Adaptor for an air compressor and an air compressor

[0001] This invention relates to an attachment to a compressor generating compressed air, and in particular but not exclusively to a system operating with a compressor.

Background of the invention [0002] Compressors for producing compressed air can have various configurations, for example, they can be screw or reciprocating compressors. Compressed air is supplied via conduits to one or more pneumatic tools, for example pneumatic drills, pistol staplers and other pneumatic drive devices. These tools contain a pneumatic motor driven by compressed air generated by the compressor. A pneumatic motor generates a stream of used air that is released into the atmosphere. Escaping air can be a source of noise. Usually, the compressor does not allow continuous tool operation due to the resulting pressure drop.

[0003] In the German Patent Application No. 24 10 832, a method of reusing the air escaping from a pneumatic tool has been proposed, which under pressure, through an additional tank, is supplied to the compressor inlet. This design contains many components, including pipes, valves, sensors, which must be attached to an existing compressor. The pipe, with which the compressed air escaping from the additional pressure tank returns, is connected to only one cylinder of the multi-cylinder compressor. An additional pressure tank collects used air escaping from the tool. Due to the large size of the additional pressure vessel and due to the need to use many additional elements necessary for the operation of such a system, its practical use proves to be burdensome.

[0004] US 4 089 623 A discloses the design of an inlet damper housed in the compressor suction channel regulating the air supply depending on the compressor load. The safety valve connected to the exhaust duct opens when the air pressure in the exhaust duct exceeds the set value, whereby compressed air is supplied to the compressor inlet duct at the point between the inlet damper and the suction manifold of the compressor and the damper closes.

[0005] In published Japanese Patent Application Number 2002-174203 a pneumatic cylinder is disclosed. This application explains the use of pneumatic cylinders in pneumatic presses rather than the construction of pneumatic motors. As a result of the air flow through the compressor inlet duct, the cylinders' exhaust duct creates a vacuum and the air accumulating in this area is not compressed. In the preferred embodiment, it is recommended to use many valves servicing the actuators and electronic systems to control the entire system.

Summary of the Invention

[0006] Thus, the object of the present invention is to create an attachment that can be attached to any compressor to ensure uninterrupted operation of a pneumatic drive tool connected to this compressor.

[0007] Another object of the present invention is to create an attachment that will provide increased compressor performance.

[0008] Still another object of the present invention is to create an attachment that can be easily connected or integrated with a compressor producing compressed air without the need for a large number of mechanical components and electronic systems.

[0009] Given the objectives of the present invention thus defined, the most important aspect is to create a compressor adapter according to claim. 1. Furthermore, said attachment includes a pressure relief valve that opens when the pressure of the compressed air in the outlet duct exceeds the second of the predefined values.

[0010] It is preferred to use a plurality of said exhaust ducts, adapted to be connected to subsequent inlet ducts in multi-cylinder compressors.

[0011] Furthermore, the object of the invention is to create a compressor generating compressed air, with a suction manifold equipped with an inlet channel adapted to connect to the outlet channel at least one pneumatic tool in which a pneumatic motor is used, connected during operation to this compressor, and with an outlet channel adapted for connection during operation to the inlet channel of this compressor, with an open inlet for taking air from the atmosphere, and with a valve mechanism located near the inlet duct, which during operation closes said air inlet when the pressure of the compressed air produced by this compressor reaches the first pre-set value of approximately 1 bar or 14.5 psi or exceeds this value.

Brief description of the drawings [0012] For easier understanding of the essence of the invention and for its easier implementation, reference will be made to the accompanying drawings, among which:

Fig. 1 is a schematic view of an attachment made in accordance with the first preferred embodiment of the invention, intended to cooperate with a screw compressor;

Fig. 2 is a perspective view of the attachment shown in Fig. 1;

Fig. 3 is a schematic view of an attachment made in accordance with the second preferred embodiment of the invention, intended to cooperate with a single cylinder compressor.

Fig. 4 is a perspective view of the attachment shown in Fig. 3;

Fig. 5 is a schematic cross-sectional view of the adapter explaining its operation;

Fig. 6 is a schematic view of the attachment shown in Fig. 5, made in accordance with the third preferred embodiment of the invention, intended to cooperate with a multi-cylinder compressor.

Detailed description of the invention [0013] In Figs. 1 and 2, an adapter 10 is shown for connection to a screw compressor 11. The make or type of compressor does not affect the operation of the present invention. This design variant has been tested on a 5kW Ceccato rotary screw compressor.

-3 The adapter 10 is connected to the air inlet 12 of the compressor 11. The compressor 11 is equipped with a tank 13 for collecting compressed air driving the pneumatic tool 34. The adapter 10 includes a collector 14 in which the atmospheric air stream 5 indicated by arrows 17 taken from the environment by the inlet 16 is mixed with the used compressed air 18 supplied through the inlet 20. The compressed air inlet 20 is equipped with a nipple 24 which is inserted into the sleeve 26 located inside the collector 14. The sleeve 26 includes two one-way valves 30 whose through holes 31 open when the pressure of used compressed air 32 escaping from the tool (s) pneumatic 34 reaches a predetermined value. An adjustable pressure relief valve or a pair of adjustable pressure relief valves (as shown in the figure) is (are) introduced into the manifold 14 and is used to remove excess compressed air through the outlets 38. Typically, pressure relief valves 36 remove excess compressed air when its pressure reaches about 4 bar, so you can be sure that the recovered compressed air 32 does not create too much back pressure in the inlet channel 12. In Fig. 2 an embodiment of the actual construction of the manifold 14 with two pressure relief valves 36 located on its lateral part, used in this embodiment of the invention, is shown, and for a clearer explanation of the operation of the adapter 10, the adjustable pressure relief valves shown in Fig. 1 are located in top of the collector 14. Adjustable pressure (s) pressure relief valve (s) 36 can (can) be placed (positioned) at any of these locations. During operation, the adapter 10 is applied to the compressor 11 as described. When the compressor 11 starts to operate, the valve 30 is closed because the holes 31 are covered and the air flow is drawn through the inlet 16, as shown by arrows 17. The stream of air to be compressed and placed in the tank 13 is fed directly to the inlet 12. The outlet 19 of the tank with compressed air 13 is connected by means of a connector 25 to a pneumatic (pneumatic) tool (s) 34, whose outlet (outlets) can be connected to the collector 14 via a nipple 24. It is not necessary to connect all outlets of all pneumatic tools to a nipple 24. For example, a spray gun that does not include a pneumatic motor will not have such a connection, while a drill may. The air pressure in the sleeve 26 will increase until the valve 30 opens. By using the pressure relief valve (s) 36 the pressure will be kept at 4 bar. When the valve 30 is opened, the air supply 16 is closed by the valve 33 and a closed loop is formed starting from the exhaust air outlet from the pneumatic tool 34 and leading to the inlet 12. In this particularly preferred embodiment of the invention, the valve 33 will serve to close the air inlet 16 when the pressure reaches 1 bar or 14.5 psi or higher. The adapter 10 will stop introducing moist air into the compressor taken from its surroundings. As a result, the compressed air will be cleaner, which will improve the life of the compressor 11 and the pneumatic tool 34 connected to it. Due to the fact that the stream of compressed air (marked with arrows 35) is introduced into the compressor 11, the compressor 11 has less work to do, since the circulating air has already been compressed and has a pressure of 4 bar. This circulation increases the efficiency of the compressor 11. The described embodiment of the invention was tested and compared with a compressor to which the adapter 10 was not attached. In the case of a compressor in operation

-4 without an attachment it took 3 to 5 minutes to obtain a pressure of 8.5 bar and after connecting to a pneumatic drill compressor, the pressure dropped to 5.2 bar. At that time, the air expelled from the cooling system was 32 ° C, the air in the inlet was 57 ° C and the air in the outlet pipe of the tank was 22 ° C.

[0014] In the compressor to which the adapter 10 was connected, the pressure dropped to 5.7 bar only after 9 minutes and remained at this level for 16 minutes, after which the test was completed. At 5.7 bar, the pneumatic drill can continue to operate at full capacity. At the end of the test, the air expelled from the cooling system was 27 ° C (compared to 32 ° C), the air in the inlet was 45 ° C (compared to 57 ° C) and the air in the outlet pipe of the tank was 18 ° C ( compared 22 ° C). When the compressed air temperature is lower than the ambient temperature, the compressor will heat up less. The compressor will work automatically and will not require manual air removal to avoid excessive pressure build-up or manual air intake. These temperature drops are important because long-term maintenance will be limited due to the compressor's lower operating temperature. Pneumatic tools will be less noisy because the used air is re-introduced into the compressor and not discharged into the environment. For these reasons, smaller compressors can be used to avoid the use of compressors powered from a three-phase power grid.

[0015] In Fig. 3 to Fig. 6, the adapter 50 is shown. In this embodiment of the invention, the adapter 50 is connected to a piston compressor 51. In Fig. 3 to Fig. 5, the adapter for a single-cylinder compressor is shown, and in Fig. 6 there is a three-cylinder compressor attachment (not shown). The attachment 50 shown in Fig. 6 includes a manifold 52 with three (3) outlets 54, 56, 58 adapted to be connected to respective inlet ports (not shown) of each of the compressor cylinders. An adjustable pressure relief valve 60 is located at the end of the manifold 52 near the outlet 54. Pressure relief valve 60 operates in a similar manner to valves 36 shown in Fig. 1 and includes outlet (outlets) 62. The branch 64 extending from the collector 52 includes a one-way valve 66 that allows air from outside the compressor 68 to pass through inlet 70. The waste air stream 72 passes through the waste air inlet 74.

[0016] The operation of this embodiment of the invention is similar to the operation of the variants shown in Fig. 1 and Fig. 2. The air flow 68 is introduced through the inlet 70 and passes through the open non-return valve 66 and is supplied to the manifold 52. The air flows through the outlets 54 , 56, 58 and is compressed by the compressor. When the operating pressure is reached, the valve 66 closes and a closed loop is created from the exhaust air outlet from tool (s) 34 to manifold 52.

[0017] In this embodiment of the invention, the adapter 50 has been tested with a 2.2kW single-phase McMillian compressor having three (3) cylinders. This embodiment was compared with a compressor to which the 50 adapter was not connected. Without the use of the adapter, starting from 8.5 bar, the compressor with a pneumatic drill connected took 57 seconds to fall to 4 bar. Using the 50 attachment, the compressor took 6.5 minutes to reach 5.0 bar and this pressure level was maintained for 9 minutes until the test was completed. With a pressure of 5.0 bar, the pneumatic drill can still work at full capacity

-5wydajnością.

[0018] Although the embodiment shown in Fig. 6 is intended to work with multi-cylinder compressors, the invention can be used with single-cylinder compressors, as shown in Fig. 3 to Fig. 5. To avoid having to duplicate the descriptions, in Fig. 3 to Fig. 5 uses the same reference numbers as in Fig. 6. In the embodiments shown in Fig. 1 and Fig. 2 the structure of the collector 50 is visible with the outlet 54 located at the location indicated in Fig. 4, while in Fig. 5 the structure is shown in which the outlet 54 is located in the upper part of the collector 52. This is to provide a clearer illustration of the principle of the attachment 50. Elements such as outlet 54, pressure relief valve 36, intake for air 70 and exhaust air 74 can be located in any suitable places. The invention will work with any type of compressor and there are no restrictions as to whether these will be screw, rotor or piston compressors.

[0019] The present invention does not require the use of electronic, pneumatic devices, switches, electromagnets, additional tanks or other utensils that require prior solutions. The number of elements used has been drastically limited, which makes compressor maintenance considerably simplified. The simplicity of the present invention contributes to the total elimination of failures resulting from its use. Because air is introduced into the compressor at a pressure greater than 1 atmosphere, a lower compression ratio is required to achieve the required pressure from the compressor. In contrast to the situation where the air pressure supplied to the compressor cylinder is only 1 bar (atmospheric pressure), when the present invention has a pressure of up to four bars, each rotation of the compressor shaft compresses three times more air. Considering that the present invention allows the production of four times more power, the operation of the machine in such conditions causes a significant load on the engine driving the compressor. To limit this load on the motor driving the compressor, when optimizing the machine operating conditions, it is assumed that the present invention is adjusted in such a way that it provides approximately twice the pressure compared to conventional compressors of similar sizes. In addition, compressors that produce compressed air are noisy machines, and the present invention allows a noise reduction of up to 50 percent. The application of the present invention also results in other benefits, which include the improvement of occupational health and safety conditions, since the potential risk resulting from the harmful effect of the exhausted air on the operator operating pneumatic tools has been eliminated. The access of steam was limited and the pneumatic system heats up less, which increases the service life of pneumatic tools. When compressing air, a large amount of heat is emitted, while during expansion in pneumatic tools it cools down considerably (up to 35 degrees). In the present invention, cool, used air is introduced into the compression system to keep the system at a low temperature. Access to steam is limited, because during compression the attachment does not suck in fresh air (in which moisture is contained) from the surroundings of the compressor. The air is simply circulating.

[0020] Embodiments illustrate attachments 10, 50 which can be a new part of compressors, they can also be integrated into the structure of the compressor as such. The present invention maintains the flexibility that it can be used with existing ones

-6 compressors or can be integrated with newly constructed compressors.