ABSTRACT

An adjustable roller conveyor module includes a first sup- port structure comprising first and second laterally spaced, longitudinally extending frame members. A first roller set supported by the first support structure includes rollers rotatable about lateral axes equi-spaced in accordance with a predetermined roller-axis spacing. A second support struc- ture is carried between the first and second frame members of the first support structure for longitudinal reciprocation between fully retracted and extended positions. The second support structure supports a second roller set including rollers rotatable about lateral axes coplanar with the axes of the first roller set and equi-spaced in accordance with the predetermined roller-axis spacing. Selected rollers of the first roller set are removable to accommodate retraction of the second support structure. A set of extension apparatus is extendable beyond each end of the conveyor module and reciprocable between fully retracted and extended positions separated by a distance corresponding to at least one half of the roller-axis spacing.

Predetermined  Roller Axis  Spacing RS

ADJUSTABLE ROLLER CONVEYOR MODULE

BACKGROUND 5

1. Field

Although not so limited in its utility or scope, implemen- tations of the present invention are particularly well suited for incorporation in intra-facility transport systems such  as

those used in moving mail pieces through various stages of processing in a mail processing facility, for  example.

2. Brief Description of an Illustrative Environment and Related Art

Large-scale   material   handling   operations   frequently 15

involve the use of  intra-facility  transport  systems such  as conveyor belts and power roller conveyors. A module of a typical power roller conveyor includes a support structure defined by first and second laterally spaced, elongated frame members arranged in parallel and extending along a central 20

longitudinal axis. Extending between, and supported by, the parallel frame members is a  plurality  of  rollers,  each of which rollers rotates about an axis  perpendicular  to  the central longitudinal axis and parallel to the  axes of  other rollers  among  the  plurality.  The  axes  of  the  rollers  are  25

typically   spaced   apart   in   accordance   with recognized industry-standard specifications. For instance, the roller spacing (i.e., distance between the roller axes) of a typical power  roller  conveyor  in  a  mail-processing  facility  is  3 and second conveyor modules are arranged in series between units A and B. Each conveyor module is ten times the fixed roller spacing (frs) plus a constant “c” in length and the distance between units A and B is 20 frs+2 c. In FIG. C, unit B' has replaced unit B and is set in place a distance equal to 20 frs+2 c+d from unit A, thereby leaving a gap of length d between the second conveyor module and unit B'.

Situations such as the one illustrated in FIGS. B and C result in dilemmas presenting choices such as adjusting the position of the replacement equipment and changing the roller spacing between two or more rollers near one or both ends of the roller conveyor module. Moving the piece of equipment is often not practical for any of various reasons. A single piece of mail-processing equipment, for example, can measure well in excess of one hundred feet long and weigh several tons. Moreover, these machines are frequently situated between two sets of conveyor apparatus, rendering movement away from one set of conveyor apparatus toward the other impossible. Adjusting the roller spacing near the end of a roller conveyor module presents difficulties of its own. For instance, the frame members may require cutting to shorten them or the addition of custom-cut lengths to lengthen them, new holes need to be bored in the frame members and the rollers mounted in the new holes. An obstacle other than the actual customization of the conveyor module is that changes in the spacing between rollers require drive belts or o-rings of different, and often, non-standard sizes thereby creating a need for customized o-rings.