Gas generator for a tool, use of the gas generator, and tool equipped with the gas generator

Abstract

The present invention discloses a gas generator 20 for a tool, including an electrolytic cell 30 for generating hydrogen-oxygen gas having a hollow tank 31, and an electrode pair 32 including a first electrode 33 and a second electrode 35. The first electrode 33 and the second electrode 35 are separated by a non-conductive separator 37 within the hollow tank 31. A gas extraction pipe 55 is disposed within the hollow tank 31. Further, the invention discloses the use of such a gas generator within a tool and a tool equipped with such a gas generator.

Description

Technical Field

[0001] The present invention relates to a gas generator according to claim 1, the use of said gas generator in a tool according to claim 12, and a tool provided with said gas generator according to claim 13.

[0002] Various embodiments of the present invention relate to a gas generator for a tool. Typically, the tool is a handheld tool, specifically a handheld nail driving tool. Conventional energy sources for handheld tools include a power cord, a battery, a gas cylinder, a power cartridge, or pneumatic pressure. At a construction site, portable tools can be used in various ways, often above the user, and can be easily removed by the user after use. As a result, during use, the portable tool often quickly changes its spatial orientation.

Background Art

[0003] Gas generators are well recognized for stationary uses such as welders and flame grinders. Hydrogen and oxygen gas bubbles are generated during the electrolysis of water, and these bubbles must be separated from the aqueous electrolyte. In stationary applications, gases and liquids are typically separated by gravity, i.e., the bubbles rise to the surface of the liquid and the gas is collected above the surface of the liquid. However, since the direction of gravity is no longer taken for granted, this method is not practical for handheld instruments.

[0004] Patent Document 1 discloses an electrolytic cell. The electrolytic cell consists of flat or shaped parallel electrodes with slots and holes that create paths for gas and electrolysis. The space between the electrodes is filled with an electrolyte while current is supplied externally. The electrodes are interconnected by conductive buses to form a set. The central electrode of all said sets with 2n + 1 electrodes is placed between two adjacent sets, while the other 2n electrodes of this set are arranged at the center of the gap between the electrodes of the adjacent sets in contact with the bus. Thus, a small electrolytic cell is provided.

[0005] Patent Document 2 discloses a welding apparatus including an electrolytic cell for generating hydrogen and oxygen for industrial use, which is used to perform different types of welding operations based on the utilization of hydrogen and oxygen. The electrolytic cell is immersed in an electrolyte composed of a solution of KOH in water and contains two plate electrodes that can be connected to an AC or DC power source through their respective terminals. The power source is a transformer connected to the cell through a bridge rectifier. The flashback arrester is constituted by a water bath, and the gas liberated in the electrolytic cell enters the water bath through a pipe and then enters the incinerator through the pipe.

[0006] The drawback of these disclosures is that they are related to the welding process and industrial use and are not suitable for tools, especially not suitable for handheld tools.

[0007] Patent Document 3 discloses a power tool that utilizes hydrogen from a tank filled with a stationary gas generator including an electrolytic cell. The gas generator includes a base housing where a switch and a microprocessor for controlling the flow of line voltage to a voltage rectifier are placed. The voltage rectifier supplies a DC voltage to an anode and a cathode placed in a storage container fitted inside the base housing. The cylindrical chamber in the storage container is generally divided into a semi-cylindrical chamber by a non-permeable divider that allows the liquid to flow freely to the bottom of the storage container for the free flow of electrons between the anode and the cathode. This non-permeable divider prevents gas movement once separation occurs. The cathode is placed in the chamber, and when activated, the cathode generates hydrogen from the water in the chamber. When sufficient hydrogen gas is generated by the cathode, the liquid level in the chamber is reduced, and the liquid level indicator sends a signal to the microprocessor to activate the compressor. The hydrogen gas from the low-pressure hose is compressed in the compressor, and the hydrogen gas under high pressure flows from the compressor to the upper part of the tank. The tank filled with hydrogen gas under pressure is removed from the gas generator and can be used as a fuel source for any number of mechanisms, including a lawn mower, a nail gun, and a portable power tool system for operating saws and drills.

[0008] A drawback of the present disclosure is that the stationary gas generator is a heavy and ungainly self - contained hydrogen generator with a complex mechanism for filling the tank with compressed hydrogen.

[0009] Patent Document 4 discloses an electric tool that utilizes hydrogen gas from a gas generator to drive a movable tool facility. The gas generator is disposed within a tool housing and includes an electrolytic cell, whereby the electrolytic cell includes at least one electrode pair arranged within an aqueous electrolytic solution. A drawback of the present disclosure is that when the tool orientation is reversed, the electrolyte may flow out of the gas generator.

[0010] Another embodiment of the gas generator in Patent Document 4 uses a chemical reaction of an aqueous solution of sodium borohydride to produce hydrogen gas. The gas generator includes a hydrophobic membrane at the gas outlet. The hydrophobic membrane utilizes the negative bubble point pressure of a porous hydrophobic structure for liquid separation. A drawback of the present disclosure is that liquid separation functions reliably only when the membrane is covered with liquid only in part. When the membrane is completely covered with liquid and the differential pressure is large enough, liquid separation cannot occur and the liquid permeates the hydrophobic membrane. This can occur, for example, when the tool orientation is reversed. Liquid separation may also not be possible when the tool is subject to high acceleration, which occurs regularly during the operation of a nail - driving tool.

[0011] Patent Document 5 discloses a hydrogen generator for supplying hydrogen to drive a hydrogen - powered engine. The regulator can supply hydrogen not only to drive an engine for operating a cutter assembly of a lawn mower, but also supply the output of the hydrogen - powered engine to operate various electric devices such as drills, saws, grinders, and others. In addition, the hydrogen generator can supply hydrogen to operate an electric piston for driving a fastener.

[0012] Patent Document 6 relates to an electrolysis device that is a cabin and has a good yield of the generated gas. In this electrolysis device, the spiral electrode is installed inside the electrolytic cell, and the ring-shaped magnet is installed below the spiral electrode of the honeycomb body. After treating the spot layer liquid with a magnetic field, the decomposition by the spiral electrode and electrolysis is carried out by an electric current. However, the problem to be solved is to reduce the size of the device and improve the gas generation rate.

[0013] Patent Document 7 shows an electrolytic cell including a storage container, a first electrode, a second electrode, a current source in electrical communication with the first electrode and the second electrode, an electrolyte in fluid communication with the first electrode and the second electrode, a gas that is formed during electrolysis at or near the first electrode, and a separator that includes an inclined surface for directing the flow of the electrolyte and the gas due to the difference between the density of the electrolyte and the combined density of the electrolyte and the gas such that the gas flows substantially in the distal direction of the second electrode.

[0014] Patent Document 8 discloses an electrolysis reaction system for generating hydrogen gas and oxygen gas, including a reaction chamber for containing an electrolyte and an electrode arrangement forming an anode and a cathode. At least one flow channel for the electrolyte is formed between the sides of the electrodes arranged to be spaced apart from each other, which extends between a first axial end for receiving the electrolyte into the electrode arrangement and a second axial end for discharging the electrolyte from the electrode arrangement.

Prior Art Documents

Patent Documents

[0015]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

[0016] An object of the present invention is to overcome at least one of the drawbacks of the prior art. A further object of the present invention is to provide a gas generator for a tool, particularly a handheld tool, including an electrolytic cell that operates consistently regardless of its spatial orientation. [Means for Solving the Problems]

[0017] At least one of these objects is solved by the features of the independent patent claims. Other preferred embodiments are described in the dependent claims.

[0018] Specifically, according to a first aspect of the present disclosure, the object is achieved by a gas generator for a tool including an electrolytic cell having a hollow cell body, a first electrode, and a second electrode. The first electrode and the second electrode are separated by at least one electrically non-conductive separator within the hollow cell body, and a gas extraction tube is disposed within the hollow cell body. The aforementioned gas extraction tube is used to extract the working gas from the hollow cell body while also preventing the electrolyte from leaking out of the cell body. Due to the consistent operation of such a gas generator, it is suitable for tools, particularly handheld tools, regardless of its spatial orientation. The spatial orientation of the tool can be permanently changed during use without losing the electrolyte. Due to its advantageous design, the gas generator lacks any liquid electrolyte.

[0019] Preferably, the working gas is a mixture of oxygen and hydrogen gas, called oxyhydrogen gas, generated in the electrolytic cell. Oxyhydrogen gas is generated in the electrolytic cell when the first and second electrodes are electrically supplied by an electric supply such as a battery. A DC-DC converter may be used for load regulation in the electrolytic cell. Conveniently, the electrical supply is a current supply that provides a desired current to operate the at least one electrolytic cell.

[0020] Preferably, the gas generator includes a pressure vessel. The gas generator can generate compressed working gas because the working gas is compressed using electrolysis. This is convenient for gas buffering for intermittent demand. Additionally, this is convenient for higher power density and efficiency in combustion engines where gas is consumed. The increase in voltage with respect to the internal pressure in the electrolytic cell is up to 3 - 4% for a working gas pressure of 25 bar, 4 - 5% for 50 bar, and 4 - 6% for 100 bar. Alternatively or additionally, a polymer electrolyte membrane (PEM) is used in the electrolytic cell to generate hydrogen and oxygen. The PEM may be introduced to overcome partial load problems and low current density in the electrolytic cell.

[0021] In a convenient embodiment, the hollow cell body is at least partially filled with an electrolyte so that the electrolyte does not flow into the gas extraction tube regardless of the orientation of the gas generator. The hollow cell body covers the entire first electrode, the non-conductive separator, and the second electrode. The electrolyte is preferably a liquid electrolyte such as, for example, water or other alkaline or aqueous liquids and may contain at least additives such as KOH (potassium hydroxide) or NaOH (sodium hydroxide). Such liquid electrolytes are inexpensive and provide a wide operating temperature range of -60°C to 110°C, especially with a 30 wt% KOH solution and water. Here, the mass fraction between the additive and the electrolyte is important. For example, 1 kg of 30 wt% electrolyte requires 0.3 kg of KOH and 0.7 kg of water.

[0022] KOH is preferably added to the electrolyte in the electrolytic cell at 15-45 wt%, and alternatively, NaOH is preferably added to the electrolyte in the electrolytic cell at 10-25 wt%. At these concentrations, the freezing point of the electrolyte is less than -10°C. To improve water separation, a suitable defoaming agent can be added to the electrolyte.

[0023] Preferably, the electrodes of the electrode pair are made of stainless steel. Thus, an increased electrolysis efficiency of over 60% is achieved. Further, the electrodes may include a metal sheet, a metal wire mesh, such as a plain weave or a metal fiber fleece. A practical and economical electrode is a mesh made of metal wires. For example, a sheet or wire mesh of stainless steel or nickel alloy should be beneficial.

[0024] In another embodiment, the gas extraction pipe is connected to the opening of the hollow tank body. Without any leakage, the gas extraction pipe transfers the working gas from the hollow tank body to the combustion chamber of the tool.

[0025] Preferably, the gas extraction pipe is connected to the opening of one of the first electrode contact or the second electrode contact. The working gas is collected, compressed in the hollow tank body, and discharged through the opening of the first electrode contact or the second electrode contact from the gas extraction pipe. The electrode contacts are electrically connected to the first electrode and the second electrode respectively by an electrical supply such as the battery. The electrode contacts are electrically connected to the first and second electrodes respectively by an electrical supply such as the battery. The first electrode thus acts as an anode and the second electrode acts as a cathode. A single electrolytic cell should ideally operate at a voltage of 2-2.5V.

[0026] More preferably, the gas extraction pipe extends through at least one of the described openings. Thus, the gas extraction pipe is easily connected to the gas dosing valve or the combustion chamber.

[0027] This hollow tank body includes a gas storage volume that serves as a pressure buffer for the intermittent gas demand of the gas supply valve. This hollow tank body also functions as a low-cost, portable, small energy storage device for operations such as the rupture setting of a nail driving tool. The gas storage volume may also include a part of the gas generator that is not entirely filled with the electrolyte in question.

[0028] In an advantageous embodiment, the hollow body includes a length in at least one dimension, and the gas extraction tube extends for at least one-third to two-thirds of the length of the hollow tank body. Thus, the amount of electrolyte in the electrolytic cell can be optimized, and no electrolyte leakage occurs during operation.

[0029] Preferably, the gas extraction tube extends for less than 60% of the length of the hollow tank body within the void. Thus, the working gas is efficiently transferred from the void, preventing any electrolyte leakage from the gas generator. Preferably, the gas extraction tube extends for at least 40% of the length of the hollow tank body within the void. Thus, the working gas is ideally transferred from the void, preventing any electrolyte leakage from the gas generator.

[0030] In an advantageous embodiment, the first electrode and the second electrode are wound up to form a reel inside the hollow tank body. The reel structure can ensure a large electrolytic area within the small volume of the hollow tank body. The electrodes on the plane of the reel are connected to the first electrode contact and the second electrode contact respectively for electrically supplying the first electrode and the second electrode. The first electrode and the second electrode are separated by a first non-conductive separator and a second non-conductive separator wound up in an electrode pair. The electrodes may be arranged axially with respect to the non-conductive separator so that the electrodes can each be in contact at the electrode contact. The advantage is that the production of the tank is simple.

[0031] Preferably, the first electrode and the second electrode are disposed in the hollow cell body in such a way that they form a void at the center of the hollow cell body. The first electrode and the second electrode can permeate the working gas. With this electrolytic separation structure, the working gas can flow radially toward the void toward the center of the electrolytic cell. Further, the working gas may advantageously flow axially to the end of the electrolytic cell and toward the center of the electrolytic cell toward the void.

[0032] In another advantageous embodiment, the first electrode and the second electrode include a disk-shaped structure, form a stack in the hollow cell body, and the disk-shaped structure includes a void at the center of the structure. The first electrode and the second electrode are separated by a non-conductive separator. The first electrode and the second electrode are disposed on individual disks. Several individual disks are stacked on top of each other, and the non-conductive separator is sandwiched between adjacent disks in each case. With this electrode separation structure, the working gas can flow radially to the void at the center of the electrolytic cell.

[0033] For example, a number of flat disk-shaped cells connected in series are used. For this purpose, bipolar plates without holes and separator membrane blanks are stacked alternately. The bipolar plate serves as the first electrode (anode) for one cell and as the second electrode (cathode) for the adjacent cell. The advantage is that the cell current is low for a given gas generation rate due to the large number of cells.

[0034] Alternatively, the first electrode and the second electrode include a circular inner winding structure within a hollow cavity, and the circular inner winding structure includes a void at the center of its structure. The first electrode and the second electrode are connected in parallel and separated by the non-conductive separator. The non-conductive separator is impermeable to the working gas. Alternatively, at least one of the first electrode or the second electrode is impermeable to the working gas. The working gas is directed into the void along the circular inner winding structure of the electrodes. Since oxygen gas cannot react with the cathode during gas transfer in the electrolytic cell, this structure provides high efficiency within the electrolytic cell. Typically, the process of gas production in the electrolytic cell generates heat. When the electrodes are designed with a circular inner winding structure, enhanced heat dissipation occurs within the electrolytic cell.

[0035] Preferably, the circular inner winding structure includes a plurality of sheets, and the plurality of sheets are divided into a first electrode and a second electrode, while the first electrode is used as an anode and the second electrode is used as a cathode. All the first electrodes may be connected in parallel, and all the second electrodes may be connected in parallel.

[0036] For example, an electrolytic cell consisting of many electrodes folded into a circular inner winding shape connected in parallel and provided with a separator in between. The electrodes are arranged axially so that the electrodes can easily contact the electrode contacts. This cell has the advantage of good radial thermal conductivity. In addition, the generated working gas can flow radially along the electrodes into the void at the center of the electrolytic cell, and the electrolyte can be drawn from the hollow cell wall. Countercurrent does not occur, and the electrolyte entrained in the gas flow additionally convectively cools the electrolytic cell.

[0037] In an advantageous embodiment, the gas extraction tube extends into the reel or the void of the structure. The gas extraction tube is connected to only one contact of the electrode and does not contact any other part of the electrolytic cell, so it is mainly exposed within the void. The working gas is collected within the void, and only the gas extraction tube can discharge the working gas from the electrolytic cell.

[0038] In an advantageous embodiment, the non-conductive separator comprises a porous material, specifically a net, cloth or non-woven fabric made of, for example, polypropylene (PP), polypropylene sulfide (PPS) or polyether ether ketone (PEEK), which is treated to have hydrophilic behavior. The porous separator absorbs and distributes the electrolyte into the electrolytic cell by capillary action. Preferably, the porous material is chemically resistant to concentrated additives such as KOH or NaOH. Alternatively, a membrane made of polyethersulfone (PES), and a membrane based on polyethersulfone (PES) with inorganic fillers such as zirconium dioxide, aluminum oxide, titanium dioxide or barium sulfate, etc., may be used as the non-conductive porous separator. Thus, the efficiency of hydrogen production in the electrolytic cell is stabilized. Oxidizing gas (hydrogen production) at the cathode can lead to parasitic side reactions, so a certain gas-tight wet separation membrane (bubble point test) is advantageous. This is preferably achieved by the good hydration of the separation membrane and the size of the largest pores. Furthermore, the water absorption effect of the separation membrane is advantageous for achieving uniform distribution of the electrolyte in the cell.

[0039] In an advantageous embodiment, at least a second electrolytic cell with an electrode pair consists of a first electrode, and the second electrode is arranged within the hollow cell body. Thus, the working gas is generated with higher efficiency.

[0040] Preferably, the at least second electrolytic cell is connected continuously to the first electrolytic cell. Thereby, the required electrolytic voltage increases, but the electrolytic current, and thus the ohmic losses in the gas generator, are also reduced. The advantage is that the current can be bisected to the same gas production rate, and thus the ohmic resistance losses are smaller.

[0041] Preferably, the bipolar contact plate is placed between the first electrolytic cell and the second electrolytic cell to reduce leakage current. A plurality of independent spring-loaded contacts provide good contact quality. Preferably, the bipolar contact plate has no holes, thus increasing the contribution of both electrolytic cells to gas production and thereby increasing efficiency.

[0042] In an advantageous embodiment, a hydrophobic filter is arranged in the gas extraction pipe. The hydrophobic filter ensures that there is no electrolyte coming out of the electrolytic cell when there is excess electrolyte in the gas generator. For example, a filter made of sintered or expanded polytetrafluoroethylene (PTFE), polypropylene (PP) or polyethylene (PE) should be advantageous due to its high hydrophobicity.

[0043] In an advantageous embodiment, the hollow tank body includes a filling opening for refilling the electrolyte into the electrolytic cell. Thus, the electrolytic cell can operate permanently. Preferably, the filling opening is connected to a liquid transfer pump for transferring water or electrolyte from a reservoir to the gas generator.

[0044] Preferably, the filling opening is arranged at one of the first electrode contact or the second electrode contact. Thus, the filling opening is arranged opposite to the inlet of the gas extraction pipe.

[0045] In an advantageous embodiment, a housing is provided to at least partially assimilate the hollow tank body. The housing provides mechanical protection for the electrolytic cell. The housing may be a pressure vessel. The pressure vessel needs to withstand the operating gas pressure and, more importantly, the pressure from an internal explosion of hydrogen-oxygen gas without rupturing the housing. The housing may include an insulator for insulating the housing from the electrode pair. The insulator includes a first insulating disk for the first electrode contact and a second insulating disk for the second electrode contact. The hollow tank body in question may have an insulating layer on the inside. A gasket for protecting the electrolytic cell may be included in the housing.

[0046] The housing can preferably be arranged on a tool for providing a replaceable gas generator. Thus, the gas generator can be replaced, for example, from a tool for refilling the electrolyte in the electrolytic cell.

[0047] According to a further aspect of the present disclosure, the object is achieved by the use of a gas generator as disclosed above within a tool, preferably within a hand-held tool. The gas generator operates constantly regardless of its spatial orientation, thereby becoming a gas generator particularly suitable for a tool, specifically a hand-held tool.

[0048] According to a further aspect of the present disclosure, the object is achieved by a tool including the above gas generator. The tool including the above gas generator operates constantly regardless of its spatial orientation.

[0049] The present invention will be described in more detail by way of examples of embodiments with reference to the following figures. The description of the reference signs is part of the present disclosure.

[0050] Position indicators such as "upper", "lower", "right" or "left" are related to the corresponding embodiments in each case and should not be understood as limitations.

[0051] Indicators such as "first", "second" or "further" are related to the corresponding devices in each case and should not be understood as limitations or enumerations.

[0052] For a better understanding of the present invention, reference is made to the drawings below. These merely show exemplary embodiments of the subject matter of the present invention. These embodiments, provided only for illustration and teaching, not for limiting the present invention, are shown and described in sufficient detail for those skilled in the art to be able to implement or realize the present invention. Therefore, the description may omit certain information known to those skilled in the art where appropriate to avoid obscuring the present invention.

[0053] In the figures and the associated description, parts that are the same or have similar functions are provided with the same reference numerals.

[0054] The present invention also encompasses the individual features shown in the figures, even if not shown and / or described above in connection with other features. Further, the terms "comprising" and its derivatives do not exclude other elements or steps. Similarly, the indefinite articles "a" or "one" and their derivatives do not exclude a plurality. The functions of the plurality of features recited in the claims may be performed by a single form. Terms such as "substantially", "about", "approximately" in relation to a characteristic or quantity also define exactly that characteristic or exactly that quantity. All reference signs in the claims should not be construed as limiting the scope of the claims.

Brief Description of the Drawings

[0055]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0056] Figures 1 and 2 show the gas generator 20 of the present invention for tools, including an electrolytic cell 30 with a hollow tank body 31 and an electrode pair 32 with a first electrode 33 and a second electrode 35. The first electrode 33 and the second electrode 35 are wound up to form a reel 39 inside the hollow tank body 31. The first electrode 33 and the second electrode 35 are separated by two non-conductive porous separators 37, 38 in the hollow tank body 31. The electrodes 33, 35 are connected to a first electrode contact 34 and a second electrode contact 36 on the plane of the reel 39 respectively for electrically supplying the first electrode 33 and the second electrode 35. The non-conductive porous separators 37, 38 are wound up with the electrode pair 32. The first electrode 33 and the second electrode 35 are arranged in the hollow tank body 31 in such a way that they form a void 40 at the center of the hollow tank body 31. The electrodes 33, 35 are arranged axially with respect to the non-conductive porous separators 37, 38.

[0057] The electrodes 33, 35 are in contact with the electrode contacts 34, 36 respectively. The electrode contacts 34, 36 are connected to an electrical supply, here a battery 50. When electrically contacted via wiring 51, the first electrode 33 provides an anode and the second electrode 35 provides a cathode. The hollow tank body 31 is at least partially filled with water containing KOH (potassium hydroxide) as a liquid electrolyte 45 as an additive. The additive remains in the electrolytic cell 30 while the water is refilled occasionally. The electrically contacted electrodes 33, 35 generate oxyhydrogen as a working gas 48 by an electrolyte moving in the direction of the void 40. The first electrode 33 and the second electrode 35 are permeable to the working gas 48. The reel 39 can flow the working gas 48 radially and axially towards the center of the electrolytic cell 30 into the void 40. The first electrode contact 34 includes a refill opening 43 for refilling water into the electrolytic cell 30.

[0058] The electrodes 33, 35 are wire meshes made of stainless steel. The non-conductive separators 37, 38 include wire meshes made of a porous material, namely polypropylene (PP). Alternative materials for the electrodes 33, 35 or the non-conductive separators 37, 38 are described above.

[0059] The electrolytic cell 30 includes a gas extraction pipe 55, and the gas extraction pipe 55 is disposed within the hollow cell body 31. The gas extraction pipe 55 is connected to the opening 44 of the second electrode contact 36. The hollow body 31 includes a length L in at least one dimension, and the gas extraction pipe 55 extends for less than at least half of the length L of the hollow cell body 31. The gas extraction pipe 55 extends into the gap 40 of the reel 39. Since the gas extraction pipe 55 is connected only to the second electrode contact 36 and does not contact another part of the electrolytic cell 30, most of the gas extraction pipe 55 is exposed within the gap 40. The working gas 48 is collected within the gap 40 and exits the electrolytic cell 30 exclusively through the gas extraction pipe 55.

[0060] The gas generator 20 includes a housing 22 for covering the hollow cell body 31. The housing 22 includes an insulator 24 for insulating the electrodes 33, 35 from the housing 22. The insulator 24 includes a first insulating disk 25 adjacent to the first electrode contact 34 and a second insulating disk 26 adjacent to the second electrode contact 38. The hollow cell body 31 includes an insulating layer 28 on the inside of the hollow cell body 31. The housing includes a gasket 29 for sealing the electrolytic cell 30, see FIG. 2.

[0061] FIG. 3 shows a further embodiment of the gas generator 120 of the present invention. The gas generator 120 includes generally the same structure and functional components as the gas generator 20 with respect to FIGS. 1 and 2. The gas generator 120 additionally includes a second electrolytic cell 130 connected continuously to the electrolytic cell 30. The second electrolytic cell 130 is structured identically to the electrolytic cell 30, and the first electrode 133 and the second electrode 135 form a reel 139. A solid bipolar contact plate 160 is placed between the electrolytic cell 30 and the second electrolytic cell 130 to reduce leakage current. A plurality of independent spring load contacts between the electrodes 33, 35 and 133, 135 provide good contact quality.

[0062] Figure 4 shows a further embodiment of the gas generator 220 of the present invention. The gas generator 220 includes substantially the same structure and functional components as the gas generator 20 with respect to FIGS. 1 and 2, but has a different electrode structure. The gas generator 220 includes an electrolytic cell 230 having a number of first electrodes 233 and a number of second electrodes 235 connected in series. The first electrode 233 and the second electrode 235 include a disk-shaped structure, form a stack within the hollow cell body 31, and the disk-shaped structure includes a void 40 at the center of the structure. For this purpose, in this example, a solid bipolar plate 231 and a separator membrane blank 237 made of polyethersulfone (PES) are alternately stacked. The bipolar plate functions as the first electrode 233 for one cell and as the second electrode 235 for an adjacent cell. The gas extraction tube 55 extends into the void 40. Since the gas extraction tube 55 is connected only to the second electrode contact 34 and does not contact another part of the electrolytic cell 230, most of the gas extraction tube 55 is exposed within the void 40.

[0063] Figure 5 shows a further embodiment of the gas generator 320 of the present invention. The gas generator 320 includes substantially the same structure and functional components as the gas generator 20 with respect to FIGS. 1 and 2, but has a different electrode structure. The gas generator 320 includes an electrolytic cell 330 having a number of first electrodes 333 and a number of second electrodes 335 that are connected in parallel and are bent into a circular inner winding 339 shape with a non-conductive separator 337 therebetween. The electrodes 333, 335 and the separator 337 are each arranged axially so that the electrodes 333, 335 can contact the electrode contacts 34, 36. The working gas 48 is guided to the void 40 along the circular inner winding structure 339 of the electrodes 333, 335. The gas extraction tube 55 extends into the void 40. Since the gas extraction tube 55 is connected only to the second electrode contact 34 and does not contact another part of the electrolytic cell 330, most of the gas extraction tube 55 is exposed within the void 40.

[0064] FIG. 6 shows one of the gas generators 20, 120, 220, 320 disposed within a tool 500, particularly a hand-held nail driving tool. The tool 500 includes a tool housing 501 with a movable tool installation 505 and one of the gas generators 20, 120, 220, 320 for operating the movable tool installation 505. For example, the gas generator 20 is disposed in the tool housing 501 and includes at least one electrolytic cell 30 for generating the hydrogen peroxide as the working gas 48. In addition, a temperature measuring device 518 is provided for measuring the temperature on the electrolytic cell 30. The tool 500 includes a liquid reservoir 510 for storing water 512. The liquid reservoir 510 is connected via a pipe 511 equipped with a pump 515 for transferring the water 512 into the electrolytic cell 30. The electrolytic cell includes KOH as an additive to the water 512. In addition, a check valve 514 is connected in between to avoid backflow. The electrolytic cell 30 includes the gas extraction pipe 55 as described above. The gas extraction pipe 55 is connected to a gas pressure measuring device 520 provided for measuring the gas pressure of the working gas 48.

[0065] The gas extraction pipe 55 is further connected to a dosing valve 525 for administering the working gas 48 extending from at least one electrolytic cell 30. By controlling the valve opening interval, the amount of the working gas 48 guided to the combustion chamber 506 of the movable tool installation 505 is controlled.

[0066] The tool 500 includes an electric circuit 507, and the electric circuit 507 is connected to the energy supply 50. The electric circuit is configured to control an ignition device 508 for igniting the working gas 48 in the combustion chamber 506 depending on the operation of the dosing valve and is connected to the pressure measuring device 520 and the temperature measuring device 518.

Explanation of Reference Numerals

[0067] 20 Gas generator 22 Housing 24 Insulator 25 Insulating disk 26 Insulating Disk 28 Insulating Layer 29 Gasket 30 Electrolytic Cell 31 Hollow Cell Body 32 Electrode Pair 33 The First Electrode of 32 34 First Electrode Contact 35 The Second Electrode of 32 36 Second Electrode Contact 37 Separator 38 Separator 39 Reel 40 Gap 43 Filling Opening 44 Opening 45 Electrolyte 48 Working Gas 50 Battery 51 Wiring 55 Gas Extraction Pipe L The Length of 30 120 Gas Generator 130 Electrolytic Cell 133 The First Electrode of 130 135 The Second Electrode of 130 139 Reel 160 Contact Plate 220 Gas Generator 230 Electrolytic Cell 231 Bipolar Plate 233 The First Electrode of 230 235 The Second Electrode of 230 237 Membrane 320 Gas Generator 330 Electrolytic Cell 333 The First Electrode of 330 335 The Second Electrode of 330 337 Separator 339 Circular Inner Winding 500 Tool 501 Tool Housing 505 Tool Equipment 506 Combustion Chamber 507 Power Circuit 508 Ignition Device 510 Reservoir 511 Pipe 512 Water 514 Check Valve 515 Pump 518 Temperature Measurement Device 520 Gas Pressure Measurement Device 525 Dosing Valve

Claims

**Claim 1** A gas generator (20, 120, 220, 320) for a tool (500) including an electrolytic cell (30, 130, 230, 330) having a hollow cell body (31), a first electrode (33, 133, 233, 333) and a second electrode, specifically for a hand-held tool, wherein the first electrode (33, 133, 233, 333) and the second electrode (35, 135, 235, 335) are separated by at least one electrically non-conductive separator (37, 38, 137, 138, 237, 337) within the hollow cell body (31), a gas extraction pipe (55) is disposed within the hollow cell body (31), the hollow body (31) includes a length in at least one dimension, and the gas extraction pipe (55) extends at least one-third to two-thirds of the length of the hollow cell body (31). **Claim 2** The gas generator according to claim 1, wherein the hollow cell body (31) is at least partially filled with an electrolyte. **Claim 3** The gas generator according to claim 1 or 2, wherein the gas extraction pipe (55) is connected to an opening (43) of the hollow cell body (31), preferably to an opening of one of a first electrode contact (34) or a second electrode contact (36). **Claim 4** The gas generator according to claim 1 or 2, wherein the first electrode (33, 133) and the second electrode (35, 135) are wound up to form a reel inside the hollow cell body (31), preferably the first electrode (33, 133) and the second electrode (35, 135) are arranged inside the hollow cell body (31) in such a way as to form a gap (40) at the center of the hollow cell body (31). **Claim 5** The gas generator according to claim 1 or 2, wherein the first electrode (233) and the second electrode (233) include a disc-shaped structure, form a stack inside the hollow cell body (31), the disc-shaped structure includes a gap (40) at the center of the structure, or the first electrode (333) and the second electrode (335) include an inner-wound structure inside the hollow cell body (31), and the inner-wound structure includes a gap (40) at the center of the structure. **Claim 6** The gas generator according to claim 4, wherein the gas extraction pipe (55) extends into the gap (40) of the reel or the structure. **Claim 7** The gas generator according to claim 1 or 2, wherein the non-conductive separator (37, 38, 137, 138, 237, 337) comprises a porous material, specifically a mesh.

8. At least a second electrolytic cell (130) provided with a first electrode (133) and a second electrode (135) is disposed within the hollow tank body (31), whereby the at least second electrolytic cell (130) is preferably connected continuously to the first electrolytic cell (30, 230, 330). The gas generator according to claim 1 or 2, characterized by this.

9. The gas generator according to claim 1 or 2, characterized in that a hydrophobic filter is disposed in the gas extraction pipe (55).

10. A housing (22) is provided to assimilate at least part of the hollow tank body (31), and the housing (22) can preferably be disposed on a tool (500) for providing an exchangeable gas generator. The gas generator according to claim 1 or 2, characterized by this.

11. The hollow tank body includes a refill opening (43) for refilling the electrolyte into the electrolytic cell (30, 130, 230, 330), and the refill opening (43) is preferably disposed at one of the first electrode contact (34) or the second electrode contact (36). The gas generator according to claim 1 or 2, characterized by this.

12. Use of the gas generator (20, 120, 220, 320) according to claim 1 or 2 within a tool (500), preferably within a handheld tool.

13. A tool (500), preferably a handheld tool, comprising the gas generator (20, 120, 220, 320) according to claim 1 or 2.

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