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Title:
A CONVEYING DEVICE
Document Type and Number:
WIPO Patent Application WO/2016/039649
Kind Code:
A1
Abstract:
The present disclosure relates to an automated carton transfer system. The system includes a delivery conveyor configured to convey a sequence of cartons. At least one pre-sort buffer conveyor configured to receive the sequence of cartons is provided, including a plurality of outfeed positions, at least one conveying device configured to move individual cartons received from the delivery conveyor along a series of loading positions aligned with the outfeed positions, at least one carton actuation device configured to move a selected carton from a loading position on the conveying device to a selected outfeed position. The system also includes a plurality of storage racks having a plurality of storage positions, at least one robotic storage and retrieval platform configured to load cartons from the outfeed positions and transport them to selected storage positions within the storage racks, and at least one controller configured to control operation of the pre-sort buffer conveyor and the at least one robotic storage and retrieval platform.

Inventors:
ROBINSON, Roy, Noel Tucker (Level 12 KPMG Centre,85 Alexandra Street,Private Bag 314, Waikato Mail Centre Hamilton 3204, 3204, NZ)
Application Number:
NZ2015/050145
Publication Date:
March 17, 2016
Filing Date:
September 14, 2015
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
MILMEQ LIMITED (Level 12 KPMG Centre,85 Alexandra Street,Private Bag 314, Waikato Mail Centre Hamilton 3204, 3204, NZ)
International Classes:
B07C5/34; B07C5/36; B65G1/04; B65G25/00; B65G25/10; B65G37/00; B65G43/10; B65G47/00; B65G47/52; B65G47/74
Domestic Patent References:
2007-01-11
Foreign References:
EP1273359A12003-01-08
US20040074824A12004-04-22
JP2002037418A2002-02-06
US4411355A1983-10-25
US3888344A1975-06-10
Attorney, Agent or Firm:
TUCK, Jason et al. (James & Wells, Private Bag 3140Hamilton 3240,New Zealan, Hamilton 3240, 3240, NZ)
Download PDF:
Claims:
CLAIMS:

1. An automated carton transfer system, including; a delivery conveyor configured to convey a sequence of cartons; at least one pre-sort buffer conveyor configured to receive the sequence of cartons, including:

a plurality of outfeed positions; at least one conveying device configured to move individual cartons received from the delivery conveyor along a series of loading positions aligned with the outfeed positions; at least one carton actuation device configured to move a selected carton from a loading position on the conveying device to a selected outfeed position;

a plurality of storage racks having a plurality of storage positions; at least one robotic storage and retrieval platform configured to load cartons from the outfeed positions and transport them to selected storage positions within the storage racks; and at least one controller configured to control operation of the pre-sort buffer conveyor and the at least one robotic storage and retrieval platform.

2. An automated carton transfer system as claimed in claim 1 , wherein the storage racks are temperature controlled.

3. An automated carton transfer system as claimed in claim 2, wherein the controller is configured to select a storage position for cartons based, at least in part, on temperature control requirements for the contents of the cartons.

4. An automated carton transfer system as claimed in any one of claims 1 to 3, wherein the conveying device includes:

two elongate support members, including an upper support member and a lower support member configured to reciprocate relative to each other along their length; a plurality of pushing toggles, each pivotally attached to the lower support member, and including a curved guidance recess configured to receive a guidance projection of the upper support member; and a linear travel restriction device configured to limit travel of the upper support member relative to the lower support member.

5. An automated carton transfer system as claimed in claim 4, wherein each pushing toggle is configured to be moved between a pushing position in which a pushing surface of the toggle is substantially upright relative to the upper support member, and a retracted position in which the pushing surface is lowered.

6. An automated carton transfer system as claimed in claim 5, wherein the conveying device is positioned between carton supports having upwards facing support surfaces, such that in the pushing position at least a portion of the pushing surface projects above the level of the support surfaces, and in the retracted position the pushing toggles are below the level of the support surfaces.

7. An automated carton transfer system as claimed in either claim 5 or claim 6, wherein each pushing toggle and its curved guidance recess are configured such that the pushing toggle transitions between the pushing position and the retracted position within a distance between a following edge of a first carton in the sequence of cartons to be processed, and a leading edge of a second carton following the first carton.

8. An automated carton transfer system as claimed in any one of claims 5 to 7, wherein a top edge of the pushing surface moves along a substantially vertical plane perpendicular with the longitudinal axis of the upper support member when transitioning between the pushing position and the retracted position.

9. An automated carton transfer system as claimed in any one of claims 4 to 8, wherein the distance of the limited travel is less than the distance between loading positions of the pre-sort buffer conveyor.

10. An automated carton transfer system as claimed in any one of claims 4 to 9, wherein the linear travel restriction device includes an elongate drive recess in one of the support members, configured to receive a drive projection extending from the other support member.

11. An automated carton transfer system as claimed in any one of claims 4 to 10, wherein the linear travel restriction device is configured to limit travel of the upper support member relative to the lower support member to a distance less than the distance between ends of the guidance recesses of the pushing toggles.

12. An automated carton transfer system as claimed in any one of claims 4 to 11 , wherein the conveying device is actuated by driving either one of the upper or lower support members.

13. An automated carton transfer system as claimed in any one of claims 1 to 3, wherein the conveying device includes: an elongate support member; a plurality of pushing toggles, each pivotally attached to the support member, wherein each pushing toggle includes:

a first toggle portion on a first side of the toggle's pivotal attachment to the support member, and having a pushing surface; and a second toggle portion on a second side of the toggle's pivotal attachment to the support member, wherein the second toggle portion is heavier than the first toggle portion.

14. A method of operating an automated carton transfer system, including:

conveying a sequence of cartons using a delivery conveyor;

receiving the sequence of cartons at a pre-sort buffer conveyor; moving individual cartons received from the delivery conveyor along a series of loading positions aligned with outfeed positions; moving a selected carton from a loading position to a selected outfeed position; loading cartons from the outfeed positions and transporting them to selected storage positions within storage racks using at least one robotic storage and retrieval platform,

Description:
A CONVEYING DEVICE

TECHNICAL FIELD

Embodiments of the present invention relate to a conveying device and method of operation.

STATEMENT OF CORRESPONDING APPLICATIONS

This application is based on the specification filed in relation to New Zealand Patent Application Number 631030, the entire contents of which are incorporated herein by reference.

BACKGROUND

Large food processing operations can require cartons of perishable food product to be sorted, stored (often within a temperature-controlled environment storage), and subsequently retrieved for transport from the facility. Perishable products are often required to reside within the system for a fixed period of time until they reach a predetermined storage temperature, after which they may be stored at that temperature in excess of 24 hours.

Mobile robotic storage and retrieval platforms, or "cranes", are known for loading cartons emerging from a processing line(s), and placing them in predetermined shelves within a racking system. With automated tracking and control over placement and retrieval, agglomeration of cartons for transportation may be performed as part of the storage process. This simplifies retrieval and effectively eliminates 'give-away' (i.e. the shipping of more product than intended, the incorrect product, or product of a higher value than Intended) that can occur with manual picking and order building.

Efficient use of the cranes is important to maintain overall system performance and keep up with the demands presented by normal production throughputs of a typical perishable food production facility. Since the crane represents a significant portion of the overall capital cost outlay of the overall storage facility, it is desirable to utilise such cranes as much as possible given the associated costs - due to the technical complexity there is a significant capital outlay in commissioning a system utilising such a crane.

A challenge to efficient use of the cranes is the fact that cartons of differing product types emerge in random order from one or more processing lines entering the storage facility in an indeterminate order. In order to store like product in adjacent storage racks, the crane ideally needs to load and unload groups of like product. As such, some form of pre-sorting is required to group product in like lots in order to optimise the crane's performance and throughput,

It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice. All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.

Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of "including, but not limited to".

Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

SUMMARY According to an exemplary embodiment there is provided an automated carton transfer system, including: a delivery conveyor configured to convey a sequence of cartons; at least one pre-sort buffer conveyor configured to receive the sequence of cartons, including: a plurality of outfeed positions; at least one conveying device configured to move individual cartons received from the delivery conveyor along a series of loading positions aligned with the outfeed positions; at least one carton actuation device configured to move a selected carton from a loading position on the conveying device to a selected outfeed position; a plurality of storage racks having a plurality of storage positions; at least one robotic storage and retrieval platform configured to load cartons from the outfeed positions and transport them to selected storage positions within the storage racks; and at least one controller configured to control operation of the pre-sort buffer conveyor and the at least one robotic storage and retrieval platform.

The delivery conveyer may be any suitable means for conveying product known to those skilled in the art. It is envisaged that the sequence of cartons conveyed by the delivery conveyor may be random with regard to content - thereby requiring sorting in order to enable greater efficiencies with regard to loading and transportation of the cartons by the robotic platform.

In an exemplary embodiment, multiple robotic storage and retrieval platforms may operate within respective sets of storage racks and pre-sort buffer conveyors. It is envisaged that a diverter may be positioned in the delivery conveyor to distribute the cartons between the presort conveyor buffers.

In an exemplary embodiment the storage racks may be temperature controlled - for example located within a chilled or frozen storage facility. Placement of a carton on, or retrieval from, the storage rack may be influenced, at least in part, on temperature control requirements for the content of the carton. For example, cartons may be made eligible for unloading based on been whether they have in storage for sufficient time to reach a required product temperature. Further, unloading may not occur until there is sufficient product at that required product temperature to fill an order.

The carton may be required to reside within the storage rack for a fixed period of time until it reaches a predetermined storage temperature. The carton may then be stored at this temperature until retrieval.

Each robotic storage and retrieval platform may have three degrees of freedom - able to move horizontally along a rail in order to access every column within the storage racks, be raised vertically to reach all rows within the storage racks, and extend the product platform horizontally into the storage racks (potentially on either side of the platform) either simultaneously or sequentially to retrieve or place cartons into the appropriate rack position.

In exemplary embodiments, the robotic storage and retrieval platform may be controlled to retrieve cartons from the storage racks and deliver the retrieved cartons to a transportation location. With tracking of carton location, the platform may be controlled to deliver production lots varying from as little as, for example, one pallet of product up to an entire 40 foot container load. The production lot may include a single product type, or a custom mix of product.

It may be desirable to reduce the platform's translational movements to be as short as possible in order to increase maximise the number of cartons that can be loaded and unloaded in any particular time period. The allocation of particular product types to storage racks, along with providing a plurality of storage positions within the storage rack system, contribute to achieving this. However, prior experience of the applicant indicates that the rate of production of product and the random nature of differing product types being delivered can result in a bottleneck at the point of delivery from the delivery conveyor - thereby impacting platform utilisation and hence system throughput.

In order to assist with increasing efficiency, it may be desirable to have the platform loading and unloading cartons in groups of maximum capacity of the platform. In an exemplary embodiment, each robotic storage and retrieval platform may be capable of holding eight cartons - for example composed of two rows of two cartons on each side of the platform's horizontal translational axis. In this exemplary embodiment, the pre-sort buffer conveyor may be configured to group cartons to the maximum capacity of the platform.

In an exemplary embodiment, the platform may be located between two storage racks, and the conveying device may run beside one of the storage racks on an opposite side to the platform. Having the outfeed positions align with storage positions may assist in reducing transit time of the platform in comparison to travelling beyond the boundary of the storage racks to collect cartons.

In exemplary embodiments the system may Include a scanning device positioned prior to entry to the pre-sort conveyor, configured to identify the contents of the carton which may then be used in determining a desired outfeed position. The pre-sort buffer conveyor essentially operates to sort a serial input into a parallel output, in which cartons are grouped at the outfeed positions for collection by the platform. The accuracy in positioning a carton at an outfeed location has been identified as being highly influential with regard to effectiveness of the system.

According to an exemplary embodiment, a conveying device may be provided, including: two elongate support members, Including an upper support member and a lower support member configured to reciprocate relative to each other along their length; a plurality of pushing toggles, each pivotally attached to the lower support member, and including a curved guidance recess configured to receive a guidance projection of the upper support member; and a linear travel restriction device configured to limit travel of the upper support member relative to the lower support member.

According to an exemplary embodiment, a conveying device may be provided, including: an elongate support member; a plurality of weighted pushing toggles, each pivotally attached to the support member, wherein each weighted pushing toggle includes: a first toggle portion on a first side of the pivotal attachment and having a pushing surface; and a second toggle portion on a second side of the pivotal attachment, wherein the second toggle portion is heavier than the first toggle portion.

Reference to a pushing toggle should be understood to mean a device configured to be moved between a pushing position in which a pushing surface of the toggle is substantially upright relative to the upper support member, and a retracted position in which the pushing surface is lowered. The pushing surface may bear against a side of a carton to push it along the conveyor between loading positions, before being lowered to pass back under the carton and subsequently act against the next carton in the sequence.

In an exemplary embodiment the conveying device may be positioned between carton supports having upwards facing support surfaces, such that in the pushing position at least a portion of the pushing surface projects above the level of the support surfaces, and in the retracted position the pushing toggles are below the level of the support surfaces.

In an exemplary embodiment, the carton supports may be rollers. Each roller may have a longitudinal axis substantially parallel with a longitudinal axis of the conveying device, such that the carton may be rolled laterally from its present loading position to an associated outfeed position.

In an exemplary embodiment, the distance of the limited travel may be less than the distance between loading positions of the pre-sort buffer conveyor.

By limiting the travel of the upper support member relative to the lower support member, the linear travel restriction device effectively acts as a drive linkage between the support members. Because the degree to which the lower support member can move with respect to the upper support member is limited, once the pushing toggle has been raised, the lower support member reaches the limit of its travel with respect to the upper support member and the entire assembly is then translated in the direction of the conveyor travel.

For example, the linear travel restriction device may include an elongate drive recess in one of the support members, configured to receive a drive projection extending from the other support member - wherein linear movement of the drive projection relative to the drive recess in one direction by a distance greater than the limited travel will cause it to bear against an end of the recess and push the associate support member in that direction. In an exemplary embodiment, the linear travel restriction device may be configure to limit travel of the upper support member relative to the lower support member to a distance less than the length of the guidance recesses of the pushing toggles.

In doing so, it is envisaged that the pushing toggles may be permitted to rise and fall without bearing the load of the upper and lower support members being driven relative to each other. This may assist in reducing wear on the pushing toggles, thereby increasing their useful life.

In an exemplary embodiment, the pushing toggle and its curved guidance recess may be configured such that the pushing toggle transitions between the pushing position and the retracted position within the distance between the following edge of a first carton in the sequence of cartons to be processed, and the leading edge of a second carton following the first carton.

In an exemplary embodiment a top edge of the pushing surface may move along a substantially vertical plane perpendicular with the longitudinal axis of the upper support member, when transitioning between the pushing position and the retracted position. It is envisaged that this may reduce the likelihood of the pushing toggle contacting a carton once it has been located at the desired loading position.

In an exemplary embodiment in which the second toggle portion is heavier than the first toggle portion, a retreating surface extending from the top edge of the pushing surface may be at a substantially acute angle relative to the pushing surface. In the absence of any other forces acting on it, a weighted toggle may always sit with its pushing surface upright. However, on the return stroke when the retreating surface comes in contact with the next carton in the sequence, the angle of the retreating surface will lead the weighted toggle to pivot such that the top edge of the pushing surface drops below the carton.

In an exemplary embodiment, the conveying device may be actuated by driving either one of the upper or lower support members, or in relevant embodiments, the single support member. Actuation may be achieved using any suitable means known in the art of conveyors - for example a linear or rotary drive.

The carton actuation device may be any suitable actuator as known in the art. For example, the carton actuation device may be configured to tilt the carton supports towards the outfeed position. In other exemplary embodiments the carton actuation device may include driven rollers, or a pusher configured to act against the carton to push it into the outfeed position.

Operation of the system may be controlled by a controller having at least one processor. The processor may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices or controllers (PLDs, PLCs), field programmable gate arrays (FPGAs), computers, lap tops, controllers, micro-controllers, microprocessors, electronic devices, other electronic units (whether analogue of digital) designed to perform the functions described herein, or a combination thereof.

In an embodiment, the controller is configured to operate as a supervisory control and data acquisition (SCADA) system.

For a firmware and/or software (also known as a computer program) implementation, the techniques of the present invention may be implemented as instructions (for example, procedures, functions, and so on) that perform the functions described. It should be appreciated that the present invention is not described with reference to any particular programming languages, and that a variety of programming languages could be used to implement the present invention. The firmware and/or software codes may be stored in a memory, or embodied in any other processor readable medium, and executed by a processor or processors. The memory may be integrated within the processor or external to the processor.

The steps of a method, process, or algorithm described in connection with the present invention may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The various steps or acts in a method or process may be performed in the order shown, or may be performed in another order. Additionally, one or more process or method steps may be omitted or one or more process or method steps may be added to the methods and processes. An additional step, block, or action may be added in the beginning, end, or intervening existing elements of the methods and processes.

BRIEF DESCRIPTION OF THE DRAWINGS

Further aspects of the present Invention will become apparent from the ensuing description which is given by way of example only and with reference to the accompanying drawings in which:

FIG. 1 is a birds-eye schematic view of an exemplary automated carton transfer system;

FIG. 2A is a perspective view of a section of an exemplary conveying device in a first configuration;

FIG. 2B is a perspective view of the section of the exemplary conveying device in a second configuration;

FIG. 2C is a series of side views showing the transition of the section of the exemplary conveying device between three positions, and FIG, 3 is a side view of an exemplary pusher toggle.

DETAILED DESCRIPTION

FIG. 1 illustrates an automated carton transfer system 100. The system 100 includes a delivery conveyor 102 configured to convey a sequence of cartons 104a-g to a pre-sort buffer conveyor ("pre-sort buffer" 106). A carton scanner 108 (for example a barcode scanner or RFID reader) is provided at the entrance to the pre-sort buffer 106, to identify the product type of arriving cartons in order that cartons having like products can be grouped.

Pre-sort buffer 106 has a series of loading positions 110 configured to sequentially receive the cartons, and including a plurality of carton supports in the form of rollers 112. The rollers 112 may be actuated, for example by tilting a rack of rollers, or powering the rollers, to move cartons thereon into outfeed positions 114 for collection by a crane 116. For example, cartons 104a-c have been identified as being of the same product type and grouped together accordingly - and are awaiting a fourth carton of the same product type to be positioned behind carton 104a before pickup by the crane 116.

The outfeed positions essentially form a row, or part thereof, in a storage rack having a number of storage positions formed in racks and columns. In the exemplary embodiment shown, a second storage rack (not shown) is located on the other side of the crane 116. The crane 116 is a robotic storage and retrieval platform having three degrees of freedom - able to move horizontally along the storage racks, be raised vertically to reach all rows within the storage racks, and extend the product platform horizontally into the storage racks (potentially on either side of the platform) either simultaneously or sequentially to retrieve or place cartons into the storage position.

Movement between loading positions 110 is achieved by way of a pair of conveying devices 200 spaced in parallel, operation of which will be described herein with reference to FIG. 2A-3.

The conveying device 200 in includes an upper elongate support member and a lower elongate support member in the form of upper and lower beams 202 and 204 respectively. The beams 202 and 204 reciprocate synchronously relative to each other along their length to raise and lower a plurality of pushing toggles 300.

Referring to FIG. 3, each pushing toggle 300 is made of a hardwearing plastics material with good abrasion resistance such as ultra-high-molecular-weight polyethylene (UHMWPE). The toggle 300 includes a pivot aperture 302 in the side 304 of the toggle 300, configured to receive a toggle pivot pin 206 of the lower beam 204 of conveying device 200 (see FIG. 2A for example), and a curved toggle guidance slot 306. The toggle guidance slot 306 defines a maximum distance 308 through which a toggle guide pin 208 of the upper beam 202 (see FIG. 2A for example) may travel,

The pushing toggle 300 has a pushing surface 310 with a top edge 312. A retreating surface 314 extending from the top edge 312 of the pushing surface 310 is at a substantially acute angle relative to the pushing surface 310.

Returning to FIG. 2A, the conveying device 200 includes a linear travel restriction device in the form of an elongate slide guide aperture 210 in slide block 212 secured to the upper beam 202, into which slide guide pin 214 (secured to the lower beam 204) projects. The distance between the ends of the slide guide aperture 210 limits travel of the upper beam 202 relative to the lower beam 204. This distance is less than the distance 308 through which toggle guide pin 208 may travel - such that the toggle guide pin 208 does not bear against the ends of the toggle guidance slot 306 with the load of the conveying device 200.

FIG. 2A illustrates the conveying device 200 where the relative position of the upper and lower beams 202 and 204 are such that the slide guide pin 214 is at a first end of the elongate slide guide aperture 210. The resulting positioning of the toggle pivot pin 206 relative to the toggle guide pin 208 is such that the toggle 300 is at a pushing position in which the pushing surface 310 is substantially upright relative to the upper beam 202.

In this position, the pushing surface 310 projects above the rollers 112 of FIG, 1. While the slide guide pin 214 is at the first end of the elongate slide guide aperture 210, movement of the lower beam 204 in the direction the pushing surface 310 is facing will carry the upper beam 202 with it to cause the pushing surface 310 to act against a carton to push it between loading positions 110.

FIG. 2B illustrates the conveying device 200 where the relative position of the upper and lower beams 202 and 204 are such that the slide guide pin 214 is at the second end of the elongate slide guide aperture 210. As the result of the shorter travel distance in slide guide aperture 210 relative to toggle guidance slot 306, the toggle 300 is actively drawn down by its own weight due to the spaced relationship of the toggle pivot pin 206 relative to the toggle guide pin 208, to a retracted position.

In this position, the toggle 300 is below the top surface of the rollers 112 of FIG. 1. While the slide guide pin 214 is at the second end of the elongate slide guide aperture 210, continued movement of the lower beam 204 in that direction will carry the upper beam 202 with it to cause the toggle 300 to travel beneath any carton at its associated loading position 110.

FIG. 2C illustrates the motion of the toggle 300 as the upper and lower beams 202 and 204 are moved between three relative positions 216, 218 and 220. In the first position 216, upper and lower beans 202 and 204 are arranged as illustrated in FIG. 2A, and the pushing surface 310 of the toggle 300 is generally upright and parallel with a vertical plane 222.

In the second position 218, the lower beam 204 is actuated relative to the upper beam 202 such that the toggle pivot pin 206 is drawn away from the toggle guide pin 208. Because of the travel within slide guide aperture 210 (see FIG. 2A for example), the upper beam 202 is not actively moved, and the toggle 300 is drawn down due to the curved toggle guidance slot 306.

During this, the top edge 312 of the pushing surface 310 may move substantially in parallel along the plane to reduce the likelihood of the toggle 300 contacting a carton once it has been located at the desired loading position.

In the third position 220, as the slide guide pin 214 reaches the second end of the elongate slide guide aperture 210 the toggle 300 has been drawn down below the top level of the upper beam 202. This transition between the first and third positions 216 and 218 respectively may occur within the distance between the following edge of a first carton in the sequence of cartons to be processed, and the leading edge of a second carton following the first carton.

Either one of the upper or lower beams may be actuated to achieve the relative movement thereof described.

The entire disclosures of all applications, patents and publications cited above and below, if any, are herein incorporated by reference.

Reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in the field of endeavour in any country in the world.

The invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features.

Where in the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth.

It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be included within the present invention. Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims.