Abstract:
A braking system is provided along one of a pair of guide rails of an air conveyor that transports plastic bottles along a pathway between the pair of guide rails. The braking system is selectively actuated to move into the pathway defined by the guide rails decreasing its width and positioning a stop of the braking system in the pathway where it will engage with bottles conveyed by the air conveyor slowing and eventually stopping the bottles.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    (1) Field of the Invention  
           [0002]    The present invention pertains to a braking system for air conveyors. In particular, the present invention provides a braking system along the guide rails of an air conveyor that transports plastic bottles along a pathway between the guide rails. The braking system is selectively actuated to move into the pathway defined by the guide rails decreasing its width and positioning a stop of the braking system in the pathway where it will engage with bottles conveyed along the pathway by the air conveyor slowing and eventually stopping the bottles.  
           [0003]    (2) Description of the Related Art  
           [0004]    Air conveyors are typically employed in the rapid transport of empty plastic bottles of the type having an annular rim or a neck ring at the base of the bottle neck. A typical air conveyor includes a pair of flanges that are spaced from each other defining an elongated slot between the flanges. The spacing between the flanges is sufficiently large to enable a portion of the bottle just below the neck ring to pass through the spacing with the bottle suspended from the top surfaces of the flanges by the neck ring engaging on the top surfaces. A series of air ducts are positioned along the flanges above and/or below the elongated slot. A plenum of the air conveyor supplies a flow of air to the air ducts. The air ducts are oriented so that air ejected from the ducts will contact the plastic bottles pushing the bottles along the pathway defined by the elongated slot with the neck rings of the bottles sliding along the top surfaces of the spaced flanges.  
           [0005]    Preferably, air conveyors transport bottles in closely spaced succession and at a substantial speed. A typical air conveyor is constructed with both straight sections and curved sections in order to transport the succession of bottles from one area to another. Air conveyors often have guide rails positioned below the slot defined by the pair of flanges. Pairs of guide rails positioned on opposite sides of the slot follow the conveyor path defined by the slot. The guide rails are usually spaced further apart from each other than are the flanges to allow the width of a bottle suspended from the flanges to pass easily between the guide rails. The guide rails limit the side-to-side movement of the succession of bottles conveyed by the air conveyor and thereby limit the extent to which the body of the bottle can swing outwardly or transversely from the air conveyor path, for example when the air conveyor rounds a curve, and thereby avoids a bottle neck or neck ring potentially becoming jammed in the air conveyor slot and stopping the succession of conveyed bottles.  
           [0006]    With a typical air conveyor being capable of transporting a large succession of plastic bottles at a considerable speed, problems can be encountered when a large succession of bottles are stopped and accumulated at the end of the air conveyor. In prior art air conveyors, the leading bottle in a succession would be stopped at the end of the air conveyor by a selectively operated gate mechanism. This first bottle stopped by the gate mechanism would in turn stop all subsequent bottles that trailed it in the line of succession of bottles conveyed by the air conveyor. Thus, this first stop bottle would have a force exerted on it by each of the trailing bottles conveyed by the conveyor mechanism. With a long line of succession of bottles, the force exerted on the first stopped bottle could be sufficient to damage the bottle. In a like manner, the second bottle in the sequence has a force exerted on it by each of its trailing bottles. This force could also be sufficiently large in a long succession of bottles to cause damage. In this manner, several bottles at the forward end of a long succession of bottles stopped by the conveyor system could be damaged. In addition, when the air conveyor is conveying a large number of bottles in a group and they come to one or more bottles stopped by the gate of the air conveyor, the impact of the large group of conveyed bottles with the stopped bottle or bottles can cause the forward most stop bottle to be forced through the gate.  
           [0007]    To overcome this problem, a mechanism is needed that not only engages with the forward most bottle in a succession of bottles to stop the succession of bottles, but engages with and brakes several of the bottles in the succession of bottles. In addition, it is desirable that the mechanism have a simplified construction that would enable it to be retrofit to an existing air conveyor at several spots along the length of the air conveyor to enable stopping groups of bottles conveyed by the air conveyor at controlled points along the air conveyor length to thereby control the number of bottles that would accumulate at any one position along the length of the air conveyor where the succession of conveyed bottles are stopped.  
         SUMMARY OF THE INVENTION  
         [0008]    The conveyor braking system of the invention can be employed with virtually any type of conveyor system that conveys a succession of articles along a flow path, where the succession of articles can be engaged by the braking system from opposite sides of the flow path. In the operative environment of the braking system to be described, the system is employed on an air conveyor that transports plastic bottles. The bottles are of a conventional type with each bottle having a neck at its upper end and an annular shoulder below the neck that defines the upper portion of the body of the bottle. An outwardly projecting annular rim or neck ring is positioned below the neck of the bottle and above the bottle shoulder.  
           [0009]    The air conveyor with which the braking system of the invention is described employs a pair of spaced flanges through which the neck and neck ring of the bottle project. The neck ring rests on top surfaces of the spaced flanges suspending the shoulder and body of the bottle below the flanges. The air conveyor includes a series of air ducts that direct a supply of air against the bottle causing the bottle to move along the length of the air conveyor with the neck ring of the bottle sliding along the top surfaces of the flanges. Typical air conveyors of this type are described in the U.S. Patents of Ouellette U.S. Pat. No. 5,437,521, issued Aug. 1, 1995, and U.S. Pat. No. 5,611,647 issued Mar. 18, 1997, both which are assigned the assignee of the present invention and incorporated herein by reference.  
           [0010]    Air conveyors typically include a framework that supports the conveyor. They also often include guide rails that are support from the framework or suspended from the air conveyor in positions just below the air conveyor slot. The guide rails are provided in pairs that extend along the length of the conveyor with a spacing between the pair of guide rails that is centered below the spacing between the air conveyor slot. The spacing between the guide rails is usually slightly larger than the body of the bottles to be conveyed by the air conveyor. The guide rails limit the extent to which bottles conveyed by the air conveyor can rock side-to-side or transversely to their direction or path of conveyance.  
           [0011]    The braking system of the invention is designed to enable its simple addition to an existing air conveyor system. The braking system is designed to be mounted adjacent the guide rails of the air conveyor. The system includes at least one stop that is mounted adjacent to one of the guide rails of the pair of guide rails of the air conveyor system. The stop includes an actuator that is selectively actuated to move the stop transversely toward and away from the spacing between the air conveyor guide rails. Thus, when the stop is actuated it moves into the pathway defined by the pair of guide rails of the air conveyor, reducing the transverse spacing or width of this pathway. Depending on the extent to which the stop moves into the pathway, the stop can come into engagement with the body of a bottle being conveyed along the pathway gripping the bottle between the stop and the guide rail on the opposite side of the pathway, or the stop can reduce the width of the pathway to the extent where the body of a bottle conveyed through the pathway will contact both the stop and the guide rail on the opposite side of the pathway with the engagement on the opposite sides of the bottle gradually braking the bottle and slowing its speed of conveyance as it passes along the stop.  
           [0012]    The stop is constructed of first and second elongated bar sections that are connected end to end by a pivot joint. A first end, or upstream end of the first elongated bar section is mounted adjacent one of the pair of air conveyor guide rails by a pivot pin. The pivot pin extends through an oblong hole in the first end of the first bar section. The oblong hole extends in a direction along a center axis of the first bar section.  
           [0013]    The second bar section has a pair of oblong holes therethrough adjacent its opposite ends. However, the oblong holes or slots of the second bar section extend in directions that are oriented at an angle to the center axis of the second bar section. Posts pass through each of the angled oblong slots of the second bar section mounting that section adjacent the one guide rail of the air conveyor and positioned downstream of the conveyor path from the first bar section.  
           [0014]    An actuator is mounted between the second bar section of the stop and a stationary support of the air conveyor guide rail. The actuator of the preferred embodiment is a pneumatic actuator that is selectively supplied with pressurized air at its opposite ends to selectively extend and retract the length of the actuator. When the actuator is retracted, reducing its length, it pulls both the first and second bar sections of the stop toward the adjacent guide rail. The first and second bar sections of the stop extend along the length of the adjacent guide rail and do not project into the conveyor path between the pair of guide rails. Actuation of the actuator, causing its length to be extended, moves the second bar section in a translatory movement out into the spacing between the pair of guide rails. This movement of the second bar section also causes the first bar section to move in a pivoting movement about the pivot pin at its upstream end out into the spacing between the pair of guide rails. This movement of the two bar sections reduces the spacing between the opposite guide rail and the two bar sections of the stop, which also reduces the width of the conveyor pathway through which the bodies of the bottles are conveyed by the air conveyor. As bottles are conveyed along the conveyor pathway and begin to pass between the length of the first bar section of the stop and the opposite guide rail, the spacing between the first bar section and the opposite guide rail begins to decrease as the bottles continue in a downstream direction. The decreasing width or spacing between the stop and the opposite guide rail continues until the bottles reach the second bar section where the spacing between the second bar section of the stop and the opposite guide rail is the smallest. As the bottles continue to be conveyed downstream between the second bar section and the opposite guide rail, the engagement of the bodies of the bottles between the second bar section and opposite guide rail gradually slows the speed of conveyance of the bottles and, depending on the spacing between the second bar section and the opposite guide rail and the width of the bodies of the bottles, can gradually be brought to a complete stop by the braking system of the invention. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    Further objects and features of the present invention are revealed in the following detailed description of the preferred embodiment of the invention and in the drawing figures, wherein:  
         [0016]    [0016]FIG. 1 is an end elevation view of a four lane air conveyor system where the braking system of the invention is installed on two of the four lanes;  
         [0017]    [0017]FIG. 2 is a partial side elevation view of the braking system of the invention installed above a guide rails of an air conveyor, although it could also be mounted below the guide rail;  
         [0018]    [0018]FIG. 3 is a partial fragmented, side elevation view of the braking system of FIG. 2;  
         [0019]    [0019]FIG. 4 is a partial, fragmented, plan view of the braking system in its retracted position relative to the guide rails; and  
         [0020]    [0020]FIG. 5 is a partial, fragmented, plan view of the braking system extended relative to the guide rails. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0021]    [0021]FIGS. 1 and 2 show a multi-channel air conveyor that serves as the operative environment of the present invention. Although a multi-channel air conveyor is shown, it should be understood that the present invention may be employed with a single channel air conveyor. FIG. 1 shows an end elevation view of the air conveyor  10 . The conveyor includes four conveyor channels  12 , each having a generally inverted U-shaped configuration with a top wall  14  and laterally spaced side walls  16 . Together, the channel top wall  14  and the side walls  16  give each of the channels  12  their generally, inverted U-shaped configuration surrounding an interior volume of each conveyor channel. The side walls  16  of each conveyor channel have lower sections  18  connected to the upper side walls  16  by threaded fasteners  22 . The lower sections  18  of the side walls have pluralities of air duct outlets (not shown) that extend through the conveyor channel side walls  16  and side wall lower sections  18 . The configurations of the air duct outlets direct jets of air ejected from the outlets to strike bottle containers  24  conveyed by the air conveyors in the area of the shoulder of the bottles, thereby forcing the bottles to travel downstream along the length of the air conveyor. In viewing FIG. 2, the downstream direction is from left to right.  
         [0022]    Each of the air duct outlets in the side wall lower sections  18  is fed with pressurized air directed through air conduits that pass through the upper side walls  16  of the conveyor channels. These air conduits extend from the top surface of the conveyor channel top walls  14  completely through the side walls  16  to the air ducts of the side wall lower sections  18 . This construction of the air ducts and air conduits is employed in air conveyors of the type disclosed in the U.S. Patent of Ouellette, U.S. Pat. No. 5,628,588, issued May 13, 1997 and incorporated herein by reference.  
         [0023]    Referring to FIG. 1, the interior volume of each of the channels  12  is comprised of an upper portion and a lower portion separated by pairs of laterally spaced, longitudinally extending flanges  32 . Opposed pairs of flanges  32  extend from the opposed side walls  16  of each of the channels  12  into the interior volume of the channels and define slots  34  between each pair of flanges. The flanges  32  are held between the upper portions of the channel side walls  16  and the lower sections  18  of the channel side walls. Set screws (not shown) are employed to secure the flanges  32  in their positions on the side walls  16 . By loosening the set screws, opposed pairs of flanges  32  can be adjustably positioned laterally toward or away from each other to adjust the lateral widths of the slots  34 . In a bottle conveyor of the type shown in FIGS. 1 and 2, the lateral widths of the slots  34  is adjusted to be sufficiently large to receive the neck of the bottle container  24  therein with the annular rim or neck ring  36  of the bottle container supported on the top surfaces of the flanges  34  and with the tapered shoulder and body of the bottle suspended below the pair of flanges.  
         [0024]    An air plenum  38  extends longitudinally along the top wall  14  of the conveyor channels  12 . The plenum  38  is an elongated hollow box comprised of a pair of side walls  42  and a top wall  44  that surround an interior volume of the plenum. As shown in FIG. 1, the plenum includes a connecting plate  46  that attaches adjacent bottom walls of the plenum. The connecting plate  46  is attached to the top wall  14  of the conveyor channels  12  and to the side walls  42  of the plenum. The connecting plate is employed in connecting together adjacent lengths of the air conveyor end to end. The connecting plate is attached to the conveyor channels top wall  14  by threaded fasteners (not shown) and is also connected to the plenum side walls  42  by threaded fasteners (not shown). When the connecting plate overlays air conduits of the conveyor channels  12 , holes are provided through the plate in order to maintain communication of the pressurized air in the air plenum  38  with the conveyor channel air conduits and air ducts.  
         [0025]    Suspended below the air conveyor  10  are a plurality of brackets  52 . As shown in FIG. 1, each bracket  52  has a general U-shaped configuration and its top ends are attached to the undersides of the outer most side wall lower sections  18  of the conveyor channels  12  by threaded fasteners. The brackets  52  are spacially arranged along the length of the air conveyor  10 . As shown in FIG. 1, pairs of supports  54  are attached to the bottom of the brackets  52 . Each pair of supports  54  projects upwardly and is centered below the slots  34  of each of the conveyor channels  12 . The spacing between each pair of supports  54  is sufficiently large to provide ample clearance for a bottle container  24  to pass therethrough as is shown in FIG. 1.  
         [0026]    Guide rails  56  are mounted to the supports  54 . Pairs of guide rails  56  are positioned within the pairs of supports  54  mutually opposing each other. The guide rails  56  extend along the length of the air conveyor  10  and can be provided in sections that are positioned end to end along the length of the air conveyor  10  in the same manner that sections of the air conveyor are positioned end to end. The guide rails  56  limit the extent of side to side movement of bottles  24  conveyed by the air conveyor  10  and prevent bottles from becoming jammed in the air conveyor by excessive side to side movement.  
         [0027]    The air conveyor  10 , the series of brackets  52  and the supports  54  and guide rails  56  are all suspended from a framework  58 . The framework  58  extends along and supports the entire length of the air conveyor  10 . Although only a short, straight length of the air conveyor  10  is shown in FIGS. 1 and 2, air conveyors are constructed with substantial lengths that can curve from side to side and incline upwardly and downwardly along their lengths.  
         [0028]    The air conveyor described to this point is conventional and many of the component parts of the air conveyor described are found in various different types of air conveyors. It should be understood that the air conveyor described is only one operative environment of the braking system and that the braking system may be employed in different types of air conveyors having constructions that are different from the construction of the air conveyor described herein. The air conveyor  10  is only one operative environment of the braking system and the braking system is not limited to use with air conveyors of the type described.  
         [0029]    The braking system of the invention is designed to enable it to be easily retrofit to existing air conveyors by attaching it to the guide rail brackets  52  and supports  54  of an existing air conveyor, or by including brackets and supports with the braking system that enable it to be attached to the side walls  16  of the conveyor channels  12 . Although the braking system will be described as being employed with a multi-channel air conveyor, it is equally well-suited for use with a single channel air conveyor.  
         [0030]    The braking system of the present invention is basically comprised of a stop  62  that is supported by three mounts  64 ,  66 ,  68  adjacent a guide rail of an air conveyor channel, and an actuator  72  that selectively moves the stop  62  a short distance into the spacing between opposed guide rails of the conveyor channel to reduce the spacing of the conveyor pathway between the guide rails and stop bottles conveyed through this portion of the pathway. FIG. 1 shows a downstream mount  68  of the three mounts of the braking system on one of the supports  54  of the conveyor guide rails  56 . FIG. 1 illustrates the ability of mounting the braking system at different elevations adjacent the guide rails  56  in order to best position the braking system for engagement with a generally flat portion of the bottle body to obtain the optimum performance of the braking system. In the preferred embodiment of the invention, it is only necessary to mount the braking system on one side of the pathway defined between the pair of opposed guide rails  56 . When the stop  62  of the braking system is extended outwardly into this pathway by actuation of the actuator  72 , the spacing between the braking system stop and the opposite guide rail is reduced to the extent that a bottle  24  cannot pass through the pathway and is stopped. Pairs of the braking systems to be described could be mounted adjacent the pairs of guide rails  56  that define each pathway of the air conveyor, but only one braking system is needed to operate properly and therefore only one braking system mounted on one side of the pathway defined by the guide rails  56  will be described.  
         [0031]    [0031]FIG. 2 shows a side view of the braking system of the invention installed along a length of the air conveyor  10  and FIG. 3 shows a fragmented view of the side of the conveyor shown in FIG. 2 and also shows an enlargement of the component parts of the braking system. Again, it is pointed out that the braking system is installed on one side of the pathway defined by opposed guide rails  56  and one guide rail of the pair of opposed guide rails is positioned on the opposite side of the conveyor pathway from the braking system.  
         [0032]    The three mounts of the braking system include an upstream mount  64 , an intermediate mount  66 , and a downstream mount  68 . Each of the mounts is secured to one of the air conveyor supports  54  just above the guide rail  56  supported by the support. Each of the mounts could also be mounted below the guide rail if required by the shape of the bottles. The upstream and downstream mounts have basically the same construction and the construction of the intermediate mount is only slightly different from the other two. The upstream mount  64  is mounted to its support  54  in a reversed orientation from the orientations of the intermediate mount  66  and the downstream mount  68 . Because the upstream and downstream mounts have the same basic construction, only the construction of the upstream mount  64  will be described with it being understood the component parts of the downstream mount  68  are the same and are identified by the same reference numbers. The upstream mount  64  has a general C-shape with an upper arm  74  and lower arm  76  that are vertically spaced from each other. The spacing is sufficient to accommodate a portion of the stop  62  therein, as will be described. The opposite end of the mount  64  from its projecting arms  74 ,  76  is mounted to the support  54  on the same side of the support as the guide rail  56 . This positions the mount just above the guide rail. As shown in FIGS. 4 and 5, the mount has a transverse width that is substantially equal to that of the guide rail  56  so that it does not project out into the pathway of the conveyed bottles any more than does the guide rail. The mount is preferably attached to the support  54  by threaded fasteners (not shown). At the opposite end of the mount  64 , a pivot pin  78  extends through the distal ends of the arm  74 ,  76  across the spacing between the arms.  
         [0033]    The intermediate mount  66  is also attached to one of the guide rail supports  54  but in an orientation that is the reverse of that of the upstream mount  64 . Like the upstream mount, the intermediate mount  66  has an upper arm  74 ′ and lower arm  76 ′ separated by a vertical spacing and a pivot pin  78 ′ spanning the spacing at the distal ends of the arms. However, the intermediate mount  66  differs from both the upstream mount  64  and the downstream mount  68  in that it is not formed in a general C-shape. Instead it is formed with the upper and lower arms  74 ,  76  being separated from each other by the spacing between the arms. Unlike the upstream mount  64  and downstream mount  68 , the spacing between the arms of the intermediate mount  66  extends along the entire length of the mount  66 . This enables sections of the stop  62  to be described to be positioned between the two arms  74 ′,  76 ′ of the intermediate mount  66 . As an alternative, the arms of the intermediate mount  66  could be formed as one-piece with a slot extending along the entire length of the mount that is dimensioned to receive sections of the stop to be described within the slot and between the two arms. Like the upstream mount  64 , the two separate arms  74 ′,  76 ′ of the intermediate mount  66  are attached to the guide rail support  54  by threaded fasteners (not shown).  
         [0034]    The downstream mount  68  is similar to the upstream mount  64  except that its orientation mounted on the guide rail support  54  is reversed from the upstream mount. It also includes a pair of arms  74 ,  76  that are separated by a vertical spacing. A pivot pin  78  passes through the arms at their distal ends and spans the spacing between the arms. The mount  68  is secured to the guide rail support  54  by threaded fasteners (not shown).  
         [0035]    A reinforcement rod  92  extends across the tops of the three mounts  64 ,  66 ,  68  and is secured thereto by threaded fasteners (not shown). The reinforcement rod  92  adds rigidity to the braking system.  
         [0036]    The stop  62  of the braking system that is selectively extended into and retracted from the pathway defined by the pair of guide rails  56  is constructed of first  94  and second  96  elongated, articulated bar sections that together form a rail similar to the guide rails. The two bar sections  94 ,  96  have transverse width and vertical height dimensions substantially the same as those of the guide rails  56 . Referring to FIGS.  3 - 5 , the first bar section  94  has opposite upstream  98  and downstream  102  ends. A hole  104  passes vertically through the first bar section  94  adjacent its upstream end  98 . As seen in FIGS. 4 and 5, the hole  104  has an oblong shape and extends along the end of the first bar section  94  in a direction generally parallel with the length of the first bar section. The opposite downstream end  102  of the first bar section is connected by an articulation joint to the upstream end  106  of the second bar section  96 . The downstream end  102  of the first bar section is formed with a center pivot knuckle and the upstream end  106  of the second bar section is formed with a pair of vertically spaced knuckles that receive the center knuckle of the first bar section therebetween. A pivot pin  108  passes through these three knuckles and provides the pivot connection of the articulation joint between the two bar sections. An oblong slot  112  also passes vertically through the second bar section  96  adjacent its upstream end  106 . A similar oblong slot  114  passes vertically through the second bar section  96  adjacent its downstream end  116 . Both oblong slots  112 ,  114  have lengths that extend in a direction oriented at an angle relative to the center axis of the length of the second bar section  96 .  
         [0037]    The pivot pin  78  through the upstream mount  64  also passes through the hole  104  at the upstream end  98  of the first bar section  94 . The pivot pin  78 ′ of the intermediate mount  66  passes through the oblong slot  112  at the upstream end  106  of the second bar section  96 . The pivot pin  78  of the downstream mount  68  passes through the oblong slot  114  at the downstream end  116  of the second bar section  96 . In this manner, the two bar sections  94 ,  96  of the stop  62  are supported by the three mounts  64 ,  66 ,  68  above the guide rail  56  of the air conveyor. Again, they could also be mounted below the guide rails.  
         [0038]    The actuator  72  in the preferred embodiment of the invention is a linear actuator. In the preferred embodiment, the linear actuator is a double-acting pneumatic piston and cylinder. Other types of linear actuators may be employed as the actuator for the braking system. In addition, it is not necessary that the actuator be a linear actuator as a rotary actuator may also be employed to operate the braking system. The actuator includes a cylinder  122  with a piston (not shown) mounted therein for reciprocating movement. A piston rod  124  extends from the cylinder. A retraction air inlet  126  is provided at one end of the cylinder and an extension air inlet  128  is provided at the opposite end of the cylinder. The right-hand end of the cylinder  122  as viewed in FIGS.  2 - 5  is mounted by a pivot connection  132  to a brace  134  that in turn is secured to the mount  68  at the downstream end, or right-hand end of the braking system as shown in the drawing figures. The piston rod  124  is connected by a pivot connection  136  to a brace  138  that is secured to the second bar section  96  of the braking system stop. Two separate hoses (not shown) are connected to the retraction air inlet  126  and the extension air inlet  128  of the cylinder  122  and are selectively supplied with air to control the retraction of the piston rod  124  into the cylinder  122  and the extension of the piston rod from the cylinder, respectively.  
         [0039]    The operation of the braking system is illustrated in FIGS. 4 and 5. In FIGS. 4 and 5, the guide rail  56  opposite the braking system is represented by a dashed line with the path of conveyance of bottle containers being between the braking systems shown in the drawing figures and the dashed line representation of the guide rail  56 . The direction of conveyance from the upstream end to the downstream end of the path of conveyance is from left to right in the drawing figures.  
         [0040]    [0040]FIG. 4 shows the braking system in its retracted position relative to the guide rails  56 . From this view, it can be seen that neither the first bar section  94  or the second bar section  96  of the stop extends into the pathway defined between the pair of guide rails  56 . Therefore, the braking system would not interfere with the free conveyance of bottles through the pathway defined by the guide rails.  
         [0041]    [0041]FIG. 5 shows the positions of the first bar section  94  and the second bar section  96  when air pressure has been supplied to the extension air inlet  128  of the actuator cylinder  122 . This causes the piston rod  124  to be extended from the cylinder  122 . The extension of the piston rod causes the second bar section  96  to move in a translatory movement controlled by the sliding of the intermediate mount pin  78 ′ and downstream mount pin  78  through the oblong slots  112 ,  114  at the opposite ends of the second bar section. The angled orientation of the two oblong slots  112 ,  114  at the opposite ends of the second bar section  96  relative to its center axis causes the second bar section  96  to move in a translatory movement in the upstream direction, or to the left as viewed in FIG. 5, while simultaneously moving transversely relative to the flow path of the conveyed bottles between the guide rails  56 , thus reducing the spacing between the opposite guide rail  56  shown as a dashed line in FIG. 5 and the second bar section  96 . The second bar section  96  moves in this translatory manner until the two pins  78 ′,  78  of the intermediate mount  66  and the downstream mount  68  reach the ends of the angled oblong slots  112 ,  114  as shown in FIG. 5.  
         [0042]    As the second bar section  96  moves in its translatory movement, it imparts motion to the first bar section  94  due to the articulated joint connection provided by the pivot pin  108  connecting these two sections. The downstream end  102  of the first bar section  94  follows the translatory movement of the upstream end  106  of the second bar section  96  due to the articulating connection provided by the pivot pin  108 . However, the movement of the upstream end  98  of the first bar section  94  is controlled by the pivot pin  78  of the upstream mount  64  passing through the oblong hole  104  and the orientation of the hole along the center axis of the first bar section  94 . As the first bar section  94  is caused to move to the left or in an upstream direction by the movement of the second bar section  96 , the hole  104  slides along the pivot pin  78  of the upstream mount  64  and causes the upstream end  98  of the first bar section to pivot about the pin. This gives the first bar section  94  an angled orientation relative to the guide rail  56  opposite the braking system. In addition, the angled orientation of the first bar section  94  causes the transverse width of the flow path of the conveyed bottles to gradually decrease as that flow path extends downstream from the upstream end  98  of the first bar section to its downstream end  102 .  
         [0043]    It can be seen from FIG. 5 that as bottles are conveyed in the downstream direction with the first and second bar sections  94 ,  96  of the stop extended, the spacing between the bottle and the opposite guide rail  56  represented by the dashed line in  56  and between the bottle and the first and second bar sections  94 ,  96  gradually decreases until the bottle reaches the articulation joint  108  between the first and second bar sections. This gradual decrease in the spacing functions to gradually slow the speed of the bottle being conveyed past the extended braking system until it reaches the second bar section  96  where the friction force between the second bar section and the guide rail represented by the dashed line on opposite sides of the conveyed bottle gradually brings the bottle to a stop. Because subsequently conveyed bottles will be gradually slowed and stopped in the same manner, the earlier described problems associated with prior art bottle braking gates such as damaging the forward most stopped bottles or forcing these bottles through the braking gates are eliminated.  
         [0044]    To again start the stream of conveyed bottles, the air supply to the extension air inlet  128  is removed and air is supplied to the retraction air inlet  126  causing the piston rod  124  to be retracted back into the cylinder  122 . This pulls the first bar section  94  and second bar section  96  to the right, or in the downstream direction, causing them to move to their positions shown in FIG. 4 where they are both positioned outside the spacing between the opposing pairs of guide rails  56 .  
         [0045]    Although in the preferred embodiment of the invention the stop is constructed of first and second articulated bar sections  94 ,  96 , a variation of the braking system could include a single bar section with its upstream end mounted as the upstream end of the first bar section  94  and the downstream end mounted as the downstream end of the second bar section  96  in the above-described embodiment, thus eliminating the articulation joint between the two sections and the mounting of the second section to the intermediate mount  66 .  
         [0046]    While the present invention has been described by reference to a specific embodiment, it should be understood that modifications and variations of the invention may be constructed without departing from the scope of the invention defined in the following claims.