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EP 2 280 169 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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01.05.2013 Bulletin 2013/18 |
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Date of filing: 28.08.2000 |
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International Patent Classification (IPC):
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Airless spray pump
Luftlose Zerstäuberpumpe
Pompe à pulvérisation sans air comprimé
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Designated Contracting States: |
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DE ES FR GB IT |
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Priority: |
31.08.1999 US 151794 P 22.11.1999 US 166946 P
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Date of publication of application: |
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02.02.2011 Bulletin 2011/05 |
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Application number of the earlier application in accordance with Art. 76 EPC: |
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05077480.1 / 1635062 |
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00961390.2 / 1208287 |
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Proprietor: Graco Minnesota Inc. |
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Minneapolis, MN 55440-1441 (US) |
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Inventors: |
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- Davidson, Glen W
Roseville, MN 55113 (US)
- Kapelevich, Alexander P
Shoreview, MN 55126 (US)
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Representative: Cloughley, Peter Andrew |
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Miller Sturt Kenyon
9 John Street London WC1N 2ES London WC1N 2ES (GB) |
(56) |
References cited: :
US-A- 2 366 237 US-A- 3 067 624 US-A- 5 769 321
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US-A- 2 366 238 US-A- 5 435 697
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Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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TECHNICAL FIELD
[0001] Airless spray pumps for the spraying of paints and other coatings.
BACKGROUND ART
[0002] Airless spray pumps for the spraying of paints and other coatings via the airless
method are well known and have traditionally been divided into two types, diaphragm
pumps for the lower end of the market and reciprocating piston pumps for the higher
end.
[0003] US 5769321 which is considered to be the closest prior art discloses a piston paint pump in
which a motor and pinion are provided in-line with a centreline of the pump.
DISCLOSURE OF THE INVENTION
[0004] According to the present invention there is provided a spray pump according to claim
1 powered by a rotary motor having a pinion thereon and comprising: a housing; a single-acting
piston pump having a pump rod and connected to said housing; a drive gear assembly
comprising a gear and an eccentric located on said gear; a bearing located about said
eccentric; and a yoke reciprocatingly located in said housing and about said bearing,
characterised in that said motor and pinion are offset from a centreline of said pump,
whereby thrust loads on the yoke are reduced and pump forces are offset and reduced.
[0005] An airless spray pump is provided with a single-acting piston pump which allows the
use of a low-cost yoke drive. Motor and pump shaft are offset for most efficient force
utilization. The pump preferably includes the following features:
[0006] The main drive housing has a motor mounted to the rear thereof. A gear assembly uses
gear teeth which are formed with a 5° helical angle and have a 25° pressure angle.
This geometry combines the higher efficiency of straight cut gears with the noise
reduction typified in a helical design.
[0007] An eccentric is molded onto the front of the gear assembly and has located thereabout
a bearing assembly which rides inside a yoke. The yoke moves vertically on guide rods
which are retained in pockets of the drive housing. The yoke is molded of plastic
as is the gear assembly leading to lower cost and easier manufacture.
[0008] The pump rod is provided with a cap over the top end thereof which has bearing. Pump
assembly is designed as a single acting pump, that is, the pump only pumps on the
downward stroke and loads on the upward stroke. This allows the components of the
drive train, including the yoke and gear, to be much lighter as the yoke ends up being
more of a guidance device rather than a force-applying device.
[0009] The motor and pinion are offset from the centerline of the pump assembly. This arrangement
does not have any significant cantilevering as the pump rod, pinion, yoke, eccentric
and cap are all located in the same plane. The location of the rod and the single
acting pump with respect to the gear centerline reduces the thrust loads on the yoke.
The location of the pinion on the gear partially offsets and reduces the pump forces
on the gear shaft and bearings. By locating the eccentric bearing directly on the
end of the pump rod cap which is press-fit it eliminates the transfer of pumping force
through an intermediate member such as the yoke which provides longer life, efficiency
and allows the manufacture of a more inexpensive yoke assembly.
[0010] The shaft packing assembly is comprised of a packing housing which screws into the
pump housing and which contains a felt member which has been soaked with throat seal
lubricant or other solvent or lubricant. A stack of v-packings are compressed in place
by wave spring which is tightened by tightening the seal housing into the pump housing
.
[0011] The inlet check is provided with a check ball and a check seat which is pressed into
a check housing and which is held in place by a retainer. These parts all press-fit
into one another such that the complete assembly be merely screwed into main pump
housing for replacement. Similarly, outlet check assembly is formed of an outlet check
housing which is screwed into a pump housing and similarly is provided with a check
ball held in place by a retainer. The outlet passageway is angled relative to the
axis of the pump shaft. This allows the outlet check assembly to operate essentially
via gravity and yet requires only the drilling and provision of one passageway while
maintaining an essentially vertical ball-seat relationship.
[0012] These and other objects and advantages of the invention will appear more fully from
the following description made in conjunction with the accompanying drawings wherein
like reference characters refer to the same or similar parts throughout the several
views.
BRIEF DESCRIPTION OF DRAWINGS
[0013]
FIG. 1 is a prospective exploded view showing the airless spray pump with the instant
invention.
FIG. 2 is a simple front plan view of the drive assembly and pump of the instant invention.
FIG. 3 is a side plan view of the assembly shown in FIG. 1.
FIG. 4 is a detailed exploded view of the circled area in FIG. 3.
FIG. 5 is a cross-sectional view of the pump of the instant invention.
FIG. 6 shows more details of the drive assembly of the instant invention.
FIG. 7 is another cross-sectional view of the pump portion of the instant invention.
FIG. 8 is a cross-section of the outlet filter of the instant invention.
FIG. 9 is an exploded view of the outlet filter of the instant invention.
FIG. 10 is a perspective exploded view of the instant invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0014] The instant invention generally designated 10 is comprised of a main drive housing
12 having a motor 14 mounted to the rear thereof. A gear assembly 16 having a rear
bearing 17 and gear teeth 22 is inserted into the bearing housing 20 of drive housing
12. Gear teeth 22 on gear assembly 16 mate with the teeth on pinion 24 on the end
of motor 14. The teeth 22 and on pinion 24 are formed with a 5° helical angle and
have a 25° pressure angle. This geometry combines the higher efficiency of straight
cut gears with the noise reduction typified in a helical design.
[0015] An eccentric 25 is also molded onto the front of gear assembly 16 and has located
thereabout a bearing assembly 28 which rides inside a yoke 30. Yoke 30 moves vertically
on guide rods 32 which are retained in pockets 34 of drive housing 12. Yoke 30 is
molded of plastic. Gear assembly 16 is cast in ZA-12 with an integral counterweight
leading to lower cost and easier manufacture.
[0016] Pump rod 36 is provided with a cap 38 over the top end thereof which has bearing
upon it bearing 28. Pump assembly 40 is designed as a single acting pump that is the
pump only pumps on the downward stroke and loads on the upward stroke. In doing so
this allows the components of the drive train, including the yoke and gear, to be
much lighter as the yoke 30 ends up being more of a guidance device rather than a
force-applying device.
[0017] As can be seen more particularly in FIG. 2, motor and pinion 24 are offset from the
centerline 42 of pump assembly 40 which also has offset therefrom bearing 20 in the
opposite direction. Also, this arrangement does not have any significant cantilevering
as the pump rod, pinion, yoke, eccentric and cap are all located in the same plane.
The location of the rod and the single acting pump with respect to the gear centerline
reduces the thrust loads on the yoke. The location of the pinion on the gear partially
offsets and reduces the pump forces on the gear shaft and bearings. By locating the
eccentric bearing directly on the end of the pump rod cap which is press-fit it eliminates
the transfer of pumping force through an intermediate member such as the yoke which
provides longer life, efficiency and allows the manufacture of a more inexpensive
yoke assembly.
[0018] The shaft packing assembly 44 shown in FIG. 4 is comprised of a packing housing 46
which screws into pump housing 48 and which contains a felt member 50 which has been
soaked with throat seal lubricant or other solvent or lubricant. A stack of v-packings
52 are compressed in place by wave spring 54 which is tightened by tightening seal
housing 46 into pump housing 48.
[0019] Turning to FIG. 7, inlet check 56 is provided with a check ball 58, a check seat
60 which is pressed into check housing 62 and which is held in place by retainer and
integral ball guide 64. These parts all press-fit into one another such that the complete
assembly be merely screwed into main pump housing 48 for replacement. Similarly, outlet
check assembly is formed of an outlet check housing 60 which is screwed into pump
housing 48 and similarly is provided with a check ball 62 held in place by ball seat
65. As can also be seen in FIG. 7, the outlet passageway 66 is angled relative to
the axis of pump shaft 36. This allows the outlet check assembly 58 to operate essentially
via gravity and yet requires only the drilling and provision of one passageway while
maintaining an essentially vertical ball-seat relationship.
[0020] FIGs. 8 and 9 show the outlet filter assembly 80 which is comprised of a filter element
82 contained in passage 84 of pump assembly 40 and which is retained by fitting 86.
[0021] Turning to FIG. 10, inlet tube 70 is provided with a female threaded end 70a. Inlet
filter screen assembly 72 has a male threaded end 72a for threaded engagement with
end 70a. Ends 70a and 72a use the same size and thread as a common garden hose such
that a user need merely remove screen assembly 72, attach a garden hose to inlet tube
70, turn on the water and flush out the assembly.
[0022] It is contemplated that various changes and modifications may be made to the airless
spray pump without departing from the scope of the invention as defined by the following
claims.
1. A spray pump powered by a rotary motor (14) having a pinion (24) thereon and comprising:
a housing (12);
a single-acting piston pump (40) having a pump rod (36) said single -acting pisten
pump being connected to said housing;
a drive gear assembly (16) comprising a gear, a gear shaft and an eccentric (25) located
on said gear;
a bearing (28) located about said eccentric; and
a yoke (30) reciprocatingly located in said housing and about said bearing,
characterised in that said rotary motor (14) and pinion (24) are offset from a centreline of said single-acting
piston pump, whereby thrust loads on the yoke are reduced and pump forces on said
gear shaft and beanring are offset and reduced.
2. The spray pump of claim 1, wherein the gear is rotatable about a gear centreline,
wherein said gear centreline is offset from the centreline of said pump.
3. The spray pump of claim 1 or claim 2, wherein said pump rod (36), said pinion (24),
said yoke (30) and said eccentric (25) are all located in substantially the same plane.
4. The spray pump of any one of the preceding claims, wherein teeth (22) on said gear
are formed with about a 5° helical angle and about a 25 ° pressure angle.
5. The spray pump of any one of the preceding claims, wherein the pinion (24) is driven
by the motor (14) and engages teeth (22) of the gear to rotate the gear and the eccentric
(25) about the gear centreline.
6. The spray pump of any one of the preceding claims, wherein the single-acting piston
pump (40) is arranged to pump up on a downward stroke and to load on an upward stroke
of the pump rod (36).
7. The spray pump of claim 6, wherein the pump rod (36) is aligned with the centreline
of the pump.
8. The spray pump of any one of the preceding claims, wherein the eccentric (25) is integral
with a front of the gear assembly (16).
9. The spray pump of any one of the preceding claims, wherein the motor (14) is mounted
to the rear portion of the housing (12).
1. Zerstäuberpumpe, die durch einen Rotationsmotor (14) mit einem Ritzel (24) daran angetrieben
wird und die Folgendes umfasst:
ein Gehäuse (12);
eine einfach-wirkende Kolbenpumpe (40) mit einer Pumpestange (36), wobei die einfach-wirkende
Kolbenpumpe mit dem Gehäuse verbunden ist;
eine Treibradbaugruppe (16), die ein Zahnrad, eine Getriebewelle und einen Exzenter
(25), der an dem Zahnrad angeordnet ist, umfasst;
ein Lager (28), das um den Exzenter herum angeordnet ist; und
ein Joch (30), das in einer hin- und hergehenden Weise in dem Gehäuse und um das Lager
herum angeordnet ist,
dadurch gekennzeichnet, dass der Rotationsmotor (14) und das Ritzel (24) von einer Mittelachse der einfachwirkenden
Kolbenpumpe versetzt sind, wobei Axiallasten auf das Joch reduziert werden und die
Pumpenkräfte auf die Getriebewelle und das Lager versetzt sind und reduziert werden.
2. Zerstäuberpumpe nach Anspruch 1, wobei das Zahnrad um eine Zahnradmittelachse herum
drehbar ist, wobei die Zahnradmittelachse von der Mittelachse der Pumpe versetzt ist.
3. Zerstäuberpumpe nach Anspruch 1 oder Anspruch 2, wobei die Pumpestange (36), das Ritzel
(24), das Joch (30) und der Exzenter (25) alle im Wesentlichen in derselben Ebene
angeordnet sind.
4. Zerstäuberpumpe nach einem der vorangehenden Ansprüche, wobei Zähne (22) an dem Zahnrad
mit einem Schraubenwinkel von etwa 5° und einem Eingriffswinkel von etwa 25° ausgebildet
sind.
5. Zerstäuberpumpe nach einem der vorangehenden Ansprüche, wobei das Ritzel (24) durch
den Motor (14) angetrieben wird und Zähne (22) des Zahnrades in Eingriff nehmen, um
das Zahnrad und den Exzenter (25) um die Zahnradmittelachse zu drehen.
6. Zerstäuberpumpe nach einem der vorangehenden Ansprüche, wobei die einfach-wirkende
Kolbenpumpe (40) dafür geeignet ist, bei einem Abwärtshub heraufzupumpen und bei einem
Aufwärtshub der Pumpenstange (36) zu laden.
7. Zerstäuberpumpe nach Anspruch 6, wobei die Pumpestange (36) auf die Mittelachse der
Pumpe ausgerichtet ist.
8. Zerstäuberpumpe nach einem der vorangehenden Ansprüche, wobei der Exzenter (25) integral
mit einer Vorderseite der Zahnradbaugruppe (16) ausgebildet ist.
9. Zerstäuberpumpe nach einem der vorangehenden Ansprüche, wobei der Motor (14) am hinteren
Abschnitt des Gehäuses (12) montiert ist.
1. Pompe de pulvérisation actionnée par un moteur rotatif (14) sur lequel est disposé
un pignon (24) et comprenant :
un carter (12) ;
une pompe à piston à action unique (40) ayant une tige de piston (36), ladite pompe
à piston à action unique étant raccordée audit carter ;
un ensemble d'engrenages d'entraînement (16) comprenant un engrenage, un arbre d'engrenage
et un excentrique (25) situé sur ledit pignon ;
un palier (28) situé autour dudit excentrique ; et
une culasse (30) située mutuellement dans ledit carter et autour dudit palier,
caractérisé en ce que ledit moteur rotatif (14) et le pignon (24) sont décalés d'une ligne centrale de
ladite pompe à piston à action unique, moyennant quoi les poussées axiales sur la
culasse sont réduites et les forces de pompage sur ledit arbre de pignon et ledit
palier sont décalées et réduites.
2. Pompe de pulvérisation selon la revendication 1, dans laquelle l'engrenage est rotatif
autour d'une ligne centrale d'engrenage, dans laquelle la ligne centrale d'engrenage
est décalée de la ligne centrale de ladite pompe.
3. Pompe de pulvérisation selon les revendications 1 ou 2, dans laquelle ladite tige
de pompe (36), ledit pignon (24), ladite culasse (30) et ledit excentrique (25) sont
tous situés dans substantiellement le même plan.
4. Pompe de pulvérisation selon une quelconque des revendications précédentes, dans laquelle
des dents (22) sur ledit engrenage sont formées avec un angle d'hélice d'environ 5°
et un angle d'incidence d'environ 25°.
5. Pompe de pulvérisation selon une quelconque des revendications précédentes, dans lequel
le pignon (24) est entraîné par le moteur (14) et vient en prise avec les dents (22)
de l'engrenage afin de tourner l'engrenage et l'excentrique (25) autour de la ligne
centrale d'engrenage.
6. Pompe de pulvérisation selon une quelconque des revendications précédentes, dans lequel
la pompe à piston à action unique (40) est agencée afin de pomper sur une course vers
le bas et de charger sur une course vers le haut de la tige de pompe (36).
7. Pompe de pulvérisation selon la revendication 6, dans lequel la tige de pompe (36)
est alignée avec la ligne centrale de la pompe.
8. Pompe de pulvérisation selon une quelconque des revendications précédentes, dans lequel
l'excentrique (25) est en un seul tenant avec un avant de l'ensemble d'engrenage (16).
9. Pompe de pulvérisation selon une quelconque des revendications précédentes, dans lequel
le moteur (14) est monté sur la portion arrière du carter (12).
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