MXPA97005108A

MXPA97005108A - Sierra de autopropuls

Info

Publication number: MXPA97005108A
Application number: MXPA/A/1997/005108A
Authority: MX
Inventors: Michael G Kingsley; Kevin R Wilson; Donald F Meister
Original assignee: Diamant Boart Inc
Priority date: 1995-01-09
Filing date: 1997-07-08
Publication date: 2000-06-05

Abstract

A concrete saw is provided having a motor (2) aligned along a longitudinal axis of the saw frame to minimize the width of the saw and provide a more balanced system. A right-angled gearbox (60) is provided proximate the active side of a clutch assembly for transmitting rotational driving forces from the motor to a transversely aligned active shaft (58). The active shaft includes activated pulleys (70, 71) mounted on opposite ends there, which are aligned with active pulleys (172, 174) mounted on opposite ends of a blade support shaft (178) and linked together by multiple bands (144). , 14

Description

* 'SIERRA DE AUTOPROPULSION " FIELD OF INVENTION The present invention is related to a saw for cutting concrete, stone, asphalt and other similar surfaces and, in particular, with a self-propelled saw that uses a motor assembly in line with speed, and performance and control controls. improved depth. BACKGROUND OF THE INVENTION The present invention is described below in connection with the concrete industry only by way of example but is equally useful for cutting other hard surfaces. In the concrete industry, when they are built bridges, buildings, roads and other similar, it is often necessary to strain large horizontal plates of concrete. Once cast, it is desirable to mill the plate. Such milling action can include cutting joints completely through the plate (to form expansion joints and allow the foundation is moved), cutting slots partially into the plate (to create tension slots along which the plate will split), cutting multiple slots in the plate to create a high friction surface such as for bridges, grinding the surface the plate and the like. Several types of concrete saws can be used to carry out these milling tasks. In larger industrial applications, large self-propelled saws are used which are activated in a variety of ways, such as gasoline, disel, electrically, with propane and natural gas engines mounted on the saw. While performing the cut, the operator walks behind the saw to control the direction, cutting speed, depth of cut and the like. The concrete propulsion saws are mounted on rear-wheel drive and on an articulated front axle assembly which is hydraulically raised and the front end of the saw lowered. The front axle assembly includes a height adjustment cylinder which is attached to a front axle assembly having front wheels there. The front axle assembly pivots down and out of, and up and in, the saw frame when the cylinder extends and retracts by raising and lowering the saw in that way. The saw blade is mounted on a blade support shaft near the front of the saw, and therefore, as the front end is raised and lowered, the depth of cut is varied. When cutting a groove partially on the plate, it is desirable to keep the cut at a pre-established and homogeneous depth. Also when cutting extremely deep grooves or when cutting through very thick concrete, the concrete saw is unable to do it with a single pass.

Consequently, multiple passes are necessary within a single slot. Generally, it is desirable to remove an even portion of the concrete during each pass. Self-propelled saws have been proposed for concrete which use a depth stop mechanism attached to the front axle assembly. The depth stop mechanism includes a threaded rod that extends vertically between the front axle assembly and the control panel. The upper end of the rod includes a hook and the lower end 10 is threadably secured within a link to the front axle assembly. The linkage commands a depth at which the front axle assembly can lower the saw. As the operator screws the rod in one direction, the linkage moves outward and away from the frame to prevent the front axle assembly from ing off against the frame, thus establishing the depth of the cut. The conventional mechanical depth stop mechanism has met with limited success since it requires the operator to turn the rod a plurality of times in any direction to adjust the depth of the cut. This operation is time consuming and undesirable (usually, the operator must rotate the rod 13 times to vary the depth of cut by two inches). Additionally, the rod has proved that it is not reliable and has the tendency to fail as it becomes fatigued and vibrates during the operation until it breaks. Also, often the saw falls during loading and unloading and when it is moving to remove it from the edge of a concrete plate. The forces of shaking on the front tires are transmitted directly to the rod and, very often, they flex or break the rod. When the rod flexes, it is difficult to turn and this creates an unpredictable relationship between the number of _ turns of the rod and variation in the depth of the rod. In addition, the rod is subject to weather conditions Adverse and often rusty, which also results in difficulty for the rod to rotate. Previous concrete saws have also provided an indicator to measure the depth of the cut. These systems show the approximate depth of the cut in relation to a fixed reference point, namely, the surface ^ - of the concrete. The depth indicator system includes a lever arm that has one end attached to the front axle assembly and attached to a cable and pulley configuration that drives a dial indicator. The lever arm moves the cable around the pulleys, while the cable is tensioned by a spring. The pulleys rotate the indicator dial. However, this system has proven to be unreliable since the spring breaks and the cables slip on the pulleys. This system also requires a direct path between the quarter and the lever arm for the cable, which further complicates the design of the system. Self-propelled concrete saws include a gasoline, disel, propane or electric motor aligned along an axis transverse to the longitudinal axis of the saw frame. This cross-section aligns the crank axis of the motor parallel to the axis of rotation of the saw blade, to allow a simple design for interconnecting the pulleys on the crank shaft and the saw blade. t "However, this transverse alignment of the engine limits the physical size of the engine that can be practically used since the length of the engine is limited by a maximum acceptable width of the saw to allow the saw to pass through the opening. of the door (eg 36 inches) In addition, the driven motors are typically de-balanced between the front and rear ends (to which • ^ is also referred to as the fan end and the drive end). Therefore the concrete saw receives an unbalanced motor load across its width. Additionally, some types of engines include one end of heavy drive (close to the crank shaft) while other types of motors include a heavy fan end (next to the fan blade). Each concrete saw must be balanced and therefore must be designed to compensate for the unbalanced load of the engine. Consequently, the concrete saws that use the first type of motor are unable to be used with the second type of motor and vice versa. During a cutting operation, the concrete saw is supported on the rear wheels and the saw blade in a triangular support pattern. The blade of the saw and the diagonally opposite rear rim form a hypotenuse of the triangular support pattern. The shims of the saw cross this hypotenuse in a direction ordered by the lateral position of the center of gravity. As an example, when the blade is mounted on the right side of the saw and when a motor having a heavy drive end (near the left side) is used, the saw shims cross the hypotenuse of the support triangle to the left side of the saw. the saw (moving away from the other rear wheel of support). Divergingly, when the blade is mounted on the right side and a motor having a heavy fan end is used, the saw shims cross the hypotenuse towards the right side of the saw (towards the other rear support rim) . When the shims of the saw cross this hi-potenusa away from the rear support wheel, this bends the blade, induces the lateral tension there and causes the center of the blade to crack, all of which shortens the life of the blade . Therefore, it is extremely important to design the saw in such a way that its lateral center of gravity is located on the side of the triangular support pattern adjacent to the rear wheels. Previous systems have faced this situation by including a torsion bar support system within the frame or by placing excessive weight close to the base of the triangular support pattern (i.e., close to the rear wheel remotely positioned with respect to the hypotenuse). However, once the saw is balanced for a particular type of motor and for a saw blade mounted on one side of the saw, the saw is not modified in any way. simple to mount the blade on the opposite side. As noted above, the saw is balanced to locate the center of gravity on the side of the triangular support pattern of the hypotenuse close to the saw blade and the rear wheels. Once the blade of the saw moves to the side opposite, this modification changes the triangular support pattern in such a way that the hypotenuse extends there between the new position of the saw blade and the diagonally opposed rear wheel. However, moving the blade of the saw does not deviate the center of gravity. In contrast, the hypotension of the triangular support pattern is shifted to the side opposite the center of gravity such that the shims of the saw cross the hypotenuse in a direction away from the rear support wheel. Therefore, when the blade of the saw moves to the opposite side of the saw, the saw becomes unbalanced and shortens the life of the blade due to the stresses Le? A.1 ou, to dob im i cnl Or, the < -tia i team i nLo and ÜUOII LIIIÍ ncu. This unbalanced arrangement also causes the saw to cut crooked, causing the blade to wear unevenly and make it more difficult to handle the saw. 5 Additionally, the above balancing problem prevents the use of different types of motors with the same saw frame. As explained above, changing the type of _ motor similarly moves the center of gravity laterally to ^ P through the saw and through the triangular support pattern of the hypotenuse. As a result, saws that have transversely aligned motors operate optimally with only one type of motor and with the saw blade mounted on a predefined side. Any variation of this basic design results in an unbalanced saw and shortens the life of this one by so much. In addition, the transverse alignment of the motor has prevented conventional saws from adequately isolating the motor vibration from the saw blade. The vibrations of the motor, when transmitted to the blade of the saw, cause the blade to vibrate in a similar manner which induces shaking, high intensity impact loads between the blade and the concrete surface. These impact loads cause the diamonds inside the blade to crack and splinter, thus shortening the life of the blade. On the move, the motors have been mounted on mounting blocks of « ? rubber in an attempt to dissolve the frame motor of the concrete saw, and therefore of the blade of the saw. As noted above, the crank shaft projects from one side of the concrete saw. The pulleys are provided on the external end of the crank shaft and on the support shaft of the saw blade. Once the bands are taut, a substantial bending force is induced on the driving end of the crank shaft and on the end of the supporting shaft of the next blade. to the pulley. This bending force, in combination with the unbalanced weight of the motor, requires the use of extremely rigid motor mounting blocks near the drive end of the motor and the assembly of the belt and the pulley. As the hardness of the mounting blocks increases, the ability of the block to suppress vibrations. As a result, hard blocks provide little vibration suppression. Therefore, unbalanced load of the motor across the saw's width Prevents the use of assembly blocks of the appropriate type, which would effectively isolate the vibrations of the blade motor of the saw. The effectiveness of the mounting blocks in this unbalanced environment is further reduced by the fact that the assembly of the belt and the pulley induces a substantial bending force on the drive end of the belt shaft. This bending force creates an unbalanced force on * the mounting blocks », where» the mounting blocks undergo vibrations in a substantially cutting direction (ie, across the width of the blocks). The mounting blocks operate optimally when the vibration forces are directed directly into the block (in a compression direction), and are not designed to suppress vibrations induced in a lateral or cutting direction. The effect of bending on the crank shaft also reduces the life of the engine. Generally, the engines are designed with lightweight shell-type bearings to support the crank shaft. These shell-type bearings are not designed to, nor are they capable of providing substantial lateral loads (ie, load forces in a direction transverse to the axis of rotation of the crank shaft) throughout of a substantial period of time. Consequently, conventional saws required the use of engines containing coji¬ * netes specially designed in order to provide such lateral loads. Alternatively, when the engines are used with lightweight shell-type bearings, a additional bearing assembly next to the drive pulleys to be able to provide additional support against lateral loading. These conventional systems have proven to be undesirable as they increase the cost and complexity of the system. Moreover, conventional engines have experienced a reduced life since the bearings of these fail prematurely. Additionally, the life of the pulley and belt assembly is further reduced by the fact that the belts flex the crank shaft and the blade support shaft until the pulleys run unevenly. This uneven alignment causes the innermost band to be more taut than the outermost band, thus causing uneven wear in the bands. When loading the bands unevenly, the conventional belt and pulley assemblies were less efficient in transferring motor power 10 to the blade axis. As the number of bands increases, the uneven load between them increases in a similar manner and therefore the conventional belt and pulley assembly was limited in the number of bands to be used. 15 The concrete saws mount the support shaft of the saw blade in rotating bearings located in the lower part of the saw frame. These bearings are subjected to difficult operating conditions because they are constantly subjected to the concrete and to the gouges emitted from the cut. Past bearing bearings have been unable to properly seal the bearing from the environment. The concrete saws of the past have been unable to protect these bearing pads from the concrete paste that wears the seals 25 of the bearings and causes failures.

These co-ordinate systems require daily lubrication to purge contaminants. However, even with daily lubrication, these bearings have a very limited life time. The life of the bearings is further reduced by the uneven load created by the belt-pulley assembly located at one end of the blade support shaft. In the past, saws for concrete t have been proposed using a gearbox near the blade of the saw and along one side of the frame adjacent to the motor transversely aligned. Conventional gearboxes include an output shaft that hooks directly to the blade of the saw. However, these conventional gearbox designs place the gearbox immediately adjacent to and around the axis of rotation of the gearbox. saw blade. Therefore, the gearbox, if it becomes too large, interferes with the available depth of cut because the frame of the gearbox comes in contact with the concrete surface if the saw is lowered completely. To avoid such interference, the gearbox is kept small or replaced with a pulley. However, as the gearbox reduces in size, it is less able to dissipate heat and overheats easily. To reduce the temperature inside the gearbox, cooled gearboxes have been proposed with water. Gear boxes cooled with water circulate water through an exchange! from water to oil. However, the oil inside the gearbox still experiences extreme temperatures as it passes through the gears. In fact, the lubricant inside the gears can be fired at a temperature of up to 270 ° at the point of contact with the gears, even if the remaining oil reservoir has cooled to approximately 180 °. When the oil lubricant is fired at this extremely high temperature, its chemical compound decomposes reducing this way the life of the gearbox. Additionally, it is often desirable to perform a dry cutting operation in which a separate water source is not necessary to sprinkle water on the blade (water is used during wet cutting to cool the blade and to remove the concrete particles from the cut). The dry cut -ají is desirable to avoid water lines and the extra water treatment equipment used in the wet cutting operation. However, the advantage of reduced equipment is obviated when using a gearbox cooled with water and that the water reservoir and water lines should be used with the gearbox. The saw motors also experience overheating because the motor is cooled either with air or when cooled by a radiator that is located along one side of the saw frame and exposed to conditions of "adverse operation." which tend to cover the radiator. The above saws also provide the opening for the fuel tank at an intermediate point along the tank. Generally, when fuel is added, the saw is in an elevated position thus tilting the fuel tank in such a way that the opening is at an intermediate height inside the tank. Therefore, the fuel tended to spill once it was filled. Also, conventional fuel tanks draw fuel from the tank through an opening in the bottom of the tank through a fitting and a hose. Therefore, when the fit or hose drips, the tank empties. When you use an opening in the bottom of the tank you also take out extraneous material from the tank with the fuel. 15 Additionally, conventional combus¬ systems ? They use a gauge located inside the fuel cap of the tank. The caliber included a dial connected to a rod that extended into the tank and had a float at its lower end. The rod to rotate the caliber of fuel depending on the position of the float. However, a hole was required inside the cap between the fuel tank and the gauge to admit the rod. The fuel tended to splash the caliber around the rod. Additionally, air was allowed to enter the fuel tank around the rod.

The conventional concrete saws use a mechanical regulator to control the RPMS (revolutions per minute) of the motor and the blade of the saw. Each type of saw blade operates at a different optimal rotation speed. The optimum speed for a given blade is achieved by adjusting the regulator to direct the motor to rotate at a corresponding speed. ^ Mechanical regulators are usually controlled ^ by some form of polarization force, such as the one can provide a spring, to control the regulator. The polarization force is adjusted to adjust the speed of the motor operation. Therefore, the polarization force that controls the regulator is changed each time the blade type is changed to one with a different rotation speed.

These changes were annoying and time consuming. Additionally, operators improperly manipulate the mechanical regulators during their use since the mechanical regulator is very accessible to the operator. Normally, the regulator is set to operate the engine at an optimum level of RPM for a given type and size of blade. While the manufacturers set the regulator to reach the optimum RPM level, operators often set it to increase the speed of engine operation (and therefore the speed of the blade). However, these operator settings may exceeding the optimum RPM level for the particular blade, thus causing an "over speed on the blade" and thereby shortening the life of the blade. Increasing the speed of the blade also places the saw in an unsafe operating condition. The risk of excessive blade speed is further complicated by the fact that most concrete saws are designed to operate with a plurality of saw sizes and are therefore capable of rotating at extremely high speeds . Improper operation of the regulator by the operator can also cause the engine to run at an unsafe RPM level. To convert between different blade sizes, the engine speed must be adjusted, in conjunction with the ratio of belt and pulley between the motor and the blade of the saw. In the past, the necessary adjustments were quite difficult and required that multiple components of the sierra be changed. In addition, the pre-assemblies of belts and pulleys provided a small speed reduction between the blade speed of the saw and the engine RPM level. As a result, the RPM level of the motor was set at the optimum RPM level of the saw blade. Generally, the optimum RPM level of the blade is below the optimum engine RPM level (ie, the RPM level at which the engine generates the maximum horsepower). Therefore, the motor can rotate more slowly with reference to its optimum RPM level and reduced horsepower.

Conventional concrete saws were not able to operate at an optimum engine speed because the pulley assembly offered little or no gear reduction between the saw blade and the motor. The driven pulley is placed on the blade support shaft of the saw near the blade of the saw. As the diameter of the saw blade pulley increases, it interferes with, and reduces the depth of cut available. To maximize the At the available cutting depth, small pulleys are provided on the blade axis, thus limiting the reduction of the cutting edge. gear between the motor and the blade. It is difficult to reconfigure conventional saws to reverse the direction of rotation between cuts downward (ie, with normal operations of cutting concrete or slit) and cuts upwards (ie, to clean an "open cut or slit and to perform grinding or grooving operations.) The cuts are cleaned to remove any excess cutting material before adding a base material. rubber or silicone, such as an elastomer to form a expansion joint (ie allow expansion and contraction due to temperature changes). The grooving and grinding operations use a cut up since the saw uses a stack of saw blades arranged side by side. These blades have a tendency, when is rotated in the downward direction, to drag or pull lp ñiocra h cpp forward sea! fast what you want. To avoid such drag, the blades are rotated in an upward direction, thereby creating a backward force pushing the saw backward. Self-propelled saws include drive wheels that push the routers or grinders forward to a desired capacity. Additionally, conventional saws that have a transverse alignment are limited in the amount of transferable energy between the crank shaft of the motor and the blade support shaft. As noted above, the saws are limited in width in order to pass through standard doors. The conventional saws connect the drive pulleys to the crank shaft and therefore the drive pulleys extend beyond the motor drive. The number of pulleys is limited by the width of the saw. The number of pulleys and belts dictates the amount of energy that is transferable between the crank shaft and the saw blade. The number of pulleys useful with the motor is limited by the width of the saw, and therefore the transferable energy to the saw blade is similarly limited. Additionally, conventional saws use a drive mechanism to move the saw which provides a unique gearing capability. The drive mechanism uses a variable speed hydrostatic pump and * motor that is adjustable in rotary speed and rotary direction. The hydrostat is connected by gears and a chain to the drive wheels. This conventional drive mechanism allowed the operator a single operating limit dependent on the combination of gears between the drive wheel and the motor. It is often desirable to operate the saw at a low ground speed, as when you are performing * Cutting deep cuts, where the electrical ground speed is adjustable in extremely small increments. At other times, it is desirable to operate the saw at high electrical ground speed, such as when shallow cuts are being made or when moving between cuts. The conventional drive mechanism allowed a only operating limit for electric ground speed. Therefore, when the operator wishes to change between velo¬ For low and high electrical ground, the operator must change the chain gears or pulleys on one or both wheels of the drive motor and drive wheels. To the When changing these chain pulleys, the operator was able to change the gear ratio and therefore the electric ground speed limit. This mechanical change took time and was not desirable. Additionally, the conventional drive mechanism maintained a linkage relationship between the drive wheels. and the drive motor at all times. EJ drive motor rotated in forward and backward directions and allowed a closed or stopped position. Consequently, the saw was immovable to the operator when the engine 5 was turned off. Moreover, the conventional saw used multiple control levers including separate levers to lift and < AJL lower the saw, move the saw forward and backward, and to activate and stop the saw. These control levers 10 proved difficult to use. Finally, the conventional saw offered little comfort for the operator since the saw was extremely noisy and transferred substantial vibrations to the operator through the control levers and the crank bars. Conventional sieves were particularly noisy due to IJU that the transversely aligned engine directed air and engine noise to one side that effectively surrounded the operator. A need exists within the industry for an improved concrete saw. It is an object of the present invention to satisfy this need and overcome the disadvantages experienced above. SUMMARY OF THE INVENTION In accordance with the present invention, a concrete saw is provided which is characterized by a motor mounted with its longitudinal axis extending parallel and in-line with the longitudinal axis of the concrete saw. This in-line configuration is arranged in such a way that the crank axis extends substantially along the central axis of the saw frame and parallel to the direction of the cut. The present in-line assembly allows the use of larger motors, such as water-cooled motors, since the length of the motor is not limited by the width of the saw. Larger motors translate into more productive cutting, longer saw life, less maintenance, less machine noise, less emissions and greater fuel efficiency. The speed of the motor is controlled by an electronic regulator which maintains the speed of the motor at one of a plurality of constant speeds desired by a speed selector switch which is set by the operator. These speeds may include an idle speed, a maneuver speed, and multiple predetermined operating speeds. The electronic regulator with the selector switch maintains a constant motor speed for any load and up to a maximum load thus providing a constant RPM speed (to maximize power, fuel efficiency and blade utilization efficiency) . The electronic regulator also prevents undue manipulation of the regulator fixing thus eliminating the over-speed of the blade to give greater security. The drive end of the crank shaft receives a drive assembly (which may include a clutch) and a right-angle gearbox directly there. The gearbox is located in the remote position of the saw blade and provides a double-ended driven shaft that extends from both ends across the width of the saw. Both ends of the gearbox shaft receive equally loaded gearbox pulleys with an equal number of belts that are attached to corresponding pulleys at opposite ends of the saw blade support shaft. The mounting of the right-angle gearbox di-vide the drive load equally between both sides of the saw, thus avoiding the induced bending loads on the crank shaft and thus extending the life of the motor, the life of the bearing and the life of the band. Similarly, loading the belts also allows more pulleys and belts to be used to transfer the drive force from the motor to the saw blade because the inner and outer belts are tensioned in the same way. These additional belts and pulleys maximize the transfer of power from the motor to the blade and increase the cutting power. Additionally, the even tension of the belts allows a longer * life to the belt, prolongs the life of the engine and the bearing and allows a consistent energy output. The present gearbox assembly also provides the ability to reverse the rotary direction of the blade from a cut 5 down to a cut up by simply rotating the gearbox by 180 °. The present gearbox is located in a , Remote position of the cutting area and therefore the size of the gear box does not interfere with the depth of cut available. Therefore, the present gearbox is sufficiently large in such a way that it does not require to be cooled with water. The gearbox also provides any desired amount of speed reduction thus allowing the motor and saw blade to rotate at different optimum speeds. By balancing the load of the an- terior form, the in-line configuration allows the saw to cut equally well with blades mounted on either side. a The opposite ends of the output shaft of the box gear includes tapered sections of stainless steel to receive the pulleys. These tapered sections allow pulleys to be removed quickly and easily. The gearbox is mounted on and separated from the motor frame by means of insulators. The opposite ends of the gearbox are charged in an equal manner, and therefore the vibration forces of the motor are directed directly towards the insulators. Therefore, these forces are effectively eliminated. By evenly distributing the load on insulators in direct compression, less rigid insulators can be used which in turn more effectively suppresses engine vibrations. The present gearbox and insulator assemblies prevent the transfer of vibrations to the frame and the blade of the saw which significantly lengthens the life of the blade, decreases the fatigue of the components, reduces engine noise and provides greater comfort to the operator Operator comfort is further enhanced by using a soft molded crank for the control levers and providing soft molded handle lugs on the lever bars. The support shaft of the saw blade is mounted, at opposite ends, to the frame through high performance bearings. A shell extends between the inner sides of the bearings to protect them from the environment. The outer sides of the bearings are located immediately adjacent to the pulleys which in turn protect the bearings from the dust and the concrete wash. The letters pulleys evenly the bearings. The bearing assembly provides multiple seals between the bearings and the environment to extend the life of the bearing.

The present concrete saw includes a two-speed transmission with a neutral position attached to the rear drive wheels. The transmission is activated by a hydraulic motor which is provided with oil flow by means of a variable speed reversing hydrostatic pump. A single control lever controls both the speed transmission and the volumetric flow rate of the hydrostatic pump as well as the direction of fluid flow. This high-performance transmission assembly provides a longer transmission life and allows the operator to easily switch from the high to the low limit (such as when deep and shallow cuts are being made) without changing the drive pulley chain. The neutral position allows the operator to move the saw with the engine off (OFF). A neutral safety conductor switch is also provided which prevents the engine from being started unless the transmission is in neutral position. A parking brake is provided to prevent the saw from moving if the transmission is left in a neutral position. Optionally, an indicator light is included to notify the operator when the transmission is in neutral position. A unique control lever is provided by which the hydrostatic pump changes from forward to reverse to form the control valve moving between the forward, middle and rear positions. The lever also changes the transmission between high levels, neutral and low when moving from side to side. Finally, the lever includes an oscillator switch that raises and lowers the saw. The present concrete saw includes a front axle assembly that is pivotally mounted at its rear end to the saw frame. The front or opposite end receives wheels to carry the front end of the concrete saw. The front axle assembly includes first and second cylinders attached there near their frame mounting pivot point. The first cylinder is controlled to rotate the axle assembly around its pivot point to raise and lower the saw. The second cylinder represents an adjustable hydraulic depth stop mechanism that prevents the front end of the saw blade from being lowered below a maximum depth of cut. This adjustable hydraulic stop cylinder is controlled by an adjustment / reset switch on the saw control board. The adjustment / reset switch opens a valve that is normally closed which allows a quantity of hydraulic fluid to be delivered into and captured within the depth stop cylinder. During the operation, the operator opens the valve and adjusts the height of the sieve, by means of the lifting cylinder, at a desired height. Once this valve is closed the depth stop cylinder will allow the saw to be raised, but lowered below the set depth. The saw of the invention also uses an electronic depth indicator which identifies the depth of the cut in relation to a variable reference point or ^ Resettable. The depth indicator is connected to a potentiometer connected to the front axle assembly. The potentiometer changes its resistance reading as the front axle assembly rotates. The depth indicator measures this resistance and indicates a corresponding depth. Once the user adjusts the depth stop mechanism to the desired depth, the user - similarly - readjusts the depth indicator by "zeroing" the sensor (using a second potentiometer) when the blade touches the cutting surface. The depth gauge can be attached to the transmission or to the hydrostatic pump to reduce the speed of the saw when the depth of the cut begins to decrease. Often, when the saw starts to move too fast, the depth of the cut decreases. The depth indicator senses this depth variation and decreases the speed of the transmission. Once the speed of the saw is resumed long enough, the saw blade returns to the desired depth of cut. The present concrete saw is further characterized by a medium radiator mounted on the fan end of the motor away from the cutting area. A mounted crank shaft fan allows low pass air flow that reduces the overall height of the saw. The fan is aligned to bring air from the rear end of the saw to the engine and blow hot air from the operator. This assembly also focuses the weight of the radiator on the frame and brings clean fresh air through the radiator. The radiator includes a wide fin spacing to pass dust easily. The fan is provided with reinforced nylon blades that minimize the effects of engine vibrations transferred through the crank axle. The nylon blade allows a ventilator mounted on a crank shaft while past systems mounted the fan on the water pump to prevent such vibration. A foam plate is provided on the inlet side of the radiator to collect the dust and particulate material that arrives there. The foam plate is provided with a hydrolith activator which collects the water from the air to more effectively retain the particulate material. The plate is easily removed and easily cleaned, thus eliminating the need to wash the fins inside the radiator, as is done with a high-pressure washer, thus reducing the risk of bending the radiator fins. This independent filtration plate increases the life of the radiator as well as its effectiveness. Additionally, a hood or hood is provided to place the motor inside it. The hood or hood reduces engine noise and includes vents on its front face. The fan directs hot air forward through the vents at the front end of the motor hood away from the operator, thus reducing noise.

# ^ Optionally, a hood can be provided ^ along the bottom of the frame making a transverse line there and located at a point along the length to prevent air circulation from the front of the saw returning below the saw and upwards by the radiator. A single hydraulic tank is used for the lift assembly and the hydrostatic unit for lower maintenance and higher reliability. A replaceable rotary filter is provided to collect the particulate material within the hydraulic fluid. The present concrete saw also includes a superior fuel collection system, thus reducing the chance of fuel leaking from the tank if the hose breaks. The filler cap for the fuel tank is located at the highest and front point of the fuel tank to prevent spillage and dripping fuel when the saw is raised. The fuel tank is surrounded by a sloping bottom side to maximize air flow and radiator capacity. A motor hood is included to reduce engine noise and protect it from the environment. The electronic motor gears are included for greater reliability, less leakage and less maintenance. An insulated handle bar system with ribbed handles is provided to reduce vibrations for greater comfort # operator. Replaceable collars are used to provide adjustable handlebars. A circuit breaker board 10 is provided to protect electrical components from overload. A battery acid drip tray is included around the battery to protect the frame and paint against corrosion. Battery cable assemblies are provided for greater safety and 15 better cable connections. & t Brief description of the drawings The objectives and features of the invention shown above are explained in more detail with reference to the drawings, in which like reference numbers 20 denote like elements, and in which: Figure 1 illustrates a raised side view of a concrete saw in accordance with the present invention when in the down position. Figure 2 illustrates a raised side view of a lower portion of the concrete saw of Figure 1 when in its raised position. Figure 3 illustrates a raised front view of the concrete saw of Figure 1; Figure 4 illustrates a side view of the end of the present saw with a portion thereof open to illustrate the drive assembly; Figure 5 illustrates a sectioned top view of # a right angle gearbox of a saw for concrete according to the present invention; Figure 6 illustrates a sectioned side view of an insulator and a mounting bracket for supporting the right angle gear box taken along line 6-6 in Figure 3; Figure 7 illustrates a planar top view of the front axle assembly with the lifting stop assembly and F depth, in conjunction with a sectioned top view of the transmission, taken along line 7-7 in Figure 1; Figure 8 illustrates a schematic diagram of the hydraulic system 20 used to control the lift and depth stop assembly of Figure 7; Figure 9 illustrates a sectional side view of an electronic clutch assembly that can be used in an alternative embodiment of the present invention; Figure 10 illustrates a perspective view of the control board with a side plate removed therein to expose the handle bar assembly; Figure 11 illustrates a sectional side view of the rear upper portion of the present saw showing the fuel tank; Figure 12 illustrates a schematic view of the control system for controlling the electronic regulator, the depth gauge and the automatic control mechanism pro¬ * foundation; Figure 13 illustrates a raised side view of the control assembly that connects the control lever with the hydrostatic pump; Figure 14 illustrates a raised side view of the control assembly that connects the control lever to the trans mission. Figure 15 illustrates a raised end view, as viewed from the rear of the saw, of the control assembly. connecting the control lever with the transmission; and Figures 16A and 16B illustrate alternate embodiments for the lift switch on the control lever. DETAILED DESCRIPTION OF THE INVENTION Figure 1 generally illustrates a concrete saw according to the present invention having a motor 2 mounted to and extending along the longitudinal axis of the saw frame 4. The driving end of the crank shaft actively receives a drive plate assembly 20 mounted directly thereon and on an operating end of the motor 2. A gear assembly 6 is mounted on the outer end of the plate assembly. 20. The gear assembly 6 provides a right-angle power coupling to drive a saw blade, whose external line is usually shown in dotted lines. A fan end of the motor 2 is activated by a blade of fan directly mounted on the opposite end 10 of the crank shaft. The fan blade (not shown) is placed near the radiator 12 to cool the motor 2. A multi-speed transmission 14 is mounted on the rear end of the frame 4 in activated engagement with the drive wheels 474 by a chain 470. The transmission 14 is activated by a hydraulic motor 18 (Figure 7) which is driven by a hydrostatic pump 15 (Figure 7). A depth control assembly 16 is mounted on the underside of the frame 4 to control the depth of a cut made by the blade of the saw. A control handle 7 and a control handle linkage 9 control the hydrostatic pump 15 (Figure 7), the transmission 14 and the depth control assembly 16. The remaining sections and subsections of the saw of the invention will be described with greater detailed below in relation to the corresponding drawings.

With reference to Figure 4, the gear assembly 6 and the mounting of the drive plate 20 securely mounted to the drive end of the motor 2 are described in greater detail. The drive plate assembly 20 includes a flywheel frame 42 securely mounted to the face of the motor along one side and securely receiving a plate from the gearbox 44, by bolts 45 along the external opposite face. The gearbox plate 44 is securely bolted to the frame of the gearbox 46 by bolts 47. A crank handle 8 is provided including a skid 22, mounted on an outer end, which rotates with the crank handle 8. during the operation. The skate 22 extends into the flywheel frame 42. A flywheel 24 is pinned to the skate 22 at the points 25. The flywheel 24 serves to balance the engine when in operation. The flywheel 24 includes a flat base 26 having a flange 27 extending from a rear side, to securely receive the skate 22. The base 26 includes an outer ring 28 formed with a stepped cross section. The flywheel 24 provides the inertial weight necessary to balance the rotation of the motor. The ring 28 includes a shoulder 30 in an intermediate passage around it for receiving a drive plate 32 which is there securely bolted. The shoulder 30 includes an external face 33 that extends outwardly to fit without play against the drive plate 32. The drive plate 32 is mounted to the flywheel 24 by bolts 34. The drive plate 32 includes a hole a through the center which receives a slotted coupling 36 of the drive plate extending there partially. The coupling 36 includes a skate 37 around its periphery having through holes for receiving rivets 5 securing the skate 37 to the drive plate 32. The coupling 36 includes a plurality of grooves that surround it from its inner periphery and extend therein. transversally. The slots slidably receive a splined shaft 40 from the gearbox 6. The slotted connection provides a direct drive connection between the gear assembly 6 and the flywheel 24. This slotted connection gives linear movement between the gear assembly 6. and the motor 2 to prevent k linear load transfer directly along the axis of rotation of the splined shaft 40. A pilot bearing 48 is received within a recess in the front of the flywheel 24. The pilot bearing 48 receives an end Smooth outermost of the splined shaft 40 for centrally locating the splined shaft within the flywheel 24 and carrying any lateral load of the splined shaft 40. The gearbox plate 44 assembles the gearbox 6 to the motor. With reference to Figure 5, the internal workings of «25 gear assembly 6 are explained in detail in relation to ^^ P this one. The gear assembly 6 includes a gearbox frame 60 having openings through the opposite sides and on the face. The gearbox frame 60 securely receives tapered support extensions 72 at their opposite sides 5. The splined shaft 40 includes a leading or trailing end 41 which is received within a bevelled spiral differential pinion 50. The support bearings 52 and 54 are located ^^ around the outer end 41 of the splined shaft 40 and on opposite sides of the pinion differential 50. Differential pinion 50 is engaged in a driven manner with a second bevelled spiral gear 56 positioned at a right angle of differential pinion 50. Second gear 56 is fixedly mounted on a driven shaft 58 which extends through the sides of the gearbox 60 and through the extensions of support 72. The beveled spiral differential gears 50 JJ and 56 provide a right angle transfer of the rotational force of the motor between the splined shaft 40 and the driven shaft 58. The beveled spiral design allows a right angle transfer of a high driving force at high speed while minimizing noise. The driven shaft 58 extends outwardly in both directions from opposite sides of the gearbox frame 60 and includes tapered sections 62 and 64 at their opposite ends. The driven shaft 58 is formed of a material of high resistance to stress resistant to corrosion, as ß ^ is stainless steel. The driven shaft 58 is rotatably mounted within the bearings 66-69 seated within trunnion recess boxes along the support extensions 72. The tapered ends 62 and 64 allow for easy removal and installation of the pulleys of the gearbox 70 and 71. When the pulleys of the gearbox 70 and 71 are removed, the user simply needs to "jump" and loosen the pulleys 70 and 71 of the tapered ends 62 and 64 of the * axis 58. Then the pulleys 70 and 71 fall easily from the driven shaft 58. The sides of the frame of the gearbox 60 are bolted 78 to the support extensions 72 and the force of the frame 60 mounted to the rear face of the gearbox plate 44 with the bolts 47. The gearbox allows a gear reduction amount to be reached between the engine speed and the L rotation speed of the driven shaft 58 when adjusting the diameters of the differential pinions 56 and 52. By providing an optional gear reduction, the gearbox is able to keep the engine at its optimum RPM level, ie as of 3000-3500 RPM while allowing the blade of the saw to rotate at an optional blade speed. The gear assembly 6 provides a mechanism for easily reversing the rotary direction of the saw blade. To do this, the plate of the gearbox 44 (FIG. 4) is simply separated and rotated about 180 degrees. In particular, to reverse the direction of rotation of the blade of the saw, the plate of the gearbox 44 is released from the frame of the flywheel 42 by removing the bolts 45. The bands are also removed. As the plate is removed from the gearbox 44, the splined shaft 40 is released by sliding it from the coupling 36. The frame of the gearbox 60 is rotated 180 degrees about the axis of rotation of the splined shaft 40 to reverse the direction of rotation of the driven shaft 58. The plate of the gearbox 44 becomes to be mounted in such a way that the splined shaft 40 engages again with the coupling 36. The bolts 45 are reinserted. By rotating the gearbox in this manner, an operator is able to convert between a hack-down operation and an up-cut operation. With respect to Fig. 3, the bra extensions 72 ^ B ^ include the upper and lower supporting flanges 100 and 102, respectively, which are located at opposite ends of the same extensions. The flanges 100 and 102 upper e The lower bearing members are located diametrically opposite one from the other at the respective ends of the box. The bearing flanges 100 and 102 include threaded recesses for receiving the mounting bolts 104. While the upper and lower bearing flanges 100 and 102 are the mirror image of each other, only the supporting flanges that face down ÜOII used at any time. The upper bearing flanges 100 are provided for use when the gear case 60 is rotated 180 degrees about the rotary axis of the splined shaft 40 (Fig. 4). The upper and lower isolators 110 and 112 are provided to effectively isolate the vibrations within the motor and frame gearbox 4. The gear assembly 6 is mounted, by means of the isolators 110 and 112, on a bearing 114 back of the engine that has external arms 116 extending in opposite directions and legs 118 which are directed downwards. As illustrated in greater detail in FIG. 6, the arm 116 of the motor bearing 114 is positioned in the middle of the upper and lower insulators 110 and 112. The upper insulator 110 is also compressed between the arm 116 and the lower bearing flange jfm 102. The upper insulator 110 includes an integral insulating collar 120. The insulating collar 120 includes a hole therethrough to receive a sleeve 126 around the bolt 124. Optionally, the insulator The lower 112 may be formed with the collar or both insulators 110 and 112 may include concentrically formed insulators. Similar variations can be used while insulators 110 and 112 provide a complete and continuous barrier of elastic flexible material between the arm 116 and the bolt 124 and the bearing flange 102. The bolt 124 is received inside the tubular sleeve 126 which extends through the holes in the upper and lower insulators 110 and 112. The sleeve 126 extends from the rim 102 to the flat washer 128. An enclosure washer 130 5 is provided adjacent to the bolt head 124 to prevent the previous one from being released. The insulators 110 and 112 are made of a resilient flexible material to absorb the vibrations induced thereon by the motor bearing 114 and the gear case 60. In this way, the insulators 110 and 112 prevent the transfer of vibratory forces between the flanges 102 and the arms J16. The sleeve 126 provides a rigid core by means of which the bolt 124 is pressed against the flat washer 128 at one end and against the shoulder 102 at the opposite end. Insulators are also used in the end of the motor fan between the motor and the frame. Returning to FIG. 3, the bearing 114 of the motor is bolted to the frame 4, by means of "L-shaped brackets 130 and pins 132 and 134. As illustrated in FIG. 4, the strips 118 they include holes through them aligned along a vertical axis L-shaped brackets 130 include elongated slots 136 which align with the holes to provide a through passage for receiving the bearing pins 132. The bearing 114 engine also includes projections 138 projecting forward on opposite sides # thereof. The shoulders 138 have threaded holes therethrough. The holes can receive the pins 142 by means of the thread. The bolts 142 can have their heads at the upper or lower ends while the bolts 142 firmly embed against the upper surface of the frame 4. The bolts 142, when engaged by means of the threading with the shoulders 138, function to tighten the bands and as safety stops to prevent the motor bearing 114 % descend below a minimum desired height. To adjust the tension in the webs 144 and 146, the pins 132 (Fig. 3) are released to allow linear movement between the legs 118 and the vertical portion of the L-shaped brackets 130. The pins 142 of vertical bearings are turned to cover the distance between the shoulders 138 and the upper surface 143 of the frame 4. Once the heads of the pins 142 Sk mesh with the frame 4, they lift the bearing 114 of the motor. Moving the motor bearing 114 in this manner moves the pulleys 70 and 71 in a similar manner and along a vertical path to tighten and release the webs 144 and 146. Once Since the strips 144 and 146 are sufficiently tight, the retaining pins 132 are tightened to prevent any further movement between the motor support 114 and the frame 4. A balanced force of tension is maintained on the opposite sides of the gear box 60 when adjusting couple • to bolts 142, loading, therefore, and equally to the pulleys 70 and 71 of the gearbox. By maintaining this balanced force, the load is directed evenly downward along opposite sides of the gear case 60 in a direction parallel to the longitudinal axis of the bands 144 and 146. This loading force is uniformly applied to the insulators 110 and 112, applying, therefore, compression loads directly along the longitudinal axes 148 and 150 (Fig. 3) of the insulators 110 and 112 and minimizing the shear forces applied thereto. Therefore, the insulators 110 and 112 do not have to be designed from a material sufficiently rigid to withstand the excessive shear forces. The insulators provide a characteristic of increased damping against vibrations, which is characteristic as their rigidity decreases. By using even loads, the damping ability of the insulation system increases. With reference to Figs. 1 to 7, the frame 4 is constructed of a pair of channel pieces 152 extending longitudinally and are secured to the opposite ends and at the intermediate points to transverse bearing brackets 156. The upper sides of the longitudinal pieces 152 and 154 and the bearing brackets 156 receive a flat mounting shell 158. The front corners of the helmet 158 (Fig. 1) include the recesses 160 that extend along opposite sides of the channel pieces 152. The recesses 160 provide a region of operation for the bands 144 and 146, and the pulleys 172 and 174 of the saw blade. Returning to Fig. 3, the lower sides of the forwardmost ends of the channel pieces 152 securely receive the blade shaft mounting bearings. The mounting pads 166 include flat upper surfaces with threaded holes that embed against the pieces 152 of the channel. The bolts 134 extend through the brackets 130 and the channel pieces 152 and are fixedly closed on the bearings 166. Each bearing 166 includes a housing around the sealed bearings 181. The internal seals 183 are surrounded with grease 185. The internal and external headers 165 and 167 are mounted to the housing by means of the bolts. The internal and external heads 165 and 167 are rotatably connected, by means of the flexible seals 168 with a shaft 175 of transmission of the saw blade. The shaft 175 of the blade is constructed of a stainless steel material and includes outer portions extending beyond the opposite ends of the external heads 167. The outermost portions of the shaft 175 of the blade extend beyond the bearings 166 and include the notched notches 170 extending longitudinally along the outer surface of the same shaft. The outer sections of the shaft 175 of the blade receive pulleys 172 and 174 of transmission. The pulleys 172 and 174 are held on the shaft 168 of the blade by means of tapered lock hubs 187. The internal heads 165 are enclosed between opposite ends of a flexible shield 178 and secured thereto, as with a hose clamp (not shown). The shield 178 prevents exposure of the sealed inner ends of the bearings to contaminants produced during a cutting operation. The shield 178 also prevents the user's clothing from being wrapped around the axis 168 of the blade. The shield 178 is formed of a semi-elastic material to maintain its shape during use. The outer seals within the outer flanges 167 of the seal are partially protected from environmental contaminants by the pulleys 172 and 174 although a slight air gap is formed between them. The pulleys 172 and 174 create B a "suspension effect" during the operation which tends to prevent contaminants from being collected near the seals within the external headers 167. Therefore, the pulleys 172 and 174 and the shield 178 protect and lengthen the life of the bearing seals. Referring to Fig. 9, an alternative embodiment for mounting 20 of the transmission plate where an electronic clutch is used is illustrated. The electronic clutch 220 includes a housing 42 which is mounted in a secured manner to the end of a motor with the crank shaft 8 extending within and through an opening in its front surface. The crank shaft 8 includes a rim 222 on its outer end that is bolted to the rear side of the flywheel 224 within an edge 227. In this alternative embodiment, the flywheel 224 is constructed differently since it includes an outer or forward planar surface having a slightly raised circular ridge 229 located concentrically with respect to the face and close to the portion * steering wheel center 224. Circular rim 229 receives springs 231 planes extending radially outward therefrom and mounted by means of the pins 233. The outer ends of the springs 231 are mounted securely to a disk 235 of the armature and form a ring having an inner circumference that it extends concentrically about the outer circumference of the circular edges 229. The armature disk 235 includes an armature engaging surface 237 which is directed away from the flywheel 224 and which is aligned immediately adjacent the corresponding grater surface 239 of the rotor on a disk 241 of the rotor. Rivet recesses 254 are provided within the armature disk 235 to secure the springs 231 to the disk 235. When disengaged, an air space 243 is provided between the adjustment surfaces 237 and 239. The disk 235 of the armature is mounted to the steering wheel 224 by means of the springs 231 to maintain a fixed rotational position therebetween. However, the flat springs 231 allow a longitudinal movement between the flywheel 224 and the armature steel disc 235 in a direction parallel to the rotary axis of the flywheel. This longitudinal movement allows the armature disk 235 to close the air space 243 when the armature and rotor adjusting surfaces 237 and 239 magnetically approach each other. Flat planes 231 normally tip the armature disk 235 away from the rotor disk 241 to maintain space 243 of air between the adjusting surfaces 237, 239 while placed in these remote positions, in which the disks 235, 241 of the armature and the rotor are allowed to rotate relative to each other. The disc 241 of the rotor is mounted in a secured manner on a coupling 236 of the transmission plate that extends along the core and through the center of the rotor disk 241. The coupling 236 is mounted securely on an input shaft 240 of the gearbox by means of a nut 242. Optionally, an grooved shaft and a coupling as in Fig. 4 or a serrated right axis and similar to this axis. An outer end portion 218 of the journal of the input shaft 240 is received in a secured manner within a pilot bearing 248 which rotatably centers the input shaft 240 with respect to to the steering wheel 224. The pilot bearing 248 is received within a journal recess close to the center of the flywheel 224. The disk 241 of the rotor includes internal and external rings 245 and 247, raised and concentric, located on the rear side thereof and spaced by a space. The inner and outer rings 245 and 247 receive a field coil 249 having a rectangular cross section between them. The rings 245 and 247 maintain a near extreme tolerance with the field coil 249. The field coil 249 is mounted and secured on the gearbox plate 244 with a mounting ring 217 interposed between the above. A hole through the gearbox plate 244 admits a power cable 252 for supplying power to the field coil 240. The power cable 252 is connected to a battery and to a switch located on the control panel of the saw. The switch enables the user to turn on and off the field coil 249 when switching between a first and a second position. Optionally, the switch can be adjusted with a braking mechanism once the clutch is misaligned when it is changed to a third position. When the user selectively applies energy to the field coil, the electronic clutch assembly 220 is adjusted and mismatched. In particular, when no current is applied to the field coil 249, the armature disk 235 is inclined, by means of the flat springs 231, to a position next to the flywheel 224 (as shown in Fig. 9) and away from the disk 241 of the rotor. When in this normally inclined position, an air gap 243 is provided between the armature and the rotor disks 235, 241. At this time, the handwheel 224, which is driven by the crank shaft 8, rotates freely without actuating the input shaft 240 of the gearbox. The user adjusts the saw blade when turning on the control switch, thereby exciting the field coil 249. Once energized, the field coil 249 induces a magnetic field through the disk 241 ^ of the rotor which attracts the armature steel disk 235 against the rotor disk 241. Once these surfaces are adjusted by means of friction between them, the disk 241 of the rotor is rotated with drive by the disk 235 of the armature, and therefore driving in a manner similar to the input shaft 240 and the saw blade. While the embodiment of Fig. 9 illustrates an input shaft 240 that is securely mounted to the coupling 236 by means of a nut 242, the electronic clutch assembly 220 can be implemented in a similar manner using the grooved configuration illustrated in FIG. Fig. 3. Optionally, a blade brake can be provided in combination with the electronic clutch to provide mechanisms to stop rotation of the saw blade once the clutch is disengaged. The brake of the blade may be included within the case 242 of the electronic clutch, within the frame 60 of the gearbox or along the axis 168 of the blade. For example, as shown in FIG. 9, the electronic brake can be provided around the outer periphery of the rotor disk 241 by including an extension flange 270 around the rotor disk 241 and which is integrally formed at that location. The extension tab 270 includes- # and an internal edge 272 that securely receives a second flat spring 274. The spring 274 is attached to the edge 272 by means of the bolts 276. The outer ends of the spring 274 are secured by means of the rivets 278 to a second disk 280 of the armature. The plate 244 of the gearbox includes the surfaces 284 and 286 which are adjusted by means of friction with each other to resist a greater rotation of the H disk 241 of the rotor. The raised tab 282 includes a hollow recess 284 therein that receives a second field coil 287 having the control cables 288. The control cables 288 are attached to the same switch used for control the electronic clutch. When the user turns the switch to a position that disengages the field coil 249 and engages the field coil 286, the field coil 249 releases the armature disk 235 while the field coil 286 attracts the armature disk 280. Therefore, the disk 241 of the rotor disengages the disk 235 from the armature while the disk 280 of the armature is adjusted with the outer flange 282. In this way, braking is carried out. Alternatively, a disc brake assembly may be provided along the transmission shaft 58 of the gearbox or along the axis 168 of the blade. As illustrated in FIG. 5, the disc brake assembly 800 may be located near the outer end of the driven shaft 58. The disk brake assembly 800 includes a brake 802 of • disk mounted securely on shaft 58 driven and is located near the tapered end 62 thereof. The disc 802 extends around the shaft 58 urged between the pulley 70 and the outer end of the holding extension 72. A brake housing 804 is located on the outer end of the plate 44 of the gear case and includes a camera 806 recessed therein, together with a slot 808 to receive the H disk 802. The recess chamber 806 includes internal and external brake pads 810 and 812 located immediately adjacent to and on opposite sides of the disk 802. The brake pads are mounted in a mobile way to the 804 box pads 814 actuator means. Actuators 814 may consist of electronic actuators energized by a remote source of 12 volts and connected to a brake switch located on the control panel. Actuators 814 may be constructed to extend when energized by the switch on the control panel. When excited, the actuators lead pads 810 and 812 of the brakes against opposite sides of disk 802 to establish an adjustment by friction between them. The switch that controls the disc brake can be included within a three-way switch, where the switch engages with the electronic clutch when in a first position, disengages the electronic clutch in a second position and engages the disc brake when it is in * a third position. Optionally, the disc brakes may be provided at both ends of the driven shaft 58. As another alternative, the brake assembly may include mechanical springs to normally tilt the brake pads toward an adjustment ratio by means of the friction with shaft 58 driven or with shaft 168 of the cuchi¬ «Í lla. When adjusted in this way, the pads would prevent the rotation of the adjusted shaft. The brake assembly will also include an unadjusted actuator, such as an electric, magnetic, pneumatic or hydraulic actuator for contracting fí¬ only to the mechanical springs and disengage the brake pad from the corresponding shaft. For example, if an electronic actuator is used, when the user turns on the control switch to adjust the electronic clutch, the electronic actuator disengages the brake by force disengaged.

Rotate the brake pads of the corresponding shaft. The electronic actuator would keep the brake pads in this disengaged position until the user turned the control switch to release the electronic clutch. When the clutch is released, the electronic actuator similarly releases the disc brake, thereby allowing the automatic spring to automatically tilt the brake pad against the driven shaft 58 or shaft 168 of the blade. This, in turn, automatically stops the rotation of the cuchi¬ • Mountain range. Alternatively, mounting the brake of the blade can be controlled from a separate switch provided to the user. Additionally, the electronic clutch assembly is controlled in such a way that the operator is only able to adjust the clutch when the vector selector switch speed is set at one of the slowest speeds of the machine. * machine (i.e., a speed in empty or speed of maneuver). This assembly prevents the operator from engaging the clutch when the engine is operating at the highest cutting speeds, making the system therefore safer. This characteristic security ca can be implemented in a variety of ways. For example, the clutch adjustment switch may be connected in series with a rotary speed sensor of the steering wheel. The handwheel detector will only enter a closed circuit state, thus connecting the switch of the electronic clutch with the same electronic clutch, * when the steering wheel is rotating below a maximum safety threshold (i.e., below a cutting speed of the machine). Alternatively, the electronic clutch can be connected to the micro-controller 950 (Fig. 12) and controlled by it, such that the electronic clutch switch only excites the field coil within the electronic clutch when the 950 micro-controller determines that the speed selection switch 606 is set at one of the speeds • minor values (i.e., in the empty speed array or in the maneuver speed arrangement). As another option, a series of relays can be installed between the electronic clutch switch and the electronic clutch field coil. These relays may be attached to conductors 953 and 951 to provide a closed circuit between the electronic clutch switch and the electronic clutch & only when the leads 951 and 953 indicate that the speed selection switch 606 is set to one of the first or second positions (i.e., in a vacuum position or in a maneuvering position). 20 Returning to Figs. 1, 2 and 7, the limit stop mechanism of elevation and depth is explained in more detail. The elevation and depth limiting stop mechanism 16 includes a front shaft assembly 302 formed as a rectangular shaped channel having pins 304 and 306 of front and rear pivots extending from the opposite sides thereof and which are positioned close to the front and rear ends thereof. The front pivot pins 304 rotatably support the wheels 308 that hold the forward end of the concrete saw. The rear pivot pins 306 are rotatably mounted within the bolted bearings 310 and secured to the underside of the frame 4. The bearings 310 are located at an intermediate point along the frame 4 to position the wheels 308 forward of the center of severity of saw for concrete. The front shaft assembly 302 also includes thrust brackets that are mounted between the rear pivot pins 306 and extend radially outwardly of the rotary shaft defined by the rear pins 306. The thrust mines 312-314 are positioned to extend upwardly at an obtuse angle with respect to the plane formed by the ? ^ W- surface of the front axle assembly 302. The push brackets 312-314 are pivotally mounted by means of the rod 315 to the lifting pads 316 and 318 of the cylinders 320 and 322, respectively. The hydraulic cylinders 320 and 322 include rearward ends mounted to the frame 4 by means of a pivot pin 324. The hydraulic cylinders 320 and 322 are energized by a hydraulic pump located at a position remote from them. The hydraulic cylinder 320 operates to raise the sieve. The hydraulic cylinder 322 functions as a limit stop mechanism of the depth to establish a maximum depth of a cut by the e of the saw. When the hydraulic cylinder 320 extends, the ram 316 drives the forward thrust brackets 312-314, thereby causing the front axle assembly 302 to rotate about the pivot axis formed along the rear pins 306 of the axle. pivot. As the front axle assembly 302 rotates about the rear pivot pins 306, the wheels 308 are driven downwards, thus lifting the front end of the concrete saw (Fig. 2). Divergingly, when cylinder 320 is contracted, the front tree assembly rotates in an opposite direction to lower the forward end of the concrete saw (Fig. 1). The cylinder 322 depth limiter stop is fixed in a controlled manner ^^? - to capture an established amount of fluid, defining, by means of this procedure, a maximum depth of cut previously defined. Returning to FIG. 8, a schematic of the hydraulic system used to control the lift and depth stop mounts is described hereinafter. An oil reservoir is generally illustrated at point 400 and supplies hydraulic fluid to a hydraulic pump 405 by means of a filter or sieve 302. The pump 405 is driven by a motor 404 DC which is controlled by an electro-oscillator switch located on the control lever 7 (Fig. 1). This switch includes an excitation plate which is generally designated by the reference number 532. The pump 405 delivers fluid to a node 408 communicating with a control valve 410. The control valve 410 may be set at any desired level such as, for example, approximately 2600 psi, where it opens when the pressure at node 408 exceeds the previously established level. When the fluid pressure exceeds the previously established level of the valve 410, the hydraulic fluid is returned to the reservoir 400 via the return line 412. From the node 408, the hydraulic fluid is transported to a check valve 414 which operates as a valve in one direction to transport the hydraulic fluid to its discharge side and to not allow a flow of hydraulic fluid in an opposite direction. The fluid from the check valve 414 flows through the node 416 from which the separated hydraulic lines 418 and 420 distribute fluid to the lift cylinder 320 and the cylinder 322 depth stop, respectively. The node 416 also connects to a second sieve or filter 422 which, in turn, connects to a normally closed control solenoid valve 424 and to a flow control safety valve 426. The flow control safety valve 426 determines a maximum flow rate at which the fluid can be re-drawn, via line 428 to tank 400.

• The control valve 424 is normally closed until it is energized by a contact plate 530 within the oscillator switch 514 on the control lever. When excited, it allows the oil to flow along the return line 428. During operation, when the operator rotates the oscillating switch to a lifting position, the switch 514 energizes the contact 532 and activates the motor 404 to drive the pump 405, thereby delivering hydraulic fluid. * lico to cylinder 320 of elevation by means of line 418 of supply. When the operator wishes to descend the saw, the oscillator switch 514 is lever controlled in an opposite direction (i.e. to a descent state) where a contact plate 530 is energized and the normally closed control valve 424 is opened. When open, the control valve 424 allows the hydraulic fluid to be discharged from the cylinder 320 and returned to the reservoir 400. A second flow rate control valve 420 is provided within the hydraulic line 418 for set the maximum flow velocity with which the hydraulic fluid is discharged of the lifting cylinder 320. The operator variably adjusts the flow rate control valve 430 to change the flow rate, thereby changing the speed at which the saw is lowered. The safety valve 426 for controlling the flow rate determines a maximum speed at which the cylinder 320 can collapse -F se, fixing, by this, the maximum descent speed. Returning to node 416, a second normally closed control solenoid valve 432 is provided within hydraulic line 420 to control the fluid flow of cylinder 322 depth limiting stop. The second valve 432 control solenoid normally closed is controlled by means of a switch 604 for adjusting and adjusting the depth located on the control panel. F As illustrated in Fig. 10, switch 604 of The depth limiting control includes a condition 608 adjusted and a condition 610 readjusted. When in the adjustment condition, the control switch 604 keeps the control solenoid valve 432 in an un-energized condition (i.e. in a closed condition). Therefore, when it is in the adjustment position, the control switch 604 prevents the flow of cylinder fluid 322 limit stop of the pro¬ ^^^^ fundity. In a divergent manner, when the control switch 604 is set in the reset position, it excites the control valve 432 thus allowing the flow of fluid along the line 420 to and from the depth limiting cylinder 322. During the operation, when a user wishes to adjust the height of the saw and fix the depth stop mechanism at a new height, the operator switches the depth limiting control switch 604 to its reset position, by exciting, by means of the above, to the control valve 432 and allowing the fluid to flow to and from the cylinder 322. Then, the operator uses the oscillator switch 514 on the control handle to raise and lower the saw, means of the cylinder 320. Once the desired height is reached, the operator operates the control switch 604 to the adjustment position with the lever, thereby closing valve 432 and capturing the previously defined amount of fluid within the cylinder. 322. When in this condition, the ram inside the cylinder 322 can extend, however, it can not be retracted beyond a length determined by the amount of fluid captured. inside it. By capturing fluid in the cylinder 322, the valve 432 adjusts the maximum depth of the cut. 15 Returning to Fig. 7, transmission 14 is activated? by a hydraulic motor 18 which receives fluid from a hydrostatic pump 15 by means of hydraulic lines connected between the ports 17. In the preferred embodiment, the motor 18 drives the rotary way to a two-speed transmission 14 at a variable speed in forward and reverse directions. The direction of transmission and the speed of the motor 18 are determined by the fluid flow velocity and the direction of the pump 15. The pump 15 represents a variable displacement pump., whose volumetric displacement varies as a control lever of the oscillating plate moves. A control cable 11 is connected, at one end, to the oscillating plate to adjust the position thereof and, therefore, control the flow velocity of the fluid and its direction. The opposite end of the control cable 11 is connected to the lever 7. A link rod 13 connects the transmission 14 and the control lever 7. As explained later in more detail, the movement of lever 7 of con¬ F trol along a first path (ie, forward and backwards) causes the movement of the control cable 11, thereby changing the fluid flow velocity and the direction of the pump 15. Therefore, the backward and forward movement of the control lever 7 varies the rotational speed and direction of the motor 18 and the speed with respect to the land of the sierra. As explained below, the tt movement of the control lever 7 along a second path (i.e., from side to side) causes the movement of the link rod 13, thereby shifting the transmission between gear ratios. high, neutral and low. By Therefore, by moving the lever 7 from side to side, the operator can change the amplitude of the speeds with respect to ground. Fig. 7 illustrates transmission 14 in greater detail. The transmission 14 is driven by the hydraulic motor 18 by means of an output grooved shaft 450 which is received in an operable manner within a grooved recess in a differential pinion 452. The motor 18 is mounted securely to the transmission case 454. The differential pinion 452 is constructed in tubular form with a grooved interior and an exterior of 5 gears and is received within the box 454. The transmission 14 also includes a gear train assembly 456 and an external gear assembly 458. The external assembly of en-.¿fc. The gears includes gears 460 and 462 large and small separated by a spacer 462 and mounted in a secured manner on an output shaft 464 that is rotatably supported between bearings (not shown). The bearings are supported within die recesses in the transmission case 454. The output shaft 464 extends through a hole in the transmission case to receive a drive gear 468 (Fig. 1) on the outside thereof. The drive gear B 468 meshes with a chain 470 (Fig. 1) which is securely received around a wheel gear 472 located close to the drive wheels 474 at the rear end of the frame. The assembly 456 of the gear train (Fig. 7) includes large and small gears 476 and 478 mounted securely immediately adjacent to each other in an embedment relationship. The assembly 456 of the gear train is received rotatably on an axis 480 of the gear train so that the assembly 456 of the gear train rotates about the axis 480 of the gear train and slides along the rotational axis thereof. Mounting 456 of the gear train also includes a flared part 482 of the end near one end of the assembly to form a slot 483 that receives a crescent-shaped end 484 located on the outer end of a sliding fork 486. The sliding fork 486 is constructed in an L-shape with the sliding end 484 at one end thereof and with a 487 box on the opposite end thereof to achieve a secure engagement with an outer end of a shaft journal. 488 sliding. The sliding shaft 488 is mounted in a secured manner, by means of a lever-action intermediate arm 489, to the lower end of the hinge rod 13 which is slidably controlled by a lever 9. When the user JBL moves the lever 9 in a transverse direction, the link rod 13 slides along its longitudinal axis by pivoting the lever action arm 489 about its pivot center point. As the arm 489 acts as a pivot, it drives the sliding axle 488 along its longitudinal axis. As the shaft 488 slides in this manner, it similarly moves, by means of the sliding jib 486, to the gear train 456 along its rotary axis and along the axis 480 of the gear train. According to the train 456 of gears slides along its rotary axis, it shifts between low and high amplitudes. While at a low amplitude, the small gear train 478 is positioned to interchangeably engage the major output shaft 460. While at high amplitude, the gear train is positioned such that the larger gear train 476 meshes with the small output gear 462. The larger gear train 476 maintains a drive gear with the differential pinion 452 through the ope¬ • ration despite its axial position along axis 480 of the gear train. The transmission 14 also includes a neutral position in which the gear train assembly 456 and the output gear assembly 458 are disengaged from each other. The 486 sliding gallows moves the train assembly 456 of gears to a neutral position when the gears 476 and 478 are located between and are disengaged from the gears 462 and 460. The transmission 14 also includes a safety neutral switch 490 which senses the position of the fork 486 as shown in FIG. crimps and transmits an electronic signal corresponding to the conductor switch. This signal indicates when the gear train assembly 456 is engaged with the output gear assembly 458. The safety neutral switch 490 creates an open circuit position within the electrical loop between the driver switch and the driver when the gears are engaged. F.sl to open circuit position prevents the driver from acting while the transmission 14 is in gear. The safety neutral switch 490 creates a closed circuit position between the conductor and the driver switch when the transmission 14 is in a neutral position. The transmission 14 allows the user greater flexibility with respect to the speed at which the concrete saw # is going to move. For example, when the operator is carrying After a deep cut, or a grooving or grinding operation, the transmission 14 can be placed at its low amplitude, while the pump 15 allows a fine-tuning adjustment of the saw speed. Once the operator completes a cut and wishes to move the saw to the next cut, the operator can move the transmission 14 to its high amplitude while maintaining control of the speed of the saw by means of the hydrostatic pump 15. . Optionally, transmission 14 can be implemented using a single-speed transmission with a neutral and a driver safety switch. When a single-speed transmission is used with a neutral, the control handle configuration is simplified to allow linear movement of the control handle along a single direction. As the control lever 7 moves to the along a single direction, the control cable 11 connected to F thereof controls the hydrostatic pump 15 as explained above. A transmission can also be included that offers more than two speeds, such as a three or four speed transmission, as long as the transmission includes a neutral and a driver safety switch. When a multi-speed transmission is used, the configuration of the control panel only needs to be modified to allow side-by-side movement of the lever 7 of con¬ F trol along a path sufficient to move between these gears. It will be understood that if a multi-speed transmission is used (such as a five-speed transmission), the control handle assembly can be modified to provide the displacement of the gears between such positions. j B Fig. 11 illustrates a sectional side view of the control lever 7 containing an electronic height control switch (also referred to as an oscillator switch) generally designated by the number 500 of reference. The control lever 7 includes a rod 502 with a top end securely mounted within the base 504 of the grip 506 of the handle. The grip 506 of the handle includes a chamber 508 withdrawn therein which communicates with the front surface 510 of the grip 506 of the handle by means of an opening 512. The chamber 508 and the opening 512 partially receive a switch. 514 oscillator projecting through the opening 512 and beyond the surface 510. The oscillator switch 514 is mounted on a pivot pin 516 which is secured, at opposite ends, to the grip 506 of the handle. The switch 514 includes a substantially circular cross section with a V-shaped notch 418 cut into the outermost section thereof. The oscillator switch 514 is hinged to a plate * 520 of support contact at point 522 located radially outwardly from its pivot pin 516. The support contact plate 520 is formed in a substantially rectangular cross section with the connection contact point 522 near the center of its forwardmost side. The support contact plate 520 is pivotally mounted to the grip 506 of the handle at point 524 near the center of its rear side. The support contact plate 520 and the oscillator switch 514 are inclined in an intermediate position (as illustrated in Fig. 11) where the points 516 and 524 of the vote and the connection point 522 are aligned to the along a common central axis. The support contact plate 520 includes the upper and lower contacts 526 and 528 mounted therein and extending along the upper and lower sides of the plate. The grip 506 of the handle also keeps the receivers 530 and 532 aligned in an embedding relationship with the support contact plate 520 and placed immediately above and below the corresponding upper and lower contacts 526 and 528. The support contact plate 520 is positioned in such a way that the upper contact region 526 is electronically adjusted with the receiving contact 530 when the plate F 520 of support is rotated upwardly around pivot point 524. Similarly, support plate 520 is located in such a way that the lower contact area 528 is electronically adjusted with the lower receiver contact 532 when the support plate 520 is pivoted down about the pivot point 524. During operation, the oscillator switch 514 can be pivoted about its central pin 516 in the upward direction (as illustrated by arrow 534 in a clockwise direction) or downward (as in FIG. it is illustrated by arrow 536 in the counterclockwise direction). When it is rotated in the direction of watch hands, the oscillator switch 514 causes the support contact plate 520 to rotate down around the pin 524 until the lower contact area 528 is adjusted with the receiving contact 532. Similarly, when rotated downwardly, the oscillator switch 514 ac- cesses the support plate 520 upwards until the upper contact 526 is adjusted with the receiving contact 530. Returning to FIG. 8, when the oscillator switch 514 is rotated clockwise (ie, upwardly), the contacts 528 and 532 are adjusted and, therefore, the motor 404 is excited and directed the pump 405 to supply fluid to the lifting cylinder 320. In this way, the cylinder 320 is electronically controlled for ask, lifting the concrete saw by actuating the oscillator switch 514 upwards. To carry out an operation In the descent, the oscillator switch 514 is rotated downwardly (i.e., counterclockwise) in such a manner that the contacts 526 and 530 fit together. As illustrated in Fig. 8, when the contact 530 is energized, it opens the normally closed control valve 424 allowing, by means of this action, the fluid to be discharged from the cylinder 320 along the lines 418 and 428 towards the reservoir 400. In this way, the hydraulic cylinder 320 is electronically controlled to lower the saw. As another alternative, the oscillator switch can be implemented as illustrated in Fig. 16. Fig. 16 illustrates the control lever 7 having an oscillator switch 1000 included therein with three conductors 1002 extending through a hollow channel inside the lever control. Switch 1000 includes a 1004 oscillator grip • within its outer surface that is normally inclined to a neutral mid position. The oscillator 1004 can be actuated by lever up or down to close a circuit between conductors 1002 that control an electric motor and a control valve (Fig. 8) to raise and lower the saw. Switch 1000 may be one commercially available from the Otto Controls company of Otto Engineering Inc. of Carpentersville, Illinois. Returning to FIG. 10, a portion of the control screen containing the depth indicator 600, a depth adjustment zero disc 602, the depth limiting adjustment / reset switch 604 and the 606 speed switch of the machine. The depth indicator 600 includes an analogous disc which indicates the actual depth of the cut that is being carried out by means of the saw blade with respect to a previously defined reference level. This reference level can be readjusted at any time during the operation of the actual adjustment of the saw blade by rotating the zero control 602 depth indicator. When the depth limiting mechanism is used to establish the maximum depth of a cut, the depth limiting adjustment / reset switch 604 is used. Adjustment / reset switch 604 includes a two state switch.

When in the adjustment state 608 (as illustrated in Fig. 10), the control valve 432 (Fig. 8) closes, thereby capturing an updated amount of fluid in the cylinder 322 depth limiting stop. . When it is desired to reset the depth control cylinder 322 to a different level 5, the adjustment / reset switch 604 is actuated by a lever to the reset condition 610, thereby exciting the normally closed control valve 432 and enabling the cfc. that fluid flows through it along line 420 (Fig. 8). This condition 610 of readjustment is maintained until the height control cylinder 320 is adjusted by means of the oscillator switch 514 to a desired height. Then, the adjustment / reset switch 604 is actuated by a lever to the adjustment condition 608 and the valve 432 is closed to capture an updated amount of fluid inside the cylinder. 322 depth limiter. When captured in this manner, this fluid prevents the cylinder 322 from retracting beyond its current position, thus preventing the front shaft assembly from descending beyond this level. It should be understood that cylinder 322 depth limiter stop will be while the control valve 432 is closed, since it will simply form a vacuum within the fluid chamber. Returning to Figs. 13-15, the control assembly for the control lever 7 is illustrated, and is generally designated for the reference number 700. This control assembly 700 includes a top surface plate 708 having an H-shaped pattern 710 cut through it and defining the control path of the lever 7. The control lever 7 can be moved within the pattern 710 control along a forward and reverse direction (as defined by arrow 712) and along a side-to-side direction (as delineated by arrow 714). The control lever 7 includes a lower end pivotally mounted at an intermediate point along a transverse support bracket 702. The support bracket is mounted on a pivot pin 704 secured at opposite ends of the mounting box 706. The pivot pin 704 has a longitudinal axis extending parallel to the direction of movement 712. The support bracket 702 allows the lever 7 to be moved from side to side along the arrow 714 as the bracket 702 rotates about the spigot 704. The control lever 7 is also mounted along its side to a strut 716 having a lower end pivotally mounted at the point 718 to an upper flange 720 of the support bracket 702. The strut 716 provides support for the control lever 7. The strut 716 and the control lever 7 have between them a half-moon-shaped guiding plate 722 which is mounted securely on the flange 720 and which extends upwards from there in relation to engagement with the lever 7 of control. A teardrop-shaped link 724 is mounted on an opposite side of the tip L / l 6 at point 718. The teardrop link 724 extends outwardly from the pivot point 718 to pivotally receive the pivot point 718. control cable 11 at its outermost 728 point. 5 The teardrop shaped link 724 is mounted and fixed along the outer side of the bracket 716, to maintain a fixed angular relationship between them permanently. This fixed arrangement causes the link 724 to pivot about 718, thereby driving the cable 11 forward and backward to along the arrow 730 as the strut 716 is pivoted about the point 718. This pivoting movement is caused by the handle 7 when the operator moves the handle along either side of the H-shaped pattern 710 in one direction parallel to the arrow 712. The support bracket 702 includes an inward extension in-fff 754 having a triangular shape and extending downwardly below the pivot pin 704. The extension 754 includes a flared lower end 756 that securely receives the coating for the control cable 11. The extension 754 includes a ball joint connector 758 on one side of the same extension. The ball joint 758 pivotally couples one end of a link arm 760. An opposite end of the link arm 760 is pivotally connected to the lever action arm 489. The arm 489 pivots around its point 762 central on a strut 764. The lower end of the ^ K arm 489 joins pivot axis 488 of displacement. As the lever 7 is moved along the path 714, the lower extension 754 pulls and pushes on the link arm 760 pivoting to the lever action arm 489. Lever action arm 489 directs linear movement within axis 488, shifting transmission between high, neutral and low conditions. In order to make the explanation clearer, F considers that regions 740 correspond to the movement of the saw for concrete while regions 742 correspond to the inverse movement of the saw for concrete. The regions 744 correspond to stop positions while the region 746 corresponds to the neutral position. During the operation, when a user wishes to move the forward concrete saw, the control lever 7 moves in one of the regions 740. When moved in this way, the link 716 rotates forward, causing the link 724 to rotate downward and push the cable 11. In In response to this action, the cable 11 directs the hydrostatic pump 15 to pump fluid in a direction necessary to rotate the motor in a direction corresponding to the forward movement of the saw. As the lever 7 is moved further forward from the stop position 744 to the forwardmost position 740, the volumetric displacement of the pump 15 increases, thereby increasing the forward rotary speed of the motor 18. from a limited position to a faster rotary speed. Similarly, when the operator wishes to move the concrete saw in a reverse direction, the lever 7 of control is moved to one of points 742. According to the lever 7 is moved in this direction, the strut 716 rotates with it, causing the link 724 to pull on the cable 11. As the cable 11 is jacked, it directs the hydrostatic pump 15 to pump the fluid in a direction to rotate to engine 18 in one direction corresponding to the reverse movement of the concrete saw. As the lever 7 is moved from the stop positions 744 to one of the reverse end positions 742, the cable 11 directs the hydrostatic pump to increase its flow rate, thereby increasing the speed rotary in reverse of the engine. In this way, the operator can move the concrete saw back and forth or keep it in a stopped position by moving the lever 7 from one of the points 742 to one of the points 740 or 744. The control lever 17, of similarly, it effects Displacement of transmission 14 between high, neutral and low limits by moving it laterally in the direction of arrow 714. As an example, region 748 may correspond to a high amplitude. When the user wishes to operate in the low amplitude, the lever 7 is displaced laterally to the area 748 of low amplitude, causing by means of this action, that the support mandrel 702 pivots in a clockwise direction (as seen in Fig. 15), which causes the extension 754 to push the link 760 downwards, by rotating the lever action arm 489 counterclockwise in the direction 5 (in Fig. 15) and by actuating the shaft 488 inwardly in the direction of transmission 14. Therefore, shaft 488 causes low-amplitude gears to mesh. Divergently, when the user wishes to operate at a high amplitude, the lever 7 is moved laterally along the direction 714 towards the region 750. This lateral movement causes the support bracket 702 to rotate in the opposite direction causing, therefore, , that the extension rotates in the opposite direction and pull the arm 760 upwards. The upward movement of the arm 760 rotates the lever action arm 489 in a clockwise direction (Fig. 15), thus pulling outward on the shaft 488 and moving the gears to a high amplitude . If the lever 7 is maintained in the neutral state 746, the link link arm 760, the lever action arm 489 and the shaft 488 move the gears in a neutral state. Fig. 10 illustrates control panel 850 which contains a raised rear surface 852 and front and rear walls 854 and 856, respectively. The front and rear walls include holes 855 and 857 through them to align with each other. The aligned pairs of holes are located on opposite sides of the front and rear walls 854 and 856. While only one side of the control panel is illustrated, the opposite side includes a similar handle assembly. Each pair of holes receives a hollow tube 858 from the handle that is stored and supported within insulators 860? . elastics. The insulators may be constructed of rubber or any similar elastic material. The insulators are recycled by fractions within U-shaped channel seals 862 having external flared sides. The flared outer sides of the detents 862 are mounted to the side panels in a fixed manner for the control panel 850 (the side panel has been removed for illustration purposes.) Once the detents 862 are fixed in a secure manner. To the side panels, the detents 862 are joined with the insulators 860 in a position that similarly squeezes the handle tube 858 against a linear movement. 860 are located in an embedding relationship with the holes 855 and 857 to seal them and in this way, prevent dust from entering the control board and the noise escaping. The rear end of each handle tube 858 receives a lock collar 864 therein. A set screw secures the collar 864 with the tube 858. The handle tube 858 has, in a slidable manner, a handle bar 866 at a rear end thereof. The 866 handle bar includes an elastic handle handle 868 on its rear end for the operator to handle and direct the saw. A lock pin 870 is received threadably within the collar 864 and 5 passes through a hole in the tube 858. The lower end of the pin 870 meshes with the handle bar 866 to hold it in a fixed position within the tube 858 of handle. ^ The handle assembly of Fig. 10 provides the user with adjustable steering knuckles that are insulated from the saw and the vibrations of the motor. The raised rear face 852 of the control board includes an upper surface 872 located above the control board and the rear face 852. The upper surface 872 includes a hole 874 therethrough which admits a Fuel tank filling 876 sealed with JB a fuel cap 878. Fig. 11 illustrates the placement and arrangement of the fuel tank in detail. A fuel tank 900 is located immediately below the control board 850 and crosses the distance between the front and the rear walls 854 and 856. The fuel tank 900 is mounted in place by means of a front support bracket 902 and bolts 904. The fuel tank 900 is formed in a trapezoid shape with a lower side 906 in the form of a ramp and with a bottom 908 well. The forwardmost end of the tank 900 includes a filling nipple 910, which is received as a seal within a lower end of a flexible hose 912. An upper end of the hose 912 is securely received within the filling spout 876 which is securely mounted to the upper surface 872 of the control board 850. The filling spout 876 ensures that the fuel filling point remains located above the fuel level at all times despite the fact that the saw is raised or lowered. The rear end of the tank The fuel receives a fuel drag tube 914 including an open lower end 916 that draws the fuel from the bottom of the tank. The tube 914 is supported by and attached to a fitting 917 that also connects to a fuel line (not shown) that delivers fuel to the engine.

The fuel tank 900 includes a float 918 J ^ - attached to a rod 920 which is supported by an electronic fuel level controller 922. The controller 922 delivers an electronic signal, through an electrical wire (not shown) to an electronic fuel gauge located in the control board 850. The upper outer surface 924 of the fuel tank includes a trough along its length extending between the rear and front ends of the fuel tank. The trough provides a passage for the fuel line and for the power line. 25 Fig. 12 illustrates the control circuits for the monitor, the depth indicator and the automatic depth controller. The electronic regulator system includes a microcontroller 950, the four-speed control switch 606, a rotary actuator 952 and a carburetor 954. The control switch 606 is connected to the controller 950 through the first and second lines 951. and 953, each of which outputs a high or low signal (eg, 0 V or 12 V) to identify the updated position of the 606 switch.

For example, when the switch is set to the first speed (1), both lines 951 and 953 emit a low signal. When the switch is set to the second (2) speed, the first control line 951 emits a high signal and the second line 953 emits a low signal. When the switch is set to the third speed (3), the second line 953 emits JB, a high signal, while the first line 951 emits a low signal. When the switch is set to the fourth speed (4), both lines 951 and 953 emit a high signal. The 950 controller receives these high and low signals and identifies the desired speed setting. Once the controller 950 receives a speed selection signal, it issues a control signal along the line 957 to the actuator 957 which directs the actuator 952 to adjust the setting of the carburetor 954. For example, the actuator 952 may be adjusted in a linear relationship with respect to the signal level from the controller 950 to effect the desired amount of variation within the carburetor setting. The controller 950 internally stores a separate actuator control signal for each combination of input signal on lines 951 and 953 from the selection switch 606, and outputs the corresponding actuator control signal based on the selection switch signal. incoming. The controller 950 includes a communications port to allow the controller to be reprogrammed periodically to adjust the positions of the actuator associated with each of the positions of the speed selection switch. In this way, the regulator can be reprogrammed as desired by the manufacturer or the distributor. However, the controller is only adjustable through this software communication link, thus preventing the operator from adjusting the carburetor. Fig. 12 further illustrates the depth indicator system including the depth indicator 600, the depth adjustment hook 602 and the depth sensor 958. The depth sensor 958 can be a potentiometer (i.e., a variable resistor) located on the front axle assembly, close to that of the axis of the pivot bolts 306. The depth sensor 958 is located in such a way that the resistance of the potentiometer varies as the front axle assembly rotates. This variation in resistance maintains a relationship with the • rotary position of the front axle assembly. The depth indicator 600 includes an ohmmeter that records the resistance variation through the sensor 958. As this resistance varies, the quadrant within the indicator 600 moves in a similar manner to identify the depth of the cut. The depth adjustment hook 602 can also represent a potentiometer connected in series with the indicator 600 and the sensor 958. The reset hook 602 can be varied by the operator to adjust the resistance recorded by the indicator 600. In operation, once the user adjusts the level of the saw to a desired reference level (i.e., ground level or drag with the bottom of a previous cut), the user rotates the reset hook 602 until the indicator 600 marks "Zero". As the hook 602 rotates, the resistance recorded by the indicator 600 varies until it shows a reading of zero. For example, the indicator 600 can have a maximum depth of cut when reading 0 ohms of resistance and a minimum depth of cut when reading 100 ohms of resistance. The sensor 958 can be configured to vary between a resistance of 1000 and 0 ohms, as the front axle assembly rotates between a zero cutting depth and a maximum cutting depth (which is presented on the indicator ,600). The resistance inside the depth reset button can be varied between 0 and 1000 ohms. Suppose an operator wishes to make a second pass through a 3-inch deep cut and remove an additional 3 inches of concrete during the second pass. First, the operator lowers the blade toward a 3-inch pre-cut. At this time the sensor outputs a resistance reading corresponding to a 3 inch cut (e.g., .700 ohms) and the reset hook 602 issues a resistance F minimum (e.g., 0 ohms). The 600 indicator reads 700 ohms which corresponds to a cut of 3 inches. At zero, the indicator 600, the operator rotates the hook 602, thereby increasing the output resistance thereof to 1000 ohms. Now the indicator reads 1Q00 ohms of resistance (i.e., 700 from the sensor and 300 from the hook) and has a zero depth of cut. Then, as the blade of the saw lowers, the sensor 958 increases its resistance output, thereby decreasing the resistance recorded by the indicator 600 which identifies a new cutting depth. Optionally, the depth indicator circuit can be implemented using a microcontroller and any other equivalent electronic circuit. Fig. 12 further shows a microcontroller 960 which performs an automatic depth control function. The controller 960 includes a converter 970 connected to the input drivers 961 and 963, which are connected in parallel F with the sensor 958. The converter 970 registers the resistance through the conductors 961 and 963 and outputs a signal representative of this resistance. The controller 960 reads the output signal of the converter to determine whether the cutting depth varies. The controller 960 is activated through a signal from the control switch on the control board. The controller 960 outputs an output signal to control an actuator attached to the control cable 11 to vary the displacement of the pump 15 and thus varies the ground speed of the saw according to the depth of cut. When the operator wants to activate an automatic depth control function, first, the operator adjusts the saw blade to the desired depth. After the The operator triggers the automatic depth switch on the controller 960. Once energized, the controller 960 records the updated signal from the converter 960 representative of the actual resistance value through the sensor 958. The controller 960 stores this signal as its signal reference and then continuously record the signal from the 970 converter. When the saw's ground speed exceeds the maximum speed at which the saw blade is able to maintain an updated depth, the saw blade begins to lift at a lower depth of cut. The front axle assembly moves in a similar manner, therefore, it adjusts the resistance through the sensor 958. This change in resistance is sensed by the converter 970 which emits a different output voltage corresponding to the controller 960. controller 960 reads the converter signal, determines that the reference signal is not equal and calculates a difference between the new converter signal and the inverter reference signal. Therefore, the controller 960 issues a signal to the actuator directing the actuator to adjust the control cable 11, therefore, it reduces the volumetric displacement of the pump 15 and retards the earth speeds of the saws. The 960 controller continuously registers the output of the converter and outputs a corresponding control signal of the actuator until the output signal of the converter equals the reference signal of the converter. In this manner, the 960 controller is capable of retarding the ground speed of the saw when the saw blade is raised above the desired cutting depth. The 960 controller increases the ground speed of the saw as soon as the blade of the saw descends to its desired depth. From the above description it can be seen that this invention is well adapted to achieve all the aims and objectives set forth above together with the other advantages that are obvious and that are inherent in the structure. 25 It should be understood that certain characteristics and combinations are useful and should be used without reordering other characteristics and combinations. For example, the characteristics of the depth limiter and the depth indicator can be used in any type of sieve to cut hard surfaces. This depth stop feature is not only for use with saws that have an inline motor arrangement. Additionally, the clutch and brake characteristics can be used in any type of saws even though the saw includes an in-line engine arrangement or the inventive depth stop feature. In addition, the inventive drive assembly includes the transmission with a hydrostatic and neutral pump that can be used with any type of saw despite an alignment of the motor, despite the mechanism of the depth stop and despite the fact that the saw Include an electronic clutch. Similarly, the inventive electronic regulator assembly with a multiple speed selection switch can be used in any type of saw, such as the gas tank, belt, and any other inventive feature. The versatility of the inventive characteristics is contemplated by and is recited within the scope of the clauses. In addition, it should be understood that the control panel will include additional control indicators, such as a calibrator electronic fuel, a tachometer, an oil pressure gauge, water temperature gauge, an amp meter, and their peers. In addition, the board may include an automatic 987 depth control switch. Because many possible embodiments of the invention can be made, without departing from the panorama thereof, all the information set forth herein or shown in the accompanying drawings should be understood. It should be interpreted as illustrative and not limiting. fifteen * twenty

Claims

$ NOVELTY OF THE INVENTION Having described the invention is considered as a novelty, and therefore, the content of the following clauses is claimed as property. CLAUSES 1. A saw for cutting hard surfaces, consisting of: a frame having a longitudinal axis of frame extending between the front and rear ends of said ar¬

1 »mazón and along a direction of a cut; a motor mounted on said frame and having a longitudinal axis of the frame aligned to extend parallel with said longitudinal axis of the frame; a saw blade mounted rotatably on one side of said frame and driven engaged with said motor; and control mechanisms to control a speed of the motor.

2. A saw for cutting hard surfaces, according to Clause 1, wherein said motor includes an electronic regulator to control the speed of rotation of the motor, said electronic regulator maintains a constant speed of 20 motor during the cutting operations and not cut; said electronic motor regulator eliminates the over-speed of the blade of the saw and prevents pulsations in the speed of the motor.

3. A saw for cutting hard surfaces, in accordance with Clause 1, which also consists of: a right-angle gear box, mounted by drive to said motor, to provide a right angle transfer of the Drive forces from the motor to the saw blade. 4. A saw for cutting hard surfaces, in accordance with Clause 1, which also consists of: a right-angle gearbox mounted by drive at one end of said engine; said gearbox includes a drive shaft • that is projected from the opposite ends of the same, Said drive shaft has drive pulleys mounted at opposite ends thereof along a common axis of rotation extending in a direction transverse to said longitudinal axis of the motor, wherein at least one of said drive pulleys gear by drive said 15 blade of the saw. 5. A saw for cutting hard surfaces, in accordance with Clause 4, wherein said saw blade is mounted on a saw blade support shaft having blade pulleys mounted at opposite ends thereof, 20 bands that by means of drive connect said pulleys of the gear box at both ends of said drive shaft to the pulleys of the corresponding blades at both ends of said blade support shaft to thereby provide the even load of said shaft of box drive 25 gears and said blade support shaft. # 6. A cuchi 1 The pair cut hard surfaces, according to Clause 1, which also consists of: a clutch assembly mounted directly to a front end of said engine, said clutch assembly includes a steering wheel to engage and selectively actuating said saw blade. 7. A saw for cutting hard surfaces, in accordance with Clause 6, wherein said clutch assembly includes an electronic clutch having a rotor disk mounted on said flywheel and having a meshing disk geared 10 by actuation with said saw blade, said electronic clutch selectively drives said saw blade when said rotor and said armature engages by means of friction with another. 8. A saw for cutting hard surfaces, in accordance with Clause 1, which further comprises: mechanisms of bands and pulleys which are mounted along axes of rotation extending in a direction transverse to said longitudinal axis of said motor, said belt and pulley mechanisms maintain the tension forces along both sides of said frame and along the opposite ends of said axes of rotation. 9. A saw for cutting hard surfaces, according to Clause 1, which also consists of a right-angle gearbox near a front end of said engine 25 to transfer driving forces from said motor to said saw blade, said gearbox includes output drive pulleys on opposite sides thereof, both of which are driven by engagement to said saw blade, said The gearbox is mounted on opposite sides thereof on insulators to minimize the transfer of vibration forces between said gearbox and said frame. 10. A saw for cutting hard surfaces, in accordance with Clause 9, wherein said insulators include elastic pieces of conical shape, each of which is mounted proximate to a lower flange of said gearbox, each insulator is sandwiched between said flange and a support piece on said frame. 11. A saw for cutting hard surfaces, according to Clause 1, which also consists of: a support shaft of the blade of the saw to rotatably support said blade of the saw, first and second bearings mounted on the sides opposite of said frame to rotatably support the opposite ends of said support shaft of the saw blade, a flexible cover extending between said first and second bearing and enclosing said blade support shaft of the saw to isolate said support axis of an operating environment. 12. A saw for cutting hard surfaces, according to Clause 11, wherein said supporting shaft of the saw blade also includes first and second pulleys driven on opposite sides thereof and along the sides opposite of said frame, both driven pulleys are driven by means of drive to said motor. 13. A saw for cutting hard surfaces consisting of: a motor and a saw blade mounted by drive to said motor, said blade of the saw effects a F cutting inside said hard surface for a desired depth of cut; a body to support said motor and blade 10 of the sierra; front and rear wheels to support said body; and a depth stop and lift assembly, securely mounted between the front tires and said body, including a first cylinder for raising and lowering a front end of said body and a second cylinder for 15 adjust a minimum height at which the said body descends, said minimum height corresponds to said desired depth of cut. 14. A saw for cutting hard surfaces, in accordance with Clause 13, wherein said stop assembly The depth and lifting also includes a front axle assembly having a front end that rotatably receives said front wheels and having a rear end articulated by means of pivots to said body, the first and second cylinders are mounted to said assembly of axis 25 front near said rear end to rotate said front axle • assembly over said rear pivot point to raise and lower the saw blade, wherein at least one of said cylinders is adjusted in a controlled manner to capture a Predefined amount of fluid to prevent the lowering of said saw blade below said desired cutting depth. 15. A saw to cut hard surfaces, from In accordance with Clause 13, said depth stop assembly includes a pump for driving said first and second cylinders through first and second supply lines, first and second valve mechanisms located within their corresponding ones. first and second supply lines, to interrupt the flow of fluid between said cylinders and said engine, and control mechanisms for 15 closing said second valve mechanisms to capture a desired amount of fluid within said second cylinder, thereby preventing said second cylinder from contracting beyond a previously defined level, while allowing said second cylinder to expand as directed by said second cylinder. first 20 cylinder. 16. A saw for cutting hard surfaces, in accordance with Clause 13, which furthermore consists of a depth limiting stop indicator to identify an updated depth at which said saw blade is descended, with respect to a level of previously defined reference, * said depth topo indicator includes mechanisms for readjusting said reference level to any desired depth. 17. A saw for cutting hard surfaces, according to Clause 13, wherein said depth stop assembly further includes an electronic switch, mounted on a control board of said saw, to adjust and readjust said minimum height for which said second cylinder will contract, thereby adjusting and readjusting said desired cutting depth. 18. A saw for cutting hard surfaces, consisting of: a motor mounted on a body; a saw blade, driven by said motor, to cut said hard surfaces, drive rims mounted on said body 15 to move said saw forward and backward; a "TBF transmission of multiple speeds with a neutral state, mounted by drive to and to drive said drive wheels, said transmission includes at least high and low speed limits, and a hydrostatic motor, mounted 20 for driving said transmission, for adjusting a speed and direction of rotation of said transmission. 19. A saw for cutting hard surfaces, in accordance with Clause 18, wherein the multiple speed transmission includes a gear train assembly that 25 includes small and large gears to reach the high and low F limits for such transmission. 20. A saw for cutting hard surfaces, according to Clause 18, wherein said hydrostatic motor is mounted in a secured manner through a false tongue connection, with said transmission, said hydrostatic motor being continuously adjustable between a static position, a maximum speed of rotation in a forward direction and F a maximum speed of rotation in a reverse direction, therefore provides continuous control of the speed of the 10 saw within the high and low limits. 21. A saw for cutting hard surfaces, in accordance with Clause 18, wherein said transmission includes a safe neutral ignition switch that prevents said engine from turning on when said transmission is engaged. 22. A saw to cut hard surfaces, from

4 according to Clause 3, wherein said gearbox is reversibly mounted on said motor in one of the two positions to provide rotation of said saw blade in any direction. 23. A saw for cutting hard surfaces consisting of: a saw blade and an engine mount to cut said hard surfaces; drive mechanisms for moving said blade and motor assembly forward and backward; lifting mechanisms for raising and lowering a front end of said blade and motor assembly; F and a single control lever to control said drive and lifting mechanism. 24. A saw for cutting hard surfaces, in accordance with Clause 23, wherein said single control lever is mounted on a control board and is movable within an H-shaped control pattern to control a speed and direction of movement of said saw, said pa¬ The control lantern changes said drive mechanisms between the high and low limits when it moves along a 10 first path, said control lever directs the forward and backward movement of said drive mechanism by moving said control lever along a second path perpendicular to said first path. 25. A saw to cut hard surfaces, according to Clause 23, wherein said single control lever directs and places the drive mechanisms in a neutral position when said control lever is placed in a neutral position. 26. A saw for cutting hard surfaces, according to Clause 23, wherein said control lever includes a lever action switch that is normally placed in a state in which said lifting mechanism maintains a leading end of said lever. blade and said motor assembly at a current level, said lever action switch 25 directs said lifting mechanism to raise "7 # and descending said blade and said motor assembly when said lever action switch rotates in an opposite direction. 27. A saw for cutting hard surfaces, in accordance with Clause 23, wherein said single control lever includes a first and second control rods, both are attached to said drive mechanism, said first control rod changes said control mechanism. drive between the high and low limits when said control lever is 10 moves along a first direction, said second control rod directs said control mechanism between the directions of rotation forward and backward, to move said motor assembly forward and backward, when said control lever moves along a second direction perpendicular to said first direction. twenty 25 AMENDED CLAUSES (Received by the International Bureau on May 17, 1996 (05/17/96) Original clauses 1-5 amended, remaining clauses, remain unchanged (2 pages)). A saw for cutting concrete consisting of: a frame having a longitudinal axis of frame extending between the front and rear ends of said frame and in a cutting direction; rims connected to said frame to movably support the frame on the surface to be cut to allow the frame to advance in the cutting direction; a motor mounted on said frame and having a rotating output shaft with a longitudinal axis extending parallel to said longitudinal axis of the frame; a saw blade mounted fixedly to said frame for rotation on said blade axis perpendicular to said longitudinal axis of the frame, wherein said blade of the saw is placed in a fixed relationship with said motor in said frame; mechanically driven linkage mechanisms interconnected with the output shaft of said motor with said saw blade to rotationally drive said blade; and control mechanism for controlling the speed of rotation of said output shaft of said motor and the speed of rotation of said saw blade. 2. The concrete saw according to Clause 1, in which said control mechanism includes an electronic regulator to control the speed and rotation of the shaft axis, output of said motor, said electronic regulator maintains a constant speed of rotation of said output shaft of said motor during the cutting and non-cutting operations, said electronic motor regulator eliminates the overspeed of rotation of the blade of the saw and avoids the pulsations in the speed of rotation of said output shaft of said motor. 3. The concrete saw according to Clause 1, wherein said mechanical drive linkage mechanism includes: a right-angle gearbox mounted on said frame and connected to said output shaft of said motor and said blade of the saw, to provide a right angle transfer of rotational drive forces from the output shaft of the motor to the saw blade, 4. The concrete saw according to Clause 3, wherein said right-angled gear box includes: a common axis of rotation extending in a direction transverse to said longitudinal axis of said motor output shaft and connected intermediate to the ends thereof with said axis of engine output; and a pair of drive pulleys mounted on the ends of said common axis of rotation, wherein at least one of said drive pulleys meshes with said saw blade.

5. The concrete saw according to Clause 4, which also consists of; a drive shaft of the saw blade mounted on said frame and extending in a direction transverse to said longitudinal axis of said frame for rotary transporting said blade of the saw, blade pulleys mounted thereon close to the opposite ends of said blade axis, and driven belts joining said two gearbox pulleys to their corresponding blade pulleys to provide an even load of said axis of rotation of the gearbox and said blade shaft.