JPH0866974A - Flexible endless seam belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it impossible to mechanically distinguish the joint of a joint belt and substantially equalize the joint belt with a jointless belt in terms of performance. SOLUTION: The flexible joint belt is formed by joining each end part of a belt material with that of the other belt material. Each end part has plural mutually engaging elements 14, 16 of a puzzle cut pattern. The opposite faces of the puzzle cut pattern are fitted into each other in order to prevent the end parts from being disengaged and are physically joined together to form a joint. The joint has a clearance or a groove between the surfaces of the mutually engaging elements and the opposite faces of the puzzle cut pattern are mutually joined together by heat and/or pressure, or an adhesive which chemically or physically fits to the belt material.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention has improved seam quality and smoothness with substantially no thickness differences between the seams of the belt and the adjacent areas of the belt, and the belt material and chemicals. It relates to an endless flexible seamed belt having a strengthening bond formed in the interstices of the mutually mating elements of the belt with a physically and physically compatible material.

[0002]

The most important inventions made so far are:
Probably the invention of the wheel. One of the subsequent inventions of approximately equal importance is probably belts. Belts were initially manufactured by taking the two ends of the web material and securing them together by various techniques such as stitching, wire fastening, stapling, adhesive bonding and the like. Belts joined or spliced in this way are suitable for many applications, such as transmitting rotary motion from a power source such as a motor to implement a device such as a saw blade, Many of the more sophisticated belt technology applications in today's common practice are unsatisfactory. With current technology, many belt applications require ever higher quality and utility. In particular, photoreceptors, intermediate sheets and / or image transport devices, fusing members
In particular applications, such as in electrostatographic and electrographic imaging devices and processes for use as members or transfix devices, the action performed by the belt or on the belt. The action to be performed is physically (mechani
It is ideal to provide a seamless belt that does not interfere with the belt. While ideal, manufacturing seamless belts requires a fairly precise and expensive manufacturing process, especially for large belts the manufacturing process is more precise, difficult and much more expensive. As a result, various attempts have been made to provide seam belts that can be used in these processes. Previous attempts to produce seam belts have relied heavily on belts, in which the two ends of the belt material are overlaid or overlapped to form a seam, or butted against each other, It was physically fixed by heat or by the use of adhesives or other adhesive means such as ultrasonic welding.

Although belts formed according to typical butt techniques meet many objectives, the small contact area formed by simply abutting the two ends of the belt material results in a bond, strength and flexibility. Sex is limited. In addition, belts formed according to the butt or superposition technique impart bumps or other discontinuities on the belt surface, which may result in 0.02 between adjacent portions of the belt depending on the thickness of the belt.
Differences in height of 10 inches or more can result in performance failures in many applications.
For example, one of the most severe problems involves cleaning residual toner on the imaging belt after transfer of the toner image. Intimate contact between the belt and the cleaning blade is required. Belts with ridges, cracks or other discontinuities will interfere with the blade's tuck.
Toner passes under the blade and is no longer cleaned. Further, when the seams having different heights are repeatedly collided by the cleaning blade, the untransferred residual toner may be trapped on the irregular surface of the seam. Further, in the photoreceptor that is repeatedly subjected to this collision operation, when the seam is constantly worn by the cleaning blade, the seam is easily peeled off. As a result, both the cleaning life of the blade and the total life of the photoreceptor are significantly reduced, and copy quality is also reduced. Moreover, such seam height irregularities add vibration noise to the xerographic development. Vibration noise disturbs the toner image on the belt, reducing the resolution and quality of the transfer of the toner image to the final copy sheet. This is especially common in applications that require the application of a multicolored layer of liquid or dry developer onto the photoreceptor belt, which is subsequently transferred to the final copy sheet. In these applications, 0.0 between the seam and the unsealed adjacency.
It is desired to provide a seam height difference of less than 01 inches. Further, the presence of discontinuities in belt thickness reduces flex life and durability of belt strength. Belt durability is desirably 80-90% of the unsealed matrix material for long term use. In addition, such belt discontinuities or ridges
Translational vibrations result in inaccurate image registration during development, inaccurate belt tracking, and overall deterioration of motion quality.

Although the endless puzzle cut seam belt described in US patent application Ser. No. 08 / 297,200 works well in many applications, there are additional applications where a tighter bond of the belt ends at the seam is desired. Exists. The present invention is directed to this end.

[0005]

SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to provide a seam belt that has mechanically invisible seams that are substantially equivalent in performance to a seamless belt. Is.

It is a further object of the present invention that differences in ridges or heights that result in performance impairments, namely cleaning blade performance due to translating vibrations, image registration, belt tracking or poor run quality, are
An object of the present invention is to provide an endless seam belt that is substantially absent between the seam portion and the non-sealed portions adjacent to both sides of the seam.

[0007]

SUMMARY OF THE INVENTION In accordance with a primary aspect of the present invention, a flexible formed by joining two ends of a belt material, each end having a plurality of interdigitated elements of a puzzle cut pattern. The above object is achieved by providing a seam belt. The opposing surfaces of the puzzle cut pattern are in mating relationship to prevent separation of the ends and are physically joined to form a seam, and the flexible seam belt has an endless shape with a substantially uniform thickness. Allow it to essentially function as a belt. The seams have gaps or kerfs between the surfaces of the interengaging elements, and the opposing surfaces of the puzzle cut pattern are joined together to allow the flexible seam belt to essentially function as an endless belt.

In a further aspect of the invention, the opposing surfaces of the puzzle cut pattern are joined by application of heat or pressure or a combination of heat and pressure, or by an adhesive that is chemically and physically compatible with the belt material. It

In a further aspect of the invention, the compatibility is
(compatible) The melt volume of the adhesive material is sufficient to fill the interstices or grooves between the interengaging elements.

[0010]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in more detail with continued reference to the drawings and further reference to the following description. The seams formed in accordance with the present invention are held together by the geometric relationship between the ends of the belt material to improve strength, flexibility and mechanical life. The belt material ends are fixed to each other by a puzzle cut. This means that the two ends fit together like a normal puzzle. Here, the seam has gaps or grooves 20 between the surfaces of the mutually mating elements and the opposing surfaces of the puzzle cut pattern are joined together so that the flexible seam belt is essentially an endless belt. To be able to function. The joining of the opposing surfaces of the interengaging elements forming the seam may be either physical joining, chemical joining, or a combination of physical and chemical joining. Alternatively, the opposing surfaces of the puzzle cut pattern may be bonded with an adhesive that is physically and chemically compatible with the belt material. Typically, this bond provides a bond between opposing surfaces of the interlocking elements that provides improved seam quality and smoothness with substantially no thickness difference between the seam and the adjacent portion of the belt. provide. This improves image formation, alignment and control, as described above. At this point, it should be noted that the smaller the height difference, the faster the belt can move. Regardless, the opposing surfaces of the puzzle-cut patterns that are joined together are physically fully bonded to allow the flexible seam belt to essentially function as an endless belt. 2 of the seam belt
The two ends can be joined by heating such as welding including ultrasonic welding, arc welding and impulse welding. In welding,
The top and bottom elements, similar to those used to seal plastic bags, have two arms exerting pressure and then the elements are heated. In the case of thermoplastic belt materials, the thermoplastic nodes are deformed by heating and flow into the interstices to form or bond with each other and physically form a bond. As shown in FIG. 8, the very narrow groove between the ends of the thermoplastic belt is filled by the application of heat and pressure. this is,
Similar to welding two nodes together. This technique is of course not applicable to thermosetting materials.

Alternatively, two belt ends having a puzzle cut pattern at each end can be joined by a chemical reaction. This occurs when the belt material is thermoplastic and when heated, the thermoplastic material at least softens, even if it does not melt, and flows to fill the seam gap.

Another alternative is to apply the adhesive to the interstices between the interengaging elements, especially the opposing surfaces of the puzzle cut pattern. The use of an adhesive allows the use of much wider grooves than the very narrow grooves that can be used to bond thermoplastic materials with heat and pressure only. It also allows the adhesive to wick into the gap or groove area. In this regard, the performance of the adhesive depends on the gaps or grooves 20 between adjacent cut pieces of the pattern.
The viscosity of the adhesive is important because it depends on its ability to penetrate into it. Therefore, a relatively high viscosity adhesive will not perform as well as a low viscosity adhesive. In addition, the surface energy of the adhesive must be compatible with the material from which the belt is formed so that it wets and spreads reasonably at the belt seam. As mentioned above, good adhesion is required to enable the performance requirements discussed above with respect to the original material. If the belt is made of a thermoplastic or thermosetting material, use a thermoplastic or thermosetting adhesive that melts and flows at a lower temperature than the belt material but does not soften or flow sufficiently during belt operation. Is very convenient. The distance between the groove 20, the adjacent surface of the interlocking elements of the belt end, is created at the belt end by a mechanical die. Alternatively, it can be produced by cutting a laser pattern. If the belt material is thermoplastic, a thermoplastic or thermoset or cross-linked adhesive may also be used and may be based on the same material from which the belt is made. However, if the belt material is thermoset, a thermoplastic or thermoset adhesive can be used to fill the gaps between the opposing surfaces of the puzzle cut pattern. Typically, hot melt adhesives that are solid at room temperature but flow when heated can be used. Typical thermoplastic hot melt adhesives include polyamides, urethanes, polyesters.
Typical thermosetting materials include epoxies, polyimides, cyanoacrylates and urethanes. Following the bond (whether physical, chemical or adhesive, or any combination thereof), the seam is pressed to make the seam as uniform as possible and to control thickness differences. Flattening is not essential but desirable.

Referring to FIG. 1, when the belt 10 is placed on a flat surface (whether horizontal or vertical),
It should be noted that the mechanical fit relationship of the seam 11 lies in the two-dimensional plane. Although the seam is shown in FIG. 1 to be perpendicular to the two parallel sides of the belt, it is angled with respect to the parallel sides,
That is, it will be appreciated that it may be slanted. This allows the noise generated in the system to be more evenly distributed, reducing the forces on each meshing element or node.

The flexible endless seam belt can be made of any suitable material. Any suitable belt material can be used. Typical materials include US Pat.
65,990, including multi-layered photoreceptor materials and various thermoplastic and thermosetting belt materials. Typical materials include polyesters, polyurethanes, polyimides, polyvinyl chloride, polyolefins such as polyethylene and polypropylene, polyamides such as nylon, polycarbonates, acrylic resins.
(acrylics) are included. In addition, silicone, fluorocarbons such as DuPont's Viton,
Also included are elastomeric materials such as EPDM and nitriles. Even metal cloth and paper can be used for certain purposes. The belt material has tensile strength, Young's modulus (typically 1 × 10 ^{3 to} 1 × 10 ⁶ ), electric conductivity (typically 10 ^{8 to} 10 ¹¹ ohm · cm), volume resistivity, thermal conductivity, Stability, flexural strength, etc. (and in some applications, transfix, ability to be exposed to high temperatures, etc.) are selected to have appropriate physical properties for a particular application. Other important properties of the belt material include surface energy (e.g. low is desired for good toner release), gloss, dielectric constant and strength.

Puzzle-cut patterns are conventional such as die cutting and laser cutting using commercially available lasers such as C0 ₂ lasers or excimer lasers that produce a beam of sufficient width and intensity to provide the desired cut in an acceptable time. It can be formed according to the molding technique of. Following cutting with the laser beam, deburring and cleaning, if necessary, by air, ultrasound or brushing. In addition to the puzzle cut pattern formed by joining two ends, the puzzle cut pattern can also be formed at each end by male and female punches that insert a belt material in between to punch out the shape. .
Alternatively, it may be a pattern on wheels that rolls over the material.

As can be seen from the drawings, the puzzle cut pattern is virtually the same post or neck 14 and head or node 16 pattern of the mating portion of the male and female halves 15 and 15 as shown in FIG. 3, it may take any form, including a mushroom-like pattern having male parts 18 and 19 and female parts 21 and 23, and a node pattern such as the dovetail pattern shown in FIG. it can. The puzzle cut pattern shown in FIG. 5 includes a plurality of male fingers 22 with mating teeth 24 and a plurality of female fingers 26 having recesses 28 for mating with teeth 24 when assembled. With. In order to reduce stress concentrations between the mating elements and prevent complete disengagement when traveling around a curved member such as the roll 12 of FIG. 1, the mating elements may all have curved mating elements. is important.

It has been found that the stress concentration with curved interlocking elements is lower than with square corners. With square corners, stress is concentrated rather than evenly distributed, further leading to potential failure. Physical bond, strength and bond flexibility of at least 50,000
It must be able to support 0 cycles of belt circulation, the height difference between the seam and the unsealed parts on both sides of the seam is about 0.001 inch, the seam being the strength of the belt matrix material. Has a tensile strength of at least 80%, preferably 90%.

The following is the mechanical integrity of the seam (mechanica
is a discussion of the interrelationships between various belt and material parameters required for integrity.

The physical integrity of the seams was investigated and analyzed for a number of shapes, especially the preferred shape, which included nodes forming a circle and interconnected by opposite necks. To determine the strain under load,
Each such node is considered as a beam fixed to the narrowest part of the neck connecting the node to the base, the strain of each tooth (node and neck) being calculated by the direction of the load with respect to the beam. In order to ensure that the seams do not fall apart under load, the maximum strain on each tooth under worst conditions of load normal to the beam should not exceed the thickness of the belt itself. Obviously, if the tooth distortion exceeds the thickness of the belt, the seams will be staggered. In the above simple analysis, the main relations connecting the material parameter M representing the shape and the geometrical parameter G are as follows so that the belt does not fall apart under load.

[0020]

[Equation 1]

In this relation, M is a dimensionless quantity given by the following equation.

[0022]

[Equation 2]

G represents the following ratio.

[0024]

(Equation 3)

Where N is the total load per unit width acting on the belt (ie, pounds per inch), E is the elastic modulus of the belt material, t is the thickness of the belt, and R is the circular node forming the seam. , W is the wavelength of one full cycle between two adjacent nodes. Equation (1) is a one-to-one relationship between the material parameter M and the geometric parameter G. Thus, given one of them, the other parameter is known. Furthermore, due to the dimensionless nature of these two parameters, there is an infinite number of combinations of variables contained in a particular value pair of M and G, so that there are many values in each value pair satisfying equation (1). The shape of is embodied. Upon inspection of the node's geometry, the structure is characterized by two main features: the shoulder, ie where there is interference between adjacent teeth supporting the seam, and the neck of each tooth showing strength under load. It is shown to be attached. The size of the shoulders should be sufficient to ensure the physical integrity of the seam without making the neck small enough to reduce its strength. At this point, attention is directed to FIGS. 6A, 6B and 6C. Visually observable in these figures is that the neck size in Figure 6A is very small,
Although the shoulder size in FIG. 6C does not provide sufficient interference contact,
The geometry in FIG. 6B is to look optimal. Table 1 below
And Table 2 shows various parameters for the identified belt properties. All samples will work as described above, but a value of G of 0.6 is a good compromise. Of course, many of the samples are impractical to perform with respect to factors such as ease of manufacture, cost, stress tolerances and the like. According to equation (3), G can only fluctuate between 1/2 and 1, the first value being relevant when the shoulder is zero, the second value being the tooth neck at zero and the node giving strength. It turns out to be relevant when you do not have it. Knowing either M or G, the complete shape is determined with the help of the above equations and other standard geometric relationships. Measurements on actual belts generally confirmed the above analysis. To explain the solution methodology, Young's modulus E = 5 × 10 ⁵ psi and thickness t
= 0.004 inch belt material N = 2.0 lbs /
It is assumed to be subjected to an inch (belt width) pull. H is the vertical height between the centers of one node on one side of the seam and the node on the other side of the seam. Potential solutions that prevent the seams from falling apart are given in Tables 1 and 2 below. If the value G = 0.6 is chosen as the compromise between seam integrity and node strength, the following is found.

Node diameter D = 0.448 mm Period w = 0.747 mm Neck width g = 0.299 mm Node height H = 0.69696

[0027]

[Table 1]

[0028]

[Table 2]

It is desirable to have the width of the seam as narrow as possible to minimize belt time outs or non-functional areas. In addition, this allows the seams to be shown to be unrelated to belt functionality such as toner and developer image formation and transfer. Generally, the seam is about 1 mm to about 3 mm wide.

Referring to the embodiment shown in FIG. 2, the seam typically has a width of approximately 1 inch on a belt 16 to 18 inches long depending on roll diameter, material modulus or other parameters. Have. Also, the post and head pattern are formed from male / female punch cuts, each end is cut separately and joined sequentially, similar to the one used as a wallpaper stitcher that is manually rotated over the seam. Seams are formed with rollers to complete the mating characteristics of the puzzle cut pattern.

The two ends of the belt material are joined by physically being placed in a mating relationship with each other. this is,
Pressure is required to properly position or engage the mating elements. The adhesive material may be the same as or different from the material from which the belt is made and can be selected from the materials mentioned above. Typically, it is a thermosensitive thermoplastic or thermosetting material. Chemically and / or physically bonded to the belt material. Also, the chemical and / or physical bond between the adhesive and the belt material may be affected by heat and / or heat after the adhesive is applied.
Alternatively, it can be formed by applying pressure.
In certain applications, heat and pressure are simultaneously applied to at least soften the belt material and the compatible adhesive material 17 (see FIG. 7) to fill the groove and form an adhesive bond with the belt material. Impulse welding can be applied. In this regard, it is important that the heat applied does not exceed the heat that melts or decomposes to form and break the seam. Other heat sources include conventional heated rolls, simple heated irons, ultrasonic welding, or two roll heated nips (providing a combination of heat and pressure).

Preferably, the applied adhesive material has a thickness that provides an amount of adhesive to fill the groove space between the two sides of the puzzle cut seam member. In this regard, it is possible to first apply heat and then pressure to the seam of the belt material and the adhesive, but forcing the softened adhesive into the groove or space between the two sides of the puzzle cut seam member. It should also be noted that in order to do so, it is still under softening conditions. The applied pressure should be sufficient to fill the groove and minimize the thickness of the bonded joint. This process obviously provides a physical bond between the belt seam material and the adhesive material, but may also provide a chemical bond. A typical example of this is when the belt material is polyimide and the adhesive is polyimide.

Following manufacture, the belt is finished by buffing or polishing with abrasive grains, and typically has a thickness of 0.0.
A 01 to 0.003 inch topcoat is applied. This can initially be applied to the unsealed belts, the belt seams, and the back seamed areas of the belt from the back of the belt to preserve the uniformity of the functional surface.
Preferably, and also the most economical is to first form the belt seam and then apply the desired topcoat.

The seam belt according to the invention can be manufactured in an environmentally acceptable manner without the need for solvents. The adhesive is applied to the belt in any suitable manner, such as by application from a tubular applicator by squeezing or extruding, or by a spatula. Adhesive is applied to one or both sides of the groove or interstitial area, preferably its surface is smoothed to provide a smooth surface to the seam area of the belt.

The following example illustrates the assembly and testing of a seam belt with multiple puzzle cut seams in accordance with the practice of the invention.

[0036] Using the example die cutter, a polyimide material of one inch wide by mechanical cutting, node radius and about 0.7 to about 0.5mm
A center-to-center spacing of 0 mm was provided. Next, both ends of a 1-inch wide polyimide material piece were fitted together and rolled with a roller to flatten the seam. Impulse welding machine (Model No. 24 from Vertrod Co.)
It was placed in the lower jaw of H / HT1 / 4). The previously bonded seam is then centered on the webbing material and then heated at about 350 ° F for about 20 seconds with light pressure to melt the polyamide web material into the seam region. It was While leaving the seam on the lower jaw of the impulse welder, then mask both sides of the seam with conventional masking tape, extrude the bead of polyimide adhesive into the area formed by the masking tape and let it flash for about 15 minutes. After stripping off the solvent, the masking was removed. The impulse welder was retightened and the seams were heated at 350 ° F for 30 seconds for 2 cycles.
After seaming the impulse welder for 30 seconds, it was removed and post-cured at 400 ° F for 2 hours, then left at room temperature for at least 12 hours. Fourteen 12 inch long belts were tested on the flexure tester and all had flex cycles in excess of 750000, with nine samples exceeding one million cycles. The test was interrupted for nine belts that were flexed over one million cycles without causing belt failure. 25 mm with a 2 lb load
Samples were tested in a flexure tester at a process speed of 17 inches per second around a drum roller.

[0037]

Therefore, according to the present invention, a flexible endless seam belt which is mechanically indistinguishable and has substantially the same performance as a seamless belt is formed. Further, the seam belt is provided by joining two ends, each end being manufactured with a plurality of interlocking elements in a puzzle cut pattern. The puzzle cut patterns are mating in at least one plane to prevent separation of the ends. The seam is heated and the opposing surfaces flow into the groove. Alternatively, a compatible adhesive may be applied and heated to form the bond. Pressure may be applied to smooth the surface. The assembly process allows for precise placement of the mating elements, which facilitates assembly by simply engaging the two pieces together or filling the groove with an adhesive. Furthermore, the main advantage is that there is no height difference between adjacent parts of the seam, which introduces the difficulties mentioned above in connection with seam belts made by overlapping or abutting seams. In the case of seam belts made by overlapping or abutting seams, there are height differences or insufficient adhesion, which results in xerographic development and transfer,
Also, vibration noise occurs that affects ineffective cleaning of residual toner from the photoreceptor material (toner transferred from it), belt tracking and other features. Moreover, seams formed in accordance with the present invention are believed to provide excellent strength, flexibility and longer mechanical life.

While the above invention has been described with reference to particular embodiments, it is not intended to be limited thereto, and those skilled in the art will perceive variations and modifications within the spirit and scope of the claims. I will admit that it is possible.

[Brief description of drawings]

FIG. 1 is an isometric view of a flexible puzzle cut seam belt formed in accordance with the present invention that provides mechanically indistinguishable seams with substantially the same performance as a seamless belt.

FIG. 2 is an enlarged view of the puzzle cut pattern used at both mating ends of the belt material to provide a mating element having a post portion 14 and a larger head portion 16.

FIG. 3: Two of the belt materials to which the mating parts of male dies 18, 19 and female dies 21, 23 having curved mating elements are joined.
FIG. 8 is a view of another shape used for one end.

FIG. 4 is yet another embodiment in which the mating elements 30, 32 form a dovetail pattern having curved mating elements.

FIG. 5 is yet another embodiment in which the mating relationship between the puzzle cut patterns on both ends is formed from a plurality of finger joints 22, 26.

FIG. 6A, B and C are three views of the puzzle cut shape discussed above.

FIG. 7 shows, for example, that there is substantially no space between mating elements that have been die-cut or laser-cut accurately from two separate pieces of material, respectively, and that the cutting of one element is relative to the groove or space between the elements. It is the figure which expanded the scale which shows being compensated greatly.

FIG. 8 is a greatly enlarged view of the scale of the seam-shaped, very narrow groove 20 that is joined only by heat and pressure.

FIG. 9 is a highly magnified view of a belt seam 11 with grooves 20 filled with a belt compatible material shown in slashes.

[Explanation of Codes] 10 Belt 11 Seam 12 Roll 13 Male Fitting Part 14 Post or Neck 15 Female Fitting Part 16 Head or Node 17 Adhesive Material 18, 19 Male Part 20 Gap or Groove 21, 23 Female Part 22 Male finger 24 Fitting tooth 26 Female finger 28 Recess

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location // B29L 29:00 (72) Inventor Thomas C. Parker New York, USA 14617 Rochester Titus Avenue 1200 Apartment 1 (72) Inventor Lucille M. Scharf New York, USA 14534 Pittsford East Street 243 (72) Inventor Edward Elle. S screwer, New York, USA 14612 Rochester Glenside Way 53 (72) Inventor James G. Russell Jr. New York, USA 14450 Fairport Squallers Heath 72 (72) Inventor Robert M. Fegson New York, USA 14526 Penfield Penfield Road 2316 (72) Inventor Robert N. Finsterwalder New York, USA 14580 Webster Plank Road 1572

Claims (4)

[Claims] 1. A flexible endless seam belt formed by joining two ends of material from which the belt is manufactured, each end having a plurality of interlocking elements in a puzzle cut pattern. , The opposing surfaces are in mating relationship to prevent separation of the ends and form a seam when physically joined so that the flexible seam belt has a substantially uniform thickness To enable it to function essentially as an endless belt, said seams having a gap between the surfaces of the interengaging elements, and the opposing surfaces of the puzzle-cut pattern being joined together so that the flexible seam belt is essentially an endless belt. Flexible endless seam belt that allows to function as a. 2. The flexible endless seam belt of claim 1, wherein opposing surfaces of the puzzle cut pattern are joined by applying heat. 3. The flexible endless seam belt of claim 1, wherein the opposing surfaces of the puzzle cut pattern are joined by applying heat and pressure. 4. The flexible endless seam belt of claim 1, wherein opposing surfaces of the puzzle cut pattern are joined by an adhesive that is physically and chemically compatible with the belt material.