Automated sidewall assembly machine

An automated sidewall assembly machine is provided for attaching a sidewall panel to a top and bottom rail of a wheeled trailer. The machine comprises a frame, a carriage for longitudinal movement relative to the frame, an automated punch mounted proximate the frame and an automated riveting press mounted proximate the frame so that the sidewall assembly is movable by the carriage with respect to the frame, the automated punching machine and the automated riveting machine so that holes can be punched through one or more of the sidewall, the bottom rail and the top rail and rivets can be inserted into the punched holes to be mashed. A sensor is operably mounted to the sidewall assembly machine so that information obtained by the sensor can be used to drive the carriage, the automated punching machine and the automated riveting press. A drive motor in communication with the carriage moves the carriage longitudinally with respect to the frame, and a control system having a processor is in operative communication with the carriage, the automated puncher, the automated riveting press, the sensor, and the drive motor.

BACKGROUND OF THE INVENTION

The present invention relates to automatic fastening machines and methods thereof and, more specifically to an apparatus and method for automatic assembly of major subassemblies.

Large transportation vehicles, such as highway trailers, aircraft, and railroad cars typically comprise multiple subassemblies that are fastened together. For example, a highway trailer includes a chassis, a roof, a floor, and a pair of sidewalls. Generally, a trailer's sidewalls are attached to both the floor and roof of the trailer. In the case of a sixty-foot long highway trailer, the load demands and sheer size of the sidewalls, roof, and floor require that the sidewalls be attached to both the roof and floor by rails that provide sufficient structural support to withstand such loads.

To increase a trailer's structural integrity, it is preferable to attach a sidewall to a top and a bottom rail using multiple points of attachment for rivets or screws. In the case of sidewalls that have vertical support posts, extra support and points of connection must be provided to both securely fasten the sidewall, post, and rail together and to ensure that the increased localized weight and stress due to the vertical posts is adequately supported. For example, a sidewall may be connected to a rail by a single line of rivets parallel to the longitudinal axis of the sidewall and appropriately spaced to securely fasten the sidewall and rail together. However, multiple rivets may be required to securely fasten the sidewall, sidewall rails and sidewall post. Additionally, manufacturing tolerances and human error may result in slight variations in the spacing between sidewall posts on each individual trailer.

SUMMARY OF THE INVENTION

The present invention recognizes and addresses considerations of prior art constructions and methods. In an embodiment of the present invention an automated punch and rivet machine for riveting a work piece at sequential work sites on the work piece, the machine comprising a frame for supporting the workpiece, the frame having a longitudinal axis, a carriage disposed proximate to the frame for movement relative thereto along the longitudinal axis, the carriage for transporting the work piece relative to the frame, at least one automated puncher fixed relative to said carriage proximate the frame and at least one automated masher fixed relative to the carriage proximate the frame. A first sensor is fixed relative to the frame so that when the carriage is proximate to the first sensor, the first sensor detects the workpiece. A drive is in communication with the carriage for moving the carriage with respect to the frame along the longitudinal axis. A control system in operative communication with the carriage, the at least one automated puncher, the at least one automated masher, the drive, and the first sensor has a processor operable in a first mode to move the carriage relative to the at least one automated puncher so that the at least one automated puncher can punch one or more holes in the work piece at a work site and the at least one automated masher can mash rivets located in one or more holes punched at another work site, and second mode following operation of the at least one automated puncher and the at least one automated masher, to move the carriage to a new work site of the sequential work sites responsively to the sensor so that the at least one puncher can punch one or more holes in the workpiece at the new work site.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS. 1 and 2illustrate an automated sidewall assembly machine10that receives a sidewall panel2, a bottom rail4, and a top rail6, all shown in phantom onFIG. 1, and automatically fastens all three components together. Assembly machine10includes a machine frame12, a center cart mechanism14, a bottom rail punching press16, a top rail punching press18, a bottom rail riveting press20a, a top rail riveting press20band an overhead vision system24.

Referring toFIG. 2, a plurality of skates32extend along the entire length of frame12and are arranged into a first set34and a second set35. Frame12supports both skate first set34, positioned adjacent to the bottom rail receiving side machine of10, and skate second set35, positioned adjacent to the top rail receiving side of machine10. Each skate set comprises three skates32arranged in parallel columns. In one embodiment, each skate32is approximately 10 feet long and is equipped with rollers36, which are staggered along the length of skates32. In this way, the skates provide rolling support for the sidewall assembly as it progresses along the length of automated sidewall assembly machine10. As shown inFIG. 4B, machine frame12supports a plurality of skate lifters29, comprising a skate cylinder31and two skate posts33. Skate lifters29support skates32and allows for the lifting or lowering of skate32, as described more fully below.

Referring again toFIGS. 2 and 3, frame12supports a center rail40, which guides center cart mechanism14as it is indexed along the length of rail40by a drive belt42. A belt motor44, located at the end of center rail40, rotates an output shaft (not shown) outfitted with a drive pulley46that drives belt42. A follower pulley47(FIG. 1) located at the end of center rail40proximate to frame second end30(FIG. 1) works in conjunction with drive pulley46to tension belt42. Belt42may be fixed to center cart mechanism14by one or more bolts, rivets, clamps or other suitable hardware. In one embodiment, drive motor44is a servo motor, but it should be understood that any suitable type of motor may be used. Also, instead of a belt system, center cart mechanism14may be indexed by other means such as a ball screw mechanism, a gear and chain system, a cable and pulley system, or a rack and pinion system. Rail40is equipped with an angle iron guide48that spans the length of center rail40and allows carriage mechanism brake calipers50and52(FIG. 5) to securely lock carriage mechanism14in place when not in motion.

Referring again toFIG. 1, sidewall rail alignment roller assemblies are provided along the sides of machine frame12to properly align the sidewall assembly with the punching and riveting presses. In one embodiment, four manually operated alignment rollers assemblies60aare spaced along the bottom rail side of frame12, and four automatic alignment roller assemblies60bare spaced along top rail side of frame12. Referring toFIGS. 22A and 22B, each manual roller assembly60ahas an alignment roller62a, a roller arm63a, and a support frame64a, which rotatably supports roller arm63aby a pivot pin65a. When not in use, roller62aand roller arm63ahang from pivot pin65aso that roller arm63adoes not impede the loading of a sidewall assembly onto assembly machine skate32. When a sidewall assembly has been loaded, an operator swings roller arm63aup into alignment about pivot pin65aand inserts a locking pin67ainto aligned receiving holes (not shown) in roller arm63aand frame64a, as shown inFIG. 22B.

Referring toFIGS. 23A-23C, each automatic roller assembly60bhas a roller62b, a roller arm63b, a frame64b, a pneumatic rotating cylinder66b, a pneumatic linear cylinder68band a rail sensor69b. As previously mentioned, in a preferred embodiment, the automated assembly machine has four manual roller assemblies and four automatic roller assemblies. However, it should be appreciated that any appropriate number of alignment rollers may be employed to keep the wall assembly square with the punching and riveting presses during the assembly process.

Turning toFIGS. 4A and 5, center carriage mechanism14is illustrated in a sidewall gripping position. Carriage mechanism14includes two carts: a first cart70for attaching to and pulling the sidewall assembly, and a second cart72attached to drive belt42(FIG. 3) that indexes the entire mechanism14along center rail40. Second cart72has a belt bracket71(FIG. 4A) that supports a belt clamp (not shown) for fixing drive belt42to second cart72. Thus, as drive motor44(FIG. 3) indexes the drive belt, the second cart moves. It should, however, be understood that any alternative method of fixing the drive belt to the second cart is contemplated within the scope of the invention.

First cart70supports a jaw assembly74equipped with a pair of gripper jaws76that releasably engage sidewall panel2. Gripper jaws76are supported by jaw assembly support member78, which is connected to first cart70by a cylinder piston rod80and two guiding posts82(FIG. 5). Thus, when a pneumatic cylinder84actuates, piston rod80retracts pulling jaw assembly74down proximate to center rail40. In this way, jaw assembly74may be lowered beneath the sidewall assembly to facilitate removal of the sidewall at the completion of the riveting process.

Referring in particular toFIG. 4A, gripper jaws76are depicted in a closed position that allows center cart mechanism14to pull the sidewall assembly as it indexes along the length of rail40(FIG. 2). Jaws76are normally in an open position to allow sidewall panel2to be inserted into the jaws. A toggle switch86is mounted onto jaw assembly support member78and senses when the sidewall panel has been inserted into the jaws. That is, the position of toggle switch86corresponds to whether sidewall panel2is in position for gripping by the jaws76, and therefore the switch sends a signal to a programmable logic control (PLC, not shown). The PLC controls the pneumatic cylinders (not shown) that actuate jaws76between a normally open position and a closed gripping position. Jaws76are equipped with rubber upper grippers90and serrated metal lower grippers92to securely hold the sidewall panel during operation. It should be appreciated that the upper and lower grippers may be formed from any other material suitable for securely gripping the sidewall, such as urethane, silicone, alloy, etc.

Referring toFIG. 5, first cart70is equipped with a brake caliper50that locks onto the horizontal flange48aof angle iron guide48. When first cart caliper50is locked onto guide flange48a, it holds first cart70securely in place and resists motion along machine longitudinal axis26(FIG. 1). Second cart72supports a horizontally-mounted pneumatic cylinder94that is connected to a first cart70by a piston rod96. Cylinder piston rod96pulls first cart70towards second cart72after each indexing move performed by second cart72. Second cart72is also equipped with a brake caliper52that locks onto horizontal flange48a. As a result, when second cart caliper52locks onto guide48, caliper52holds second cart72securely in place while cylinder94actuates to retract piston rod96and pulls first cart70towards second cart72, as described in detail below.

Second cart72is equipped with a shock absorber93that engages with a corresponding bolt95mounted on the first cart. When cylinder94retracts piston rod96far enough for bolt95to contact shock absorber93, the shock absorber retards further motion of first cart70towards second cart72and prevents the carts from crashing into each other. A proximity switch98on the end of second cart72senses a proximity switch flag100attached to first cart70. In a preferred embodiment, flag100is a bolt, but it should be understood that a cap screw, bracket or any similar hardware made of a ferrous material may be used. Thus, when proximity switch98senses flag100, a signal is relayed to a PLC (not shown) to discontinue the actuation of pneumatic cylinder94and first cart70comes to a stop. In this manner, shock absorber93slows the progress of first cart70until proximity switch98senses flag100, at which time a signal is sent to the PLC to stop the actuation of cylinder94.

Referring toFIGS. 6 and 7, bottom rail punching press16is shown having a C-shaped body200with an upper portion202, a lower portion204, a vertical portion206, and a punching area generally denoted by208(FIG. 6). Bottom rail punching press16is also equipped with a lift cylinder210, a punch cylinder212, bottom gag proximity switches generally denoted by214, a bottom die216, a top die assembly218, a separating mat220, a top die upper proximity switch223, a top die lower proximity switch222, and safety guarding203(FIG. 7). Lift cylinder210is positioned between a lift cylinder anchor bracket224and a lift cylinder body bracket225. Four lift guide posts209, mounted to anchor bracket224, are received by four respective bushings211, coupled to body bracket225, to provide alignment and support between the anchor bracket and the body bracket. Bushings211slide along posts209as lift cylinder210actuates to raise and lower C-shaped body200relative to machine frame12(FIG. 2).

Referring toFIGS. 8 and 9, bottom die216connects to punch body lower portion204(FIG. 8) by a bottom die shoe226that rigidly supports two die posts228(FIGS. 6 and 7), a lower rail punch spacer230, a pair of gag guides232and a pair of gags234and235. Referring toFIG. 8, bottom die shoe226also supports two front proximity switch brackets215aand two rear proximity switch brackets215b. Each front proximity switch bracket215asupports a front proximity switch214a, while each rear proximity switch bracket215bsupports both an intermediate proximity switch214band a rear proximity switch214c. The operation of the proximity switches214a,214b, and214cwill be described in detail below.

Referring toFIG. 9, gags234and235are positioned parallel to each other and are slidably received by gag guides232. Each gag234and235defines a respective (1) sloped leading edge234aand235a, (2) first stage surface234band235b, (3) second stage surface234cand235c, and (4) sloped transition surface234dand235dintermediate the first and second stage surfaces. Gag234slides into gag guides232when cylinders276and/or282actuate, while gag235slides into gag guides232when cylinders277and/or283actuate. Gag cylinders276,277,282, and283are situated in a gag cylinder bank269in a stacked arrangement that is rigidly supported by a gag cylinder bank bracket271. Gag cylinder bank bracket271attaches to both C-shaped body vertical portion206(FIGS. 6 and 7) and to bottom die shoe226(shown in phantom inFIG. 9). Bracket271defines two guideways272that slidably receive two cylinder sliders274and275. Lower gag cylinders282and283connect to a rear cylinder support278and to sliders274and275, respectively. Thus, gag cylinders276and277can actuate to move gags234and235, respectively, into gag guides232a predefined distance, after which lower gag cylinders282and283can actuate to extend piston rods279and280forward. This additional movement in turns extends gags234and235, respectively, into gag guides232an additional predetermined distance for punching field holes.

Punch spacers230and gag guides232support bottom die216, which defines six slots arranged into a first set238of three slots and a second set240of three slots. All slots in a single set are parallel to each other, and the slots are arranged so that each slot in one set is aligned with and parallel to a respective slot of the second set. Each slot extends inwardly from one of two opposite outer sides of bottom die216toward the bottom die's center, and each slot slopes downwardly from the die's center to a slot open end. First slots238do not communicate with second slots240, but rather terminate to define inner ends242.

Bottom die216also slidably receives two rail punches244, which are positioned perpendicular to the longitudinal axes of the slots and proximate to slot inner ends242. Each rail punch244supports three die buttons246having a central bore245in communication with a respective exit portal245a(FIGS. 26A and 26B). Thus, the material punched out of the sidewall panel assembly during the punching process exits the punch through die button central bore245out of exit portal245aand out one of the two slot sets238and240. In this way, the refuse material slides out of the bottom of die press216, which prevents the machine from becoming jammed.

Referring toFIG. 10, top die assembly218comprises a bottom rail punch retainer252, six punches254, two field gags256aand256band two post gags258aand258b. Bottom rail punch retainer252may be secured to top die shoe248by screws, bolts, or any other suitable fastener and defines six gag slots260, each of which slidably receives a field or post gag. Gag cylinders262aand262bdrive field gags256aand256binto their respective slots while cylinders262cand262ddrive post gags258aand258binto their respective slots. In one embodiment, the gag cylinders may be pneumatic cylinders powered by air hoses255(FIG. 6) connected to air valves236.

Gag slots260are arranged in two sets of three parallel slots, and an inner end of each gag slot defines a vertical, counterbored through-hole264that slidably receives a respective punch254. Punches254each have a flange266, a shank268, and a tip270. Each through-hole264slidably receives a punch shank268so that punch flange266rests in the counterbore (not shown) of through-hole264. Field gags256aand265band post gags258aand258bare slidably positioned in the gag slots so that when gag cylinders262a-262dactuate, the gags are biased into the gag slots and restrain punch flanges266to prevent the punches from sliding upward in through-holes264when punch tips270contact the sidewall assembly.

Four proximity switches257aand257b(shown in phantom) are attached by respective brackets (not shown) to top die shoe248and sense the rear portion of gags256a,256b,258aand258b, respectively, when the gags are retracted from their respective slots. Once gag cylinders262a-262dbias the gags into their corresponding gag slots260, proximity switches257aand/or257bno longer sense the rear portion of the gags, and the proximity switches send a signal to a PLC (not shown) indicating that the gags are in a punching position. Punch cylinder212(FIG. 8) may actuate causing top die assembly218to slide downward, into a hole-punching stroke.

Field gags256aand256bare single gags that restrain only one punch each, but post gags258aand258bare U-shaped and, therefore, simultaneously restrain two punches each. In this configuration, post gag258arestrains post punches254c, while post gag258brestrains post punches254d. This arrangement provides an added advantage of requiring only two post gag cylinders262for four punches. It should be understood though that any number of alternative arrangements, including six gags with corresponding cylinders, may be used to restrain the punches in accordance with the present invention.

Referring again toFIGS. 6 and 7, bottom rail top die assembly218attaches to punching press upper portion202by punch cylinder212. Top die assembly218is rigidly attached to a piston rod213(FIG. 6) of cylinder212by top die shoe248. Top die shoe248is equipped with two bushings250that ride about die posts228. Consequently, as piston rod213extends, top die assembly218lowers towards bottom die216along die posts228.

Punch cylinder212is a hydraulic cylinder that actuates to either push piston rod213vertically downward or pull piston rod213vertically upward. During punching, hydraulic oil is forced into an upper chamber (not shown) of punch cylinder212, and the pressure exerted upon piston rod213by the hydraulic oil forces the piston rod downward until the piston rod is fully extended. When the piston rod fully extends, top die assembly218lowers toward bottom die assembly216, and punches254(FIG. 10) restrained by their respective gags punch holes in the sidewall assembly. Once the holes are punched in the sidewall assembly, hydraulic oil is forced out of the upper chamber (not shown) and into a lower chamber (not shown) of cylinder212. The pressure exerted upon the piston rod by the hydraulic oil forces piston rod213to retract and raise top die shoe248vertically upward towards punching press upper portion202.

Referring toFIGS. 11-12, a top rail punching press18utilizes many identical or similar components as bottom rail punching press16and function in a nearly identical manner. However, a complete description of a preferred embodiment of the top rail punching press is provided herein. Top rail punching press18has a C-shaped body300with an upper portion302, a lower portion304, a vertical portion306, and a punching area308. The top rail punching press is also equipped with a lift cylinder310, a punch cylinder312, gag proximity switches generally denoted by314, a bottom die316, a top die assembly318, a separating mat320, a top die upper proximity switch322, a top die lower proximity switch323, and safety guarding303(FIG. 11). Lift cylinder310is positioned between a lift cylinder anchor bracket324and a lift cylinder body bracket325. Four lift guide posts309, mounted to anchor bracket324, are received by four respective bushings311, coupled to body bracket325, to provide alignment and support between the anchor bracket and the body bracket. Bushings311slide along posts309as lift cylinder310actuates to raise and lower C-shaped body300relative to machine frame12(FIG. 2).

Referring particularly toFIG. 11, lift cylinder bracket324is slidably attached to two rails317and is moveable along the rails by a ball nut (not shown) driven by a drive screw319that is rotatably attached to a drive motor321. When motor321rotates drive screw319, the ball nut (not shown) advances along the drive screw thereby moving top rail punch press18linearly transverse to machine longitudinal axis26(FIG. 1). This allows for the adjustment of the position of punching press18with respect to machine central longitudinal axis26(FIG. 1). A front proximity switch307aand a rear proximity switch307bare affixed to lift cylinder bracket324to accurately position punch press18. When drive screw319has advanced punch press18to a punching position proximate to the machine longitudinal axis, front proximity switch307asenses a flag (not shown) and drive screw drive motor321stops rotating drive shaft319. In this way, punch press18is properly positioned for punching. Once the last holes have been punched in the sidewall assembly, drive motor321rotates drive shaft319in an opposite direction, and punch press18is advanced to a home position distal from the machine longitudinal axis. When punch press18reaches its home position, rear proximity sensor307bsenses a flag (not shown) and the drive screw motor stops rotating the drive shaft.

Referring toFIGS. 13 and 14, bottom die316is connected to punch body lower portion304by a bottom die shoe326that also rigidly supports two die posts328(FIG. 13), a lower rail punch spacer330, a pair of gag guides332and a pair of gags334and335. As with bottom rail punch press16, top rail punch press gags334and335are positioned parallel to each other and are slidably received by gag guides332(FIG. 14). Bottom die shoe326also supports two front proximity switch brackets315aand two rear proximity switch brackets315b(FIG. 13). Each front proximity switch bracket315asupports a front proximity switch314a, while each rear proximity switch bracket315bsupports both an intermediate proximity switch314band a rear proximity switch314c. The operation of the proximity switches314a,314b, and314cwill be described in detail below.

Referring toFIG. 14, each gag334and335defines a respective (1) sloped leading edge334aand335a, (2) first stage surface334band335b, (3) second stage surface334cand335cand (4) sloped transition surface334dand335dintermediate the first and second stage surfaces. Gag334slides into gag guides332when cylinders376and/or382actuate, and gag335slides into gag guides332when cylinders377and/or383actuate. Gag cylinders376,377,382, and383are situated in a gag cylinder bank369in a stacked arrangement that is rigidly supported by gag bank bracket371. Gag cylinder bank bracket371attaches to C-shaped body vertical portion306(FIGS. 11 and 12) and bottom die shoe326(shown in phantom inFIG. 14).

Bottom die316defines four slots arranged into a first set338of two slots and a second set340of two slots. All slots in a single set are parallel to each other, and the slots of first set338are arranged so that each slot is aligned with and parallel to a respective slot of second set340. Each slot extends inwardly from one of two opposite outer sides of bottom die316toward the bottom die's center. The slots of first set338do not communicate with the slots of second set340, but rather terminate to define inner ends342and each slot slopes downwardly from the die's center to a slot open end.

Bottom die316slidably receives two rail punches344, which are positioned perpendicular to the axis of the slots and proximate to slot inner ends342. Each rail punch344supports two die buttons346having a central bore345in communication with a respective exit portal (not shown). Thus, the material punched out of the sidewall panel assembly during the punching process exits through die button central bore345out of the exit portals (not shown) and out one of the two slot sets338and340. In this way, the refuse material slides out of the bottom of die press316, which prevents the machine from becoming jammed.

Referring toFIG. 15, top die assembly318comprises a bottom rail punch retainer352, four punches354, two field gags356aand356b, and two post gags358aand358b. Top rail punch retainer352may be secured to top die shoe348by screws, bolts, or any other suitable fasteners and defines four gag slots360, each of which slidably receives a respective field or post gag. Gag cylinders362aand363bdrive field gags356aand356b, respectively, while gag cylinders362cand362ddrive post gags post gags358aand358b, respectively. The field gags and post gags are identical single gags that restrain only one punch each. The gag cylinders may be pneumatic cylinders powered by air hoses355(FIG. 12) connected to air valves336. Once the gag cylinders bias the gags into their corresponding gag slots360, the proximity switches no longer sense the rear portion of the gags, and the switches send a signal to a PLC (not shown) indicating that the appropriate gags are in a punching position. Punch cylinder312(FIG. 11) may actuate causing top die assembly318to slide downward, into a hole-punching stroke.

Gag slots360are arranged in two sets of two parallel slots, and an inner end of each slot defines a vertical, counterbored through-hole (not shown) that slidably receives a punch354. Each punch354has a flange366, a shank368, and a tip370. Punch shank368slides through the through-hole (not shown), and the punch flange366rests in a counterbore (not shown) of the through-hole. Field gags356aand356band post gags358aand358bare slidably positioned in the gag slots so that when their respective gag cylinders are actuated, the gags restrain punch flanges366to prevent the punches from sliding upward in their through-holes when punch tips370contact the sidewall assembly. Field gags356aand356brestrain field punches354aand354b, respectively, while post gags358aand358brestrain field punches354cand354d, respectively. Four proximity switches357aand357b(shown in phantom) are attached by respective brackets (FIG. 13) to top die shoe348and sense the rear portion of gags356and358, respectively, when the gags are retracted from their respective slots360.

Top rail top die assembly318is attached to punching press upper portion302by punch cylinder312, as shown inFIGS. 11 and 12. When activated, punch cylinder312lowers top die assembly318into a punching position, as described in detail below. Top die assembly318is rigidly attached to a piston rod313(FIG. 13) of punch cylinder312by top die shoe348, which is equipped with two bushings350that ride along die posts328as cylinder312lowers the top die assembly.

Punch cylinder312is a hydraulic cylinder that actuates to either push piston rod313vertically downward or pull piston rod313vertically upward. During punching, hydraulic oil is forced into an upper chamber (not shown) of punch cylinder312, and the pressure exerted upon piston rod313by the hydraulic oil forces the piston rod downward until the piston rod is fully extended. When the piston rod fully extends, top die assembly318lowers toward bottom die assembly316, and the punches354a-354d(FIG. 15) restrained by their respective gags punch holes in the sidewall assembly. Once the holes are punched in the sidewall assembly, hydraulic oil is forced out of the upper chamber (not shown) and into a lower chamber (not shown) of cylinder312fforcing piston rod313to retract and raise top die shoe348vertically upward towards punching press upper portion302.

Referring now toFIGS. 16 and 17, a top rail riveting press20bhas a C-shaped body400, with an upper portion402, a lower portion404, a vertical portion406and a riveting area generally denoted408. Top rail riveting press20bis also equipped with a lift cylinder410, a riveting cylinder412, bottom gag proximity switches generally denoted by414, a bottom riveting die416, a top riveting die assembly418, a top riveting die upper proximity switch422, and a top riveting die lower proximity switch423.

Riveting press lift cylinder410is positioned between a lift cylinder anchor bracket424and a lift cylinder body bracket425. Four lift guide posts409are slidably received in respective bushings411that are coupled to body bracket425. The sliding connection between the guide posts and the bushings provides alignment and support between anchor bracket424and body bracket425as lift cylinder410actuates to raise and lower C-shaped body400relative to frame12(FIG. 1).

Referring particularly toFIG. 16, riveting press20b, located on the top rail side of assembly machine10(FIGS. 1 and 2), has two rails417that are slidably attached to lift cylinder bracket424. A ball nut (not shown), attached to the bottom of bracket424, is driven by a drive screw419that is rotatably attached to drive motor421. When motor421rotates drive screw419, the ball nut (not shown) advances along the drive screw thereby moving riveting press20blinearly transverse to machine longitudinal axis26(FIG. 1). A front proximity switch407aand a rear proximity switch407bare affixed to lift cylinder bracket424to accurately position riveting press20b. When drive screw419has advanced riveting press20to a riveting position proximate to the machine longitudinal axis, front proximity switch407asenses a flag (not shown) and drive screw drive motor421stops rotating drive shaft419. In this way, riveting press20bis properly positioned for compressing rivets (not shown). Once the last rivets have been compressed, drive motor421rotates drive shaft419in an opposite direction, and riveting press20bis returned to a home position distal from the machine longitudinal axis. When riveting press20breaches its home position, rear proximity sensor407bsenses a flag (not shown) and the drive screw motor stops rotating the drive shaft. This allows for the adjustment of the position of press20bfacilitating easy loading and unloading of a sidewall assembly from the assembly machine. However, rail riveting press20a, located on the bottom rail side of machine10(FIG. 1), is not equipped with a ball screw mechanism and, accordingly, can not be adjusted linearly transverse to machine longitudinal axis26. It should be understood, however, that the bottom rail rivet press20amay be formed similar to the top rail rivet press so that it too can be adjusted relative machine centerline26.

The following paragraphs address features of presses20aand20bthat are identical; therefore any reference to features specific to press20aor20bwill be particularly pointed out. Referring toFIGS. 18A,18B and19, bottom die416is rigidly connected to riveting press body lower portion404(FIG. 18A) by a bottom die shoe426. Bottom die shoe426supports two die posts428(FIGS. 18A and 18B), a lower die spacer430, a pair of gag guides432and a pair of gags434and435(FIGS. 18A and 19). Bottom die shoe426also supports two front proximity switch brackets415aand two rear proximity switch brackets415b(FIGS. 18A and 18B). Each front proximity switch bracket415asupports a front proximity switch414a, while each rear proximity switch bracket415bsupports both an intermediate proximity switch414band a rear proximity switch414c.

Referring in particular toFIG. 19, each gag434and435defines a respective (1) sloped leading edge434aand435a, (2) first stage surface434band435b, (3) second stage surface434cand434cand (4) sloped transition surface434dand435dintermediate the first and second stage surfaces. Gags434and435are positioned parallel to each other and are slidably received by gag guides432. Gags434slides into gag guides432when cylinders476and/or482actuate, while gag435slides in to gag guides432when cylinders477and/or483actuate as described below. Gag cylinders476,477,482, and483are situated in a gag cylinder bank469in a stacked arrangement that is rigidly supported by a gag bank bracket471. Gag bank bracket471is attached to both C-shaped body vertical portion406(FIGS. 16 and 17) and bottom die shoe426(shown in phantom inFIG. 19).

Bottom die416, lower die spacer430, and gag guides432support bottom die416and bottom die416slidably receives two rail anvils436that are aligned parallel to each other and to gags434and435, and each rail anvil supports three plungers438. Referring toFIG. 28C, plungers438are spring-loaded and biased upward within rail anvil436. Rail anvils436define a vertical portion436aand a horizontal flange436b. During assembly of rail anvils436, three through holes436care bored into vertical portion436a. Through holes436cdefine an upper counterbore436dthat receives plunger438and a spring439, and a lower counterbore436ethat receives the head of a cap screw437. It should be under stood that cap screw437may be replaced by a shoulder bolt or other appropriately shaped fastener.

Each upper counterbore436dreceives spring439and plunger438, and the spring biases the plunger upward. Cap screw437is inserted into lower counterbore436eso that the treaded portion of the cap screw extends into through hole436cand into upper counterbore436d. Each plunger is tapped to receive the threads of cap screw437, and the threaded portion of cap screw437is tightened into the tapped portion of plunger438. Rail anvil flange436bis then attached to rail anvil vertical portion436asealing the head of cap screw437into lower counter bore436e. Rail punch vertical portion436aand rail punch flange436bmay be attached together by screws, weldments or by any other suitable assembly method. In this configuration, a downward force exerted on plunger438will compress spring439and allow plunger436to slide downward in counterbore436dproximate to through hole436c.

Referring again toFIGS. 18A and 18B, riveting press top die assembly418comprises a top die shoe440rigidly attached to a piston rod413(FIG. 18A) of cylinder412. Top die shoe440rigidly supports anvil mount444(FIG. 18B) and top anvils446, which are positioned so that each top anvil446aligns with one of rail anvils436. Top die shoe440is equipped with two bushings442that ride along die posts428as cylinder412raises and lowers top die assembly418.

In one embodiment, riveting cylinder412is a hydraulic cylinder that actuates to either push piston rod413vertically downward or pull piston rod413vertically upward. During riveting, hydraulic oil is forced into an upper chamber (not shown) of cylinder412forcing the piston rod downward until the piston rod is fully extended. When the piston rod fully extends, the rivets (not shown) previously inserted into holes punched into the sidewall assembly by top rail punching press18are compressed between rail anvil436and top die anvil446, securely fastening top rail6to sidewall panel2. Once the rivets are compressed, hydraulic oil is forced out of the upper chamber (not shown) and into a lower chamber (not shown) of cylinder412, which forces piston rod413upward and raises top die shoe440vertically upward towards punching press upper portion402. It should be understood that the riveting process used for both the bottom rail and top rail portions of an assembled sidewall are substantially identical with the exception that the top rail riveting press has smaller anvils and is equipped with a mechanism for varying the distance between the top rail riveting press and the machine frame centerline26(FIG. 1). Because of the minor differences between the top rail and bottom rail rivet presses, a detailed description of the bottom rail rivet press is not discussed herein.

In operation, the automated sidewall assembly machine attaches a bottom rail and a top rail to a sidewall panel. In general, the assembly machine punches holes in both the sidewall and the top and bottom rails. Once the holes have been punched, an operator inserts rivet blanks into the punched holes, and the automated assembly machine compresses the rivets, thereby securely fastening the bottom and top rails to the sidewall panel. The assembly machine indexes the sidewall and rails along the length of the machine so that the punching and riveting presses may remain stationary with respect to the translating sidewall assembly. The punching and riveting process is repeated until the rails have been securely attached to the sidewall panel along the entire length of the sidewall assembly.

Referring toFIGS. 1-3, prior to executing the automated assembly process, machine10powers up and executes a homing operation in which center cart mechanism14moves along center rail40to a position proximate to drive motor44. Once center cart mechanism14reaches its home position, gripper jaws76(FIG. 20) open and the jaws are ready to receive a sidewall assembly. Operators place a sidewall panel2onto skates32at machine frame first end28and position bottom rail4and top rail6along the appropriate edges of sidewall panel2.

Once the panel and rails are positioned on machine10, an operator swings manual alignment rollers assemblies60a(FIGS. 22A and 22B) into position by rotating roller arms63ainto a vertical attitude and inserts locking pin67ainto both roller arm63aand support frame64a. The operators then slide wall panel2and bottom rail4into contact with manual alignment rollers62a. This properly aligns sidewall panel2and bottom rail4with respect to bottom rail punch press16and bottom rail riveting press20a. After aligning the bottom rail with manual alignment rollers62a, the operators actuate automated alignment roller assemblies60bto properly secure the wall assembly in machine10.

Referring toFIGS. 23A-23C, pneumatic rotating cylinder66bretracts, rotating roller arm63bfrom a horizontal attitude (FIG. 23A) into a vertical attitude (FIGS. 23B and 23C), and pneumatic linear cylinder68bactuates pulling roller62band roller arm63btowards top rail6(FIG. 23C) until rail sensor69bmakes contact with the edge of the top rail. Once rail sensor69bmakes contact with the top rail, cylinder68bstops actuating, and a rolling connection between top rail6and roller62bis maintained until the sidewall assembly is indexed beyond the automated alignment roller60b.

Multiple manual and automatic alignment roller assemblies60aand60b(FIG. 1) are provided along the length of assembly machine10, thus ensuring proper alignment of the sidewall assembly throughout the assembly process. When the sidewall assembly progresses past each automated alignment roller assembly60b, sensor69brecognizes that roller62bis no longer in contact with the top rail (not shown) and actuates linear cylinder68b, pulling roller62band roller arm63btowards cylinder68b. Rotation cylinder66bthen actuates, rotating roller62binto a horizontal attitude, where it remains until a new sidewall assembly is loaded for assembly.

Referring toFIGS. 20 and 21, once the sidewall assembly is secured between the alignment rollers, the operators roll the assembly towards center cart mechanism14, until the leading edge of sidewall2trips toggle switch86. This causes the jaw cylinders (not shown) to actuate so that gripper jaws76close and tightly clamp down onto sidewall2(FIG. 21). Once the jaws grip the sidewall assembly, brake calipers50and52disengage from angle iron guide flange48a(FIG. 5), and drive motor44(FIG. 3) slowly advances drive belt42moving cart14along rail40until a proximity sensor87(FIG. 21) attached to skate32detects the leading edge of the first support post3attached to the underside of sidewall panel2. Once proximity sensor87senses the forward edge of first post3, vision system24is positioned so that a camera25may take a picture of the forward edge of the sidewall assembly in order to determine which style of sidewall is being assembled and where the post is located.

Referring toFIG. 21, vision system24is fixedly attached to an overhead frame (not shown) located above assembly machine frame12and the sidewall assembly. When camera25takes a picture of the sidewall assembly, the image is relayed back to a CPU, which digitally processes the picture and looks for one of the following five items:

(2) a post with rivets spaced4″ apart directly below the camera;

(3) a post with rivets spaced4″ apart and offset2″ from the center of the camera;

(4) a post with rivets spaced6″ apart; or

(5) a post with rivets spaced6″ apart and offset2″ from the center of the camera.

Each of the five different images corresponds to an assembly program that is specific to the particular style of sidewall, and based on the image taken by camera25, the CPU selects the proper program to both initially position and assemble the sidewall panel2, bottom rail4, and top rail6.

Once the initial position of the sidewall assembly and the correct punching pattern is determined, the punching and riveting processes commence. The sidewall assembly travels along center rail40by the indexing movements of drive motor44(FIGS. 2 and 3) and center cart mechanism14. Throughout the assembly process, vision system24continues to take photographs of the sidewall assembly after each indexing movement to ensure that center cart mechanism14moves the sidewall assembly the proper distance. If center cart mechanism14indexes the sidewall assembly an incorrect distance, vision system24will recognize the error and determine the difference between the actual position and the proper position, and the CPU will adjust the indexing distance by 0.020″ increments towards the correct position. Additionally, based upon the data collected by each photograph, the vision system will determine the proper riveting and punching processes that must occur for each indexed position. In particular, vision system24records the data captured at a particular position, the CPU determines the proper punching and riveting patterns for that position and the information is stored in an array file. As the sidewall assembly enters the punching and riveting presses, the PLCs controlling the presses recalls the information from the array to determine the proper punching and riveting sequence for each position along the length of the sidewall assembly.

Referring toFIGS. 24A-24F, during each indexing move performed by center cart mechanism14, first cart70and second cart72move separately and at different times. Prior to the first indexing move, both first cart brake50and second cart brake52are activated, locking both carts rigidly to guide flange48a. Referring with particularity toFIG. 24A, once the carts are to index, second cart brake52disengages from center guide flange48a, and drive motor44rotates drive pulley46(FIG. 3) causing the drive belt to pull second cart72towards machine second end30. First cart brake50remains engaged on center guide48(FIG. 24A), and pneumatic cylinder94allows cylinder piston rod96to extend as second cart72is pulled away from first cart70.

Referring toFIG. 24B, when the indexing of second cart72is completed, second cart brake52engages guide flange48a, fixing second cart72rigidly in place. First cart brake50then disengages from guide flange48aand pneumatic cylinder94actuates, pulling piston rod96, first cart70, and the sidewall assembly towards second cart72. When cylinder94retracts piston rod96far enough for shoulder bolt95to contact with shock absorber93, the shock absorber will retard the motion of first cart70towards second cart72. At this point, proximity switch98senses flag100attached to first cart70signaling to the CPU to discontinue the actuation of cylinder94. As previously mentioned, proximity switch98operates to ensure that the first cart does not over-travel and damage the second cart when pulled by cylinder94. Once first cart70is indexed toward second cart72, first cart brake50re-engages guide flange48a, locking first cart70and the sidewall assembly securely in place. After each indexing step, the process repeats itself, advancing the center cart mechanism14and the sidewall assembly along the length of center rail40until the assembly process is complete.

Referring toFIGS. 24C-24F, upon the completion of the assembly process, second cart brake52disengages guide flange48a, and the drive motor indexes second cart72one final time, while first cart70is maintained in place by first cart brake caliper50. After completion of the indexing move, second cart brake52re-engages guide flange48a, locking second cart72firmly in place along center rail40. Referring with particularity toFIG. 24D, jaws76open releasing the sidewall assembly, first cart brake50disengages guide flange48a, and cylinder94actuates pulling first cart70towards second cart72. In this way, jaw mechanism74is removed from engagement with the sidewall assembly.

Referring toFIG. 24E, when proximity sensor98senses flag100, cylinder94stops actuating, and pneumatic cylinder84actuates, pulling piston rod80, which is connected to jaw assembly support member78, down proximate to center rail40into a position where jaw assembly74is below the sidewall assembly. Jaws76close and second cart brake52disengages from guide flange48aallowing drive motor44(FIG. 3) to jog belt42(FIG. 3) bringing center cart mechanism14to its home position proximate to drive motor44. Referring now toFIG. 24F, when center cart mechanism14returns to its home position, cylinder84actuates raising piston rod80, jaw assembly support member78, and jaw assembly74up distal from center rail40. Once jaw assembly74reaches its fully raised position, jaws76open, and center cart mechanism14is ready to receive the assembly of a new sidewall.

It should be understood that the punching process for both bottom rail punching press16and top rail punching press18is nearly identical. Accordingly, the description of the punching process provided herein is limited to the bottom rail. The only difference between the punching of the bottom rail and the punching of the top rail is the number of holes punched during the post hole punching steps.

Referring back toFIG. 1, during the assembly process, as center cart mechanism14advances the sidewall assembly along the length of assembly machine10, the bottom rail portion of the sidewall approaches the bottom rail punching press16. Punching press16is equipped to punch two varieties of holes: field holes and post holes. Field holes are equally spaced and are punched in a single row along the entire length of the bottom rail4parallel to machine central longitudinal axis26. Post holes are holes punched through the sidewall assembly at a post and are punched in a column of two holes transverse to machine central longitudinal axis26. Each column of post holes is aligned with a field hole, so that when the field and post holes are punched, the result is a single column of three holes with the field hole being closest to the machine central longitudinal axis26and the two post holes being further away from axis26.

Referring now toFIG. 10, press16punches field holes when gag cylinders262aand262bforce field gags256aad256binto their respective gag slots260thereby restraining field punches254aand254bfrom any vertical motion. In order to accommodate the restrained field hole punches254aand254b, bottom shoe gag cylinder bank269(FIG. 9) actuates gag cylinders282and283, which force gags234and235, respectively, into gag guides232. As gags234and235enter gag guides232, gag leading edges234aand235aengage the lower portion of their respective rail punches244lifting the rail punch up and out of bottom die block216. Cylinders282and283are sized appropriately so that when fully extended rail punches244rests on gag first stage surfaces234band235b. As a result, the combined action of gag cylinders262aand262b(FIG. 10) and gag cylinders282and283(FIG. 9) punches field holes when punching cylinder212lowers top die assembly218(FIGS. 6 and 7) into its punching position.

Referring now toFIG. 10, punching press16punches post holes when gag cylinders262cand262dforce post gags258aand258b, respectively, into their respective gag slots260thereby restraining post punches254cand254dfrom any vertical motion. In order to accommodate the restrained post hole punches254cand254d, bottom shoe gag cylinder bank269(FIG. 9) actuates gag cylinders282and283, which force gags234and235into gag guides232. As gags234and235enter gag guides232, gag leading edges234aand235aengage the lower portion of their respective rail punches244lifting the rail punches up and out of bottom die block216. The actuation of cylinders282and283forces gags234and235into gag guides232so that rail punches244rests on gag first stage surfaces234band235b. On the other hand, when punching field holes, both cylinders276and282actuate to force gag234into gag guides232while both cylinders277and283actuate to force gag235into gag guides232. In this way, rail punches244rest on second stage surfaces234cand235cwhen punching field holes.

Because gag cylinders262a,262b(FIG. 10),276,277,282and283(FIG. 9) function independently, it should be understood that punching press16may punch multiple arrangements of holes. The following arrangements are possible:a. gag cylinder262a(FIG. 10) actuates, restraining only field gag256a, while gag cylinder283(FIG. 9) actuates, and only one field hole is punched,b. gag cylinder262b(FIG. 10) actuates, restraining only field gag256b, while gag cylinder282(FIG. 9) actuates, and only one field hole is punched,c. both gag cylinders262aand262b(FIG. 10) actuate, restraining field punches256aand256b, while gag cylinders282and283(FIG. 9) extend, forcing both gags234and235into gag guides, and two field holes are punched,d. gag cylinders262aand262c(FIG. 10) actuate, and both gag cylinders277and283(FIG. 10) actuate, and one field hole and two post holes are punched,e. gag cylinders262band262d(FIG. 10) actuate, and both gag cylinders276and282(FIG. 9) actuate, and on field hole and two post holes are punched, orf. any appropriate combination there of.
It should be understood that depending upon the spacing of posts within the sidewall assembly, it may be appropriate for the gag cylinders to actuate so that only a field hole is punched for each rail punch244. It may also occur that the gag cylinders actuate so that a field hole is punched for one rail punch while both a field hole and two post holes are punched for the other rail punch. Finally, the gags may actuate so that a field hole and two post holes are punched for one rail punch while no holes are punched for the other rail punch. In this way, punching press16can accommodate for a number of different sidewall assembly designs that call for various field and post hole arrangements.

Referring back toFIG. 1, when punching a top rail, top rail punching press18punches field holes in a manner similar to bottom rail punching press16: a single hole is punched for each rail punch344(FIG. 14), and each hole corresponds to die buttons346a(FIG. 14) located at a field position that is distal from gag cylinder bank369(FIG. 14). On the other hand, when punching post holes, one rail punch may engage to punch one field hole and one post hole for a leading edge of the post while the other rail punch does not engage at all, or one rail punch may engage to punch one field hole and one post hole for a trailing edge of the post while the other rail punch engages to punch one field hole. For this reason, each gag is provided with a separate pair of cylinders in gag cylinder bank369.

Referring back toFIG. 7, prior to the punching process, two nozzles207, attached to the side of bottom rail punching press16facing the advancing sidewall, spray a lubricating agent onto the bottom rail to reduce friction and binding between the punches and the rail and to minimize wear on the tips of the punches. Once the sidewall passes under the lubricating nozzles, the sidewall assembly is indexed into the bottom rail punching press16. Referring now toFIG. 25A, as sidewall2and bottom rail4index into punching area208, rail punches244remain in their normally lowered position, and die buttons246do not contact the underside of sidewall2or bottom rail4. Referring toFIG. 25B, cylinder bank269remains in its normal arrangement where none of gag cylinders276,277,282or283actuate to force gags234into gag spacer232.

Referring back toFIG. 4B, once sidewall2and bottom rail4complete the indexing move into punching area208(FIG. 25A), skate lifter29raises the sidewall assembly up, distal from machine frame12. That is, lifting cylinder31actuates pushing outer skate32up while lifter guide posts33ensure that the skate remains properly aligned as it rises. Referring toFIGS. 26A and 26B, once the sidewall assembly has been raised, gag cylinders282and283bias gags234ad235into gag guides232, and the respective angled leading edges234aand235aslide under the bottom portion of rail punches244lifting the rail punches onto first stage surface234band235b(FIG. 25B). When resting on first stage surfaces234band235b, rail punches244are positioned such that die buttons246are proximate to the underside of sidewall2and bottom rail4in a position appropriate for punching field and/or post holes.

Alternatively, if gag cylinders276and277also actuate, gags234and235will be biased further into gag guides232and gag intermediate surfaces234dand235dwill push rail punches244upwardly until the rail punches come to rest on gag second stage surfaces234cand235c. In this position, rail punches244are positioned appropriately to only punch field holes. It should be understood that second stage surfaces234cand235care raised 0.070 inches from its respective first stage surface234band235b. This 0.070 inch step accommodates for variations in sidewall assembly thickness when punching through the sidewall panel and the rail only, as opposed to punching through the sidewall panel, the rail, and a post. Thus, first stage surfaces234band235bare used for punching holes through a bottom rail, a wall panel and a sidewall post, whereas second stage surfaces234cand235care used for punching through only a bottom rail and a wall panel in between sidewall posts.

Referring toFIG. 26B, gag cylinder bank269controls the sliding of gags234and235into gag guide232. Actuation of the lower gag cylinders282and283extends gags234and235into gag guides232so that rail punches244are in the post punching position. Upper gag cylinders276and277may then actuate and piston rods284and285, which are connected respectively to gags234and235, extend forcing gags234and235even further into gag guides232positioning rail punches244to punch the wall assembly between posts.

Referring again toFIGS. 25A and 26A, gag proximity switches214a,214band214csense the location of gags234and235to ensure that the gags are properly positioned during the punching process. In a preferred embodiment, front proximity switch brackets215aeach support front proximity switch214asuch that it will sense the gag leading edges234aand235awhen the gags are inserted into gag guides232. Rear proximity switch brackets215beach support intermediate proximity switch214band rear proximity switch214c. Intermediate proximity switch214bsenses raised gag portions234cand235c, and rear proximity switch214csense a rear edge234eand235e(FIG. 26B) of the respective gags.

When the gags are not inserted into gag guides232, only rear proximity switch214cwill sense the rear end of gag234. When the gags are inserted into gag guides232such that rail punches244are resting on first stage surfaces234band235b, front proximity switches214awill sense the leading edge234aand235aof the gags, rear proximity switches214cwill sense the rear end of the gags234and235, and intermediate proximity switches214bwill not sense anything at all and. When the gags are fully inserted into gag guides232such that rail punches244are resting on second stage surfaces234cand235c, front proximity switches214awill sense gag leading edges234aand235a, intermediate proximity switch214bwill sense gag portions234cand235c, but rear proximity switches214cwill not sense the gags because the gags will be pushed to a position that is past the location of the rear proximity switches.

The CPU receives signals sent by the proximity switches, and based upon which proximity sensors are relaying information, the CPU can determine whether the gags are in the proper position to perform the punching process. For example, if the CPU only receives information from the rear proximity switches, the CPU will recognize that the gags are in a fully retracted position. Likewise, if the CPU receives information from the front and back proximity switches, the CPU will recognize that the gags are extended only half-way into the gag slots. Finally, if the CPU receives information from only the front and intermediate proximity sensors, the CPU will recognize that the gags are fully extended into the gag slots.

Once gags234and235slide into gag guides232and rail punches246rise into a punching position, skate lifter29(FIG. 4B) lowers sidewall2and bottom rail4so that they rest on die buttons246. Referring back toFIG. 4B, skates32are lowered by skate lifters29, which pull skates32downward and distal from the underside of sidewall panel2, until sidewall panel2rests entirely upon die buttons246(FIG. 26A).

Referring toFIG. 26A, once the sidewall assembly (not shown inFIG. 26A) rests on die buttons246, top die gag cylinders262(FIG. 10) actuate, driving the appropriate gags into their respective top die gag slots260. That is, when punching field holes, only the gag cylinders connected to field gags256actuate, and only the field gags slide fully into their slots262. This ensures that when the top die is lowered toward the sidewall during punching, only the field punches254a(FIG. 10) will punch through the bottom rail4and sidewall panel2between posts. Post gags258are not driven into their slots, and, accordingly, post punches254b(FIG. 10) simply slide up through the counterbored through-holes264during punching, ensuring that only field holes are punched. When punching at a post, gag cylinders262engage both a field gag256and a post gag258on the same side of punch retainer252and drive them into their respective gag slots260. In this position, field gag proximity switches257aand post gag proximity switches257b(FIGS. 8 and 10) no longer sense the gags and relay a signal to the CPU indicating that the gags have been properly biased into the slots260for punching.

As previously discussed, punch cylinder212(FIGS. 6 and 7) may be a push type cylinder actuated to push top die assembly218upward distal from bottom punching die216or downward into a punch stroke. Referring to FIGS.10and27A-27B, once the gag cylinders drive the appropriate punch gags into their respective slots260, the CPU sends a signal to the PLC to actuate cylinder212(FIG. 8) into a punching stroke. Thus, piston rod213and top die assembly218is biased downward until lower punching proximity switch223(FIG. 8) senses top die shoe248. Top shoe bushings250slide along guide posts228ensuring that top shoe248remains parallel to the sidewall during the punching process. In a preferred embodiment, punching cylinder212is selected so that the stroke of piston rod213reaches its fully extended position to punch through both bottom rail4, sidewall panel2and a post. As a result, when piston rod213is fully extended, die button center bores245(FIG. 9) slidably receive punch tips270, as shown inFIG. 27B.

Once punching has occurred, lower punching proximity switch223, which is positioned to sense when top die shoe248is lowered far enough to fully punch through the sidewall assembly, sends a signal to the CPU that the holes have been punched. The CPU then sends a signal to the PLC, and the PLC actuates punching cylinder212so as to push piston rod213and top die assembly218upwards to its home position. When top die assembly218reaches its home position, upper punching proximity switch222senses top die shoe248and relays a signal back to the CPU that the top die assembly218has reached its home position, and the sidewall assembly may be indexed to the next punching position. Often punches254will bind in the punched holes pulling the sidewall assembly up and off of the lower die. To prevent the sidewall from binding with the punches, a separating mat220is provided at the bottom rail punch press upper portion202to separate the sidewall assembly from the punches as top die shoe248is lifted upwards away from rail punches244.

After the holes have been punched in the sidewall assembly and punching cylinder piston rod213has raised top die shoe248and top die assembly218, skate lifter cylinder31raises skate32(FIG. 4B) lifting the sidewall assembly off of rail punches244. Gag cylinder bank269pulls the gags234and235out of their gag guides232lowering rail punches244to their lowered position (FIG. 25B). After rail punches244return to their lowered positions, skate lifter cylinder31pulls skate32down proximate to machine frame12(FIG. 4B) returning sidewall assembly to a position where it may be indexed by center cart mechanism14(FIG. 2). The center cart mechanism indexes the sidewall once again, the vision system takes another picture to confirm the position of the side wall assembly relative to the punching presses, and the punching process repeats itself until holes have been punched along the entire length of the bottom rail. As previously mentioned, the same process is simultaneously followed for the top rail.

Once the newly punched holes in both the bottom and top rails pass through their respective punching presses, operators wipe bottom and top rails4and6with a rag to remove excess lubricant from the rails, and rivet blanks are inserted into the punched holes. The eight-foot spacing between the punching presses and the riveting presses gives the operators ample time and work space to clean the rails and insert the rivets before the riveting presses engage the rivet blanks.

Referring toFIGS. 19,28A and28B, as the sidewall assembly enters the riveting area408of riveting press20b, gag cylinder bank469(FIGS. 16,17, and20) actuates in exactly the same manner as described above in connection with bottom rail punching press16. Once the sidewall assembly completes the indexing move into riveting area408(FIGS. 28A and 28B), skate lifter29raises the sidewall assembly up distal from machine frame12. Lifting cylinder31actuates, pushing outer skate32up while lifter guide posts33ensure that the skate remains properly aligned as it rises (FIG. 4B).

Referring with particularity toFIG. 19, once the sidewall assembly has been raised, gag cylinders476and477and/or482and483bias gags434and435into gag guides432. If both post and field rivets are to be mashed, then only gag cylinders476and477actuate causing the respective angled leading edges434aand435ato slide under the bottom portion of rail anvils436lifting the rail anvils onto gag first stage surfaces434band435b. IF on the other hand only field rivets are to be mashed, then all four gag cylinders476,477,482and483actuate causing the respective transition portions434dand435dto slide under the bottom portion of rail anvils436lifting the anvils onto gag second stage surfaces434cand434d. When resting on either the gag first or second stage surfaces, rail anvils436are positioned such that plungers438are proximate to the underside of sidewall2and bottom rail4. It should be understood that the gag second stage surfaces are raised 0.070 inches from the gag first stage surface to accommodate for the variances in the wall thickness between a post position and a field position. That is, when mashing rivets at sidewall posts, the sidewall assembly is thicker than when only mashing field rivets in between posts.

Referring now toFIG. 28A, gag proximity switches414a,414band414csense the location of gags434and435to ensure that the gags are properly positioned during the riveting process. In one embodiment, front proximity switch brackets415aeach support front proximity switch414asuch that it will sense the sloped leading edges434aand435aof the gags when the gags are inserted into gag guides432. Rear proximity switch brackets415beach support intermediate proximity switch414band rear proximity switch414c(FIG. 28A). Intermediate proximity switch414bsenses the raised gag portions434cand435c(FIG. 19), and rear proximity switch414csense the gag rear ends434eand435e(FIG. 19).

When the gags are not inserted into gag guides432, only rear proximity switch414cwill sense the body of gags434and435. When the gags are inserted into gag guides432such that rail punch444is resting on the first stage surfaces, front proximity switch414awill sense the respective leading edges434aand435aof the gags, proximity switches414cwill sense the rear end of gags434and435, and intermediate proximity switches414bwill not sense anything at all. When the gags are fully inserted into gag guides432such that rail punch444are resting on second stage surfaces434cand435c, the front proximity switches will sense the leading edge of the gags, intermediate proximity switches414bwill sense the raised gag portions434cand435c, but rear proximity switches414cwill not sense the gags at all because gag rear end portions434eand435ewill be pushed to a position that is past the location of the rear proximity switch. The CPU receives the signals sent by the proximity switches, and based upon which proximity sensors are relaying information the CPU can determine whether the gags are in the proper position to perform the mashing process. For example, if the CPU only receives information from the rear proximity switches, the CPU will recognize that the gags are in a fully retracted position. Likewise, if the CPU receives information from the front and back proximity switches, the CPU will recognize that the gags are extended only half-way into the gag slots. Finally, if the CPU receives information from only the front and intermediate proximity sensors, the CPU will recognize that the gags are fully extended into the gag slots.

Referring back toFIG. 4B, as with the punching presses, skates32that support the sidewall assembly in the vicinity of riveting press20b, are lowered by skate lifter cylinder31until the sidewall assembly rests entirely on plungers438(FIG. 28A). Referring toFIG. 28C, plungers438extend far enough beyond the rail anvil top surface433that the shank end of the rivets blanks (not shown), which extend below the bottom surface of sidewall2and rails4or6, do not make contact with the top surface of rail anvils436. Springs439(FIG. 28C) are stiff enough to maintain plungers438in the upward position so that when the sidewall assembly rests atop the plungers, springs439do not compress and allow the rail anvils to push the rivets (not shown) out through the top of their respective holes.

Referring now toFIGS. 16-18A, once sidewall2rests exclusively on plungers438, the CPU sends a signal to the PLC, which then actuates cylinder412(FIGS. 16 and 17), driving piston rod413(FIG. 18A) and top die assembly418down until lower punching proximity switch423(FIGS. 16 and 17) senses top die shoe440. Top shoe bushings442slide along guide posts428ensuring that top die shoe440remains parallel to the sidewall as it is lowered during the riveting process. Lower riveting proximity switch423is positioned such that it senses the location of top die shoe440only when the top die shoe has been lowered far enough for anvils446to engage and compress the rivet blanks (not shown).

As the top die shoe lowers to its rivet compressing position, anvils446push the flanges of the rivet blanks (not shown) and urge them downward. Plungers438, as previously described, are spring loaded and engage the sidewall assembly between rivet blanks. As the top die shoe lowers, plungers438engage the underside of the sidewall assembly and press the assembly parts together to ensure that the parts are properly aligned and no gaps exist between the parts when the rivet blanks are compressed. The downward pressure exerted on the rivets by anvils446eventually overcomes the resilient spring-force of springs438(FIG. 28C) and forces plungers438down until the shank end of the rivets (not shown) contacts rail anvil top surface433(FIG. 28C). The downward force on riveting anvils446, anvil spacer444, and top die shoe440compresses the rivet shanks against rail anvils436causing the rivet shanks to spread along the bottom of sidewall2and rails4or6securely fastening the three components together. As previously mentioned, lower riveting proximity switch423senses top die shoe440when riveting cylinder piston rod413has fully extended allowing riveting anvils and rail anvils to properly compress the rivets. When lower proximity switch423senses top die shoe440, a signal is sent to the CPU that actuates riveting cylinder412lifting top die shoe440until it reaches its home position.

After top die shoe440returns to its home position, skate riser cylinder31actuates lifting skate32(FIG. 4B), thereby lifting the sidewall assembly off of rail anvil plungers438. Gag cylinder bank469(FIGS. 16,17and20) retracts bottom die gags434and435from gag guides432lowering rail anvils436. Once rail anvils436are lowered, skate riser cylinder actuates lowering the skate and sidewall assembly back onto frame12so that the wall can be indexed once again. After the sidewall assembly has been riveted together along the entire length of the sidewall assembly, operators remove the fully assembled sidewall, and a new, unassembled sidewall may be loaded on the machine10for assembly.

While one or more preferred embodiments of the invention have been described above, it should be understood that any and all equivalent realizations of the present invention are included within the scope and spirit thereof. The embodiments depicted are presented by way of example and are not intended as limitations upon the present invention. Thus, those of ordinary skill in this art should understand that the present invention is not limited to the embodiments disclosed herein since modifications can be made.