IMPROVED TIMING BELT
FIELD OF THE INVENTION This invention relates to a timing belt and more particularly to a discontinuous timing belt that has ends that are selectively detachably fastened together by lacings.
BACKGROUND OF THE INVENTION Timing belts are well known in the art and are typically provided as a continuous belt, wherein one surface of the belt is provided with evenly spaced apart gear teeth that mesh with and cooperate with grooves in gears of a drive system to provide a predetermined drive speed. However, continuous known timing belts are disadvantageous, as proper installation requires that the timing belt be threaded around the gears in the drive system such that the teeth of the belt are in mating contact with corresponding grooves of the gears. Improper installation may lead to damage to the belt and to the drive system components. Further, replacement of defective timing belts or routine maintenance of known timing belts is cumbersome, often requiring complete disassembly of the gear mechanism to properly access the timing belt and unthread the belt from the drive system. Moreover, each continuous timing belt must be a predetermined length to properly mate with the gears in each drive system to insure proper tension in the timing belt and smooth operation of the drive system.
Accordingly, to overcome the disadvantageous of a continuous timing belt, there is a need for a belt that permits for selective resizing of a belt and ease of assembly or disassembly.
SUMMARY OF THE INVENTION
The present invention is directed to a discontinuous timing belt having a first end, a second end and first and second surfaces. The first surface includes a plurality of spaced apart gear teeth for engaging and mating with gear teeth in a drive system. In accordance with one aspect of the invention, the first end of the timing belt is provided with a first set of spaced apart lacings. Each lacing has attachment ends fixedly secured to the first end of the belt member and a connecting eye extending outwardly away from the first end. The
second end of the timing belt is provided with a second set of spaced apart lacings. The second set of lacings are substantially identical to the first set of lacings and each include attachment ends fixedly secured to the second end of the timing belt and a connecting eye extending outwardly away from the second end. After the timing belt has been installed on the gears in a drive system, to connect the timing belt together the connecting eyes from the first and second sets of lacings are intermeshed together such that the connecting eyes are generally aligned and form a connecting aperature. The aperature receives a selectively detachable fastener. Accordingly, the timing belt can be easily installed and/or removed from a drive system. Further, the present invention contemplates utilizing standard timing belt material such that the belt material may simply be cut to length for a given application and provided with lacings. To enable use of standard belt material, at least one gear tooth adjacent both first and second ends of the timing belt are removed from the belt, forming a partial mounting trough. However the belt backing material remains in tack. The lacings are fixedly secured to either side of the belt backing material in the trough such that the lacings are disposed below the gear teeth. Thus, the lacings do not interfere with the operation of the gear teeth.
An optional layer of surface material, such as polyurethant, may also be disposed on the second surface of the timing belt, the surface opposite the gear teeth, such that the timing belt may also be used as a conveying belt. Further, the surface material also serves to protect the lacings from becoming damaged during operation.
An alternative embodiment of the present invention is also disclosed. The alternative embodiment includes a discontinuous timing belt with first and second ends and gear teeth on a first surface of the belt. The timing belt further includes a pluraltiy of spaced apart strands of reinforcing belt cording embedded within the timing belt and extending the length of the timing belt. The distal ends of the strands of belt cording are preferably interwoven together for added strength and durability.
In accordance with one aspect of the invention, the alternative embodiment further includes first and second sets of connecting members secured to first and second ends of the timing belt. Each connecting member has upper and lower arms connected together by at least one intermediate portion. The upper and lower arms include at least one securing
aperture that receives a fastener. Preferably the upper and lower arms are fixedly secured to the first and second surfaces of the timing belt such that the intermediate portions extend outwardly away from the first and second ends, respectively. The intermediate portions of the first and second sets of connection members are intermeshed together such that the intermediate portions cooperate to form a connection aperature that receives a selectively detachable fastener. An optional surface material may be disposed on the second surface of the timing belt to protect the connection members from damage. Similar to the first embodiment, standard timing belt material may be employed such that at least one gear tooth is removed from both first and second ends to form a mounting trough in which the arms of the connection members are mounted so as not to interfere with the normal operation of the timing belt.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and inventive aspects of the present invention will become more apparent upon reading the following detailed description, claims, and drawing, of which the following is a brief description.
Figure 1 shows an elevational view of a timing belt in accordance with the present invention. Figure 2 is a blow-up of region 2 of Figure 1.
Figure 3 shows an elevational view of the timing belt of Figure 1 with an optional layer of surface material.
Figure 4 is a blow-up of region 3 of Figure 2.
Figure 5 is a planar view of an alternative embodiment of a timing belt in accordance with the present invention.
Figure 6 is a planar view of a lacing flange.
Figure 7 is an enlarged cross-sectional view of the timing belt of Figure 5 with the lacing flanges of Figure 6.
Figure 8 is a perspective view of a fastener for use with the timing belt of Figure 5.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to Figure 1, a first preferred embodiment of a timing belt 20 is illustrated therein. Timing belt 20 is discontinuous and includes first and second surfaces 22 and 24, respectively, and first and second ends 26 and 28, respectively. First surface 22 includes a plurality of spaced apart gear teeth 30 for meshing with gear teeth of drive gears in a drive system (not shown). It is preferred that gear teeth 30 are evenly spaced apart, as in conventional timing belts, such that timing belt 20 cooperates with the gears to drive the gear system at a constant speed.
As best seen in Figure 2, in a first embodiment, first and second sets of lacings 32, 34 are provided to selectively detachably secure first and second ends 26 and 28 together. First set of lacings 32 has upper and lower attachment ends 36 and 38 of each lacing 32 permanently secured to first end 26 of timing belt 20. Lacings 32 are positioned so as to be spaced apart. A connecting eye 40 extends outwardly away from first end 26 of timing belt 20.
Second set of lacings 34 is generally identical to first set of lacings 32. Each lacing 34 has upper and lower attachment ends 42 and 43 permanently secured to second end 28 of timing belt 20. Each lacing 34 is preferable spaced apart slightly more that the width of each lacing 32, to be explained in further detail below. A connecting eye 40' extends outwardly away from second end 26 of timing belt 20 toward first end 26. To insure proper mounting of lacings 32 and 34 on first surface 22, a trough portion is formed adjacent to the first and second ends 26 and 28 in which lacings 32 and 34 are disposed below gear teeth 30.
To facilitate connection of first and second ends 26 and 28, second set of lacings 34 are offset from first set of lacings 32 such that first and second set of lacings 34 and 36 intermesh. Connecting eyes 40 and 40' of the first and second sets of lacings 32 and 34 are then generally aligned and cooperate to form a connection aperture 44 extending at least partially across the width of timing belt 20. Connection aperture 44 receives a selectively detachable fastener 46 to connect first and second ends 26 and 28 together. Thus, timing belt 20 may be easily manipulated onto the gears in a drive gear system and the ends connected together. Further, in the event of a timing belt failure or routine maintenance, timing belt 20 may be easily removed from the drive gear mechanism by simply removing the detachable fastener, without requiring extensive disassembly of the drive gear
mechanism. Preferably, detachable fastener 40 is a hinge pin, although other suitable fasteners may be employed.
Preferably, first and second sets of lacings 32 and 34 extend substantially the entire width of timing belt 20 to insure a strong connection and are arranged in an alternating manner such that lacings 32 are positioned between lacings 34. However, it is understood that other configurations of lacings 32 and 34 are contemplated. Further lacings 32 and 34 are preferably constructed from stainless steel for strength and durability, although other suitable material may be used.
An alternative embodiment of the present invention is disclosed in Figures 3 and 4. Figure 3 shows a timing belt 120 that is similar to timing belt 20 having first and second surfaces 122 and 124, respectively. Timing belt 120 is discontinuous and has first and second ends 126 and 128, respectively. Timing belt 120 is also provided with first and second sets of lacings 132 and 134 that have lower and upper attachment ends 136, 138 and 142,141 , respectively, fixedly connected to first and second ends 126 and 128 of the timing belt 120. Connecting eyes 140 and 140' extend outwardly from first and second ends 126 and 128 that cooperate to form a connection aperture 144 that receives a selectively detachable fastener 146 when first and second sets of lacings 132 and 134 are intermeshed together.
Timing belt 120 further includes a layer 148 of surface material applied, preferably by bonding, to second surface 122. Layer 148 serves to protect lacings 132 and 134 from damage while timing belt 120 is in operation. Further, layer 142 permits timing belt 120 to be used as a conveying belt, such that the surface material easily grips items to be conveyed. Surface material layer 142 is preferably a polyurethane material, although other suitable materials may be employed. To assemble timing belts 20, 120 to in a drive gear mechanism, one end of the timing belt 20, 120 is wrapped around the pulleys, with the gear teeth being positioned in mating engagement with the drive gears in the drive gear mechanism such that the gear teeth are meshed together. Next, lacings 32, 34 and 132, 134 are brought into an intermeshing relationship with connecting eyes 40, 40' and 140, 140' being aligned to form connecting aperture 46 and 146. Fastener 46 is then detachably secured within the aperture to connect first and second ends 26, 28 and 126 and 128 of timing belt 20, 120 together.
Once first and second ends 26, 28 and 126 and 128 of timing belt 20, 120 are secured together, timing belt 20, 120 is then tensioned by a drive gear mechanism take-up, such that the timing belt 20, 120 is operational.
Timing belt 20, 120 maybe constructed from pre-manufactured timing belt material that is already provided with preformed gear teeth. To manufacture timing belt 20, 120, gear teeth from each of first and second ends of timing belt 20, 120 are removed to form the trough section for positioning first and second sets of lacings 32, 34 and 132 and 134. However, the belt backing 48, 148 of timing belt 20, 120 remains intact after removal of the gear teeth. The lacing sets 32, 34 and 132, 134 are then fixedly secured to first and second ends 26, 28 and 126 and 128 of the timing belt 20, 120. Next, for timing belt 120, a layer of surface material is bonded to the top surface 122 of the timing belt 120.
Another alternative embodiment of a timing belt 220 is shown in Figures 5-8. Similar to timing belts 20 and 120, timing belt 220 is discontinuous and includes first and second surfaces 222 and 224, respectively, and first and second ends 226 and 228. Timing belt 220 further includes spaced apart gear teeth (not shown) positioned on first surface 222 for meshing with gear teeth of drive gears in a drive system (not shown).
Referring to Figure 5, timing belt 220 further includes at least one reinforcing member 230 embedded therein. Preferably, the reinforcing member is a plurality of strands of belt cording 230, stainless steel wire or other suitable reinforcing member that substantially extend laterally across the length of timing belt 220. In accordance with another aspect of the invention, it is preferred that distal ends 231 of belt cording 230 are interwoven together at first and second ends 226 and 228 of timing belt 220 for additional strength.
In accordance with another aspect of the invention, as best seen in Figures 6 and 7, first and second sets of connecting members 232 and 234 are provided to selectively detachably secure first and second end 226 and 228 together. Each first connecting member 232 includes an upper arm 236 and a lower arm 238 connected together by at least one intermediate portion 240 extending therebetween. Upper arm 236 is secured to second surface 224 at first end 226 and lower arm 238 is secured to first surface 222 at first end 226 such that intermediate portion 240 extends outwardly away from first end 226.
Similarly, each second connecting member 236 includes an upper arm 240 and lower arm
242 connected together by at least one intermediate portion 244 extending therebetween. Upper arm 240 is secured to second surface 224 at second end 228 and lower arm 242 is secured to first surface 222 at second end 228 such that intermediate portion 244 extends outwardly away from second end 228. First and second connecting members 232 and 234 are position so as to be inverted to one another such that intermediate portions 240 intermesh with intermediate portions 244 to form a connection aperture 246. While intermediate portions 240 and 244 are shown with a curved contour, it is understood that any suitable contour may be used. Connection aperture 246 receives a selectively detachable fastener 248 to connect first and second ends 226 and 228 together. Preferably, first and second sets connection members 232 and 234 extend substantially the entire width of timing belt 220 to insure a strong connection. Thus, timing belt 20 may be easily manipulated onto the gears in a drive gear system and the ends connected together. Further, in the event of a timing belt failure or routine maintenance, timing belt 220 may be easily removed from the drive gear mechanism by simply removing the detachable fastener, without requiring extensive disassembly of the drive gear mechanism. Preferably, detachable fastener 248 is a hinge pin, although other suitable fasteners may be employed.
To secure connection members 232 and 234 to timing belt 220, upper and lower arms 236, 238 and 240, 242 are provided with securing apertures 250, 250' that extend therethrough and receive fasteners. Securing apertures 250 of upper arms 236 and 240 generally align with securing apertures 250' of lower arms 238 and 242 when connection members are positioned on timing belt 220.
In a preferred embodiment, upper arms 236 and 240 include two securing apertures positioned within a depression 252 that extending inwardly from an outer surface 254 of upper arms 236 and 240. Corresponding mating securing apertures 250' are provided through lower arms 238, 242. A generally U-shaped fastener 256, as seen in Figure 8, having legs 258 and a base portion 260 engages securing apertures 250 and 250' to secure connection members 232 and 234 to timing belt 220. Specifically, legs 258 are positioned in securing apertures 250' and 250 and fastener 256 is moved upwardly until base portion 260 contacts an outer surface 262 of lower arms 238 and 244. Next, legs 258 are folded
over until legs 258 contact a floor 264 of depression 252 such that legs 258 are generally flush with outer surface 254 of timing belt 220.
In accordance with another aspect of the invention, it is preferred that fastener 256, or any other suitable fastener employed to secure connecting members 232, 234 to timing belt 220, extends through interwoven distal ends 231 of strands of belt cording 230 to further insure that belt cording 230 is secured within timing belt 220.
Similar to timing belt 120, timing belt 220 may further include a layer of surface material (shown in phantom) disposed, preferably by bonding, on second surface 224. The surface material serves to protect connection members 232 and 234 from damage while timing belt 220 is in operation. Further, the surface material layer permits timing belt 220 to be used as a conveying belt, such that the surface material easily grips items to be conveyed. Surface material layer 242 is preferably a polyurethane material, although other suitable materials may be employed.
While particular embodiments of the invention have been shown, it will be understood, of course, that the invention is not limited thereto since modifications may be made by those skilled in the art, particularly in light of the foregoing teachings. Reasonable variation and modification are possible within the scope of the foregoing disclosure of the invention without departing from the spirit of the invention.