WO2003033382A1

WO2003033382A1 - Load gripping conveyor

Info

Publication number: WO2003033382A1
Application number: PCT/CA2002/001587
Authority: WO
Inventors: François BEAUMONT; Régis MORIN; Yves Fortin
Original assignee: Intellium Automation Inc.
Priority date: 2001-10-18
Filing date: 2002-10-18
Publication date: 2003-04-24
Also published as: CA2359249A1

Abstract

A load gripping conveyor (10) for carrying pieces of meat includes input and output end rotors (20, 22) around which is mounted a carrier belt (16) defining a conveying forward span, and at least one gripper device (38) connected to the belt including a main lever member (40) provided with a hook (46) and being pivotally connected to the belt at a first location (53) about a main pivot axis (46). The gripper device (38) includes a link assembly (50)having a leading end (52) connected to the lever member (40) and a trailing end (54) connected to the belt at a second location (56). The link assembly (50) cooperates with the input rotor (20) upon rotation thereof from a load receiving to a load gripping position wherein the hook (46) moves inwardly through the belt for gripping the load thereon.

Description

LOAD-GRIPPING CONVEYOR

Field of the invention

The present invention relates to the field of load conveyors, and more particularly to endless load conveyors that are capable of gripping the load while it is carried forward on the conveyor surface along the conveying path. Background of the invention

Endless belt conveyors have been widely used heretofore in manufacturing and other industrial fields for the handling of many types of objects such as raw materials, components, pieces of matter, articles at many manufacturing or processing stages where the objects have to be carried forward along the manufacturing or processing line to achieve high productivity. A typical endless load conveyor includes an endless belt formed either of a continuous member of flexible sheet-type material or a plurality of laterally spaced members that are interconnected one another, the outer surface of which being provided with separately formed elements such as pins or hooks secured to and protruding from the belt surface for the purpose of maintaining the load in position on the belt surface while it is positively propelled upon the forward movement of the belt as driven by a driving device provided on the conveyor. Such load-gripping conveyor is disclosed in U.S. Patent no. 5,618,231 to Hicks, in U.S. Patent no. 4,128,916 to Fick et al. and in U.S. Patent no. 3,982,299 to Kompan in the context of meat processing. A main drawback associated with such prior art endless belt conveyor is due to the fact that hooks and pins vertically protruding from the belt surface may interfere with the manufacturing or processing operations, such as cutting operation in the context of meat processing wherein a cutting tool either operated manually or automatically with a machine or robot is required to be moved or positioned out of the travelling path of the pins or hooks to prevent tool or conveyor damage, thereby limiting the range of cut patterns that can be achieved while limiting the production rate.

In an attempt to traverse the foregoing limitations, a belt conveyor provided with a movable hook is proposed in U.S. Patent no. 4,413,375 to Cliff, wherein the movable hook is positioned within an opening in the surface of the carrying belt and is made movable between a raised position facilitating impalement of a body of meat thereon and a lowered position within the opening and generally level with the belt surface for capturing the portion of the meat between the hook and the edge of the opening to provide a more stable body of meat during cutting and avoid contact between the hook and a knife used by an operator. To allow such vertical movement of the hook, the conveyor is provided with a mechanism for holding the hook either in raised or lowered position, which includes a cam follower below the conveyor surface in combination with cam tracks at both ends of the conveyor on which the cam follower rests to hold the hook in raised position, and an intermediate cam track engageable with the cam follower to pull the hook to the lower position and hold the cam follower and hook in said position to grip the piece of meat. Although representing an improvement over conventional load-gripping conveyors, the conveyor of Cliff requires the incorporation within the inner space defined by the conveyor belt loop of a bulk system of cam follower and tracks which contribute to increase the overall dimension of the conveyor while increasing its manufacturing cost. This limitation is particularly significant where a transversal series of hooks are required on the conveyor belt to ensure gripping of large objects, wherein a multiplicity of cam follower and tracks system has to be incorporated into the conveyor. Therefore, there is still a need for an endless load-gripping conveyor that does not suffer from the limitations found in the prior art conveyor systems. Summary of the invention It is therefore a main object of the present invention to provide a load- gripping conveyor of a compact and cost effective design.

According to the above main object, from a broad aspect of the invention, there is provided a load-gripping conveyor comprising input and output end rotors, an endless carrier belt structure having an outer load conveying surface and an inner surface, said belt structure passing around said rotors and being operationally coupled to a driving device, and at least one gripper device connected to the inner surface of the belt structure. The gripper device includes a main lever member having first and second ends, said first end being provided with a gripper element and being pivotaliy connected to the belt structure inner surface at a first location thereon about a main pivot axis, and a link assembly having a leading end connected to the main lever member second end and having a trailing end connected to the belt structure inner surface at a second location thereon downstream from said first location. The link assembly cooperates with the input rotor upon rotation thereof from a load receiving position wherein at least a portion of the belt structure between the first and second locations thereon is forwardly driven over said input rotor so that the link assembly moves the main lever member forward upon flexion of the belt structure portion to pivot the gripper element backward about the main axis causing the gripper element to protrude outwardly through an opening provided on the belt structure outer surface, to a load-gripping position wherein the belt structure portion is forwardly driven past the input rotor so that the link assembly moves the main lever member backward upon extension of the belt structure portion to pivot the gripper element forward about the main axis causing the gripper element to move inwardly toward the belt structure outer surface for gripping the load thereon. Brief description of the drawings

Preferred embodiments of a load-gripping conveyor according to the present invention will now be described in detail with reference to the accompanying drawings in which:

Fig. 1 is a partially-broken side elevation view of a first embodiment of an endless belt conveyor according to the present invention;

Fig. 2 is a three-dimensional view of a portion of the conveyor belt as used in the embodiment of Fig. 1, showing the interconnected belt sections forming the conveyor belt structure;

Fig, 3 is a three-dimensional view of the gripper device used as part of the embodiment of Fig. 1 ; Fig. 4 is a three-dimensional view of an alternate gripper device as used in a second embodiment of the load-gripping conveyor according to the invention;

Figs. 5a-5f are partially-broken side elevation views of the conveyor input end of the embodiment of Fig. 1, showing the gripper device in a plurality of operating positions at the load-gripping stage of load conveying:

Figs. 6a-6b are partially-broken side elevation views of the conveyor output end according to the embodiment in Fig. 1, showing the gripper device in different positions at the load-release stage; Figs. 7a-7e are partially-broken side elevation views of the conveyor input end according to the second embodiment of the invention using the gripping device shown in Fig. 4, illustrating the gripper device in a plurality of successive operating positions at the load-gripping stage;

Figs. 8a-8b are partially-broken top plan and side elevation views respectively of a third preferred embodiment of the load-gripping conveyor according to the invention, which uses an alternate gripper device including a spring band mechanism;

Figs. 9a-9b are left end and side elevation views respectively of a head guide member as part of the gripper device of the second embodiment shown in Figs. 8a-8b;

Figs. 10a-10b are left end and side elevation views respectively of an intermediate guide element as part of the gripper device of the second embodiment shown in Figs. 8a-8b;

Figs. 11 a-11 b are side and right end elevation views respectively of a tail guide element as part of the gripper device of the second embodiment shown in Figs. 8a-8b; and

Figs 12a-12e are partially-broken side elevation views of the conveyor input end according of the embodiment of Figs. 8a-8b, showing the gripper device in a plurality of successive operating positions at the load-gripping stage. Detailed description of the preferred embodiments

In the description below, the preferred embodiments of a load-gripping conveyor according to the invention are described in the context of a meat processing application wherein pieces of meat have to be transported through a cutting station where they are required to be maintained in a stable position during the cutting operation. However, it is to be understood that the basic concept of the present invention can also be used in other fields of applications involving objects of various nature that are required to be handled in a stable position on the conveyor surface, by employing gripper element design adapted to engage the specific object or material involved.

Referring now to Fig. 1 , the load-gripping conveyor of the first preferred embodiment as generally designated at 10 includes an endless carrier belt structure generally designated at 12 having an outer load conveying surface 14 as defined by a belt 16 that also defines an inner surface 18. The endless carrier belt structure 12 also includes an input rotor in the form of a first sprocket wheel 20 of a conventional design and an output rotor in the form a second sprocket wheel 22, which sprocket wheels 20, 22 are mounted at opposed ends of the load-gripping conveyor 10 in such a manner that belt 16 passes around the sprocket wheels 20, 22 according to an endless loop in a conventional manner. One of sprocket wheels 20, 22 is operationally coupled to a driving device (not shown) in a known manner which is operated to move the belt forward in the clockwise direction as indicated by arrow 24 in such a manner that the conveying forward span as defined by the operational portion of the endless belt carrier structure 12 is moving forward along a carrying path indicated by arrows 26. It is to be understood that the driving device can either be operatively coupled to one of axles 28, 28' secured to sprocket wheels 20, 22 or be otherwise operatively coupled to the belt 16 through a separate mechanical element dedicated to this function.

As better shown in Fig. 2, the belt 16 is preferably formed of a plurality of substantially rigid link sections 30 having respective leading and trailing ends 32, 34, which link sections 30 are pivotaliy interconnected in an end-to- end relationship by means of respective edges of leading and trailing ends, which exhibit a hinge-type design allowing them to mate one another and be retained in a connected position by elongate rods 36 providing a pivoting axis. As shown in Fig. 2, more than one link sections 30 can be transversely aligned and secured one another to achieve a desired conveyor width. A number of link sections 30 are provided with one or more grip openings 76 followed by further openings 78, the purpose of which will be explained later in detail.

Returning to Fig. 1, the load-gripping conveyor 10 further includes at least one gripper device generally designated at 38 that is connected to the inner surface 18 of the belt 16, which gripper device 38 includes a main lever member 40 as better shown in Fig. 3, which has first and second ends 42, 44, the first end 42 being provided with a gripper element in the form of a hook 46 in the example shown. As better shown in Fig. 1, the gripper device first end 42 is pivotaliy connected to the inner surface 18 of belt 16 at a first location 53 thereon about a main pivot axis 48 which coaxially extends through the elongated rod 36 in the embodiment shown, so that the leading end 32 of a supporting adjacent link section 30 is made coaxial with main pivot axis 48 at first location 53 on the inner surface of belt 16. The gripper device 38 further includes a link assembly generally designated at 50 having a leading end 52 connected to the main lever member second end 44 and having a trailing end 54 connected in turn to the belt structure inner surface at a second location thereon indicated generally at 56 downstream from first location 53. As better shown in Fig. 3, the link assembly 50 is preferably formed of a head, link member 58 defining the assembly leading end 52 which is pivotaliy connected to the main lever member second end 44 at a head pivot axis indicated at 60 through an articulation formed by a U-shaped channel defined at lever member second end 44 which is adapted to receive the leading end 52 of head link member 58, which ends 44 and 52 are both provided with corresponding bores in fitting alignment to receive an hinge pin 62 extending therethrough. The head link member 58 further has a trailing end 64 pivotaliy connected at a tail pivot axis indicated at 66 on Fig. 3 to a tail link member 68 defining the assembly trailing end generally indicated at 54, the tail pivot axis 66 being located with respect to the head pivot axis 60 to allow movement of the gripper element 46 as will be explained later in more detail. The tail link member 68 is provided with a central opening adapted to receive the trailing end 64 of head link member 58, both tail link member 68 and trailing end 64 being provided with a bore through which extends an hinge pin 72 to form an articulation. The tail link member 68 is rigidly attached to an adjacent link section 30 by its end portions 74, 74' each being provided with a bore adapted to receive corresponding one of elongated rods 36, 36' as shown in Fig. 1. The end portions 74, 74' of tail link member 68 are received within the openings 78 of interconnected adjacent link sections 30 as shown in Fig. 2.

The method of operation of the first embodiment of load-gripping conveyor according to the present invention will now be explained with reference to Figs. 5a-5f and Figs. 6a-6b.

Turning to Fig. 5a, the endless belt carrier structure 12 is shown in a position where the gripper device 38 is located within the return span of the conveyor 10 just before reaching the input sprocket wheel 20 as it is driven in a clockwise direction as indicated by arrow 24 upon operation of the driving device. It can be seen from Fig. 5a that the link assembly 50 is in an extended position wherein the main lever member 40 is oriented with respect to the adjacent link section 30 so that the hook is completely received within the corresponding grip opening 76 defined by interconnected link sections 30 and 30' so that the hook 46 is substantially embedded therein.

Turning now to Fig. 5b, the endless belt carrier structure 12 of the load- gripping conveyor 10 is shown in a same position as that illustrated on the left part of Fig. 1 wherein the link assembly 50 cooperates with the input sprocket wheel 20 upon rotation thereof to bring the gripper device 38 to a load receiving position wherein at least a portion of the belt structure 12 between first and second locations 53, 56 thereon is forwardly driven over the input sprocket wheel 20 so that the link assembly 50 move the main lever member 40 forward upon flexion of the belt structure portion to pivot the hook 46 backward about the main pivot axis 48 and as indicated by movement arrow 49, causing the hook 46 to protrude outwardly through grip opening 76 provided on the interconnected link sections 30, 30' defining the belt structure upper surface.

Turning now to Fig.5c, it can be seen that the load receiving position is substantially maintained since the flexion of the belt structure portion is continuing as the belt structure portion is passing over the input sprocket wheel 20 toward the forward span of the conveyor 10. In the meantime, a load or piece 80 is fed at the input of conveyor 10 using for example a transfer conveyor (not shown) and commences to be carried on the conveying surface of belt 16 in a forward direction as indicated by arrow 82. For the application described therein, the piece 80 is a piece of meat that has to be processed in a downstream processing station (not snown) through which the load-gripping conveyor 10 extends.

Turning now to Fig. 5d, it can be seen that the load receiving position of the gripper device 38 is still substantially maintained while the piece 80 is further advanced at the conveyor input, so that the protruding hook 46 engages the load 80, while it is carried on the belt 16 in the forward direction indicated by arrow 82. Since meat from which the piece 80 is made is malleable, the piece 80 is capable of being firmly engaged by the hook 46 which penetrates therein. It is to be understood that for any applications involving other type of load made of different material, the load engagement may be achieved using a different gripper element designed to prevent any load damage that can adversely affect its quality. For example, the gripper member can be a plate or clamp that is adapted to mate with a corresponding receiving portion of the package or body of the load to firmly grip thereof onto the belt 16.

Turning now to Fig.δe, the load-gripping conveyor 10 is shown with the belt carrier structure portion between first and second locations 53, 56 of link assembly 50 as it leaves the input sprocket wheel 20, wherein the link assembly further cooperates with the sprocket wheel 20 upon rotation thereof to bring it toward a load-gripping position wherein the belt structure portion between locations 53, 56 is forwardly driven past the sprocket wheel 20 so that the link assembly 50 moves the main lever member 40 backward upon extension of the belt structure portion and as indicated by movement arrow 51 to pivot the hook 46 forward about the main axis 48 causing hook 46 to move inwardly toward the belt structure outer surface 14 for gripping the piece 80 thereon. It can be seen from Fig. 5b further in view of Fig. 5e that the tail pivot axis 66 is located with respect to the head pivot axis 48 to allow the movement of the hook 46 between the load-receiving position and the load- gripping position.

Referring now to Fig. 5f, the load-gripping conveyer 10 is shown with its link assembly 50 in its ultimate gripping position wherein the hook 46 is received within grip opening 76 so as the hook 46 is substantially embedded in the belt structure outer surface for firmly maintaining the engagement of hook 46 with the gripped portion of piece 80. It can be appreciated that in such embedded position, the hook 46 is made completely out of the operational range of any cutting tool used by a downstream processing station, thereby preventing tool damage while increasing processing rate. It should be understood that for other applications, such embedding feature may not be required, provided the gripper element used is allowed to move inwardly toward the belt structure outer surface for gripping the load thereon.

Referring now to Fig. 6a, the output end of load-gripping conveyor 10 is shown wherein the gripper device 38 reaches the forward span limit of the belt carrier structure 12 wherein the link assembly 50 of the gripper device 38 is still in an extended position just before the leading end 32 of link section 30' is engaging with the output sprocket wheel 22, while still gripping the piece 80 onto the belt structure outer surface 14. Turning now to Fig. 6b, the gripper device 38 is shown in a subsequent load-release position wherein the hook 46 disengages with the load 80 which can be then taken at the output of load-gripping conveyor 10 by an upstream handling device such as a further transfer conveyor (not shown). For so doing, the link assembly 50 further cooperates with the output sprocket wheel 22 upon rotation thereof in a clockwise direction as indicated by arrow 23 from the maintained gripping position illustrated in Fig. 6a to the load release position shown in Fig. 6b wherein at least portion of the belt structure 12 between first and second locations 53, 56 thereon is forwardly driven over the output sprocket wheel 22 so that the link assembly 50 moves the main lever member 40 forward upon flexion of the belt structure portion in a direction indicated by movement arrow 27 to pivot the hook 46 backward about the main axis 48 causing the hook 46 to protrude again outwardly through the grip opening 76 provided on the belt structure outer surface for allowing release of the piece 80.

Referring now to Fig. 4, an alternate embodiment of gripper device as generally designated at 38' will now be described in the context of a second preferred embodiment of load-gripping conveyor as provided by the invention, such gripper device 38' being used in combination with the same type of belt 16 as shown in Fig. 2 but without requiring further openings 78 to receive the pivoting elements of the device 38'. According to this alternate embodiment, the gripper device 38' includes a link assembly generally designated at 50' which also includes a head link member 58' formed of a pair of elements 55, 55' having end portions 57, 57' defining an assembly leading end which are pivotaliy connected to the main lever member 40' at a second end 44' thereof at the head pivot axis designated at 60' along which a hinge pin 62' extends through a series of aligned bores provided at main lever member end 44' and element end portions 57, 57'. The link assembly 50' further includes a tail link member 68' formed by a pair of elements 59, 59' having end portions 61 , 61' defining with a holding block 63 an assembly trailing end at a tail pivot axis designated at 66', which holding block 63 is adapted to be secured to the inner surface 18 of belt 16 as shown in Fig. 7a using conventional fastening means such as screws (not shown). Turning back to Fig. 4, the link assembly 50' further includes at least one intermediate link member 65 having respective leading and trailing end portions defined by pair of elements 71 , 71' and as designated at 67 and 69 respectively, through which the intermediate link members 65 are interconnected in an end-to-end relationship between a trailing end 64' provided on the head link member 58' and the tail link member 68', by means of at least one intermediate lever member 73 having a first end 75 pivotaliy connected to the belt structure inner surface at an intermediate location thereon generally designated at 77 in Fig. 7a about a first intermediate pivot axis designated at 79 using hinge pin 85. Each intermediate lever member 73 has also a second end 81 pivotaliy interconnecting each intermediate link member 73 at respective leading and trailing ends 67, 69 thereof about a second intermediate pivot axis 83 using a hinge pin 84. Associated with each lever member 73 is a pivot element 86 defining the first intermediate pivot axis 79 and adapted to be rigidly attached to a corresponding one of intermediate link sections 30 to pivotaliy receive the first end 75 of intermediate lever member 73 as better shown in Fig. 7a. It can also be seen from Fig. 7a that the pivot elements 79 and corresponding first intermediate pivot axis are located in the middle portion of corresponding link sections 30 in the embodiment shown. However, the gripping device 38' may preferably be designed so that pivoting axis 79 be aligned with elongated rods 36 so as to avoid the use of separate pivot elements 86, in a same way as described before regarding the first embodiment in view of Figs. 1-3. In a similar manner, the gripper device 30' shown in Fig. 4 is provided with a main pivot element 88 that is adapted to receive a hinge pin (not shown) extending through a corresponding bore provided on first end 42' of the main lever member 40'. However, the main lever member can be preferably mounted directly at a leading end of a corresponding adjacent link section in a same manner as described hereinbefore with respect to the first embodiment shown in Figs. 1-3.

As to the operation mode of the second embodiment of load-gripping apparatus according to the invention which makes use of the alternate gripper device described hereinabove with respect to Figs. 4 and 7a, it can be appreciated that this second embodiment works essentially in a same manner as the first embodiment whose operation has been described before with respect to Figs. 5a-5f and Figs. 6a-6b. The main effect of providing one or more intermediate link members 65 is to extend the distance between the first and second locations 53', 56' on the belt structure portion as will be now explained in detail with reference to Figs. 7a-7e. Referring to Fig. 7a, the link assembly 50' is shown in a completely extended position as the belt structure portion to which it is attached is still within the return span of the load-gripping conveyor 10 just before reaching the input sprocket wheel 20 which rotates in the clockwise direction as indicated by arrow 24.

Referring now to Fig. 7b, as the sprocket wheel 20 continues to rotate in clockwise direction 24, it can be seen that the head link member 50' and first intermediate link member 65 are following the corresponding portion of the belt structure between first location 53' and an intermediate location generally designated at 87, which portion being forwardly driven over the input sprocket wheel 20 so that the link assembly 50' moves the main lever member 40' forward upon partial flexion of the belt structure portion to pivot the hook 46' backward about the main axis 48' causing the hook 46' to protrude outwardly through the opening provided on-the belt 16. Referring now to Fig. 7c, the gripper device 38' is shown in a load- receiving position wherein the hook 46' engages a piece 80 fed at the input of the conveyor 10 wherein the link assembly 50' moves further the main lever member 40' forward upon complete flexion of the belt structure portion between first and second locations 53' and 56' to pivot further the hook 46' backward about main axis 48' causing the hook 46' to reach a limit load- receiving position where it still protrudes through the opening provided on the belt structure outer surface, while the piece 80 is impelled forward in the direction of arrow 82 as the belt 16 is continuously driven. It can be appreciated that the pivoting range of the hook 46' in this second embodiment of load-gripping conveyor can be set to a greater extent as compared to the pivoting range of the hook 46 of the gripper device 50 according to the first embodiment described herein above with respect to Fig. 1, without departing from the common purpose of the invention which is to firmly grip a load as it reaches the forward span of the conveyor 10. Turning now to Fig. 7d, the gripper device 38' is shown in a subsequent, intermediary position between the load-receiving position as illustrated in Fig. 7c and a load-gripping position as illustrated in Fig. 7e. In the position shown in Fig. 7d, the interconnected head link member 58' and first intermediate link member 65 are caused to extend simultaneously as the corresponding belt structure portion between location 53' and intermediate location 87 so that the link assembly 50' moves the main lever member 40' backward in the direction of movement arrow 91 upon progressive extension of the belt structure portion to pivot the. hook 46' forward about main axis 40' causing the hook 46' to move inwardly toward the belt structure outer surface 14 for gripping the piece 80 thereon.

Turning now to Fig. 7e, the link assembly 50' of the gripper device 38' is shown in a substantially complete extended position wherein the end portion 61' of tail link member 68' is leaving the input sprocket wheel 20, so that an ultimate load-gripping position is achieved to firmly grip the load 80 on the belt 16 in the same manner as explained before with respect to Fig. 5f. As to the following load-release stage of operation that is performed at the output end of the load-gripping conveyor according to the second embodiment, essentially the same principle of operation as explained in detail regarding the first embodiment in view of Figs. 6a-6b is applicable to the second embodiment, without any significant difference.

Referring now to Figs. 8a and 8b, a third embodiment of a load- gripping conveyor according to the present invention will now be described, which makes use of. a further alternate gripper device 38" that includes a link assembly 50" provided with an elongated spring band 90, which is preferably made of standard spring gage steel, having opposed leading and trailing ends 92, 94. The leading end 92 is connected to second end 44" of the main lever member 40" with a u-shaped first attachment 96 using screws 97 and hinge rod 99 extending through head pivot axis 60" at first location 53" on the belt structure inner surface 14. The trailing end 94 is in turn connected to the belt structure inner surface 14 at a second location 56" thereon downstream from first location 53" using a second attachment 98 secured to the belt 16 with screws 105, and using screws 100 for rigidly retaining the band trailing end 94 to the belt 16. Alternatively, the bend leading end 92 may be directly attached to the second end 44" of main lever member 40" without hinge rod 99, using the flexibility characteristics of the spring band 90 to allow the pivoting movement of the main lever member 40". The link assembly 50" is preferably provided with one or more guide elements 101 , 102 and 103, as better shown in Figs. 9a-9b, Figs. 10a-10b and Figs. 11 a-11b, respectively, which are connected to the belt structure inner surface 14 between first and second locations 53", 56" thereon using screws 106, each guide element defining a guiding surface 104 for the spring band 90.

The mode of operation of the third embodiment of load-gripping conveyor according to the invention, which mode is essentially the same as explained before regarding the first and second embodiments in view of Figs. 5a-6b and Figs. 7b-7e respectively, will now be explained with reference to Figs. 12a-12e.

Referring to Fig. 12a, the gripper device 38" is shown with its link assembly 50" in a completely extended position wherein the belt structure portion at first location 53" thereon starts engagement with the input sprocket wheel 20 as it is driven in clockwise direction indicated by arrow 24. In such initial position, the spring band 90 is in a fully extended position whereby the main lever member 40" is held in a back position under traction exerted by the band 90. It can be seen that in such position, the hook 46" provided on main lever member 40" is embedded within the opening provided on the adjacent link section 30 of belt 16.

Turning now to Fig. 12b, the gripper device 38" is shown in a subsequent position wherein the belt structure portion between first location 53" and an intermediate location 87' is engaged with the input sprocket wheel 20 as it is driven further in the direction 24. The spring band 90 exhibits axial compression strength sufficient to move the main lever member 40" forward in the direction of movement arrow 107 upon flexion of the belt structure portion between locations 53" and 87' to bring the hook 46" to a load receiving position. It can be seen that the guiding surface 104 of the two first guide elements 101 and 102 are in contact with an inwardly bent surface of the spring band 90 when the belt structure portion between locations 53" and 87' is forwardly driven over the sprocket wheel 20. Turning now to Fig. 12c, the gripper assembly 38" is shown with its link assembly bringing the main lever member 40" to a limit position wherein the hook 46" protrudes outwardly through the opening provided on the adjacent link section 30 of the belt 16 simultaneously to the feeding of a piece 80 at the input end of the conveyor 10, so that the piece 80 is engaged while being carried on belt 16 in the forward direction indicated by arrow 82.

Turning now to Fig. 12d, the gripper device 38" is shown in a further subsequent position as the belt 16 is further driven forward in the direction of arrow 24, wherein the link assembly 50" cooperates with the input sprocket wheel 20 upon rotation thereof to bring the main lever member 40" to a load- gripping position wherein the belt structure portion between first and intermediate locations 53" and 87' is forwardly driven past the sprocket wheel 20 so that the link assembly 50" by means of the spring band 90 which exhibits sufficient axial tensile strength to move the main lever member 40" backward in the direction of movement arrow 108 backward to bring the hook 46" to a load-gripping position that is fully reached when the whole belt structure portion between first and second locations 53", 56" is driven past the input sprocket wheel 20 as it is rotated further in the direction of arrow 24 so that the spring band 90 is brought again in a fully extended position as shown in Fig. 12 e. It can be appreciated that the position within the forward span of the load-gripping conveyor at which the hook 46" begins to move toward its load-gripping position can be set as desired by using a spring band 90 of an appropriate length. As to the load-release stage of the third embodiment of load-gripping conveyor employing the alternate spring band link assembly, the mode of operation is essentially the same as explained before regarding the first embodiment in view of Figs. 6a and 6b.

It is to be understood that the present invention can be adapted to the context of various applications other than meat processing where a hook capable of penetrating pieces of meat for engaging thereof is employed. Such engagement can be achieved using other gripping mechanical elements such as holding plates or clamps that can be secured to the main lever member of the gripper device according to the invention. It should also be understood that either a single or a plurality of gripper devices can be installed in a conveyor system according to the invention to comply with the requirements of specific applications. Although the embodiments as described hereinabove are shown with a top-carrying belt defining a forward span extending within a horizontal plane, it is to be understood that other conveying orientations are contemplated, including without limiting to vertical, slant or overhead modes of conveying.

Claims

We claim:

1. A load gripping conveyor comprising: input and output end rotors; an endless carrier belt structure having an outer load conveying surface and an inner surface, said belt structure passing around said rotors and being operationally coupled to a driving device; and at least one gripper device connected to the inner surface of the belt structure, said gripper device including a main lever member having first and second ends, said first end being provided with a gripper element and being pivotaliy connected to the belt structure inner surface at a first location thereon about a main pivot axis, and a link assembly having a leading end connected to the main lever member second end and having a trailing end connected to the belt structure inner surface at a second location thereon downstream from said first location; wherein the link assembly cooperates with the input rotor upon rotation thereof from a load receiving position wherein at least a portion of the belt structure between the first and second locations thereon is forwardly driven over said input rotor so that the link assembly moves the main lever member forward upon flexion of the belt structure portion to pivot the gripper element backward about the main axis causing the gripper element to protrude outwardly through an opening provided on the belt structure outer surface, to a load gripping position wherein the belt structure portion is forwardly driven past the input rotor so that the link assembly moves the main lever member backward upon extension of the belt structure portion to pivot the gripper element forward about the main axis causing the gripper element to move inwardly toward the belt structure outer surface for gripping the load thereon.

2. The load gripping conveyor according to claim 1 , wherein said carrier belt structure is formed of a plurality of substantially rigid link sections having respective leading and trailing ends and pivotaliy interconnected in an end-to- end relationship, the leading end of one said link section being coaxial with said main pivot axis.

3. The load gripping conveyor according to claim 1 , wherein said carrier belt structure is formed of a plurality of substantially rigid link sections having respective leading and trailing ends and pivotaliy interconnected in an end-to- end relationship, said link assembly further comprising a main pivot element defining said main pivot axis and rigidly attached to one said link section disposed at said first location to pivotaliy receive said main lever member first end.

4. The load gripping conveyor according to claim 1 , wherein at least a portion of said load in contact with said conveying surface is made of a malleable material capable of being engaged by said gripper element, said opening being shaped to receive said gripper element while it is moved inwardly toward the belt structure outer surface so as to be substantially embedded therein at said load gripping position while engaging said load portion.

5. The load gripping conveyor according to claim 1 , wherein said carrier belt structure defines between said input and output end rotors a conveying forward span along at least a portion of which said gripping position is substantially maintained, said link assembly further cooperating with said output rotor upon rotation thereof from said maintained gripping position to a load release position wherein at least a portion of the belt structure between the first and second locations thereon is forwardly driven over the output rotor so that the link assembly moves the main lever member forward upon flexion of the belt structure portion to pivot the gripper element backward about the main axis causing the gripper element to protrude outwardly through the opening provided on the belt structure outer surface for allowing release of the load.

6. The load gripping conveyor according to claim 1 , wherein said link assembly comprises a head link member defining said assembly leading end which is pivotaliy connected to said main lever member second end at a head pivot axis, said head link member having a trailing end pivotaliy connected at a tail pivot axis to a tail link member defining said assembly trailing end, said tail pivot axis being located with respect to said head pivot axis to allow the movement of said gripper element between said load receiving position and said load gripping position.

7. The load gripping conveyor according to claim 6, wherein said load is a piece of meat, said gripper element being a hook capable of penetrating said piece of meat for engaging thereof.

8. The load gripping conveyor according to claim 1 , wherein said link assembly comprises a head link member defining said assembly leading end which is pivotaliy connected to said main lever member second end at a head pivot axis, a tail link member defining said assembly trailing end at a tail pivot axis and at least one intermediate link member having respective leading and trailing ends and pivotaliy interconnected in an end-to-end relationship between a trailing end provided on said head link member and the tail link member by at least one intermediate lever member having a first end pivotaliy connected to said belt structure inner surface at an intermediate location thereon about a first intermediate pivot axis and a second end pivotaliy interconnecting said intermediate link member at one of said respective leading and trailing ends thereof about a second intermediate pivot axis being located with respect to said head pivot axis to allow the movement of said gripper element between said load receiving position and said load gripping position.

9. The load gripping conveyor according to claim 8, wherein at least a portion of said load in contact with said conveying surface is made of a malleable material capable of being engaged by said gripper element, said opening being shaped to receive said gripper element while it is moved inwardly toward the belt structure outer surface so as to be substantially embedded therein at said load gripping position while engaging said load portion.

10. The load gripping conveyor according to claim 9, wherein said load is a piece of meat, said gripper element being a hook capable of penetrating said piece of meat for engaging thereof.

11. The load gripping conveyor according to claim 8, wherein said carrier belt structure is formed of a plurality of substantially rigid link sections having respective leading and trailing ends and pivotaliy interconnected in an end-to- end relationship, the leading end of one said link section being coaxial with said main pivot axis, the leading end of at least one intermediate said section being coaxial with said first intermediate pivot axis.

12. The load gripping conveyor according to claim 8, wherein said carrier belt structure is formed of a plurality of substantially rigid link sections having respective leading and trailing ends and pivotaliy interconnected in an end-to- end relationship, said link assembly further comprising a main pivot element defining said main pivot axis and rigidly attached to one said link section disposed at said first location to pivotaliy receive said main lever member first end.

13. The load gripping conveyor according to claim 12, wherein said link assembly further comprises at least one further pivot element defining said first intermediate pivot axis and rigidly attached to corresponding at least one intermediate said link section to pivotaliy receive said intermediate lever member first end.

14. The load gripping conveyor according to claim 1 , wherein said link assembly comprises an elongate spring band having opposed ends defining said assembly leading and trailing ends, said spring band exhibiting axial compression strength sufficient to move the main lever member forward upon flexion of the belt structure portion at said load receiving position, and exhibiting axial tensile strength sufficient to move the main lever member backward upon extension of the belt structure portion at said load gripping position.

15. The load gripping conveyor according to claim 1 , wherein at least a portion of said load in contact with said conveying surface is made of a malleable material capable of being engaged by said gripper element, said opening being shaped to receive said gripper element while it is moved inwardly toward the belt structure outer surface so as to be substantially embedded therein at said load gripping position while engaging said load portion.

16. The load gripping conveyor according to claim 15, wherein said load is a piece of meat, said gripper element being a hook capable of penetrating said piece of meat for engaging thereof.

17. A load gripping conveyor according to claim 14, wherein said leading end is pivotaliy connected to said main lever member second end at a head pivot axis.

18. A load gripping conveyor according to claim 14, wherein said link assembly further comprises at least one band guide element connected to said belt structure inner surface between said first and second locations thereon, said guide element defining a guiding surface in contact with an inwardly bent surface of said band when said belt structure portion is forwardly driven over said input rotor at said load receiving position.

19. A load gripping conveyor according to claim 18, wherein said carrier belt structure is formed of a plurality of substantially rigid link sections having respective leading and trailing ends and pivotaliy interconnected in an end-to- end relationship, each said band guide element being connected to a corresponding said link section between said first and second locations.

20. A load gripping conveyor according to claim 18, wherein said guiding surface is further in contact with said inwardly bent surface of said band when said belt structure portion is forwardly driven over said output rotor at said load release position.