Sprocket with combined hinge/center drive

Abstract: A conveying apparatus comprises a modular belt (70) having a plurality of modules (73, 80) connected to adjacent modules (73, 80) and articulated by pivot rods (76) that extend through openings in the link ends (72) of the modules (73, 80). The openings extend transverse to the direction of belt travel. The apparatus also includes a drive sprocket having a plurality of teeth (58, 61) disposed around its perimeter. Each tooth (58, 61) has a center driving surface (64) and a link end driving surface (67). The teeth (58, 61) are disposed such that each belt module (73, 80) may be driven in either direction from the center by one of the teeth (58, 61) and simultaneously driven at a link end (72) by one of the other teeth (58, 61) such that there is positive engagement with each belt module (73, 80) by two teeth (58, 61).

Description: The present invention relates to a conveying apparatus comprising a modular belt and a drive sprocket for driving the modular belt. In EP-A-1 050 492 a conveying apparatus is disclosed which comprises a modular belt having a plurality of belt modules, each belt module having link ends disposed at opposite ends of the module and having in a first embodiment a rib disposed between the link ends. A drive sprocket having a plurality of teeth disposed around its perimeter is adapted to engage with the modular belt. In the first embodiment, each of the teeth has a center driving surface for center driving the belt modules by the engagement of the center driving surfaces with the ribs. In a second embodiment, each of the teeth has a link end driving surface for link end driving the belt modules by the engagement of the link end driving surfaces with the link ends. An object of the invention is to provide a conveying apparatus with improved engagement of the drive sprocket(s) with the belt modules. This object is achieved by the conveying apparatus according to independent Claim 1 and by the drive sprocket according to independent Claim 9. Independent Claim 17 refers to a method of driving a modular belt. Preferred embodiments are defined in the dependent claims. The conveying apparatus of the present invention operates to increase the transmittable torque per sprocket because each belt module is engaged at two different points by two different teeth. Accordingly, the present invention provides for improved positive engagement of the drive sprocket(s) with the belt modules because the belt modules are each engaged at both their transverse rib and at their link ends in both moving directions. The fit between the teeth and the belt modules provides for lower noise, lower risk of sprocket disengagement, lower wear and longer life. The invention is illustrated in the drawings in which like reference characters designate the same or similar parts throughout the figures of which: Fig. 1 is a perspective view, obliquely from beneath, of two belt modules connected by a pivot rod; Fig. 2 is a partial perspective view of the sprocket of the present invention; Fig. 3 is an end elevational view of the sprocket of the present invention; Fig. 4 is a sectional side elevational view of a flat top belt engaged with the sprocket; Fig. 5 is a sectional side elevational view of an open grid belt engaged with the sprocket; and, Fig. 6 is a sectional view taken along lines 6-6 of Fig. 5. Referring to Fig. 1, a flat top modular conveying belt 10 is shown with two interengaging belt modules 13 which are articulated on one another by a pivot rod 16. Each belt module 13 has a module body 19 and a first and second series of link ends 22, 25 that project from two opposite sides of the module body 19. Each link end 22, 25 includes an opening 28, 31 that is disposed transverse to the direction of belt travel indicated by arrow 34. The belt 10 may be driven in either direction. A transverse rib 37 is also disposed transverse to the direction of belt travel. The openings 28 and 31 as shown comprise slots that are arranged at angles of approximately 45° to the conveying surface. For straight running belts, round openings are also suitable as shown in Figs. 4 and 5. The link ends 22, 25 are considerably wider in their top part than in their bottom part, which has the opening 28, 31, with the result that adjacent link ends 22, 25 of interengaging modules 13 adjoin one another in a virtually gap-free manner in the top region. Moreover, the top side of the modules 13 is of flat design (Figs. 1 and 4), which results in a planar, essentially continuous conveying surface. The transverse ribs 37 extend downward from the underside of the module bodies 19, in the center of the bodies 19, and have a symmetrical, in this case trapezoidal cross section with the result that the modular conveying belt 10 can be moved just as easily forwards as backwards, perpendicularly to the transverse ribs 37. Referring to Figs. 2-3, the drive sprocket 40 illustrated comprises a twelve-sided wheel body 43 with an essentially square opening 46 formed by four opposed walls 48. The opening 46 provides for mounting the drive sprocket 40 onto a drive shaft. While the opening 46 is shown with a square shape, other shapes to accommodate other shapes for the drive shaft would also be suitable. Also, although the drive sprocket 40 is shown with a twelve-sided outer body the wheel 40 may have more or less sides or may even be round. The wheel body 43 is of considerably wider design in an outer region 49 than in an inner region 52, and on its outer circumference, forms twelve planar surfaces 55 on which two teeth 58, 61 are arranged in each case. The two teeth 58, 61 arranged on a surface 55 are each of the same shape, but have been rotated 180° with respect to one another. The ends of the two teeth 58, 61 that are directed away from one another in the direction of rotation of the drive sprocket 40 each extend as far as the border of the planar surface 55. The teeth 58, 61 are distributed in two series over the circumference of the drive sprocket 40 such that during driving of the modular conveying belt 10, one of the teeth 58, 61 on one of the surfaces 55 engages with one of the link ends 22, 25 and another tooth 58, 61 on an adjacent surface 55 engages with the transverse rib 37. Each tooth 58, 61 has a center driving face 64 and a link end driving face 67. The teeth 58, 61 are disposed in offset pairs on each surface 55 such that the modular belt 10 can be driven in either direction. In Fig. 4, a flat top belt 70 is shown in a cut-away view as it engages with the drive sprocket 40. In order to drive the modular conveying belt 70, which comprises a multiplicity of modules 73 articulated on one another by means of pivot rods 76, use is typically made of a plurality of drive sprockets 40 spaced apart from one another on a shaft. The modules 73 have opposed link ends 72 and 75 (not visible, located behind the link end 72 shown) disposed at opposite ends of module body 71. For clarity, only one drive sprocket 40 being visible here. Each transverse rib 37 is driven by a center driving surface 64 on one surface 55 and a link end driving surface 67 on an adjacent surface 55 engaging with one of the link ends 72, 75. The drive sprocket 40 engages the modules such that each module is engaged by two teeth. One of the teeth is in one pair of teeth and the other tooth is in an adjacent pair of teeth. For example, with respect to counterclockwise rotation of sprocket 40, module 80 is engaged by tooth 61 at its rib 37 and is engaged at the link end 75 by tooth 58 on the adjacent surface 55. Figs. 5-6 illustrate the drive sprocket 40 of the present invention in combination with a open grid or flush belt 100 comprised of flush grid modules 103 having openings for pivot rods 106. The flush or open grid modules 103 also have link ends 109 and 112 (not visible, located behind link ends 109 in Fig. 5) and have a transverse rib 115. The teeth 58, 61 of the drive sprocket 40 engage with the link ends 109, 112 and transverse rib 115 in the same manner as with the flat top belt modules 73. Referring to Fig. 6 and with the belt 100 moving from left to right with respect to the orientation of the figure, the teeth 58, 61 of the drive sprocket 40 engage the belt 100 at points 150, 153 such that one tooth engages with the transverse rib 115 and a second tooth located on an adjacent surface 55 engages with one of the link ends 109, 112. The belts 10, 70 and 100 and drive sprocket 40 of the present invention operate to increase the transmittable torque per sprocket because each belt module is engaged at two different points by two different teeth. Accordingly, the present invention provides for improved positive engagement because the belt modules 13, 73, 80 and 103 are each engaged at both the transverse rib and at the link ends in both moving directions. The fit between the teeth and the belt modules provides for lower noise, lower risk of sprocket disengagement, lower wear and longer life. While the invention has been described in connection with certain embodiments, it is not intended to limit the scope of the invention to the particular forms set forth, but, on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the claims.

Claims: Conveying apparatus, comprising: means for forming a modular belt (10; 70; 100) comprising a plurality of belt modules (13; 73, 80; 103); means (40) for engaging the modular belt (10; 70; 100); and, means for driving the engaging means (40); characterized in that the engaging means (40) are shaped such that each belt module (13; 73, 80; 103) is simultaneously engageable by a center driving surface (64) and a link end driving surface (67) on the engaging means (40). Conveying apparatus according to Claim 1, comprising: a modular belt (10; 70; 100) having a plurality of belt modules (13; 73, 80; 103), each belt module having link ends (22, 25; 72; 109) disposed at opposite ends of the module and having a rib (37; 115) disposed between the link ends (22, 25; 72; 109), the rib (37; 115) disposed transverse to a direction of belt travel, the link ends (22, 25; 72; 109) having an opening (28, 31) disposed transverse to the direction of belt travel, the link ends (22, 25; 72; 109) arranged such that the plurality of belt modules (13; 73, 80; 103) are capable of being intercalated by a plurality of pivot rods (16; 76; 106) extending through the openings (28, 31) in the link ends (22, 25; 72; 109); a drive sprocket (40) adapted to engage with the modular belt (10; 70; 100), the drive sprocket (40) having a plurality of teeth (58, 61) disposed around its perimeter, each of the teeth (58, 61) having a first center driving surface (64) disposed on a first side and having a second link end driving surface (67) disposed on a second side opposite the first side, the plurality of teeth (58, 61) disposed such that one of the first surfaces (64) on a first tooth (58, 61) engages one of the ribs (37; 115) on a first belt module (13; 73, 80; 103) and one of the second surfaces (67) on a second tooth (58, 61) simultaneously engages one of the link ends (22, 25; 72; 109) on the first belt module (13; 73, 80; 103); and, a rotating shaft attached to the drive sprocket (40). Conveying apparatus according to Claim 2, characterized in that the drive sprocket (40) has a body (43) with a plurality of substantially flat sides (55). Conveying apparatus according to anyone of Claims 1 to 3, characterized in that the center driving surface (64) comprises an angled wall. Conveying apparatus according to anyone of Claims 2 to 4, characterized in that the link end driving surface (67) is curved to engage with the link ends (22, 25; 72; 109). Conveying apparatus according to anyone of Claims 2 to 5, characterized in that the teeth (58, 61) are disposed such that the modular belt (10; 70; 100) can be driven either clockwise or counterclockwise. Conveying apparatus according to anyone of Claims 2 to 6, characterized in that the drive sprocket (40) has a central opening (46) for mounting to the shaft. Conveying apparatus according to Claim 7, characterized in that the central opening (46) is square. Drive sprocket (40) for a conveying apparatus according to,Claim 1, for driving a modular belt (10; 70; 100) having a plurality of belt modules (13; 73, 80; 103) with each belt module having opposed link ends (22, 25; 72; 109) and a rib (37; 115) disposed between the link ends (22, 25; 72; 109) transverse to a direction of belt travel, the drive sprocket (40) comprising: a body (43) having a plurality of teeth (58, 61) disposed around its perimeter, each of the teeth (58, 61) having a first center driving surface (64) disposed on a first side, the plurality of teeth (58, 61) disposed such that the first surface (64) on a first tooth (58, 61) is engageable with the rib (37; 115) on a first belt module (13; 73, 80; 103), characterized in that each of the teeth (58, 61) has a second link end driving surface (67) disposed on a second side opposite the first side and the plurality of teeth (58, 61) are disposed such that the second surface (67) on a second tooth (58, 61) is engageable with one of the link ends (22, 25; 72; 109) on the first belt module (13; 73, 80; 103) simultaneously with the engagement of the first surface (64) on the first tooth (58, 61) with the rib (37; 115) on the first belt module (13; 73, 80; 103). Drive sprocket (40) according to Claim 9, characterized in that the body (43) has a plurality of sides (55), with each side (55) having a pair of teeth (58, 61) disposed thereon. Drive sprocket (40) according to Claim 9 or 10, characterized in that the plurality of teeth (58, 61) are disposed in pairs such that one of the first surfaces (64) on a first tooth (58, 61) in a first pair engages one of the ribs (37; 115) on a first belt module (13; 73, 80; 103) and one of the second surfaces (67) on a second tooth (58, 61) in a second pair simultaneously engages one of the link ends (22, 25; 72; 109) on the first belt module (13; 73, 80; 103). Drive sprocket (40) according to anyone of Claims 9 to 11, characterized in that the link end driving surface (67) is curved to engage with the link end (22, 25; 72; 109). Drive sprocket (40) according to anyone of Claims 9 to 12, characterized in that the center driving surface (64) comprises an angled wall adapted to engage with one of the ribs (37; 115). Drive sprocket (40) according to anyone of Claims 9 to 13, characterized in that the teeth (58, 61) are disposed such that the modular belt (10; 70; 100) can be driven clockwise or counterclockwise. Drive sprocket (40) according to anyone of Claims 9 to 14, characterized in that the drive sprocket (40) has a central opening (46) adapted for mounting the sprocket (40) to a drive shaft. Drive sprocket (40) according to Claim 15, characterized in that the central opening (46) is square. Method of driving a modular belt (10; 70; 100) having a plurality of belt modules (13; 73, 80; 103) with each belt module having opposed link ends (22, 25; 72; 109) and a rib (37; 115) disposed between the link ends (22, 25; 72; 109) and disposed transverse to a direction of belt travel, the method comprising: providing a drive sprocket (40) adapted to engage with the modular belt (10; 70; 100), the drive sprocket (40) having a plurality of teeth (58, 61) disposed around its perimeter, each of the teeth (58, 61) having a first center driving surface (64) disposed on a first side, the plurality of teeth (58, 61) disposed such that the first surface (64) on a first tooth (58, 61) is engageable with the rib (37; 115) on a first belt module (13; 73, 80; 103); and, providing a rotating shaft attached to the drive sprocket (40); characterized in that each of the teeth (58, 61) has a second link end driving surface (67) disposed on a second side opposite the first side; in that the plurality of teeth (58, 61) are disposed such that the second surface (67) on a second tooth (58, 61) is engageable with one of the link ends (22, 25; 72; 109) on the first belt module (13; 73, 80; 103) simultaneously with the engagement of the first surface (64) on the first tooth (58, 61) with the rib (37; 115) on the first belt module (13; 73, 80; 103); and by the step of engaging the drive sprocket (40) with the modular belt (10; 70; 100) such that a belt module (13; 73, 80; 103) is simultaneously driven by a first tooth (58, 61) in a first pair of teeth (58, 61) and a second tooth (58, 61) in a second pair of teeth (58, 61) adjacent to the first pair.

Inventors: GULDENFELS DIETER, GULDENFELS, DIETER
Applicants: HABASIT AG
Application year: 2001
Main classification: B65G17
IPC codes: B65G17, F16H55, B65G23