WO2000001598A1

WO2000001598A1 - Contact assembly and accumulation conveyor with the contact assembly

Info

Publication number: WO2000001598A1
Application number: PCT/EP1999/004619
Authority: WO
Inventors: David H. Cotter; Ronald C. Ehlert; Thomas J. Pelak; Kenneth J. Kooistra
Original assignee: Atecs Mannesmann Ag
Priority date: 1998-07-02
Filing date: 1999-07-02
Publication date: 2000-01-13
Also published as: CA2336620C; EP1093434A1; AU758360B2; BR9912512A; CA2336620A1; JP2002519269A; AU5409399A

Abstract

A contact assembly (50) for an accumulation conveyor (10) includes a support member (60) having a cavity (72) dimensioned to receive a force producing device (74). A contact member (50) is positioned between the force producing device (74) and the conveying rollers (25) and reciprocates with respect to the conveying rollers (25). The contact member (50) includes a platform (80) which supports a pair of cantilevered contact rollers (84, 84', 86, 86') journaled at opposing ends of the platform (80). When the platform (80) is vertically reciprocated by the force-producing device (74), the contact rollers (84, 84', 86, 86') in driving engagement with a drive belt (30) are forced upward, placing the drive belt (30) into driving contact with the conveying rollers (25). The contact member (50) is rotatably connected to the support member (60) while the contact roller (84, 84', 86, 86') positioned first in the direction of travel of the drive belt is formed with a pair of flanges (85). Contact between the drive belt (30) and the flanges (85) rotates the contact member (50) to thereby maintain alignment of the contact rollers (84, 84', 86, 86') and the drive belt (30).

Description

CONTACT ASSEMBLY AND ACCUMULATION CONVEYOR WITH THE CONTACT ASSEMBLY

Description

The invention relates generally to accumulation conveyors and, more particularly, to pneumatically actuated accumulation conveyors.

Accumulation conveyors normally include a pair of support rails placed a preselected distance apart. These support rails receive a plurality of transversely positioned product or conveying rollers. The conveying rollers support product being conveyed and when rotated, transport the same in a particular direction. Positioned below the conveying rollers is an endless drive member, such as a conveyor belt, which is driven by a drive motor. The accumulation conveyor system is normally divided into a plurality of zones. Each zone of the conveyor is equipped with a product sensor for detecting the presence or absence of product at a particular position along the conveyor. Each of these sensors is operationally connected to a contact assembly attached to one or both of side rails positioned below the top run of the endless drive member. Each contact assembly includes a pneumatically or mechanically driven vertically reciprocal contact member which may be operationally interconnected with contact assemblies positioned in other zones of the conveyor.

In accordance with a particular control scheme dictating the selective movement of product along the conveyor, one or more of the contact assemblies are actuated to move the contact member into frictional contact with the endless drive member. When a particular contact member is in such frictional engagement with the endless drive member, the conveying rollers adjacent the control assembly are engaged by the top surface of the top run of the endless drive member and begin to rotate. This rotation in turn results in the transportation of product supported by the selected conveying rollers.

When it is desired to accumulate product within a particular zone of the conveyor, a signal is sent to the contact assembly within that zone. Receipt of this signal causes the vertical retraction of the contact member and hence moves the same out of driving engagement with the endless drive member. This in turn results in the disengagement of the top surface of the endless drive member from contact with the conveying rollers and thus, such conveying rollers cease rotation.

One area in which existing accumulation conveyors often experience inefficiencies is with the vertically reciprocal contact assemblies. When the contact member is placed in engagement with the lower surface of the top run of the endless drive member, excessive "belt pull" is often encountered. That is, due to the engagement of the top surface of the contact member with the endless drive member, the drive member encounters frictional resistance in a direction opposite to the direction of motion. This frictional resistance, or belt pull reduces the rotational efficiency of the conveying rollers and may disrupt the movement of product along the conveyor. Moreover, this frictional resistance causes excessive wear on the endless drive member and thus reduces its economic life. Additionally, for any given conveyor speed, the drive motor must compensate for belt pull and therefore energy costs are increased.

When the contact member of the contact assembly is placed in engagement with the endless drive member, the contact member absorbs vertical forces. Due to the particular structural configuration of these contact members, such vertical forces impose moments upon certain areas of the contact member. Over time, these forces may cause the structural deformation of the contact member. This in turn increases the frequency and cost of maintenance. Also, structural deformation of the contact member precludes uniform contact of the endless drive member with the conveying rollers. Uneven contact between the drive member and the conveying rollers reduces the efficiency of the accumulation conveyor, and frequently results in one or more "dead rollers," i.e. a conveying roller which is not properly engaged by the drive member.

Additionally, most accumulation conveyors are relatively long in length, and thus have a plurality of contact assemblies in each zone. Due to the cumulative effect of deviation from manufacturing tolerances, as well as any structural deformation caused by repeated use, the endless drive member has a tendency to become skewed or misaligned. Over the length of the conveyor, this misalignment becomes pronounced and often causes the endless drive member to deviate from the center of one or more contact members. This deviation may even result in contact between the endless drive member and the side support rail, causing damage to both the endless drive member and the conveyor, as well as the inefficient conveyance of product.

Many accumulation conveyors have the endless drive member positioned in proximity to one of the supporting side rails. Consequently, most existing contact assemblies are dedicated to accumulation conveyors having the endless drive member positioned near one side support rail or the other and can not be adapted to operate on the opposing side of the conveyor. Lack of adjustability of the contact assemblies to be used in conjunction with accumulation conveyors having the drive member on one side or the other increases manufacturing costs. Furthermore, existing contact assemblies are often composed of a variety of different components that are both difficult to manufacture, and expensive to replace.

Therefore, there exists a need for a contact assembly for an accumulation conveyor which overcomes the difficulties of the prior art while being exceptionally functional and economical to manufacture.

The object of the present invention is to provide an accumulation conveyor with a contact assembly which is durable, reliable and economic to manufacture. A solution for this object is given by the accumulation conveyor as described in claim 1 . Preferred embodiments of the present invention are provided by the claims 2 to 28.

According to an aspect of the invention, an accumulation conveyor includes a contact assembly having a support member mounted to one of the support rails of the accumulation conveyor. The support member supports a force producing device. A self-aligning contact member is positioned on the support member and is in operable connection with the force producing member, thereby allowing vertical reciprocation of the contact member with respect to the support member. A pair of contact rollers are attached to the contact member. At least one of the contact rollers is formed with a pair of out-turned flanges. When actuated by the force producing member, the contact rollers in contact with the drive member of the accumulation conveyor are brought into contact with, and affect the rotation of, the conveying rollers positioned above the drive member. In the event the endless drive member becomes misaligned, the endless drive member will contact one of the out turned flanges attached to a contact roller. Contact between the endless drive member and the out turned flange realigns the contact member to thereby assure that the endless drive member remains centered upon the contact rollers.

According to still yet another aspect of the invention, the contact member is rotatably connected to the support member while the rear, or first, contact roller, i.e. the contact roller positioned first in the direction of travel of the endless drive member, is formed with a pair of out-turned flanges. When the endless drive member becomes misaligned, contact is made between the endless drive member and one of the out- turned flanges, imparting a force on the contact member. This force shifts or rotates the contact member to thereby maintain alignment of the contact rollers and the endless drive member.

In a preferred embodiment, the support member is formed with a pair of guide members extending in a vertical direction. A pair of posts formed in the contact member are each formed with a channel dimensioned to receive a guide member. The post located farthest from the first contact roller is formed having a channel which is wider in diameter than the non-widened channel of the corresponding, non-widened post. In the event the endless drive member becomes misaligned due to cumulative tolerances, the endless drive member will contact one of the flanges positioned on the first contact roller, and thus exert a force upon the contact member. The impartation of this force pivots or rotates the contact member about the post positioned within the non-widened channel, while the widened post enables the position of the contact member to shift, thereby assuring that the contact rollers remain centered on the endless drive member. This rotational compliance maintains alignment between the contact rollers and the endless drive member and hence prevents the endless drive member from moving off the contact rollers and potentially causing damage to the conveyor.

According to another aspect of the invention, the contact member includes a pair of arms attached to respective sides and extending in opposite directions beyond a respective end of the contact member. The end of each arm is formed with a shaft to which a contact roller is journaled. Each contact roller is cantilevered to its shaft. When the cantilevered contact rollers are placed in contact with the endless drive member, each cantilevered contact roller produces a moment about the arm to which it is journaled. Since the arms are positioned on opposing sides of the contact member and extend in opposite directions, the moment produced by the respective rollers is canceled. This cancellation of moments in turn increases the stability of the contact assembly, assures an even application of force upon the endless drive member, and avoids structural deformation, and hence maximizes the viable period in which the contact assembly can be used. Additionally, because the contact rollers are cantilevered at opposing ends, the rollers center the endless drive member when in contact therewith, thereby avoiding misalignment and thus providing uniform engagement with the conveying rollers.

According to still yet another aspect of the present invention, the support member, the contact member and the contact rollers are each formed from a single polymeric molding process. The ability to manufacture the contact assembly from a minimum number of forming processes greatly reduces the cost of manufacturing, while providing a contact assembly with exceptional durability and reliability.

The present invention finds particular application as a contact assembly for use in conjunction with the conveyor set forth in the commonly assigned U.S. Patent 5,540,323 issued to Schiesser et al. for a MODULAR PNEUMATIC ACCUMULATION CONVEYOR, the disclosure of which is hereby incorporated herein by reference.

These and other objects, advantages and features of this invention will become apparent upon review of the following specification in conjunction with the drawings.

Fig. 1 is a perspective view of a segment of an accumulation conveyor according to the invention;

Fig. 2 is side elevation of the accumulation conveyor segment of Fig. 1 ;

Fig. 3 is an exploded perspective view of a contact assembly according to the invention;

Fig. 3a is a bottom view of the contact assembly of Fig. 3; Fig. 4 is rear perspective view of a support member of the contact assembly of Fig. 3;

Fig. 5 is a perspective view of the contact assembly of Fig. 3 illustrated in a vertically extended position and in contact with the conveying rollers;

Fig. 6 is the same view as Fig. 5 illustrating the contact assembly in a vertically retracted position;

Fig. 7 is a top view of the contact assembly of Fig. 3 illustrating an actuator in an alternative position;

Fig. 8 is a perspective view of the contact member of the contact assembly of Fig. 3;

Fig. 9 is a sectional view of a contact roller journaled to a shaft taken along line IX-IX of Fig. 3;

Fig. 10 is a perspective view of a contact member according to an alternative embodiment of the invention;

Fig. 11 is a top view of a contact assembly illustrating an alternative position of a contact member upon a support member;

Fig. 12 is a perspective view of a contact assembly according to another alternative embodiment of the invention;

Fig. 13 is a perspective view of a contact member according to still another alternative preferred embodiment of the invention;

Fig. 14 is a bottom view of the contact member depicted in Fig. 13 shown without the contact rollers attached thereto; Fig. 15 is a cross sectional view of the contact member depicted in Fig. 14, taken along line XIV-XIV of Fig 14;

Fig. 16 is a perspective view of a support member according to an alternative preferred embodiment of the invention;

Fig. 17 is a top plan view of the support member illustrated in Fig. 16;

Fig. 18 is a perspective view of a support member according to still another alternative preferred embodiment of the invention;

Fig. 19 is a top plan view of the support member illustrated in Fig. 18; and

Fig. 20 is a detailed view of a guide member according to the invention.

Referring now specifically to Fig. 1 and 2, an accumulation conveyor 10 normally includes a pair of side support rails 20 and 22. Side rails 20 and 22 are joined by cross members (not shown) positioned at longitudinally spaced intervals. A plurality of rotatably mounted conveying rollers 25 extend between side rails 20 and 22 along the entire length of accumulation conveyor 10. Conveying rollers 25 define a conveying surface upon which product is transported. Conveying rollers 25 are captured within hexagonal holes 27 formed in side rails 20 and 22. Conveying rollers 25 are placed a preselected distance apart, preferably on three inch centers. When so positioned, finger guards 28 may be provided between adjacent conveying rollers 25 in order to provide protection against a user engaging the moving components of accumulation conveyor 10. Finger guards 28 are captured within hexagonal holes 27 formed in side rails 20 and 22.

Accumulation conveyor 10 is divided into a plurality of zones. In Fig. 1 , only zone A and zone B are illustrated, however it will be appreciated by those with ordinary skill in the art that accumulation conveyor 10 may have any number of zones. An endless drive member, such as drive belt 30, provides the mechanical force for driving conveying rollers 25. Drive belt 30 is driven by a drive assembly (not shown) which imparts motion upon drive belt 30 in a preselected direction. As shown, drive belt 30 is positioned in proximity to support side rail 20. However, it will be recognized that drive belt 30 may also be positioned in proximity to side support rail 22. Each zone of accumulation conveyor 10 includes at least one contact assembly 50 juxtaposed with the upper portion 31 of drive belt 30 beneath conveying rollers 25. Each contact assembly 50 is adapted to bring upper portion 31 of drive belt 30 into driving engagement with conveying rollers 25 located immediately above the particular contact assembly 50. A product sensor 35 is provided for each zone of accumulation conveyor 10 in order to operatively control the contact assembly or assemblies 50 for that zone, in accordance with a preselected control scheme. Each product sensor 35 operatively engages an actuator 37, normally a pneumatic valve, which controls the vertically reciprocative movement of the contact assembly 50. The details of product sensor 35, actuator valve 37, and the control scheme by which they are operated is set forth in detail in U.S. Patent 5,540,323, which has hereinabove been incorporated by reference. It will be recognized by those with ordinary skill in the art that there exists a variety of product sensors and actuators, any of which may be substituted for a product sensor 35 and actuator valve 37 without departing from the spirit and scope of the present invention. An example of an alternative product sensor includes photodetectors.

Referring now specifically to Figs. 3 through 12, and the illustrative embodiments depicted therein, contact assembly 50 includes a support member 60 which is mounted to side support rail 20 of accumulation conveyor 10 by a pair of integrally formed hook and snap fasteners 68. Hook and snap fasteners 68 extend from the top region of rear surface 63 of back 64 and are received by cut-out sections 23 formed in side support rail 20. As shown in Fig. 4, a pair of pins 67 extend from bottom region of rear surface

63 of back 64. Pins 67 are received by holes 26 formed in side support rails 20 and 22. Preferably, pins 67 are D-shaped. Support member 60 includes a horizontal surface 70 extending from back 64. Horizontal surface 70 is formed having a cavity 72. Cavity 72 is configured to retainably receive a conventional fluid actuated force producing device, or pneumatic diaphragm 74 of the type normally employed in the industry. A pair of towers or guide members 75, extend substantially vertically from horizontal surface 70. Guide members 75 provide support for a contact member 79 enabling its vertical reciprocation with respect to support member 60. Contact member 79 includes a platform 80 having attached thereto a pair of contact rollers 84 and 86 which are removably placed into rotatable connection with upper portion 31 of drive belt 30. When diaphragm 74 is positioned within cavity 72 of support member 60, application of compressed air to diaphragm 74 will vertically reciprocate platform 82, causing contact rollers 84, 86 into rotational engagement with upper portion 31 of drive belt 30 (Fig. 5). This rotational engagement causes upper portion 31 of drive belt 30 to move in an upward direction and into driving engagement with conveying rollers 25 adjacent contact assembly 50. As illustrated in Fig. 6, deflation of diaphragm 74 moves platform 82 in vertically downward direction and thereby disengaging drive belt 30 from conveying rollers 25. Hence, conveying rollers 25, drive belt 30 maintains contact with contact rollers 84, 86 and they therefore continue to rotate.

Contact assembly 50 additionally includes a pneumatic block 90. A pair of clips 91 extend from the respective ends of pneumatic block 90 for snap retention with recesses 66 defined in support member 60, only one of which is shown in Fig. 3. Pneumatic block 90 is formed with three input ports 92 and three output ports 94 (See Fig. 3a). Input ports 92 and output ports 94 are interconnected with adjacent contact assemblies 50 by ribbon tubing 95 (See Fig. 2). Pneumatic block 90 also is formed with inner connect ports 96 for direct engagement with actuator valve 37 and pneumatic diaphragm 74 supported within cavity 72 of support member 60.

Depending upon the particular control scheme used in conjunction with contact assembly 50, actuator valve 37 may be positioned in a cavity 61 formed in front surface 62 of back 63.

When actuator valve 37 is positioned within cavity 61 , actuator 37 remains in a static position and does not reciprocate with contact member 80. Actuator 37 is formed with flanges 38 configured to be received by cavity 61. Alternatively, as shown in Fig. 7, depending upon the product sensor 35 used with contact assembly 50, actuator valve

37 may be positioned within a cavity 81 of a platfonn 80 of contact member 50. When positioned within cavity 81 of platform 80, actuator valve 37 moves concurrently with the movement of platform 80 when diaphragm 74 is actuated. Platform 80 of contact member 79 preferably has a hexagonal shape defined by opposing sides 100, 102, ends 104, 106 and angled segments 107 and 108. Side 100 and 102 are generally parallel as are ends 104 and 106. Platform 80 is formed with one or more cross supports or webbing 110 attached to the interior surfaces of platform 80. Webbing 110 serves to impart structural rigidity upon platform 80.

Platform 80 is also formed with a pair of vertical posts 114 and 116. As shown in Fig. 8, posts 114 and 116 are each formed with a channel 118 dimensioned to receive a guide member 75 of support member 60. A generally circular plate 120 is formed upon bottom surface 120 of webbing 111. When platform 80 is positioned in support member 60, plate 120 is in registration with diaphragm 74 and provides a flat surface for contact with diaphragm 74.

Arm 124 extends from side 100 beyond end 104 of platform 80. Similarly, arm 134 extends from side 102 and beyond end 106 of platform 80. A horizontal shaft 128 extends from end 126 of arm 124. Analogously, a shaft 138 extends from end 136 of arm 134. As shown in Fig. 8, shaft 128 and shaft 138 extend in opposite directions. Contact rollers 84, 86 are journaled to respective shafts 128 and 138 in a cantilevered fashion. When journaled to shafts 128 and 138, the peripherally of contact rollers 84, 86 define a horizontal plane above the plane defined by the top of platform 80. This enables the periphery of contact rollers 84, 86 to rotationally engage upper portion 31 of drive belt 30.

Shafts 128 and 138 each are formed with a series of tapered flanges 140. As shown most clearly in Fig. 9, each contact roller 84, 86 contains an inner bore 83 which receives a single bearing 142. Shaft 128 or 138 is inserted within bearing 142. A retaining ring 144 is positioned about the periphery of shaft 128, 138 which engages surface 143 of bearing 142. Ends 141 of flanges 140 are positioned flush against surface 145 of bearing 142. Bearing 142 is held within bore 83 of contact roller 84, 86 by compression or friction fit customarily employed within the industry.

Since shafts 128 and 138 extend in opposite directions, contact rollers 84, 86 are journaled at opposite ends. Consequently, when contact rollers 84, 86 are placed in driving engagement with upper portion 31 of drive member 30, platform 80 experiences two separate moments generated by the downward force upon contact rollers 84, 86. Because rollers 84, 86 are journaled at opposite ends, these moments cancel one another. Cancellation of these moments imparts structural stability upon platform 80, and creates a centering effect upon upper portion 31 of belt 30. This centering effect in turn assures even contact between upper portion 31 of drive belt 30 and conveying rollers 25.

In a preferred embodiment, as shown in Fig. 10, one or both of contact rollers 84, 86 is formed with out turned flanges 85 formed at the respective ends of contact rollers 84, 86. Fig. 10 depicts only contact roller 84 as having flanges 85. However it will be recognized by those with ordinary skill in the art that both contact rollers 84, 86 may be formed with flanges 85 without departing from the spirit and scope of the present invention. Flanges 85 serve to maintain proper alignment of upper portion 31 of drive belt 30 when contact rollers 84, 86 are placed in driving engagement therewith.

In an alternative preferred embodiment, as shown in Figs. 13 through 15, contact member 79 is formed with a first or rear contact roller 86' and lead or second contact roller 84'. As depicted in Fig. 13, first contact roller 86' is positioned first in the direction of endless drive member 30 (not shown). In Fig. 13, the direction of travel of endless drive member 30 is represented by the directional arrow. Platform 80 is formed with a pair of posts 114' and 1 16'. As illustrated in Fig. 14, posts 1 14' and 1 16' are formed with a channel 1 18' and 1 18", respectively, each of which is dimensioned to receive a guide member 75. Post 116' is positioned in proximity to first contact roller 86' while post 114' is positioned in proximity to second contact roller 84'. As seen most clearly in Fig. 14, channel 118' is formed having a wider diameter than channel 1 18". When endless drive member 30 becomes misaligned along contact rollers 84' and 86', endless drive member 30 will contact one of the pair of out-turned flanges 85' located at opposing ends of first contact roller 86'. Contact between endless drive member 30 and a flange 85' will exert a rotational force upon contact member 79, rotating contact member 79 about guide member 75 positioned within channel 1 18". As contact member 79 rotates about channel 1 18", the widened diameter of channel 118' enables contact member 79 to shift position in a direction opposite to the direction of rotation of contact member 79. This shift in position due to the rotation of contact member 79 maintains the alignment between contact rollers 84', 86' and endless drive member 30.

In the most preferred embodiment, guide members 75 have an outer diameter of approximately 0,0126 m (0.496 inches). Also, in the most preferred embodiment, the diameter of channel 118' is approximately 0,0154 m (0.605 inches). Moreover, as illustrated in Fig. 15, channel 118" is preferably formed with a widened lower region 117 which is narrowed in an upper region 119. The presence of a wider lower region 117 enables guide member 75 to be centered within channel 118" during assembly, while the narrower upper region 119 holds guide member 75 securely in place. In the most preferred embodiment, upper region 119 of channel 118" has a diameter of approximately 0,0128 m (0.505 inches).

In the most preferred embodiment, the distance between the center lines of shafts 128, 138 is approximately 0,152 m (6 inches) with each contact roller 84, 86 having an approximate outer diameter of 0,045 m (1.75 inches). When so dimensioned, an accumulation conveyor 10 having conveying rollers 25 spaced on 0,076 m (3 inches) centers permits contact assemblies 50 to be positioned such that each conveying roller 25 is driven by a particular contact roller 84, 86 of a particular contact assembly 50 as shown in Fig. 2. This arrangement in turn prevents the occurrence of one or more

"dead rollers," i. e. where the upper portion 31 of drive belt 30 is not placed in driving engagement with a particular conveying roller 25.

As shown in Figs. 1 and 2, contact assemblies 50 are secured to inner surface 21 of side support rail 20. However, it will be appreciated by those with ordinary skill in the art that contact assemblies 50 can also be used with accumulation conveyors having drive belt 30 positioned in proximity to opposing side support rail 22. As illustrated in Fig. 7, when the accumulation conveyor has a drive belt positioned in proximity to side support rail 20 with the flow of product going in the direction indicated by the directional arrow F, platform 80 would be positioned on support member 60 such that arm 124 is positioned proximate to back 64 of support member 60. Alternatively, as shown in Fig. 11 , if the accumulation conveyor has a drive belt positioned proximate to side support rail 22, platform 80 is positioned on support member 60 such that arm 134 is proximate to back 64 of support member 60. The reversal of position of platform 80 upon support member 60 depending upon the placement of drive belt 30 assures direct engagement between contact rollers 84, 86 of contact assembly 50 and conveying rollers 25 adjacent thereto. It should also be understood that contact assemblies 50 could be mounted to other conveyor structures, such as cross supports and the like. In a preferred embodiment, as shown in Figs. 16 through 19, support member 60 is formed with a rib 122. The presence of rib 122 prevents the improper placement of contact member 79 on support member 60. As shown in Fig. 17, when the accumulation conveyor has a drive belt positioned in proximity to side support rail 20 with the flow of product going in the direction indicated by the directional arrow, rib 122 is positioned in proximity to guide member 75". Consequently, when platform 80 is properly positioned on support member 60 such that arm 124 is positioned proximate to back 64 of support member 60, rib 122 will be positioned in a cavity defined by webbing 1 1 1. An improper attempt to place platform 80 upon support member 60 such that arm 134 is proximate to back 64 of support member 60 will result in rib 122 contacting a stop member 158 positioned mid-height between end 104 and arm 124 (Fig. 14).

As shown in Figs. 18 and 19, when the accumulation conveyor has a drive member positioned proximate to side support rail 22, with the flow of product moving in the direction indicated by the arrow F, rib 122 is positioned proximate to guide member 75'. In this position, rib 122 assures proper placement of platform 80 on support member 60 with arm 134 positioned proximate to back 64 of support member 60. Again, improper placement of platform 80 on support member 60 is prohibited by contact between rib 120 and stop member 158.

In an alternative embodiment, as depicted in Fig. 12, platform 80 assumes a square shape having opposing sides 150, 152 and opposing ends 154, 156, in contrast to the hexagonal shape described above. In all other respects, contact assembly 50 is identical to that described above.

In a preferred embodiment, as shown in Fig. 20, each guide member 75 is formed having a lower region 77. A series of circumferencially positioned barbs 78 extend from lower region 77. During assembly, when lower region 77 of guide member 75 is positioned within a mating aperture (not shown) formed in support member 60, barbs

78 maintain securement of guide member 75 within the aperture, and thus prevent guide member 75 from becoming loose due to the repetitive vertical forces imparted by vertically reciprocating contact member 79. Preferably, support member 60, contact member 79 and contact rollers 84, 86 are each manufactured of a polymeric material. Also, it is preferred that support member 60, contact member 79 and contact rollers 84, 86 are manufactured by a single forming process. In the most preferred embodiment, support member 60 and contact member 79 are formed of a glass filled polypropylene. Most preferably, the glass fibers are present in an amount of approximately 30% by weight. Also, in the most preferred embodiment, conveying rollers 84, 86 are formed of an acetal resin.

Other changes and modifications in the specifically described embodiments can be carried out without departing from the principles of the invention, which is intended to be limited only by the scope of the appended claims.

List of reference numbers

10 accumulation conveyor

20 side support rail 1 inner surface 2 side support rail 3 cut-out section 5 conveying roller 6 hole 7 hexagonal hole 8 finger guards 0 drive belt 1 upper portion of 30 5 product sensor 7 actuator valve 8 flange 0 contact assembly 0 support member 2 front surface 3 rear surface 4 back 6 recess 7 pin 8 hook and snap fastener 0 horizontal surface 2 cavity 4 force producing device 5, 75', 75"guide members 7 lower region 8 barb 9 contact member 0 platform 1 cavity 2 platform 3 inner bore 84, 84' contact roller

85 out-turned flange

86, 86' contact roller

90 pneumatic block

92 input port

94 output port

95 ribbon tubing

96 inner connect ports

100 side of 80

102 side of 80

104 end of 80

106 end of 80

107 angled segments of 80

108 angled segments of 80

110 webbing

114, 114' vertical post

116, 116' vertical post

117 widened lower region

118, 118', 118" channel

119 narrowed upper region

120 circular plate

122 rib

124 arm

126 end

128 shaft

134 arm

136 end

138 shaft

140 tapered flange

142 bearing

143 surface

144 retaining ring

145 surface

150 side of 80

152 side of 80 154 end of 80

156 end of 80

158 stop member

A zone of 10

B zone of 10

F direction of flow

Claims

1. An accumulation conveyor comprising: a first and second spaced apart support rails (20,22), at least one cross member between said support rails (20,22), a plurality of conveying rollers (25) supported by said support rails (20,22), and an endless drive member (30) juxtaposed with said conveying rollers (25), said endless drive member (30) traveling in a direction (F); a support member (60) mounted to one of said first support rail (20), said second support rail (22) and said cross member; a force-producing device (74) carried by one of said support rails (20,22) or said support member (60); and a contact assembly (50) having a first contact roller and a second contact roller, said first contact roller (84,86) positioned first in said direction of travel (F) of said endless drive member (30), wherein actuation of said force-producing device (74) moves said first contact roller (84) and said second contact roller (86) into engagement with said endless drive member (30) and said endless drive member (30) into engagement with said conveying rollers (25), wherein said contact assembly (50) is self aligning with said endless drive member (30).

2. The accumulation conveyor as recited in claim 1 , wherein one of said contact rollers (84, 84', 86, 86') has a pair of ends, at least one end of said pair of ends is formed with an out-turned flange (85), contact between said out turned flange (85) and said endless drive member (30) aligns said contact assembly (50) with said endless drive member (30).

3. The accumulation conveyor as recited in claim 2, wherein said contact assembly further comprises a platform (80) rotatably positioned between said force-producing device (74) and said conveying rollers

(25), said contact rollers (84,84', 86,86') attached to said platform (80), and wherein contact between said out turned flange (85) and said endless drive member (30) rotates said platform (80) to thereby maintain alignment between said contact rollers (84, 84', 86, 86') and said endless drive member (30).

4. The accumulation conveyor as recited in claim 2 or 3, wherein said out turned flange (85) is formed on an end of said first contact roller (84,84').

5. The accumulation conveyor as recited in claim 2 or 3, wherein each end of said first contact roller (84,84') is formed with an out-turned flange (85).

6. The accumulation conveyor as recited in any of the claims 1 to 4, wherein said support member (60) has a horizontal surface (70) and at least one guide member (75) extending from said horizontal surface, said platform (50) rotating about said at least one guide member (75).

7. The accumulation conveyor as recited in claim 5, wherein said platform (50) is formed with at least one post (114,1 14', 116,116'), said at least one post (114,114',116,116') having a channel (1 18,118',118") dimensioned to receive said at least one guide member (75).

8. The accumulation conveyor as recited in claim 6 or 7, wherein said at least one guide member (75) is a first guide member and a second guide member and wherein said at least one post formed in said platform (80) is a first post (1 14, 1 14') and a second post (116, 1 16'), said first post (114,114') having a first channel (118, 118') dimensioned to receive said first guide member, said first post (1 14,1 14') positioned proximate to said first contact roller (84,84'), said second post (116,116') having a second channel (118,118') dimensioned to receive said second guide member (75), said second post (116,116') positioned proximate to said second contact roller (86,86'), said platform (80) rotating about said first guide member (75) when said endless drive member (30) contacts said out-turned flange (85) formed on said first contact roller (84,84').

9. The accumulation conveyor as recited in claim 8, wherein said first channel (118,118') has a first diameter, wherein said second channel (118,118") has a second diameter, said second diameter being greater than said first diameter.

10. The accumulation conveyor as recited in claim 9, wherein said first diameter is approximately 0,0128 m (0.505 inches) and wherein said second diameter is approximately 0,0154 m (0.605 inches) and wherein said first guide member (75,75') has an outer diameter of approximately 0,0126 m

(0.496 inches) and said second guide member (75,75") has an outer diameter of approximately 0,0126 m (0.496 inches).

11. The accumulation conveyor as recited in any of the claims 1 to 10, wherein said at least one guide member (75,75') is formed having a lower region

(77) said lower region (77) formed with at least one circumferentially positioned barb (78) extending therefrom.

12. The accumulation conveyor as recited in any of the claims 1 to 11 , wherein said support member (60) is formed with a rib.

13. The accumulation conveyor as recited in claim 12, wherein said rib extends in a vertical direction.

14. The accumulation conveyor as recited in any of the claims 3 to 13, wherein said contact rollers (84, 84', 86, 86') attached to said platform (80), said platform (80) having a first end portion (104,154) and a second end portion (106, 156) spaced apart at least the separation distance of said first contact roller (84,84') and said second contact roller (86,86'), said first contact roller (84,84') positioned beyond said first end portion (104,154) of said platform (80), said second contact roller (86,86') positioned beyond said second end portion (106,156) of said platform (80).

15. The accumulation conveyor as recited in any of the claims 3 to 14, wherein said first contact roller (84,84') and said second contact roller (86,86') are cantilevered to said platform (80).

16. The accumulation conveyor as recited in any of the claims 3 to 15, wherein said platform (80) has a first side (100,150) and an opposing second side (102,152), a first shaft (128) extending from said first side (100,150) and beyond said first end portion (104,154) a second shaft (138) extending from said second side (102,152) and beyond said second end portion (106,156), said first contact roller (84,84') cantilevered to a first arm (124), said second contact roller cantilevered to a second arm (134).

17. The accumulation conveyor as recited in claim 16, wherein said first arm (124) has an end (126) and said second arm (134) has an end (136), said end (126) of first arm (124) having a first horizontal shaft (138) extending therefrom, said first contact roller (84) journaled in said first horizontal shaft (138), said end of said second arm (134) having a second horizontal shaft

(138) extending therefrom, said second contact roller (86) journaled in said second horizontal shaft (138), said first arm (124) and said second arm (134) extending in opposite directions.

18. The accumulation conveyor as recited in any of the claims 3 to 17, wherein said platform (80) is rotatable about a vertical axis.

19. The contact assembly as recited in any of the claims 1 to 18, wherein said contact assembly (50) is vertically reciprocated by said force- producing device (74)

20. The accumulation conveyor as recited in any of the claims 3 to 19, wherein said platform (80) further comprises a bottom (82), said bottom (82) formed with a plate, said plate (120) in registration with said force-producing device (74).

21. The accumulation conveyor as recited in any of the claims 3 to 20, wherein said platform (80) has an interior, said interior formed with at least one cross support (110).

22. The accumulation conveyor as recited in any of the claims 1 to 21 , further comprising a pneumatic block (90) mounted to said support member (60) and interconnected with said force-producing device (74).

23. The accumulation conveyor as recited in any of the claims 1 to 22, wherein said support member (60) is mounted to a support rail (20,22) of said pair of support rails.

24. The accumulation conveyor as recited in any of the claims 1 to 23, wherein said support member (60) and said contact assembly (50) are made of a polymeric material.

25. The accumulation conveyor as recited in any of the claims 1 to 23, wherein said support member (60) and said contact assembly (50) are made of polypropylene having a preselected concentration of glass filler.

26. The accumulation conveyor as recited in any of the claims 3 to 25, wherein said platform (80) has a hexagonal shape.

27. The accumulation conveyor as recited in any of the claims 1 to 26, wherein said first and said second contact rollers (84,84', 86, 86') are made of an acetal resin.

28. The contact assembly as recited in any of the claims 1 to 27, wherein said second contact roller (86,86') has a first end and a second end, said first end and said second end of said second contact roller (86,86') formed with a flange (85).