DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] Referring now to the drawings, and more particularly to FIGS. 2-5 thereof, a new and improved upstream, entry stage or section of a mail conveyor system, constructed in accordance with the principles and teachings of the present invention, is disclosed and is generally indicated by the reference character 110. It is to be noted that component parts of the new and improved upstream, entry stage or section of the mail conveyor system 110, as constructed in accordance with the principles and teachings of the present invention, which correspond to similar component parts of the PRIOR ART system disclosed within FIG. 1, will be designated by similar or corresponding reference numbers except that the reference numbers designating the component parts of the new and improved upstream, entry stage or section of the mail conveyor system 110, as constructed in accordance with the principles and teachings of the present invention, will be designated by reference numbers in the 100 series.
[0021] More particularly, as best seen in FIGS. 2-5, the new and improved upstream, entry stage or section of the mail conveyor system 110, as constructed in accordance with the principles and teachings of the present invention, is seen to comprise a first conveyor belt 112 and a second conveyor belt 114. The first and second conveyor belts 112,114 are respectively routed around, for example, first and second drive rollers 116 and 118, and it is seen that the second conveyor belt 114 also has operatively associated therewith a pinch roller 120. The second drive roller 118 is laterally or transversely spaced or offset from the first drive roller 116, as considered in the longitudinal conveyance direction, and in this manner, an upstream gap 122 is defined between the first and second drive rollers 116,118 so as to permit the incoming mail articles, pieces, or units to be readily inserted between, and thereby accordingly driven by, the first and second conveyor belts 112,114. The pinch roller 120, however, is, in effect, transversely or laterally offset with respect to or spaced from the second drive roller 118 whereby the upstream portion of second conveyor belt 114, disposed downstream from the aforenoted upstream gap 122, is caused to approach, and thereby be disposed adjacent to or in contact with, the first conveyor belt 112 whereby the individual mail pieces, articles, or units can in effect be grasped between the first and second conveyor belts 112, 114 and conveyed downstream thereby. Lastly, a serial array of photocell units 124 are disposed adjacent to and partially upstream and downstream of second drive roller 118 so as to monitor the travel or conveyance of the various different pieces, articles, or units of mail as they enter the gap 122 and the bite portion 126 of the conveyor system 110 as defined between the first and second conveyor belts 112,114.
[0022] The first and second drive rollers 116,118 have their rotational axes fixed upon a support surface, foundation, or deck 128, however, unlike the fixed disposition of the conventional PRIOR ART pinch roller 20 of the conveyor system 10 upon the support surface, foundation, or deck 28, in accordance with the unique and novel teachings and principles of the present invention, the pinch roller 120 is rotatably mounted upon a first embodiment pinch roller subassembly 130, as best seen in FIG. 5, which is adapted to be movably mounted upon the deck, foundation, or support surface 128 so as to in turn adjustably position the pinch roller 120 with respect to the upstream portion of the second conveyor belt 114 as best seen or appreciated from FIGS. 2-4. More particularly, a pivot arm 132 is provided at a first longitudinal end thereof with a through-bore 134 within which a bearing assembly 135 is positioned or operatively disposed such that the pivot arm 132 is adapted to be pivotally mounted upon the foundation or deck 128. The bearing assembly 135 comprises a bearing sleeve 136, and the lower end portion of the bearing sleeve 136 has a reduced diametrical section 138 for disposition within the through-bore 134. A lower bearing member 140 is adapted to be disposed internally within the lower end portion 138 of the bearing sleeve 136, while an upper bearing member 142 is adapted to be disposed internally within the upper end portion of the bearing sleeve 136, with a spacer member 144 also being disposed internally within the bearing sleeve 136 and interposed between the upper and lower bearing members 140,142. A bolt fastener 146, along with a washer member 148, effectively secures the bearing assembly 135 components to the underlying foundation, support surface, or deck 128 such that the pivot arm 132 is pivotally movable around the vertical axis 150 of the bearing assembly 135.
[0023] The opposite end of the pivot arm 132 is provided with an aperture 152, the lower end portion of an idler stud 154 has a reduced diameter portion 156 for threaded disposition within the aperture 152, and the pinch roller 120 is rotatably mounted upon the idler stud 154 through means of upper and lower bearing members 158 and 160, respectively. The pivot arm 132 is further provided with an integral laterally projecting mounting block 162 upon which a mounting bracket 164 is fixedly secured by means of a pair of suitable fasteners 166. A first clevis 168 is pivotally mounted upon the mounting bracket 164 through means of a pivot pin 170 and a pair of C-clip fasteners 172,174, and a pneumatic cylinder or actuator 176 is adapted to be operatively connected to the pivot arm 132, through means of first clevis 168, mounting bracket 164, and mounting block 162, so that upon extension and retraction of the pneumatic cylinder piston rod 178, the pivot arm 132 undergoes desirably controlled pivotal movements so as to in turn move the pinch roller 120 toward and away from the first conveyor belt 112.
[0024] More particularly, the free end portion of the piston rod 178 is operatively connected to the first clevis 168, while a lug member 180 fixedly mounted upon the opposite end of the pneumatic cylinder or actuator 176 is adapted to be pivotally mounted within a second clevis 182 through means of a pivot pin or dowel 184. Second clevis 182 is provided with a pair of threaded bores 186 for respectively accommodating a pair of screw fasteners 188 by means of which the second clevis 182 is fixedly mounted upon the foundation, support surface, or deck 128. In order to limit the range or the stroke of the movement of the pivot arm 132 with respect to the first conveyor belt 112, it is further noted that an intermediate portion of the pivot arm 132 is provided with an oblong or substantially elliptically shaped through-bore 190, and a shoulder bolt 192, having upper and lower washer members 194,196 operatively associated therewith, is adapted to be inserted therethrough and fixedly secured within the support surface, foundation, or deck 128.
[0025] With reference now being made to FIG. 6, the pneumatic control circuit for the pneumatic cylinder or actuator 176 will be disclosed and described. The pneumatic cylinder or actuator 176 is disclosed in FIG. 6, and has its piston member 198 disposed therein which also comprises the piston rod 178 which has its free end portion operatively connected to the first clevis 168. A source of compressed air 200 provides compressed air to the pneumatic control circuit along an input line 202 which is fluidically connected to a first upstream end of a first air line 204, and a two-position control valve 206, which is normally biased to the illustrated position by means of a suitable spring mechanism 207, is operatively associated with the first air line 204. A second downstream end of the first air line 204 is fluidically connected to the piston rod end or chamber 208 of the pneumatic cylinder or actuator 176, while a second air line 210 is also operatively associated with the two-position control valve 206. A first upstream end of the second air line 210 is fluidically connected to a piston head end or chamber 212 of the pneumatic cylinder or actuator 176, while a second downstream end of the second air line 210 is fluidically connected to an exhaust line 214. It is noted that the first upstream end of the first air line 204 is also fluidically connected to the exhaust line 214 for reasons that will be explained shortly, and a pressure regulator 216 is operatively disposed within the first upstream end of the first air line 204 so as to regulate the pressure of the incoming supply air to a predetermined pressure level. A pressure gauge 218 is operatively connected to the pressure regulator 216 by means of an air line 220 so as to readily permit the pressure within the pneumatic circuit to be readily determined or viewed by means of an operator.
[0026] In operation, when a mail handling, conveying, sorting, and distribution operation or cycle is to be commenced, an operator pushes a START button, not shown, located upon, for example, an operator console, also not shown, whereby the air regulator 216 and a first stage, infeed vacuum pickoff pump and conveyor belt, not shown, are activated. Accordingly, when articles, pieces, or units of mail are introduced into the first stage, infeed vacuum station, a vacuum sensor 222 emits a signal that mail is present within the system, and the mail-present signal is transmitted to, for example, a central processing unit (CPU) 224 by means of a signal line 226. The central processing unit (CPU) 224, in turn, emits a first control signal which is transmitted by means of a signal line 228 to the air regulator 216, and a second control signal which is transmitted by means of a signal line 229 to the two-position control valve 206 whereby the control valve 206 is moved from its normal first position, as illustrated within FIG. 6, to its second position. Consequently, air pressure at the pre-determinedly desired air pressure level is supplied to the head chamber 212 of the pneumatic cylinder or actuator 176 by means of the first upstream end of the first air line 204, the two-position valve 206, and the first upstream end of the second air line 210. The piston-piston rod assembly 198,178 is thus moved within pneumatic cylinder 176 such that the piston rod 178 is extended outwardly from the cylinder 176. The piston rod 178, through means of the first clevis 168, the mounting bracket 164, and the pivot arm mounting block 162, causes the pivot arm 132 to pivot in the clockwise direction, as viewed in FIG. 5, around axis 150 such that the pinch roller 120, in turn, causes the second conveyor belt 114 to be moved toward the first conveyor belt 112 and thus define the bite portion 126 therebetween. In addition, after a predetermined time delay, such as, for example, 0.3 seconds, the central processing unit (CPU) also transmits appropriate signals by means of a signal line 230 to first and second drive motors 232,234 which are respectively operatively connected to the first and second conveyor belt drive rollers 116,118 so as to initiate drive movement of the first and second conveyor belts 112,114.
[0027] Accordingly, articles, pieces, or units of mail are now introduced into the bite section 126 between the first and second conveyor belts 112,114 and are conveyed further downstream by means of the first and second conveyor belts 112,114 past the linear array of photocell assemblies 124 as can best be appreciated from FIGS. 2 and 3. As best seen in FIG. 6, the exhaust line 214 of the pneumatic control circuit also has fluidically associated therewith a one-way bleed orifice or mechanism 236 which will permit bleeding of air pressure from the pneumatic circuit should the air pressure within the pneumatic circuit exceed the predetermined pressure level set or established by means of the pressure regulator 216. Accordingly, as the different articles, pieces, or units of mail are conveyed through the bite section 126 defined between the first and second conveyor belts 112,114, the pressure regulator 216 serves to maintain a constant pressure level within the pneumatic circuit such that the pinch roller 120 is constantly biased toward first conveyor belt 112 by means of a constant pressure or force. In view of the fact that the different articles, units, or pieces of mail will have different thickness dimensions, then as each article, piece, or unit of mail enters the bite section 126 of the conveyor belt drive system, the pinch roller 120 will in effect be constantly forced away from the first conveyor belt 112 against the biasing force of the air pressure within the control circuit when a relatively thick article, unit, or piece of mail is being conveyed, and be forced toward the first conveyor belt 112 under the influence of the biasing force of the air pressure within the control circuit when a relatively thin article, piece, or unit of mail is being conveyed.
[0028] When the pinch roller 120 and the pivot arm 132 are moved away from the first conveyor belt 112 so as to accommodate a relatively thick article, piece, or unit of mail, the piston rod 178 of the pneumatic cylinder 176 will be slightly retracted against the normal biasing force of the air pressure within head chamber 212 of the cylinder 176 and thereby effectively increase the air pressure upon the supply side of the piston 198 above the normal pressure value predetermined by means of the air regulator 216. Accordingly, such retractive movement of the piston 198, the piston rod 178, and the pivot arm 132 will be permitted as a result of the first upstream portion of the second air line 210, the two-position control valve 206, the first upstream portion of the first air line 204, and the exhaust line 214 being fluidically connected to the bleed valve mechanism 236. In a similar, but reverse manner, the pinch roller 120 and the pivot arm 132 will be moved toward the first conveyor belt 112 under the constant biasing force of the air pressure within the control circuit as predetermined by means of the air regulator 216 so as to accommodate a relatively thin article, piece, or unit of mail. Under such circumstances, the piston rod 178 of the pneumatic cylinder 176 will again be slightly projected or extended out of the pneumatic cylinder 176. Consequently, it can be readily appreciated that depending upon the particular thickness dimensions of the various articles, pieces, or units of mail being conveyed through the conveyor belt system, and more particularly, through the bite section 126 defined between the first and second conveyor belts 112,114, the mounting system for the pinch roller 120, comprising the pivot arm 132 and the piston rod 178, will undergo, in effect, reciprocating floating movements such that articles, pieces, or units of mail having varying thickness dimensions can always be readily accommodated without causing any jamming of the conveyor belt drive system.
[0029] Continuing further with the operation, if, in accordance with a first operational instance, the vacuum sensor 222 has not detected the presence of any additional pieces, articles, or units of mail within the system for a predetermined period of time which would normally permit the last previously detected article, piece, or unit of mail to have passed through the bite section 126 defined between the first and second conveyor belts 112,114, and in addition, all of the photocell units 124 have transmitted signals indicating that the articles, pieces, or units of mail which were previously detected by means of the vacuum sensor 222 have also passed by all of the photocell units 124, then the central processing unit (CPU) 224 will send appropriate signals to the two-position control valve 206 and the conveyor belt drive motors 232,234. As a result of the signal to the two-position control valve 206, the two-position control valve 206 will be moved back to its normal position as illustrated in FIG. 6 whereby the piston rod 178 of the pneumatic cylinder 176, and the pivot arm 132 operatively connected thereto, will be retracted in view of the fact that the first air line 204, which is fluidically connected to the air regulator 216 and the incoming air line 202 at its upstream end, is also fluidically connected to the piston rod chamber 208 of the pneumatic cylinder 176 at its downstream end, while the second air line 210 is fluidically connected to the piston head chamber 212 at its upstream end as well as being fluidically connected to the exhaust line 214 at its downstream end. As a result of the signal to the copnveyor belt drive motors 232,234, the motor drive of the conveyor belts 112,114 by motors 232,234 will be terminated.
[0030] Accordingly, the pinch roller 120 and the second conveyor belt 114 will be moved away from the first conveyor belt 112 such that the bite section 126 will no longer be defined between the conveyor belts 112,114, whereas the open gap 122 will in effect again be redefined between the conveyor belts 112, 114. In this manner, if there is no jam of any article, unit, or piece of mail within the system, then the pinch roller 120 is disposed in effect in an idle state so as not to constantly extend or stretch the second conveyor belt 114 whereby the service life of the belt is extended, and the drive motors 232,234 and conveyor belts 112,114 will likewise be disposed in respective idle states. Upon the subsequent detection of an article, piece or unit of mail by means of the vacuum sensor 222, the aforenoted operative cycling of the two-position control valve 206 and the conveyor belt drive motors 232,234 can again be initiated.
[0031] On the other hand, if in accordance with a second operational instance, the vacuum sensor 222 has not detected the presence of any additional pieces, articles, or units of mail within the system for a predetermined period of time which would normally permit the last previously detected unit, article, or piece of mail to have passed through the bite section 126 defined between the first and second conveyor belts 112,114, but all of the photocell units 124 have not transmitted signals indicating that the articles, pieces, or units of mail which were previously detected by means of the vacuum sensor 222 have also passed by all of the photocell units 124, then an article jam situation or state has occurred and is present, and again, the central processing unit (CPU) 224 will send appropriate signals to the two-position control valve 206 and the conveyor belt drive motors 232,234 so as to again cause retraction of the piston rod 178, and the pivot arm 132, as well as termination of the conveyor belt drive. It is to be noted that the size of the elongated aperture 190 defined within the central portion of the pivot arm 132, which in effect limits the stroke or range of movement of the pivot arm 132, is a primary factor in predetermining the thickness limit of articles, pieces, or units of mail which may be conveyed through the system 110. It is also to be noted that the size of the aperture 190 is also predetermined so as to limit the extent of movement of the pivot arm 132, and the pinch roller 120 mounted thereon, away from the first conveyor belt 112 and back toward the non-conveying loop portion of the second conveyor belt 114 as can best be appreciated, for example, from FIGS. 2-4 such that the pinch roller 120 does not overstress or overstretch the non-conveying loop portion of the second conveyor belt 114.
[0032] Accordingly, when the system experiences a jammed situation or state, the shoulder bolt 192 may be removed from the pivot arm 132 and its fixed disposition within the support surface, foundation, or deck 128, whereby the retraction movement of the pneumatic cylinder piston rod 178, the pivot arm 132, and the pinch roller 120 mounted upon the pivot arm 132, can proceed further so as to rectify the aforenoted jammed state or situation. Accordingly, if or when an article, piece, or unit of mail, having a thickness dimension which is inordinately large, causes a jam to occur within the bite section 126 defined between the conveyor belts 112,114, then the retracted movements of the piston rod 178, and the corresponding movements of the pivot arm 132 and the pinch roller 120, eliminating the bite section 126 and again establishing the gap region 122, readily permits an operator to remove the jammed article, piece, or unit of mail from between the conveyor belts 112,114 without incurring substantial operational downtime of the conveyor system 110. During such jam-rectifying operation, the operator may also activate an OFF button or switch which terminates the operation of the air regulator 216, whereupon subsequent rectification of the jammed state of the conveyor system 110, the START button may again be depressed so as to again initiate the entire operational cycle.
[0033] With reference lastly being made to FIG. 7, a second embodiment of a new and improved pinch roller mounting arm subassembly is disclosed, and it is noted that since such subassembly comprises components which are similar to, but slightly different than, the corresponding components disclosed within the first embodiment of FIG. 5, the following discussion will be directed principally toward the structural differences comprising the different embodiments. Accordingly, the various components which are similar in both the first and second embodiments of FIGS. 5 and 7 will be designated by corresponding reference numbers except that in connection with the components disclosed within the second embodiment of FIG. 7, the reference numbers will be within the 300 series. More particularly, it is seen that the principal differences between the first and second embodiments of FIGS. 5 and 7 resides in the structure comprising the pivot arms 132 and 332, and the structural means interconnecting the pivot arms 132,332 to their respective pneumatic cylinders or actuators 176,376. It is firstly noted, for example, that the longitudinal extent or length of the pivot arm 332 is somewhat less than that of the pivot arm 132, and that the laterally or transversely projecting mounting block 162 of pivot arm 132 has effectively been eliminated from the pivot arm 332. As a result of the aforenoted structure of the pivot arm 332, the latter can be utilized within spatially limited facilities that could otherwise not accommodate the pivot arm 132. It is also noted that the mounting bracket 164 and the first clevis 168 have likewise been eliminated.
[0034] In view of the elimination of the aforenoted structure operatively associated with the pivot arm 132, the end portion of the pivot arm 332, which is disposed opposite the end portion of the pivot arm 332 within which the bearing aperture 334 is provided, is formed as a clevis member 400 within which a first end portion of a pneumatic cylinder mounting bracket 402 is rotatably secured by means of a pivot pin 404. The opposite end of the pneumatic cylinder mounting bracket 402 is adapted to be fixedly connected to the pneumatic cylinder or actuator 376, and the remainder of the structural assembly, as well as the operation thereof in accordance with the various operative cycles as have been described hereinbefore in connection with the embodiment of FIG. 5 and in accordance with the pneumatic control circuit of FIG. 6, is substantially the same as that utilized in conjunction with the pivot arm 132, and therefore further discussion will be omitted herefrom in the interest of brevity.
[0035] Thus, it may be seen that in accordance with the principles and teachings of the present invention, there has been provided a new and improved pinch roller mounting system for use within mail conveyor systems whereby as a result of the mounting of the pinch roller upon the positionally adjustable pivot arm, the pinch roller can constantly undergo pivotal or arcuate movements toward and away from the oppositely disposed or companioned conveyor belt so as to constantly adjust the bite section defined between the pair of conveyor belts. In this manner, different articles, pieces, or units of mail, characterized by different thickness dimensions, can be readily accommodated by the conveyor system without causing jamming of the system. In the unlikely event that a jam does occur, the adjustable mounting of the pinch roller upon the pivotally movable pivot arm also permits an operator to readily, easily, and quickly rectify the jammed situation whereby substantial operational downtime of the conveyor system is not incurred.
[0036] Obviously, many variations and modifications of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein.