
     FIG. 2 is a perspective view of the carrier puck of FIG. 1 showing the base of the puck; 
     FIG. 3 is a perspective view of the carrier puck of FIG. 1 on a portion of a conveyor belt with tongues; 
     FIG. 4 is a top plan view of a conveyor system using a carrier puck according to an embodiment of the present invention; 
     FIG. 5 is a cross sectional view taken along section line  5 — 5  of FIG. 4; 
     FIG. 6 is a cross sectional view taken along section line  6 — 6  of FIG. 4; 
     FIG. 7 is a cross sectional view taken along section line  7 — 7  of FIG. 4; 
     FIGS. 8 and 9 are perspective views of the top portion of a two-piece assembled puck in accordance with the present invention; 
     FIGS. 10 and 11 are perspective views of the bottom portion of a two-piece assembled puck in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 1 and 2, there is shown a preferred embodiment of the carrier puck of the present invention. Carrier Puck  10  is provided with a generally round outer rim  12  to minimize frictional contact and jamming with contiguous carrier pucks travelling on a conveying circuit. In this preferred embodiment, carrier puck  10  is adapted to carry pouches  14  which will be deposited therein as shown in FIG.  3 . In operation, pouches  14  may be held above and dropped into pucks  10 . The central opening of puck  10  is delimited by two pairs of fingers  16 , floor  18  and rear wall  20 . 
     Fingers  16  are provided with ends having angled surfaces  22  and  24  so as to guide pouch  14  in its descent into puck  10  and to tolerate slight misalignments of pouches  14  in relation to pucks  10  when pouches  14  are dropped into pucks  10 . 
     In the particular embodiment illustrated in FIG. 3, pouch  14  is provided with generally flat edges  26 . These edges  26  are capable of sliding in puck  10  by descending in the vertical groove  28  provided between each pair of fingers  16 . Thus, once pouch  14  is positioned in puck  10 , it will be securely held by edges  26  being positioned in grooves  28 . 
     A distinct advantage of cutting groove  28  between fingers  16  is to minimize the overall diameter of puck  10 . This allows puck  10  to carry a pouch  14  which is of nearly equal width. Such design is advantageous since it allows a greater number of pucks to travel on a given surface area of a conveying circuit. In addition, such design minimizes material use when manufacturing puck  10 . 
     Floor  18  is angled towards a central drainage channel  30  and away from rear wall  20  so as to allow washing, rinsing and drainage of pucks  10  even when carrying pouches  14 . It is to be noted that in this particular embodiment, pouches  14  carried on pucks  10  do not touch rear wall  20  so as to facilitate washing operations and to facilitate retrieval of pouches  14  from pucks  10  at the end of the conveying circuit. Indeed, rear wall  20  is sufficiently spaced from pouch  14  so as to allow the descent of a gripping claw (not shown) to the base of pouch  14  to ensure a positive retrieval of pouch  14 . 
     Continuing with the description of puck  10 , functional features allowing puck  10  to be steerable will now be described in more detail. Still referring to FIGS. 1 and 2, puck  10  is provided with a flat slide portion  40 . Puck  10  is provided with a generally round base  34  separated by a central groove  36  having slightly open leading edges  38 . In addition, base  34  is provided with flat slide portion  40  which is orthogonal to flat  32 . Flats  32  and  40  are used to maintain a chosen rotational orientation to puck  10  about its rotational axis during its travel on a conveying circuit. The operation of flats  32 ,  40  and groove  36  will be described in more detail herein below by reference to FIGS. 4 to  7 . 
     FIG. 4 illustrates a typical conveying circuit. Empty pucks  10  are loaded off pallets and onto bulk feed conveyor  42 . Pucks  10  will then be placed in single file on combiner  44 . Combiner  44  is provided with a lateral guide  48  against which pucks  10  are guided toward single file track  46 . Lateral guide  48  is shown on FIG.  5 . Pucks  10  will contact lateral guide  48  with their base and rotate on guide  48  until their rotation reaches flat surface  40 . From that point on, pucks  10  will stop rotating and continue to advance on the conveying surface of combiner  44  while flat surface  40  slides on lateral guide  48 . This positively steers and orients pucks  10  in a common position for receiving pouches  14  at filling station  50 . 
     In a most preferred embodiment, combiner  44  is a multi-track combiner with an increasing gradient of speed leading to higher speed single track  46  as described in co-pending and commonly assigned Canadian patent application serial no. 2,188,735 filed on Oct. 24, 1996. However, combiner  44  may also be of standard design with constant speed track. In both cases, lateral guide  48  will cause pucks  10  to rotate until locking their rotational orientation by sliding engagement of flat surface  40  on lateral guide  48 . 
     It is to be understood that the combining operation on combiner  44  and the orientation feature of lateral guide  48  can be accomplished as two separate functions. Pucks  10  could be first combined in single file and later oriented by contacting lateral guide  48  located downstream from combiner  44 . 
     Hence, pucks  10 , are guided on single file conveying track  46  until reaching a sliding chute  52  where pucks are held in lateral contact while maintaining the rotational orientation given by lateral guides  48 . Pucks  10  are then pushed, four at a time, onto a belt conveyor  54  by belt driven lateral guides  56 . Belt conveyor  54  is provided with regularly spaced tongues  58 , orthogonal to the belt and adapted to slidably engage groove  36  in the base of pucks  10  as shown in FIG.  7 . As previously mentioned, groove  36  is slightly flared as shown by numeral  38  to allow slight initial misalignment of groove  36  and tongues  58 . Belt conveyor  54  is moved forward in a stop and go fashion, preferably by a step motor, to allow pouches  14  to be suspended above and dropped, four at a time and according to a timed sequence, into pucks  10  by filler apparatus  50  which drops pouches  14 . When dropped, each pouch  14  of course will have the same spatial orientation so that it may fit the top opening of puck  10 . It is to be noted that in this arrangement, slide surface  40  on puck  10  allows rotational alignment of puck  10  so that groove  36  can engage tongue  58 . Indeed, slide surface  40  and groove  36  are parallel. 
     Once pucks  10  are loaded with pouches  14 , these exit from belt conveyor by sequentially push from lateral belt conveyor  60  provided with projecting baffles  62  which push pucks  10 , four at a time, onto single file conveyor  64  in unison with the filling rate of filler apparatus  50 . 
     Once on conveyor  64 , the pucks are weighed on weight station  66 . Any pucks  10  which failed to receive a pouch  14  or which have underfilled or overfilled pouches  14  are sorted away from conveying line  68 . 
     Line  68  leads to an accumulation conveying area  70  where bulk advancement of pucks  10  is achieved. Those skilled in the art will immediately understand that accumulation areas are very useful in a conveying circuit since they allow upstream and downstream apparatus to be temporarily down without having to shut down the entire conveying circuit. 
     A bulk flow of loaded pucks  10  then enters a combiner  74  similar to combiner  44  described above with the exception that lateral guide  76  is vertically spaced from lateral guide  48  and is adapted to functionally interact with flat surface  32  which is also vertically spaced form flat surface  40 . This allows lateral guide  76  to slidably engage flat surface  32  thereby locking the rotational orientation of pucks  10  as these move to single file conveyor  78  as shown in FIG.  6 . 
     Pucks  10  then enter processing apparatus  80  in which an article such as a label or a straw is affixed to front surface  82  of pouch  14 . Back guide  84  prevents puck  10  from tipping over while the article is affixed to pouch  14 . Back guide  84  may also prevent deformation of pouch  14  while the article is affixed to pouch  14 . 
     Pucks  10  are then routed to an unloading station (not shown) where pouches  14  are removed from pucks  10  by gripping arms which descend and grip pouches  14  by their front surface  82  and rear surface  86  and are placed in cartons. To precisely position pucks  10  below gripping arms, a screw type conveyor is preferred (not shown). This will advance pucks  10  while maintaining a constant space between each puck. Rear wall  20  on pucks  10  allows the screw type conveyor to positively advance pucks  10 . Of course, the movement and pace of the gripping arms will be synchronized to the advancing pucks  10 . 
     It is of great importance to note that the number and placement of slide surfaces such as  32  and  40  is quasi infinite. To provide a specific rotational orientation to pucks  10 , a slide surface must simply be vertically spaced apart from other slide surfaces on puck  10 . This allows a large number of possible unique orientations for pucks  10  thereby allowing precise operations to be performed on the pouches carried by pucks  10 . For example, separate distinct front and back labels and could be affixed to pouches  14  followed by the gluing on of a drinking straw. For each slide surface on puck  10 , a matching slide guide can be installed on the conveying circuit thereby rendering pucks  10  steerable in a multitude of desired rotational orientation so that processing steps may be completed while knowing the exact rotational orientation of pucks  10 . 
     Incidentally, although in a preferred embodiment pouches  14  contain liquids such as juices and fruit cocktails, the pouch could also carry dairy products or even solid particulate items such as coffee. 
     Also, although the preferred embodiment has been described as a pouch conveying puck, puck  10  can be readily designed to accommodate other articles, while still having the above mentioned characteristics. The configuration and size of the conveying circuit and of puck  10  may then vary to accommodate the size and shape of the object to convey or the accommodate the nature of the operation performed at each station. 
     It is important to note that pucks  10  can be molded in one piece or can be assembled from separate parts. The preferred material from which the puck can be made is polypropylene, but other shock resisting materials, such as polyurethane or rubber are acceptable. 
     Referring now to FIGS. 8 to  11 , in a most preferred embodiment, pucks  10  are constructed of two parts, namely a top  88  and a base  90 . This allows various tops and bases to be interchangeable depending on the specific article being conveyed and depending on the orientation required for pucks  10  throughout the conveying circuit. Another advantage of the two piece construction is the ease of injection molding wherein the top  88  and base  90  can be hollow thereby minimizing use of material and minimize cooling time after molding. A further advantage is that the inside hollow portions of top  88  and base  90  can be provided with trimmable projections (not shown) or stabilization weights  92  so as to obtain a precise and constant weight of pucks  10  prior to sealing together top  88  and base  90 . Exact weight pucks allow for precise weight measurement of pouches  14  once dropped onto pucks  10 . The precise weight of pouches  14  is obtained by simply subtracting the known weight of an empty puck  10  from the total measured weight of a puck  10  loaded with a pouch  14 . Ideally, top  88  and base  90  are sealed by ultrasonic welding. Pressure, snap, adhesive or frictional fits are also contemplated. Of course, puck  10  can be constructed of more than two pieces. Once assembled and sealed, puck  10  can be used for handling food or beverage preparations. The weights  92  which may be present inside puck  10  will not be in contact with food or beverage preparations. 
     It is also interesting to note that once pucks  10  are loaded with pouches  14 , a variety of such conveying circuit may be merged into a common conveying circuit until sorting of the pucks is required. For example, three filling stations similar to filling station  50  may separately fill pouch with apple, orange and grape juices. The streams of loaded pucks can be merged into a common stream for weighing or other operations. At the end the pucks may be sorted through a sequence of combiners having selective lateral guides vertically spaced from each other and capable of engaging matching flat surfaces on the pucks so as to obtain a sorting effect. 
     Although the present invention has been described herein above by way of preferred embodiments thereof, it can be modified, without departing from the spirit and nature of the subject invention as defined in the appended claims.