A TOOL HAVING A PUMP AND A PUMP
20210228917 · 2021-07-29
Assignee
Inventors
- Titus Ludger Van Den Brink (Breda, NL)
- Marcus Petrus Augustinus Schellekens (Breda, NL)
- Remon Vincent Wensveen (Sleeuwijk, NL)
- Rene Wilhelmus Johannes Van Eindhoven (Oisterwijk, NL)
Cpc classification
F04B23/02
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04B51/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04B17/03
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04B19/04
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
A62B3/00
HUMAN NECESSITIES
Abstract
A portable tool capable of being moved by persons, users and/or operators includes a motor; an actuable tool component at least connectable to the work cylinder; an add-on from a group at least including an extension, a connection and a fork, configured to be placed on the tool; and a controller connected to the motor and configured to determine presence of the add-on on the tool to selectively increase or reduce motor force and/or speed, depending on detected presence or absence of the add-on.
Claims
1. Portable tool, capable of being moved by persons, users and/or operators, comprising: a motor; an actuable tool component at least connectable to the motor; an add-on from a group, at least comprising an extension, a connection and a fork, configured to be placed on the tool; a controller connected to the motor and configured to determine presence of the add-on on the tool to selectively increase or reduce force and/or speed, depending on detected presence or absence of the add-on.
2. Portable tool of claim 1, wherein the add-on is configured to replace the actuable tool component.
3. Portable tool of claim 1 or 2, wherein the add-on comprises an identifier, configured to communicate its presence to the controller.
4. Portable tool of claim 3, wherein the identifier of the add-on is configured to proclaim its presence on the tool through a signal over a wire or wirelessly.
5. Portable tool of any preceding claim, further comprising: a fluid reservoir; a pump connected to the reservoir and the motor; a work cylinder connected to an output of the pump; wherein the actuable tool component is connected to the work cylinder; a sensor in the recue tool connected to any one or more than one of the motor, the reservoir, the pump, the work cylinder, and the tool; wherein the controller is configured to receive measurement signals from the sensor; and at least one controlled valve in a hydraulic circuit defined by the reservoir, the pump and the work cylinder and connected to the controller, wherein the controlled valve and the controller are configured to selectively at least substantially block or open any fluid channel in the hydraulic circuit.
6. Portable tool of claim 5, wherein the pump has a plurality of chambers, each of which comprises a fluid input channel extending from a reservoir to the chamber for fluid supply, a pressurised fluid output port and a piston, wherein the motor is configured to cyclically move the piston in the chamber to supply fluid from tire reservoir via the input channel into the chamber during a suction half of tire piston cycle and to forcibly press fluid out through the output port during a press half of the piston cycle, wherein the input channel is blocked during the press half of the piston cycle; and wherein the controlled valve is configured to selectively at least substantially block the input channel of at least one of the plurality of chambers of the pump during at least a part of the suction half of the piston cycle, independent of the piston cycle.
7. Portable tool according to any preceding claim, further comprising at least one performance sensor providing, to the controller, information for the controller to adapt tool operation to the information, wherein the sensor is configured to measure and provide the information on at least one performance parameter from a group, comprising: fluid pressure from the pump, current drawn by the motor, revolutions per time unit of the motor, torque supplied by the motor, power delivered and/or consumed by the motor, battery charge if the tool comprises a battery, rotational position of the motor, position and/or a movement of a piston in the work cylinder, approximation of an predetermined extension of the piston from the work cylinder, such as maximum and/or minimum extension, ambient temperature, fluid temperature, motor temperature, motor resistance, fluid resistance, controlled valve position, user and/or operator input, and the like.
8. Portable tool according to any preceding claim, further comprising at least one detector providing, to the controller, information for the controller to adapt tool operation to the information, wherein the detector is configured to determine and provide the information on at least one parameter from a group, comprising: presence of the tool component and/or an extension thereof, connection to a mains power supply, water intrusion into the tool, a low battery level if the tool comprises a battery, and the like.
9. Portable tool according to any one or more than one of the preceding claims, further comprising a battery, whereby the tool is self-contained without external connections, except for a power supply connector for charging the battery.
10. The tool according to any one or more than one of the preceding claims, wherein the tool is a rescue tool from a group of rescue tools, comprising: a ram; a spreader; a cutter, and the like.
11. Method of operating a portable tool, capable of being moved by persons, users and/or operators, wherein the tool comprises: a motor; an actuable tool component at least connectable to the motor; an add-on from a group, at least comprising an extension, a connection and a fork, configured to be placed on the tool; wherein the method comprises determining presence of tire add-on on the tool; and selectively increasing or reducing force and/or speed, depending on detected presence or absence of the add-on.
Description
[0041] Following the above discussion of embodiments of tools according to the present disclosure in more generic terms, corresponding with features defined in the appended claims, herein below a more detailed description is provided, referring to the figures in the appended drawing. As indicated above, in particular, features of specific embodiments will be disclosed in order to provide a sufficient disclosure for the skilled person to comprehend, but none of fire specifically revealed features of particular embodiments should be interpreted as imposing any limitation whatsoever on the scope of protection for the assembly of embodiments according to the present disclosure, in as far as covered by—in particular—the independent claims of the appended set of claims. Moreover, in separate figures of tire appended drawing, the same or similar aspects, elements, functionalities and components can be indicated using the same or similar reference numbers, evert though distinct embodiments may be involved. In the appended drawing:
[0042]
[0043]
[0044]
[0045]
[0046]
[0047]
[0048]
[0049]
[0050]
[0051]
[0052] In
[0053] Spreader 101 comprises a spreader housing 102, optionally forming a structure of the spreader 101. The housing 102 is referred to as forming a structure in that thereby separate components may be connected. Spreader housing 102 accommodates a hydraulic work cylinder 109, and a connection to a hydraulic power source via connector 104 may then serve to drive cylinder 109, as for example in other embodiments than rescue tools, such as re-railing systems, synchronous lifting systems, skidding systems, demolition, recycling, and the like. Also for such tools, considerations underlying the present disclosure may apply, such as light weight and compactness, where it may be desired that system components may be lifted and moved by a single person. Preferably, though, for instance in embodiments of rescue tools, tire tool is portable and/or even self-contained, as described in the below embodiments. Therein, the tool further comprises an integrated pump and associated electric motor, with a battery for powering the motor and a power supply for charging the battery. By providing a description of working principles of an exemplary spreader 101 as an embodiment of a tool according to the present disclosure, the basis is laid for the below embodiment description of embodiments with more explicitly disclosed there the distinguishing features according to the appended claims of the present disclosure.
[0054] Extending out of work cylinder 109 is a piston rod 111, which is not visible in
[0055] When work cylinder 109 is driven to extend its piston rod 111, then transmission 110 pushes arms 105 and 106 out, which are in the exhibited configuration thereby driven to swivel outward relative to rotation points 107, and 108 on yoke 112, and force apart any external elements, such as parts of a car wreck. Evidently a different transmission may be deployed when the tool is another type of rescue tool, such as a cutter, in which the driveable arms 105, and 106 are replaced by cutter blades and driven to be forced together and cut portions of a car wreck. Such cutter blades, drive arms 105, and 106 and/or other elements of a tool, to form actuable tool components that may be connected to piston rod 111 of work cylinder 109.
[0056] As shown in
[0057] Tool 101 may comprise a plurality of sensors 52 connected to controller 13, to provide information, based on which the controller 13 may adapt at least the motor 111 and/or pump 113 and/or the valve block 114 to the information. In such an embodiment, any one of the sensors 52 may be configured to measure and provide the information on at least one performance parameter from a group, comprising: fluid pressure from the pump, current drawn by the motor, revolutions per time unit of the motor, torque supplied by the motor, power delivered and/or consumed by the motor, battery charge if the tool comprises a battery, rotational position of the motor, position of piston 6, 111 in work cylinder 1, 109, approximation of a maximum extension of piston 6, 111 from work cylinder 1, 109, ambient temperature, fluid temperature, motor temperature, motor resistance, fluid resistance, presence of the tool component 105, 106, presence of an extension 42 thereof, connection to a mains power supply, water intrusion into the tool, a low battery level if the tool comprises a battery, and the like.
[0058] These and other internal and internal circumstances, parameters and determinations allow the controller 13 to optimize a selected force level adapted to the internal state of tool 101 or to external circumstances. For example, if the motor 111 is beginning to overheat, selecting a lower force level may allow the ongoing work to be continued and even finished at a lower force and/or pace. For example, the present disclosure allows the deployment of less pump chambers (as disclosed below) by corresponding control of the controller 13 over the pump 113, allowing torque provided and heat generated by the motor to be lowered. Thus the level of generated force may be maintained, while speed may be reduced.
[0059] As a further example of possible functionality according to the present disclosure, when the piston 6, 111 approximates full extension, the controller 13 may reduce extension force to a lower level and even nill at the maximum extension, to avoid damage to the work cylinder 1, 109 or other internal or external components. The maximum extent of the piston 6, 111 may be influenced by an extension 42, connection 43 and/or fork 44 on or instead of the actuable tool component 105, 106, in case of for example a ram. Extension 42 may even communicate its presence to the processor through a signal over a wire or wirelessly. The controller 13 may then take the extended length of the tool into account for increasing or reducing force and/or speed, for example when an additionally provided sensor on the extension 42 indicates an approaching boundary of a movement range at an obstacle, for example a beam or post of a car wreck. Once abutment is realized, the force may again be increased. It is noted that such embodiments with smart extensions proclaiming their presence on a tool, or even additional sensors on such an extension, for example a proximity sensor, are all to be considered inventions in their own right, even without features of the appended independent claim; for example without the hydraulics and using a spindle drive or other type of drive, instead of the pump and cylinder combination.
[0060] As shown in
[0061] Evidently, the present invention allows for a degree of automatic and user input control of tool 101 and 41 that was unimaginable before the present disclosure.
[0062] The spreader 101 comprises, according to the more detailed view in
[0063] Cylinder piston 6 may respectively be driven in a retracting movement and a driven advancing movement, depending on the supply of pressurized fluid.
[0064] Cylinder 1 is supplied with pressurized fluid from a pump having a cylindrical pump piston housing 9, forming part of pump house 12, with the pump piston housing defining chambers, in each of which a pump piston 28, 50 (shown in more detail in following figures, for example
[0065] Surrounding pump piston housing 9 of pump housing 12, stage ring 10 is provided. As shown in
[0066] Pistons 28, 50 of the pump in pump piston housing 9 are driven by a motor comprising motor stator 14 and motor rotor 15, where the motor is arranged on common shaft 21 with the pump 113, where the pump 113 and motor 14, 15 are arranged directly adjacent relative to one another on the common singular shaft 21. Consequently, the common shaft 21 is singular, i.e. a one-piece component without any intervening coupling or transmission, and the pump and motor are arranged thereon in a side-by-side configuration. The pump is also arranged on shaft 21, which allows for a compact design. Shaft 21 is arranged in a set of bearings 20, 22. A swivel plate 51, which backs a pivot bearing of which bearing balls are arranged in a carrier plate 53, is arranged on shaft 21 to—when shaft 21 is rotated by motor 14, 15—sequentially drive the pump pistons 28, 50 in tire cyclical movements thereof through a suction half and a press half of their cycles, which, because of the axial configuration of the pump's chambers, are sequential.
[0067] As shown in
[0068] The shaft 21 may optionally be additionally linked with a fan (not shown) to drive an air flow through the tool. The air flow thus generated may assist in cooling of the tool. In such an embodiment, an air inlet, an air flow path along the fan and an air outlet will need to be provided. However, in such an embodiment a risk may exist of penetration of fluid or at least humidity, for which a sensor 52 may be provided to determine the fluid/humidity level and allow the controller 13 to adjust the workings of the tools on the basis of detected fluid/humidity levels. Also a filter may then be provided to inhibit intrusion of particles into the tool, which could hamper cooling, if clogging an air flow path through the tool along the fan.
[0069] In the embodiment of
[0070] Spring 35 is arranged around shaft 21, between a seat of its own and carrier plate 53 or piston holding plate 36, 48, with the carrier plate 53 holding bearing balls of pivot bearing between the pivot plate 51 and pistons 28, 50, to press carrier plate 53 towards swivel plate 51. Piston holding plate 36, 48 may be attached to the carrier plate 53.
[0071]
[0072] The piston holding plate 36, 48 is attached to the carrier plate 53, and docs not rotate with shaft 21, while swivel plate 51 is fixed to and rotates with shaft 21. For the configuration of
[0073] The stage ring 10 carries tips or cover elements 49, to cover the suction input port 30 of at least one chamber, depending on the position of ring 10. This position is determined by tire controller 13, and set under control of the controller 13 via stage motor 11. Any number of internal and external sensors, like sensor 52, determining fluid input of the ports 30 and consequently pressure and fluid flow output by the pump, and additionally user inputs 140, 141, may provide a basis for the controller 13 to determine the position of the stage ring 10 and therewith determine the number contributing chambers 33, to contribute to the output of the pump, by positioning the lips or cover elements over ports 30 of the determined number of chambers that are not to contribute. Depending on versatility of the stage ring or an alternative embodiment of controlled valves, individual chambers may be designated to contribute—or not—and then an even distribution of contributing chambers along the circumference of the pump piston housing 9 may be realized, to also evenly distribute forces and loads therein. Positioning of the lips or cover elements 49 on the stage ring 10 relative to the ports 30 of the chambers may be optimized in this respect. Single lips may cover more than one of ports 30 of a plurality of chambers.
[0074] Consequently, a compact configuration is achieved by the common shaft 21, and by the simplest of measures to determine how many or even which particular ones of the chambers 33 contribute to the output of the pump, without having to deploy heavy valves to shut of the output ports 30, against the pressure in the output ports, if the simple input closing lips or cover elements 49 were replaced by such valves on the output ports.
[0075] An alternative configuration for the same purpose is generally indicated in
[0076] In the embodiment of
[0077] A further check or non-return valve 62 is preferably arranged in the channel between the chamber 33 and the cylinder 1, 109. This check or non-return valve may also be provided in the embodiment of
[0078] Referring back to
[0079] In the above described embodiment, the total cylinder volume has a number of components 27. These allow the necessary extension/contraction of the rod 111 into and out of the cylinder 1, 109, by appropriate driving via controller 13.
[0080]
[0081] The present disclosure allows a hydraulic tool to gear up or down, depending on internal or external circumstances and/or user inputs. For example, a load may be measured to determine whether to gear up or down the tool. To this end the controller 13 may adapt the motor's rpm's and adapt the number of pump chambers to contribute to the total pump output, to select for speed and/or for power and/or generated force. Other circumstances may also be taken into account, such as motor temperature, to gear down the tool, when it is detected the motor is overheating, but by gearing down, operations may be continued and the motor may be protected against a burn out as an example of internal circumstances. Any number of sensors and detectors may be used, like the pressure sensor 52 for determining the pump's output pressure, for the controller to adapt the operational state of the motor and/or pump, including user input.
[0082] In a tool, in which gearing up or down is not possible, as in the prior art hose connected tools, the transmission rate is to be selected such that at the highest anticipated cylinder force, the designed motor torque is sufficient and will not be exceeded. A tool then results, that may not be able to also provide to desired speed, comparable with a car having only a first gear.
[0083] According to the present disclosure, internal and external circumstances are taken into account as well as allowing user input, to adapt the mode of the tool in terms of gearing up or down, while preferably avoiding but not excluding large, heavy duty closing valves on output sides of a plurality of chambers. By employing a suction side closing valve and/or an output side bypass (such as the controllable valve 56 in in the embodiment of
[0084] In the embodiments with controlled valves for closing input ports of a selection of a plurality of pump chambers during the suction half of the piston movement, separate from a normal valve for closing the input port during a press half of piston cycles of pistons in chambers of the pump, the lid or covers do not even need to fully close the input ports but may merely restrict inflow into the chambers of fluid. A flexible flap, lip 49 or the like suffices. The stage ring 10 carrying the cover elements, or lips 49, can therefore be realized simply and cheaply. Stage motor 11 also needs only to be very cheap and simple, robust and small sized.
[0085] With the principles of the present disclosure, a graphic representation of ramping up the tool according to
[0086] Tire uppermost graph of
[0087] The controller 13 is configured to take internal and external circumstances and considerations for switching the number of contributing chambers 33. Such circumstances may be determined based on signals from performance sensors or detectors 52, as well as user or operator input via switches 140 and/or rotating handle 141, and the like. Additionally or alternatively, the controller 13 may be capable of adapting switch pressures between stages, as shown in
[0088] To avoid excessive load of motor 55, 111, torque delivered by the motor 55, 111 and battery current from battery cells 24—if provided on board of the tool—needs to be limited. The controller 13 provides for electronic speed control, herein below also referred to as “ESC”, based on the characteristic graphs of
[0089] The controller 13 may be provided with data from sensors 52 providing information on motor torque and battery current to the motor, and is then already capable—even without information from any pressure sensors 52, if provided—to control any of controlled valves 49, 56 to adapt the gearing to these parameters, by adding or omitting contributing chambers 33, based on a desired one of the graphs in
[0090] Here it is noted that motor torque corresponds linearly with motor current and a voltage sensor 52 may measure motor voltage, where the controller 13 may be able to determine, from the determined motor voltage and motor current, (remaining) battery capacity, and when also the battery voltage is monitored, the battery current can further also be deduced.
[0091] Combined control by controller 13 of the motor 55, 111 and the (stage motor 11 driving the) controlled valve 49 or 56, for example to set the position of the stage ring 10, offers a host of entirely new and beneficial functionalities.
[0092] Control of the motor speed in rpm, motor torque and ratios as in
[0093] Control can be easily adjusted to the (type of) tool, user or use, which requires only reasonably limited adjustments to the controller 13 and the ESC embodied thereby. Here, a few examples are noted:
[0094] operating pressure may be limited when an extension is added to a ram as described above in relation to
[0095] operating pressure can be limited when an integrated ram support 44 is provided, wherein a sensor 52 can be provided, which is configured to detect whether such a ram support is actually arranged on the ram, which is a further embodiment of smart tool extension, whereby such an integrated rani support can form an alternative for a separate ram support, whereby the tool and in particular the ram of
[0096] operating pressure may be limited with the objective of protecting the user/operator, but by providing an user operable override button or switch, to specifically enable higher pressures, does the controller allow a maximum pressure to be deployed, by appropriate adaptation of the characteristic graphs of
[0097] a broad range of tools may be equipped with essentially the same drive formed by at least motor, pump and controller, where, with simple adjustments to the programming software of the controller 13 defining the electronic speed control “ECS”, smaller tools can exhibit a more limited speed than larger tools (small and large being used here to refer to the movement ranges thereof).
[0098] Tools according to the present disclosure do not require a pressure limiting valve, because the controller 13/ESC may ensure that a safe operation speed is not exceeded, whereby the controller 13 may determine a maximum operating pressure based on motor torque and a desired transmission characteristic, with reference to the transmission stages in
[0099] In contrast, when a pressure sensor 52 is deployed, a pressure measurement signal from such a pressure sensor 52 may be beneficially employed to switch the stages, i.e. determine the number of chambers 33 to contribute, and/or gear down the motor 55, 111 to prevent damage to the tool by preventing excessive pressure from the pump.
[0100] If or when the maximum motor torque is reached at the highest operating pressure from tire pump, the motor 55, 111 can be geared down, reduced or stalled by controller 13 to save energy, compared with a pressure limiting valve or a switching valve, and moreover the user/operator is more detectably informed that the maximum power of the tool has been reached, in that the user/operator receives a manually detectable (the user/operator is able to feel the change of the motor gearing down) warning that limits of operation of tire tool have been reached.
[0101] As mentioned above, excessive heating of the motor, but also of the battery, controller and pump, can be detected by furnishing appropriate temperature sensors 52 for the controller to limit motor current, when a threshold temperature is exceeded. Gearing down under such circumstances can be referred to as “derating”, which is in principle known in prior art tools, in which such a function is realized using hydraulic switch valves in which a derating control limits the motor torque to such an extent, that the switch pressure of the hydraulic switch valves cannot arise, in which case the tool is no longer operable to generate high forces. In contrast, the present disclosure allows the tool to remain operable, also during derating, because the controller 13 can switch the pump to any of its stages (combination of contributing chambers 33). However, derating involves reducing the motor torque and consequently also involves a reduction of a maximally attainable operating pressure and/or flow and speed, but this still enables the tool to maintain functionality, and involves a marked improvement over the prior art tools, which shut down completely, which is undesirable, in particular (though not exclusively) in case of rescue tools.
[0102] In the present disclosure, switching stages (i.e, determining tire numbers of contributing chambers) may be performed based on a motor speed signal from a motor speed sensor 52 sent to controller 13. The controller 13 may then limit, if desired or even necessary, motor current and therefore also motor torque, to under a predetermined maximum threshold value. For example, relationships between motor speed signals and attainable pressures and/or flows may be stored in a memory for the controller to retrieve and base control over the pump on. When a load warrants such a torque, controller 13 may reduce motor speed. A pump chamber 33 is omitted and consequently “switched off”, when motor speed exceeds a lower threshold. Conversely, a chamber 33 may be added to contribute, when motor speed exceeds an upper threshold.
[0103] Losses in the pump are determined to a considerable extent by leakages along a piston in a chamber 33 and a chamber wall. Particles in such a leakage flow may cause wear of the piston and the chamber wall. Since the leakage flow increases with tire pump pressure, chambers 33 undergoing in the stage (combination of chambers contributing) suffer the most from this wear. By assigning alternating chamber to such stages undergoing the highest pressures, the overall life expectancy of the pump can be lengthened. By assigning differing stage ring 10 positions for the same stages (i.e. number of contributing chambers 33) different chambers will be involved in the different stages, allowing the distribution of wear and tear over the chambers and thereby the life of the pump may be lengthened.
[0104] When the controller 13 is configured to assign alternating or rotating chambers 33 and pistons therein for each stage, the life expectancy of the pump may be lengthened. To this end, stage ring 10 may carry an appropriately chosen number and extent of lips 49, and the stage ring can be rotated by motor 11 under control of controller 13 to a diversity of different rotational positions in which lips 49 exclude and include differing contributing chambers 33. It is further conceivable that such a drive of stage ring 10 is controlled by controller 13 by means of self-diagnosis to determine whether any of the chambers 33 are subject or susceptible to eminent wear. If so, other chambers 33 and pistons therein may be selected for appropriate stages, in particular for high pressure or speed stages involving a larger or lower number of the chambers 33. Self-diagnosis may be possible on the basis of the controller 13 receiving input about the tool in its end position of the work cylinder piston, measuring the operating pressure, when the tool is in the end position thereof. Worn chambers 33/pistons therein can be detected, by determining if the maximum power is not reached or reached too slowly.
[0105] Upon assembly, a program may be run by an end user or a mechanic to initially adjust the tool, wherein the tool may be calibrated, and operated to this end for a time under load. An external filter may be provided to be connected to the tool.
[0106] An end user or mechanic may initiate a diagnosis program for self diagnosis of the tool according to the present disclosure. In such a diagnosis, the controller 13 may verify if required pressures are achieved for each of the stages, or wherein ail pistons 28, 50 of the pump are arranged in a position with the smallest volume to determine whether and how quickly maximum pressure is achieved by the pistons in the respective chambers 33.
[0107] In conventional tools, motor speed in rpm is normally always constant, hut speed of the motor may be varied, where, for example, a hydraulic valve may be employed to regulate speed of the conventional tool. However, thereby reduction or shut off losses may occur. In contrast, according to the present disclosure, controller 13 may regulate speed of the motor, without reduction or shut off losses. Since in the tool, proposed herein, stages of the pump are also under control of the controller 13, a stage may be selected at any given time and regulation of speed the motor 14, 15 may therein also be takers into account. Further, a desired tool speed value, input by a user turning grip 141, may additionally also be taken into account, for selecting tire stage of the pump and speed of the motor.
[0108] Variable motor speed allows an increase in the range of the drive; using a relatively low motor torque, the motor may reach a maximum speed and the user may be made available the highest speed. Such a maximum speed may be limited by battery voltage, where the motor speed and the associated electromagnetic force can be increased until a balance occurs with battery voltage. Nevertheless, motor speed can be increased even further, by deploying field weakening. Since the controller 13 is informed about a stage of the pump, field weakening may be selectively deployed in a stage with the largest cycle volume. Then, in other stages, a disadvantage of lower efficiency associated with field weakening does not apply, but the advantage of a higher tool speed is ensured in the relevant stage.
[0109] Groove 29 at port 30 ensures an improved fill of the chamber 33, so that even at higher speeds, tire pump may function to expectation. A better till of the chamber could also be achieved by providing a plurality of input channels, but then additional input channels ail need to be also blocked during the press half of the piston cycle to prevent fluid from being pressed back to the reservoir or tank 26, and/or during the suction half of the piston cycle to adapt the total work volume of the pump in accordance with the characterizing portion of appended independent claim 1, which renders a resulting design of the pump and/or of valves in particular more complex.
[0110] The configuration according to
[0111] Piston holding plate 36, 48 in
[0112] Spring 35 in
[0113] Above, numerous described features are explained in conjunction with their benefits in relation to alternatives. Also, the portable tool of the present disclosure, often referred to herein above in an embodiment of a rescue tool, may be useable/applicable for other purposes, such as for example in other embodiments than rescue tools, such as re-railing systems, synchronous lifting systems, skidding systems, demolition, recycling, and the like. However, also alternatives for features defined in any of the appended claims, which may be less preferred, may also fall within the scope of the present disclosure, as defined in the appended claims, where also other alternatives for the specifically disclosed features may be encompassed thereby, and the scope is only limited to the definitions of the appended claims, and may also include, at least for some jurisdictions, obvious alternatives for claimed features.