DK2955380T3

DK2955380T3 - AIR COMPRESSOR LAYOUT

Info

Publication number: DK2955380T3
Application number: DK13874477.6T
Authority: DK
Inventors: Wen-San Chou
Original assignee: Chou Wen San
Priority date: 2013-02-07
Filing date: 2013-02-07
Publication date: 2018-09-03
Also published as: KR101801626B1; CN104956083B; CN104956083A; EP2955380B1; HUE040241T2; JP2016509154A; WO2014121498A1; KR20150110503A; JP6178866B2; TR201812103T4; EP2955380A4; PL2955380T3; EP2955380A1

Description

DESCRIPTION (a) Technical Field of the Invention [0001] The present invention relates to an air compressor, which can prevent a tire from overinflation without using a mechanical safety valve. (b) Description of the Prior Art [0002] The applicant has been dedicated to developing air compressors for a long time. At the early days, the applicant successfully converted a labor-intensive and complicated air compressor into an air compressor that is simple in structure and can be quickly assembled. In US Pat. No. 7,462,018, an outlet header is provided with a plurality of ducts or outlets, one of which can be connected with a safety valve. When a piston body, which conducts reciprocating motion in a cylinder, reaches top dead center, the head of the piston body almost contacts the top wall of the cylinder, there is no space between the head of the piston body and the top wall of the cylinder. The air compressor is installed with a safety valve. When the air compressor is used to inflate a tire, if the pressure of the air supply is greater than a safety pressure set for the tire, the safety valve can act automatically to release air into the environment However, after the safety valve has served for a long time, the valve may be stuck, so that it cannot work properly upon a high pressure of the compressed air produced in the air compressor. Thus, a tire may be excessively inflated, thereby causing a blowout.

[0003] From US 2 047 167 A a refrigeration compressor is known that comprises an adjustable clearance piston allowing for varying the volume of the main cylinder and thus the capacity of the compressor.

[0004] GB 1 313 306 A describes a self - regulating air compressor having a first piston movable along a first cylinder for compressing air and an adjustable clearance volume connected to the cylinder for regulating the generated outlet air pressure, whereat the clearance volume is adjusted by a movable piston, [0005] US 5 902 097 A discloses an air pumping device comprising a manually-operated relief valve comprising a button, a stem, an O-ring and a spring.

SUMMARY OF THE INVENTION

[0006] One object of the present invention is to provide an air compressor, which allows air supply to keep less than a safety pressure without using a mechanical safety valve, so that a tire can be inflated without exceeding a safety pressure thereof [0007] To achieve the above object, the present invention offers an air compressor with the features of claim 1. Further embodiments are subject matter of the dependent claims.

[0008] The air compressor according to the invention includes a box and an electrically operated compressor unit installed in the box, wherein a motor drives a piston body to conduct reciprocating motion in a cylinder to produce compressed air, which can be transferred into an air storage container provided with a plurality of outlets; when the piston body reaches top dead center, a space is existed between a head of the piston body and a top wall of the cylinder, a tube is formed integrally with the air storage container and on the cylinder, wherein the tube does not communicate with the air storage container, an adjusting bolt being threadedly fitted into the tube to define an auxiliary air chamber communicating with an inner space of the cylinder via an auxiliary exit hole.

[0009] As described above, one feature of the present invention is that when the piston body reaches top dead center, a space is existed between the head of the piston body and the top wall of the cylinder. Another feature of the present invention is that the auxiliary air chamber cooperates with the inner space of the cylinder to increase the operational security. As compared to the conventional technology, the air compressor of the present invention can keep the pressure of air supply less than a safety pressure without using a mechanical safety valve, so that a tire can be inflated without exceeding a safety pressure thereof, and at the same time, the manufacturing cost of the air compressor can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 shows a 3-dimensional view of an air compressor, including a box and a compressor unit, according to one embodiment of the present invention. FIG. 2 shows an exploded view of the compressor unit. FIG. 3 shows a 3-dimensional view of the compressor unit. FIG. 4 shows a schematically sectional view of the air compressor. FIG. 5 shows an enlarged, partial view of the air compressor shown in FIG. 4. FIG. 6 shows a schematically sectional view of the air compressor, wherein a relief valve is depressed for releasing air into the environment. FIG. 7 shows a schematically sectional view of the air compressor, wherein an adjusting bolt is turned for adjusting the volume of an auxiliary air chamber. FIG. 8 shows a schematically sectional view of the air compressor, wherein the piston body has conducted an upward stroke to reach top dead center, and a space is existed between the head of the piston body and the top wall of the cylinder. FIG. 9 shows another schematically sectional view of the air compressor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] For further illustrating the technical contents of the present invention, one embodiment is provided in the following paragraphs.

[0012] Referring first to FIGS. 1 through 4, an air compressor according to one embodiment of the present invention is shown, which generally includes a box 1 and a compressor unit installed in the box 1, wherein the box 1 is provided with a switch 11, a button 12, and a transparent window 13. The compressor unit includes a cylinder 3, which allows a piston body 25 to operate therein, and a main frame 20, which is formed integrally with the cylinder 3 and used to mount a motor 21.

[0013] The main frame 20 also mounts a transmission mechanism, which includes a pinion 22 and a gear 23 provided with a counterweight 28 and a crankpin 24. The motor 21 is fitted with a cooling fan 27. The motor 21 can drive the transmission mechanism to have the piston body 25 conduct reciprocating motion along an inner surface 34 of the cylinder 3 to produce compressed air, which can overcome a compression spring 42 and thus push a plug 41 up, so that the compressed air can be transferred into an air storage container 5 via an exit hole 32.

[0014] The air storage container 5 is provided with a plurality of outlets 52, 53, 55 (see also FIG. 9), wherein the outlet 52 is connected with a hose 91; the outlet 53 is connected with a relief valve 7; the outlet 55 is connected with a pressure gauge 9.

[0015] One primary feature of the present invention is that: when the piston body 25 has conducted an upward stroke to reach top dead center, a space 33 is existed between the top wall 31 of the cylinder 3 and the head 26 of the piston body 25, as shown in FIG. 7. Therefore, the pressure of the compressed air does not exceed a predetermined pressure set for a tire to be inflated, without requiring the compressor unit to install a mechanical safety valve, so that a user can inflate a tire more conveniently, and the tire can be protected from over-inflation. Another feature of the present invention is that a tube 54 is formed integrally with the air storage container 5 and on the cylinder 3, wherein the tube 54 does not communicate with the inner space 51 of the air storage container 5. The tube 54 defines therein an auxiliary chamber 541 communicating with the inner space 33 of the cylinder 3. An adjusting bolt 8 is threadedly fitted into the tube 54 for adjusting the volume of the auxiliary chamber 541.

[0016] Referring now to FIGS. 4 through 8, the bottom 50 of the air storage container 5 is joined to the top wall 31 of the cylinder 3. The top wall 31 defines the exit hole 32 and an auxiliary exit hole 35. The exit hole 32 allows the inner space 33 of the cylinder 3 to communicate with the inner space 51 of the air storage container 5. The auxiliary exit hole 35 allows the inner space 33 of the cylinder 3 to communicate with the auxiliary chamber 541 of the tube 54. The plug 41 is placed on the exit hole 32 defined on the top wall 31. A rectangular top cover 6 has a rotating handle 61 at its outer surface and a central column 62 extending from its inner surface (see FIG. 5). The central column 62 has a base portion and a reduced portion 64 extending from the base portion, wherein a step 63 is formed between the base portion and the reduced portion 64. The base portion of the central column 62 is provided with a plurality of annular protrusions 621 and defines a plurality of annular grooves 622 at its outer surface. A plurality of seal rings 65 are fitted into the annular grooves 622 of the central column 62.

[0017] As shown in FIG. 3, the top cover 6 can be coupled to the air storage container 6 by turning the rotating handle 61. One end of the compression spring 42 is engaged with the plug 41, while an opposite end of the compression spring 42 is engaged with a lowest one of the annular protrusions 621.

[0018] Referring to FIGS. 2 and 5, the relief valve 7 includes a hollow soft cap 71 having a tip 711 and an annular portion provided with a plurality of spaced protrusions 712 at its outer surface. Between two adjacent protrusions 712 defines a gap 713. A mounting bolt 72 defines a central through hole 722 extending from an opening 721 at one end of the mounting bolt 72, wherein the central through hole 722 of the mounting bolt 72 has a diameter smaller than the opening 721 of the mounting bolt 72. The soft cap 71 is fitted in the outlet 53. The mounting bolt 72 is fitted into the outlet 53 to have an opposite end of the mounting bolt 72 located near the soft cap 71. The annular portion of the soft cap 71 is engaged with an inner surface of the outlet 53. The tip 711 of soft cap 71 is located near the opposite end of the mounting bolt 72. A push bar 121 of the button 12 is inserted through the through hole 722 of the mounting bolt 72 to touch the tip 711 of the soft cap 71. The button 12 may be depressed to allow its push bar 121 to compress the soft cap 71 and thus deform the soft cap 71, so that excessive air in an object to be inflated can be released into the environment via the outlet 53 which connects the relief valve 7, as shown in FIG. 6. The adjusting bolt 8, which is threadedly fitted into the tube 54, defines at its outer surface an annular groove 81 to be fitted with a seal ring 82. Turning the adjusting bolt 8 can adjust the volume of the auxiliary chamber 541, which in turn affect the inner space 33 of the cylinder 3, as shown in FIGS. 5 and 7.

[0019] When the piston body 25 has conducted an upward stroke to reach top dead center, as shown in FIG. 7, the space 33 is existed between the head 26 of the piston body 25 and the top wall 31 of the cylinder 3; namely, the head 26 of the piston body 25 is not located near the top wall 31 of the cylinder 3. As shown, the space 33 has a depth indicated by the symbol (X) between the top surface of the head 26 of the piston body 25 and the top wall 31 of the cylinder 3. Furthermore, when the piston body 25 conducts an upward stroke, the compressed air contained in the inner space 33 of the cylinder 3 can overcome the compression spring 42 to push the plug 41 up and thus flow into the inner space 51 of the air storage container 5 via the exit hole 32 defined on the top wall 31 of the cylinder 3, and then can flow into an object via one of the outlets 52, 53, 55. Furthermore, the upward movement of the plug 41 can be limited by the reduced portion 64 of the central column 62 of the top cover 6, as shown in FIGS. 7 and 9.

[0020] Referring to FIGS. 6 and 7, a user may turn the adjusting bolt 8 fitted at the tube 54 to adjust the volume of the auxiliary air chamber 541 that communicates with the inner space 33 of the cylinder 3, so that the pressure of the compressed air produced in the cylinder 3 will be less than a safety pressure for an object to be inflated.

[0021] The distance (X) between the head 26 of the piston body 25 and the top wall 31 of the cylinder 3 can be obtained from the formula: X = S / (P'-1), where S is the piston stoke; P' is the ratio between the maximum permissible output pressure and the atmospheric pressure.

[0022] For example: if the atmospheric pressure is about 101.325 KPa, the piston stroke S is 16, and the maximum permissible output pressure is 350 KPa, then P' equals to 350 KPa I 101.325KPa = 3.45, and thus the distance X equals to 16 / (3.45-1) = 6.53. To change the maximum permissible output pressure of the compressor unit, a user may turn the adjusting bolt 8 fitted at the tube 54 to change the volume of the auxiliary chamber 541 which communicates with the inner space 33 of the cylinder 3. As such, the compressor unit does not require a mechanical safety valve to limit the pressure of the compressed air produced in the cylinder, so that a user can inflate a tire more conveniently, and the manufacturing cost of the compressor unit can be reduced.

[0023] In light of the foregoing, one feature of the present invention is that when the piston body 25, which conducts reciprocating motion in the cylinder 3, reaches top dead center, a space is existed between the head 26 of the piston body 25 and the top wall 31 of the cylinder 3, so that the pressure of the compressed air produced in the cylinder 3 will not exceed a safety pressure for a tire to be inflated. Another feature of the present invention is that the adjusting bolt 8 can adjust the volume of the auxiliary air chamber 541 of the tube 54 to adjust the maximum permissible output pressure of the compressor unit. These features render the present invention useful.

[0024] The above embodiment and drawings are not for limiting the shape and style of the present invention. Persons with ordinary skills in the art can make variations or modifications to the embodiment without departing from the scope of the present invention.

REFERENCES CITED IN THE DESCRIPTION

This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description • US7462018B [00021 • US2047167A [00031 • GB1313306A [0004] • US5902Q97A r0005]

Claims

An air compressor including a housing (1) and an electrically driven compressor unit mounted in the housing (1), wherein an engine (21) drives a piston body (25) to perform reciprocating motion in a cylinder (3). to produce compressed air which is transferred to an air storage vessel (5) provided with a plurality of outlets (52, 53, 55); wherein, when the piston body (25) reaches the top position, there is a space between the head (26) of the piston body (25) and the top wall (31) of the cylinder (3); wherein a tube (54) is formed integrally with the air storage container (5) and on the cylinder (3), the tube (54) not communicating with an inner space (51) of the air storage container (5), characterized in that an adjusting bolt ( 8) adapted with threaded screw into the tube (54) to define an auxiliary chamber (541) which communicates with an inner space (33) of the cylinder (3) via an auxiliary exit hole (35) and wherein the housing (1) ) is provided with a button (12); wherein one of the outlets (52, 53, 55) is connected to a relief valve (7) which includes a hollow soft cap (71) having a tip (711) and an annular portion provided with a plurality of spaced projections ( 712) on its outer surface between two adjacent projections (712) defining a gap (713); a mounting bolt (72) defining a central through-hole (722) extending from an opening (721) at one end of the mounting bolt (72), said central through-hole (722) of the mounting bolt (72) having a diameter smaller than the opening (721) of the mounting bolt (72), the soft cap (71) being fitted into the outlet connected to the relief valve (7), the mounting bolt (72) being fitted to the outlet connecting the relief valve (7) having an opposite end of the mounting bolt (72) located near the soft cap (71), which annular portion of the soft cap (71) engages an inner surface of the outlet connecting the relief valve ( 7), wherein the tip (711) of the soft cap (71) is positioned near the opposite end of the mounting bolt (72) and wherein a push button (121) of the button (12) is inserted through the through hole (722) of the mounting bolt (72) to touch the tip (711) of the soft hood (71); whereby the button (12) can be depressed to allow its push bar (121) to compress the soft cap (71) and thus deform the soft cap (71) so that excess air in an object to be inflated can flow through the slots (713) of the soft cap (71) and through the hole (722) of the mounting bolt (72) to be released to the environment.

The air compressor according to claim 1, further characterized in that the adjusting bolt (8) defines at its outer surface an annular groove (81) to be fitted with a sealing ring (82) whereby the volume of the auxiliary chamber (541) can be adjusted by turn the adjusting bolt (8).

The air compressor according to claim 1, further characterized in that a bottom (50) of the air storage container (5) is connected to the upper wall (31) of the cylinder (3), the top wall (31) defining an exit hole (32), allowing the inner space (33) of the cylinder (3) to communicate with the inner space (51) of the air storage container (5); wherein a plug (41) is disposed at the exit hole (32) of the top wall (31); wherein a rectangular top cover (6) is provided with a rotating handle (61) at its outer surface and a central column (62) extending from its inner surface, said central column (62) having a base section and a reduced section ( 64) extending from the base section, wherein a step (63) is formed between the base section and the reduced section (64), which base section of the central column (62) is provided with a plurality of annular projections (621) and defines a number of annular grooves (622) at its outer surface; wherein a plurality of sealing rings (65) are mounted in the annular grooves (622) of the central column (62); wherein the top cover (6) can be coupled to the air storage container (6) by turning the rotary handle (61); wherein one end of a compression spring (42) is connected to the plug (41) and where an opposite end of the compression spring (42) is connected to the lower of the annular projections (621).