Surface working apparatus

IS 2 174 283 T3

DESCRIPTION

Apparatus for working surfaces.

The present invention relates to a surface working apparatus and in particular, but not exclusively, to an apparatus for buffing, or otherwise polishing a surface, or for scrubbing, sweeping or otherwise cleaning a surface.

With reference to apparatus for working a surface, it is to be understood that the present invention relates to an apparatus for improving the appearance of a surface, for example by cleaning or polishing the surface. Examples of surface working apparatuses comprise cleaning or sweeping machines particularly adapted for use in cleaning or sweeping the floor space of commercial or industrial premises, such as supermarket floors or transport terminal concurrences. These machines can be called pedestrian driven because they are controlled by a pedestrian operator who controls movement across the ground surface or, alternatively, these known machines can comprise so-called vehicle machines, which support the operator during the cleaning process.

These known machines also traditionally comprise surface working head arrangements comprising brush heads which are inclined in contact with the surface to be cleaned at a particular pressure, which may be dependent on the nature of the surface being cleaned.

A known apparatus of this type is described in British patent applications 9518230.9, GK-2,283,905-A and GB-2,290,021-A, the contents of which are incorporated herein by reference.

These known apparatuses have advantages over prior systems in that the pressure at which the brushes are inclined towards the surface to be cleaned can be precisely controlled or varied over a relatively wide range and, in particular, towards the lower end of the range. rank.

However, the mode of operation of these known apparatuses still somewhat restricts the purposes for which the apparatus can be used, as the apparatus is restricted merely to surface cleaning activities and so on, if other cleaning activities are required. from the surface, on the surface that has been cleaned, or on a completely different surface, it becomes necessary to use a separate surface machining machine adapted for that particular surface.

Furthermore, US-A-4,910,824 discloses a surface working apparatus having a surface working head arrangement with means for selectively varying the speed at which the head arrangement is actuated.

The present invention seeks to provide a surface working apparatus that does not have the aforementioned restrictions, and other drawbacks, found in the prior art.

Following the present invention, a surface working apparatus is provided, comprising a machine frame supporting a motor driven surface working head arrangement, means for selectively varying the pressure exerted by said head arrangement. on said surface between at least a first value and a second value different from said first value, characterized by the fact that it comprises means to selectively vary the speed that said head arrangement is driven by said motor between at least a first speed and a second speed different from said first speed, and that it includes a plurality of selective gear arrangements having indices of transmission determined on the basis of required work operations, and control means arranged to limit operation at said first speed to operation of the apparatus at said first pressure value and to limit operation at said second speed to operation of the apparatus at said second pressure value.

By providing selectively variable speed control of the head arrangement in addition to selectively variable pressure control, the apparatus of the present invention is particularly advantageous in that it can be used for a variety of surface working operations, which they may include scrubbing and buffing. Scrubbing floors traditionally requires the operation of surface working heads, i.e. cleaning heads, at relatively high pressure and low spin speed, whereas buffing floors traditionally requires the application of surface working heads at high speeds. relatively high but at low pressures.

Preferably, the surface work head arrangement is adapted for mounting a plurality of surface work items, such as scrub brushes as commonly found in floor cleaning appliances and buffing brushes or pads, etc. as commonly found in floor polishing appliances.

Therefore, it will be appreciated that one of the same apparatus can be used to advantage for a wide variety of floor working activities.

In this manner, the surface working head arrangement is arranged for removably mounting a plurality of surface working elements, each having different surface working characteristics.

Preferably, the means for selectively varying the pressure exerted by the surface working head is arranged to alter said pressure in response to the use of said surface working head means exhibiting different characteristics.

As will be appreciated from the foregoing, two examples of these different characteristics may comprise those exhibited by a surface cleaning means, for example a scrub brush, exerted by a surface polishing means, such as a polishing head. or a polishing head.

Advantageously, the apparatus includes an actuator arrangement comprising spring means mounted to act as means for suspensions.

ES 2 174 283 T3, including means for pressing the surface work head arrangement towards a surface to be worked, tensioning means for tensioning the spring means to adjust the pressure of the surface work head arrangement, and wherein the spring means is wire tensioning means selectively adjustable over a continuous range to provide a required pressure towards the surface.

Furthermore, the apparatus may advantageously include pressure means acting between the frame and the surface work head arrangement to apply to the surface work head arrangement a selectable pressure towards the surface to be worked and mounted to act as a means. suspension between the frame and the surface work head arrangement, means to control and / or measure the applied work pressure, means for displaying an indication of the measured working pressure, means for the input by the operator of a desired working pressure for the arrangement of the surface working head and comparison means for comparing the operator's input pressure with the measured pressure and to generate a control signal in response to the difference between the desired pressure and the measured pressure, and means for applying the control signal to the voltage applying means.

Preferably, said means for selectively varying the pressure applied to the surface by the surface working head arrangement comprises pressure means acting between the frame and said surface working head arrangement, and comprising an actuator having a first element, and a second element that can be extended therefrom and whose actuator can also preferably be operated manually, hydraulically or electrically.

The biasing means may preferably comprise spring means which may also include at least one spring device that acts between a portion of the actuator and the surface work head arrangement.

In particular, the spring device may comprise a sleeve attached to said portion of said actuating means, a rod having an internal end slidable inside the sleeve, the rod projecting from the sleeve to the surface work head arrangement, and a spring located within the sleeve that engages the inner end of the rod.

Preferably, the apparatus includes an actuator arrangement for raising and lowering the surface work head arrangement and mounted between the frame and the surface work head arrangement, and means operatively connected to the shallow work head arrangement and arranged to at least partially counteract the force exerted on the shallow work head arrangement by the actuator when the shallow work head is lowered and to control the applied pressure. to the surface by arranging the surface work head in a range that includes zero pressure at a pressure corresponding to the weight of the surface work head arrangement.

Advantageously, the means for counteracting the force exerted on the surface working head arrangement by the actuator comprise counterweight means and, in addition to said means, may advantageously comprise elastic means.

In particular, the elastic means can be provided in the form of at least two elements movable relative to each other, which are arranged to move relative to one another in an elastic manner.

Preferably, the spring means may then comprise a cylinder / piston arrangement which may advantageously comprise a gas strut arrangement.

Furthermore, the elastic means can advantageously be provided in the form of one or more spring elements.

Furthermore, the means for selectively varying the pressure exerted by the surface working head arrangement may comprise an elongated balancing beam rotatably connected to the frame and connected at one end to the actuator for movement therewith, and taking into account the other end a counterweight mounted thereon.

In particular, the counterweight may have a mass that is arranged to be substantially equivalent to the mass of the surface working head arrangement.

The aforementioned balancing arrangement is particularly advantageous in providing a pressure arrangement that can be precisely controlled towards the low pressure end of the possible pressure spectrum.

The aforementioned means serve to counteract the force exerted on the surface to be worked through the actuator element, and the surface working head arrangement advantageously aids in precisely determining a net pressure to be applied to the surface to be worked particularly. in a range between zero and the weight of the shallow work head arrangement. It is particularly useful in the present invention as it enhances the variety of cleaning modes that can be adopted by the apparatus of the present invention.

Advantageously, the relatively variable pressure control system also comprises a link connecting the frame to the surface working head arrangement in such a way that the head arrangement was supported substantially horizontally. In particular, the aforementioned link may be in the form of a parallelogram link.

The apparatus also advantageously comprises means for determining the operational characteristics of the surface working head means such as those relating to the state of the head means and / or the actual pressure applied to the surface, so that said data can be used. in the rear control of the appliance.

Preferably, said apparatus also includes means for controlling and / or measuring pressure

ES 2 174 283 T3 applied, input means operable by an operator to select a desired pressure, comparison means to compare the design pressure with the desired pressure and to generate a control signal in response to the result of the comparison and means for applying the control signal to control the means for applying the pressure.

Advantageously, the feedback information provided by said control means for the brush pressure is also dependent on the desired operator input pressure, and in which the comparison means are provided to compare the measured pressure with the desired pressure.

Preferably, the comparator comprises an electronic processor and, furthermore, the display means can be adapted to display a digital value of the applied pressure.

The pressure measurement means may comprise any of a strain gauge, a pressure transducer, or a piezoelectric sensor. Furthermore, the apparatus may comprise means of analog or digital conversion to convert the input signals that represent respectively a measured working head pressure and a pressure chosen by the operator, storage means to determine the operating parameters of the system, and computing means programmed to compare the two input signals and to generate a control signal in response to the comparison and to predetermined operating parameters.

As thus appreciated from the aforementioned characteristics, means are provided to selectively vary the pressure exerted by said head arrangement on said surface to provide an accurate determination of the applied pressure, particularly at the lower end of the head. the possible pressure values, so that, In combination with the selectively varying speed at which the head arrangement can be driven by the motor, the apparatus advantageously provides a wide variety of surface work activities.

The means for selectively varying the speed at which the head arrangement is driven by said motor advantageously comprise a selective plurality of gear arrangements having drive onices determined on the basis of required work operations.

Preferably, said selectively switchable gears are located in a gearbox arrangement between the motor and the surface work head arrangement.

The gear arrangement preferably comprises respective pairs of gears in constant engagement and means for selecting one of said pairs to supply upward drive from said gearbox.

Advantageously, the means for selecting one of said pairs comprise clutch means that can advantageously be in the form of clutch means of one. Said clutch means of one of them can be particularly advantageous when two pairs of gears are provided in the gearbox.

The control means are provided to effect movement of the clutch arrangement, and these control means can comprise a solenoid actuator that can be retained in its two or more possible operating positions by means of locking means, such as locking means of solenoid.

The means for controlling the commutation in the gearbox is advantageously associated with the means for selecting the applied pressure by the shallow work head arrangement, so that the commutation of the gearbox is achieved in response to the selection of values. pressure values ​​above or below one or more limit values ​​or to the selection of specific values, or alternatively, the control arrangement may be such that the selection of any particular pressure range or value is responsible for the switching of the gearbox.

Thus, it was appreciated that the means for selectively varying the pressure exerted by the surface working head arrangement can be operated in response to the selection of the speed at which the head arrangement is to be driven by the motor. or, conversely, the speed at which the head arrangement is to be operated by the motor is altered in response to the selection of a particular pressure value, or interval, to which the head arrangement is going to be activated.

Regarding a particular feature of the present invention, that is, when the apparatus is arranged for both surface scrubbing and surface buffing operations, the higher operating speeds required of the surface working head can be easily achieved at lower pressures. of application of the surface work head element to the surface and, conversely, Lower operating speeds can be arranged to be achieved at higher pressures. This is particularly advantageous for the aforementioned surface work processes, since surface scrubbing is usually conducted at high pressure, for example 200 lbs, and low speed, for example 200 rpm, while surface buffing is usually conducted. at low pressure, for example 30 lbs, and higher speeds, for example 1,000 rpm.

To achieve operation at specific values ​​such as those mentioned above, the gear arrangement advantageously comprises a first gear pair with a 1: 1 ratio and a second gear pair with a 5: 1 ratio, so that the speeds mentioned above they can be easily obtained.

Advantageously, the control means are provided which serve to prevent the change in the gear mechanism, while the motor drives the surface head arrangement.

Furthermore, the control means advantageously places an upper limit on the pressure that can be applied by means of the head arrangement.

ES 2 174 283 T3 of surface work once the high speed transmission index has been selected.

Other control means may advantageously be provided to avoid the operational characteristics associated with the use of one or more of the particular surface work elements. For example, valve means may be provided to prevent the supply of water to the shallow work head arrangement when the apparatus is selected to provide a buffing operation.

Therefore, it will be appreciated that the present pressure advantageously provides a combined floor scrubbing / buffing machine.

The present invention is described below, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows a cross-sectional elevation view of a brush assembly for a surface cleaning / sweeping / polishing machine in front view;

Figure 2 is a perspective view of a machine that adopts the set of brushes of Figure 1;

Figure 3 is a schematic presentation of a control for the apparatus of Figures 1 and 2;

Figure 4 is a side view of the brush / pad pressure assembly of Figure 1, showing a control system, according to one embodiment of the present invention;

Figure 5 is a side view of the pressure assembly of the brushes of Figure 1, showing the control system of the present invention;

Figure 6 is a side view of a brush pressure assembly according to another embodiment of the invention;

Figure 7 is a side view of a brush press assembly according to another embodiment of the present invention;

Figure 8 comprises a circuit diagram showing another embodiment of the control means with the present invention; Y

Figure 9 is a cross-sectional view through an array of selectively drivable gears for use in selecting the speed at which the work head means of the present invention is driven.

In figure 1, the brush assembly comprises two spring tubes 1 containing springs 2. The right hand tube 1 in the figure is shown in section to represent spring 2. Each spring is attached at one end to the upper end of the tubes at 3 and at the other end to a spring rod 4 which slides through an opening 5 in the respective spring tube 1. The spring ways 4 are connected together by means of a bolt 6 and are fixed through the assembly 7 to the support plate of the brushes 8, to whose head or heads of the brushes 27 they are connected. The brush heads 27 are removably attached to the assembly to allow quick replacement of the buffing heads, or other heads, as required.

The tubes 1 are prevented from rotating or moving by a support plate 9. An actuator 10 is attached to a partition of a cleaning machine. Actuator 10 actuates actuator rod 12, which is shown in a substantially closed position in the figure. The rod of the actuator 12 is fixed by means of a pin 13 to an actuator plate 14, which is fastened to the two spring tubes 1 by clamping screws 15. In this way, as the actuator drives the actuator shaft 12 downwards, the spring tubes 1 move downwards and the springs 2 are compressed, causing a greater pressure to be exerted on the brush head assembly, while also suspension is provided to accommodate uneven floors and brush wear. Typically effective spring lengths, in an uncompressed state, are around 15 inches and this is particularly suitable for a 26/32 inch brush pressure system. This arrangement can provide a range of 0 to 450 lb of pressure in a loaded pedestrian cleaning machine placed in an apparatus according to the invention, compared to the maximum pressure of 200 lb available using known apparatus. Of course, other forms of tilting means can be used. A torsion spring has the advantage that it takes up less vertical space on a cleaning machine. In addition, a torsion spring generally has a low spring rate, which is particularly suitable for this purpose. You can also use gas struts or hydraulic or pneumatic systems.

The pressure can also be adjusted by changing the springs for others of different length or the different resistances of the clamping position of the spring tubes can be modified. However, these changes require a service engineer.

The system is particularly adjustable, as the actuator can be stopped anywhere along its path.

Typically the brush support plate 8 would be attached to a pair of circular or elliptical brushes rotating in a plane generally parallel to the floor (or surface to be cleaned or swept or scrubbed). However, up to four brushes are in use in some cleaning machines, and the apparatus of the invention can be used to control all of these four brushes together, or alternatively individually (in which case, separate actuators could be used for each). ). Of course, a cylindrical brush head mounted on the brush support plate 8 could also be easily controlled, or alternatively controlled at each end of its shaft by respective separate assemblies according to figure 1.

A 20 gauge tension beam, which can be used to measure brush pressure, is positioned under the spring tube clamp plate 18.

In Figure 2, the brush assembly of Figure 1 is shown mounted on a pedestrian cleaning apparatus. Similar parts are indicated by like reference numerals, and a pair of spring tubes 1 are attached to the actuator stem 12 by actuator plate 14. Actuator 10 is attached by connecting rod 15 to the frame of the apparatus.

ES 2 174 283 T3 ratios 16. A second rotating support 17 connects the assembly 7 and the brush support plate 8 to the frame 16. The brushes themselves are not shown in figure 2, but are mounted below the plate of support 8 behind the protection flange 17 and are driven by the motors of the scrub brushes 18 (one of which is represented in figure 2).

Figure 2 also depicts the relative positions of the water tank or tanks 19, the whipping assembly 20 for driving the scrub motors 18 together with the transverse drive of the cleaning apparatus. The direction of the transverse drive is controlled by a lever 21. A squeegee 22 has a suction applied through a vacuum motor 23.

In addition, a brush head pressure control panel 24 is provided in view of the operator.

In figure 3 the assembly of the brushes is schematically shown in a side view and a control system is represented as a block diagram.

The position of the brush head 27 relative to the floor to be cleaned is controlled by an electric or hydraulic actuator 10 raising or lowering the brush head through an actuator stem that compresses the springs in the spring tube 1. Other elastic means, such as a gas strut, can be used to apply pressure to the brush head against the ground and, of course, other means can be used to control the position of the brush head, such as hydraulic or pneumatic means. Details of actuator 10 have been described above.

A pressure sensor is located in one of the positions labeled 4, although it can be placed anywhere on the cylinder or on the arm or bottom of the actuator. In practice, this sensor controls the pressure applied by the brush to the ground and generates a signal 25. The pressure sensor can be a tension detector 20 on the actuator plate 14, as shown in figure 1, or a piezoelectric sensor or position sensor. Alternatively, the locking pin (11 in Figure 1), which connects the assembly to the frame of the apparatus, can be used as a shear detector to measure pressure. An amplifier 26 converts this pressure signal 25 into a value that can be used in the downstream circuit.

The control panel 24 is provided to be visible to an operator. It has a pressure selection knob 28 by which the operator can pre-select a particular pressure. A rotary switch 29 raises or lowers the brush head 27 relative to the ground, depending on the position of the switch. A digital display 30 shows the pressure of the brush head 27 on the ground, as measured by the pressure sensor.

A processor 31 compares the measured pressure signal with the pressure selected by the operator and generates a control signal accordingly to control (if necessary) the actuator to make the measured pressure substantially the same as the selected pressure.

This processor may be of simple construction, such as comprising an electronic comparator and an amplifier circuit, or it may comprise a standard CPU unit in chip form.

Power for the electronic components is supplied by on-board battery 12 or by alternative low-power battery sources.

Figure 4 shows the brush head with planetary brushes for scrubbing, cleaning, polishing or sweeping a floor surface mounted through the actuator 10 (only one arm of the same is shown) to the frame of the machine, specifically to the support bracket actuator 30.

The brush head is raised and lowered as indicated by arrow 31 by a screw mounted on a jack on actuator 10.

The motors to drive the brushes are mounted on the brush head but are not shown in figure 3. The water tanks for the machine, mounted on the frame, or chassis, are also omitted in figure 3 to show more clearly the characteristics. other parts of the device.

A balancing beam 32 is mounted by a rotary bearing 33 to one end of a rotary bracket 34, the other end of which is connected to the frame. The beam 32 is also connected to a drive arm 1 and on the other side of the rotary bearing 33 to a counterweight 35 corresponding to the weight of the brush head. The opposite end of beam 32 is linked to the brush head via a turnstile link adjuster 36, which is used to adjust the counterweight for brushes of different length, for example to prevent the brushes from jamming against the ground.

A potentiometer 371 to measure brush wear is connected between balance beam 32 and swivel bracket 34.

Another support for the brush head is provided by a parallelogram joint 38 between the brush head and the side of the main frame to hold the brush cover in position.

A drive wheel 39 for the machine has been shown: usually such a wheel is positioned at each corner of the chassis or frame.

The path of movement of the counterweight is shown in dashed lines, as the brushes are raised in the lower line and when they are lowered in the upper line. As the brushes are lowered to the ground by the actuator 10, the balancing beam 32 rotates around the rotating bearing 33 and the counterweight oscillates upward. The change in the position of the balancing beam 32 causes a corresponding change in the position of the potentiometer cam 37, thereby changing the measured resistance. A load sensor (not represented in figure 4) detects the position at which the brushes touch the ground, that is, a positive pressure is registered and stops the actuator momentarily to measure the potentiometer in the position to be registered. . The actuator continues

ES 2 174 283 T3 then to drive the brush head down on the ground until the desired ground pressure is achieved.

The counterweight counteracts the weight of the brush head and allows for a very low range of selectable brush pressures, much lower than previously attempted, for example less than 1 lbs. This margin is used for light cleaning or polishing, or for rough cleaning or specialized floor surfaces.

Comparison of the potentiometer readings as the brushes contact the ground is a measure of the amount of wear on the brushes and can be used to provide an indication of wear on a display panel on the operator's console.

This example is, of course, only one of the many possible embodiments of the invention. It was readily understood by a technician in the art that this system is applicable to cleaning, sweeping, polishing, and scrubbing machines of a wide variety of types, and that it can be used on machines that need to apply pressure not only downward but also downward. up and to the side, with appropriate modifications that are within the non-inventive abilities of a technician in the art. Operation within a wide pressure range can be advantageously employed according to the present invention.

Turning now to Figures 5, 6 and 7, where the characteristics corresponding to those indicated in Figure 4 have the same reference numbers, a balancing beam 32 is shown that was mounted by means of a rotating bearing 33 at one end of a rotating support. 34, the other end of which is connected to the frame. The beam was also connected to a drive arm 1 and on the other side of the rotary bearing to a counterweight means in the form of a gas strut 35, 37 to counteract the weight of the brush head. The opposite end of beam 32 is linked to the brush head by a tourniquet joint adjuster 36, which is used to adjust the counterweight for brushes of different length, for example to prevent the brushes from jamming against the ground.

A potentiometer to measure brush wear is connected between balance beam 32 and swivel bracket 34.

Another support for the brush head was provided by a 38 parallelogram joint between the brush head and the side of the main frame to hold the brush cover in position.

A drive wheel 39 for the machine has been shown: usually a wheel like this is positioned at each corner of the chassis or frame.

The trajectory of movement of the counterweight is shown by arrow A, as the brushes are raised in the lower row and as they are lowered in the upper row. As the brushes are lowered to the ground by the actuator 10, the balancing beam 32 rotates around the rotating bearing 33, serving to compress the arrangement of the gas strut 35, 37. The brush head 8 is lowered to the ground by the extension of the actuator. 1. However, as the brush head 8 approaches the ground, the pressure to be exerted by the brush head 8 on the ground is advantageously counteracted by the gas strut means 35. 37. This counterbalance action is achieved by compression of the gas strut arrangement 35, 37 which, having a sealed volume within the chamber 35, limits the degree to which the piston element 37 is slidable within the chamber. 35 and, advantageously, in an elastic manner. In this way, the relative movement between the piston element 37 and the chamber 35 advantageously allows the execution of a low pressure that can be precisely determined in the brush head 8, since the limiting effect, and the corresponding counterweight The arrangement of the gas strut 35, 37 serves to effectively reduce the pressure applied by the actuator 1, and through the brush head 8, to the ground.

When the force exerted by the actuator 1 on the brush head 8 is removed, that is, the actuator 1 contracts to raise the brush head 8, the pressure compressed in the chamber 35 is relieved and the arrangement of the gas strut 35 , 37 is extended and the volume of fluid introduced into chamber 35 is chosen such that the extended gas strut arrangement 35, 37 can easily support the brush head 8 in this raised position.

It was appreciated that, acting as a counterbalance force, the gas strut arrangement 35, 37 serves to provide support for the weight of the brush head 8 and allows the net force exerted by the actuator 1 through the brush head 8 on the ground is precisely controlled particularly in the zero pressure range at the pressure corresponding to the weight of the brush head arrangement 8.

Figure 6 is a side view of another embodiment of the present invention, in which features common to Figure 5 are provided with the same reference numerals.

The counterweight arrangement depicted in Figure 6 operates in a similar manner to that depicted with reference to Figure 5 in that, as the brush head 8 is lowered toward the ground by the actuator 1, the gas strut arrangement 35a, 37a is compressed.

As seen from Figure 6, the device includes a shorter parallelogram arrangement 38a and is found in Figure 5, and the gas strut arrangement 35a, 37a was operatively connected between a frame portion of the sweeping / cleaning machine and brush head 8 by connecting them to the lower strut of the parallelogram arrangement 38a. As noted, as the brush head 8 moves into contact with the floor surface to be swept or cleaned, the parallelogram arrangement 38a rotates clockwise, which serves to move the piston element 37a into the chamber 35a of the gas tip arrangement, and whose relative movement is gradually resisted by the pressure developed inside chamber 35a. The counterweight force offered by the 35a gas strut arrangement,

IS 2 174 283 T3

37a shown in figure 6 serves, as with the arrangement shown in figure 4, to provide a net force on the brush head 8, which can be easily controlled particularly in the zero pressure range at a pressure corresponding to the weight of the brush head 8.

Turning now to figure 7, another embodiment of the present invention is represented and in which the characteristics common to figures 4 and 5 have been given similar reference numbers.

The main difference between the embodiment of Figure 7 and the embodiments of Figures 5 and 6 is that the required net force exerted by the brushes 27 of the brush head arrangement 8 on the ground is achieved when the arrangement of the gas tip 35b, 37b was more extended than compressed. Again, it is the pressure inside chamber 35b that limits the extent to which piston element 37b can extend therefrom, and this serves to counteract the force exerted by actuator 1. Gas 35b, 37b of the embodiment of Figure 7 was operatively connected between an extension clamp 401 of the cleaning machine frame and a connecting pin 411 of the brush head arrangement 8. As seen from FIG. 7, as the actuator is actuated to lower the brush head arrangement toward the ground for sweeping / cleaning, the gas strut arrangement 35b, 37b is extended and tensioned in an effective manner to the view of the pressure developed inside the chamber 35b. In contrast, when the brush head arrangement 8 is raised from the ground, the pressure developed within the chamber 35b by prior relative movement between the chamber 35b and the piston element 37b serves to assist with the support of the weight of brush head arrangement 8 off the ground.

As with each of the embodiments described here, the gas strut arrangement can advantageously be provided in such a way that the pressure inside the chamber thereof can be selectively varied to any particular value when the pressure arrangement The brush was at rest, that is, when the brush head arrangement 8 was raised from the ground.

The circuit of Figure 8 can be used as a control system for the system and provides an advantageous arrangement for achieving precise control of the pressure and speeds required of the present invention. It comprises standard integrated circuits including a microcontroller or microprocessor U3, power supplies from integrated circuits U1, U4, and U6, a non-volatile memory store U2, and an analog-to-digital converter U5.

A pressure signal measured from a pressure bridge or strain gauge mounted on the cleaning head enters the microprocessor U3 through an instrumentation amplifier U7 and the analog-to-digital converter (ADC) U5.

The system variables are stored in the non-volatile memory store U2.

The status of the external switch inputs on the cleaning machine is tested through the JP2 buffer.

The microprocessor U3 makes the proper calculations based on the sample values ​​and the set variables of the system and the control signals output through mosfets Q5 to Q8, relays RL1, RL2, RL3, and RL4 and the buffer JP1 to contact the relays to actuate the actuator in the cleaning machine itself. For example, when the RL4 relay is energized, 36 volts are applied to the cleaning head down actuator, when the RL3 relay is energized, 36 volts are applied to raise the cleaning head, and when the RL1 relay is energized, the control of the drive or traction of the cleaning machine is inhibited. When the RL2 relay is activated, the brush motor solenoid is on. This is programmed to occur only when the actual brush pressure and the desired brush pressure are balanced and also only when the machine is in motion to prevent the brushes from marking floors while stationary.

The Direction entry in the JP1 buffer detects whether the cleaning machine is moving or not. If it was, then the circuit inhibits changes in pressure to avoid damaging the brushes.

The Speed ​​entry in the JP1 buffer detects whether the brushes have been selected for high or low speed. This information is passed to the processor U3, which limits the pressure of the high speed brushes to a predetermined range to protect the brush motors.

The JP2 buffers supply signals to the machine's control panel to display the indication of the actual measured pressure and the indication of the determined value respectively on LED screens.

Other modifications can be included in this circuit, for example a battery monitor can be advantageously incorporated to record the total use time and monitor the state of charge of the battery. Under certain predetermined conditions, as programmed into the U2 system's parameter memory circuit, the cleaning brushes were raised automaotically. These conditions would topically be long battery use and / or low battery power. The operator then necessarily has to take the machine back to the warehouse to recharge or replace the battery, preserving the warranty on the battery.

The control circuit of the invention can be adjusted very precisely and achieves extremely precise pressure settings for the brush head.

The U3 microcontroller is preferably programmed to always effect changes in pressure in a direction such that the brushes move downward, and this aids in the precision of adjustments. For example, if a pressure change from 100 lbs to 40 lbs is required by an operator, the controller will cause a jump to a value of about 20 lbs and then slowly increase the pressure to the required value of about 40 lbs. This provision overcomes friction

ES 2 174 283 T3 is static on the machine. It is particularly advantageous if phase advance calculations are also used by the microcontroller, so that the microcontroller calculates the rate at which pressure changes occur and makes the appropriate adjustments.

The circuit also preferably controls the status of the external brush head raise / lower switch, and the microprocessor U3 can be programmed to take the status of this switch into account when making decisions to perform certain operations.

Figure 9 shows a cross section through a drive arrangement of a work head 40 according to an embodiment of the present invention, and comprising a motor 41 in association with a gearbox 42.

A drive shaft 43 in the motor drives the rotary input gearbox 42, and an output shaft 44 extending from the gearbox 42 drives a drive output of the arrangement to the rotating cleaning / polishing head of the apparatus. .

The motor comprises a housing 45 extending in a direction parallel to the motor shaft 43, and a motor closure plate 46 is provided at the end of the motor housing adjacent to the gearbox 42. For its part, the The gearbox is mounted by bolt means to the closing plate of the motor 46 and such that the output shaft 44 of the gearbox 42 extends parallel to the longitudinal axis of the motor shaft 43.

The gearbox 42 includes a housing extending from the motor closure plate and which is closed, and its end remote from the motor closure 46, by a gearbox closure plate 47, through which Exit tree 44 is extended.

The input shaft 43 is coupled with a taloin shaft extending in the gearbox 42 and which is rotatably fixed, and its end away from its engagement with the input shaft 43, in a position cavity 49 provided. on the inner surface of the gearbox closure plate 47. Positioning pocket 49 provides a rotary mounting of the talon shaft 48 within the gearbox.

The bead shaft 48 is provided with two gears along its axial length. A first gear 50 is provided on the end of the bead shaft 48 adjacent to the socket 49 and its first gear 50 has a slightly smaller diameter than the bead shaft 48. A second gear 51 positioned on the bead shaft 48 and adjacent to motor closure plate 46 has a larger diameter than heel shaft 48.

As explained below, the first 50 and second 51 gears provided on the talon shaft 48 can be arranged to provide a predetermined rate of transmission in the gear arrangement of the gearbox 42.

The output shaft 44 is rotatably mounted in the gearbox and, as will be appreciated, extends between the respective sets of bearings located adjacent the motor cover plate 46 and the gearbox cover plate. 47.

As with taloin shaft 48, output shaft 44 includes two gears spaced apart along the axial direction of output shaft 44 such that one of the gears 52 is arranged to mesh with first gear 50 on the output shaft. talon 48 and the other of the gears 53 is arranged to mesh with the second gear 51 provided on the talon shaft 48.

The gear 53 provided on the output shaft 44 is arranged to have a diameter that is the same as that of the second gear 51 on the tallow shaft 48, so that the transmission ratio between gears 51 and 54 is 1: 1. .

The gear 52 provided on the upper shaft 44 has a larger diameter than the gear provided on the heel shaft 48, and even the gears 51, 54.

Gear 52 is chosen so that the transmission ratio between gears 50 and is 5: 1.

The aforementioned drive rates provide the required speed reduction when switching between a floor scrubbing operation and a floor buffing operation, and thus the gearbox of Figure 9 provides an effective two-speed gearbox. As will be appreciated, when the pair of gears 51, 54 drives the rotation of the output shaft 44, the output shaft rotates at a speed consistent with the engine speed, for example 1,000 rpm. However, when the gearbox is switched so that the gear pair 50, 52 drives the output shaft 44, the 5: 1 transmission ratio of this gear pair determines that the output shaft speed, and of this way of driving the surface working head element, is reduced to 200 rpm.

The respective speeds cited above are preferred for scrubbing and buffing operations and therefore, together with proper control of the pressure at which the surface work head element is applied to the surface, scrubbing and buffing operations can be provided by the apparatus.

As would also be appreciated from Figure 6, the gear pairs 51, 53, and 50, 52 are mounted in constant engagement, and the gears 52, 53 on the output shaft are arranged to move freely during engagement. operation of the engine and to selectively control the actuation of the output shaft 44 by a clutch of about 54.

The about 54 clutch is actuated by an actuator 55 in a reciprocal manner in the direction of arrows A to engage a face of gear 52 or a face of gear 53. The about 54 clutch is provided with opposing facing surfaces including gear cavities 56 which are arranged to receive blunt teeth 57 formed on the aforementioned faces of gears 52, 53.

In its position as depicted in Figure 6, the clutch 54 moves in engagement with the blunt teeth of gear 52 to provide rotary drive.

ES 2 thorium to the surface working head element at a speed of 200 rpm.

The actuator 55 is actuated by a gear shift actuator assembly which may be advantageously actuated by a solenoid, and which may also include solenoid locking means to advantageously prevent movement of the clutch once a rotation speed has been selected. output shaft 44.

As previously mentioned, the gear shift actuator assembly 58 can be advantageously associated with control means, whereby the selection of a particular pressure to be applied by the surface work head arrangement serves to actuate the gear shift assembly 58 to select the particular transmission rate, or alternatively, a selection of a particular transmission rate serves to effect, or limit, the pressure applied by means of selective pressure application in response to the selected transmission rate.

It will be appreciated that the present invention is not restricted to the details of the above-cited embodiments. For example, any appropriate means for selecting the applied pressure by the shallow work head arrangement can be incorporated into the present invention, as well as any appropriate form of speed selecting means. Furthermore, the apparatus can be easily incorporated in a machine on which one goes above in addition to the pedestrian machine represented here.