US 9,068,533 B2Granted

Handheld work apparatus

AssigneeAndreas Stihl AG & Co. KG

InventorsEvelyn Kullik, Philipp Neumann

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Abstract

A work apparatus has an engine with a carburetor. An actuating element is connected to the choke shaft of the choke element of the carburetor. An operating mode selector has operating, warm start and cold start positions and is connected fixedly in terms of rotation to an adjusting element. The actuating element is pivoted through a pivot angle (α1) from the operating position into the warm start position and through a pivot angle (α2) from the warm start position into the cold start position. The selector is pivoted through a pivot angle (γ1) from the operating position into the warm start position and through a pivot angle (γ2) from the warm start position into the cold start position. The ratio of the pivot angle (α2) to the pivot angle (α1) is at least approximately 1.5 times the ratio of the pivot angle (γ2) to the pivot angle (γ1).

Claims20

Dependent claims

A portable handheld work apparatus comprising:

a work tool;
a combustion engine for driving said work tool;
said combustion engine including a carburetor for supplying an air/fuel mixture;
said carburetor including a throttle element and a choke element accommodated therein;
said choke element having a choke shaft defining a first pivot axis;
said choke element being mounted in said carburetor with said choke shaft so as to be pivotable about said first pivot axis;
said choke element including an actuating element operatively connected to said choke shaft;
a throttle lever;
an operating-mode selector mounted in said apparatus so as to be pivotable about a second pivot axis to an operating position, a warm-start position and a cold-start position;
an adjusting element connected to said operating-mode selector so as to be fixedly rotatable therewith and coact with said actuating element in said warm-start position and said cold-start position;
said adjusting element having a first contact location corresponding to said warm-start position and a second contact location corresponding to said cold-start position;
said actuating element having a first contact location corresponding to said warm-start position and a second contact location corresponding to said cold-start position;
said choke element being displaced in a closing direction in response to a shift of said operating-mode selector from said warm-start position whereat said first contact location of said adjusting element coacts with said first contact location of said actuating element into said cold-start position whereat said second contact location of said adjusting element coacts with said second contact location of said actuating element;
said actuating element being pivoted through a first pivot angle (α1) when pivoted from said operating position into said warm-start position and through a second pivot angle (α2) when pivoted from said warm-start position into said cold-start position;
whereas, said operating-mode selector being pivoted through a third pivot angle (γ1) when said operating-mode selector is pivoted from said operating position into said warm-start position and through a fourth pivot angle (γ2) when pivoted from said warm-start position into said cold-start position;
and,
wherein a ratio of said second pivot angle (α2) to said first pivot angle (α1) is at least approximately 1.5 times a ratio of said fourth pivot angle (γ2) to said third pivot angle (γ1).

14 more elements

A portable handheld work apparatus comprising:

a work tool;
a combustion engine for driving said work tool;
said combustion engine including a carburetor for supplying an air/fuel mixture;
said carburetor including a throttle element and a choke element accommodated therein;
said choke element having a choke shaft defining a first pivot axis;
said choke element being mounted in said carburetor with said choke shaft so as to be pivotable about said first pivot axis;
said choke element including an actuating element operatively connected to said choke shaft;
a throttle lever;
an operating-mode selector mounted in said apparatus so as to be pivotable about a second pivot axis to an operating position, a warm-start position and a cold-start position;
an adjusting element connected to said operating-mode selector so as to be fixedly rotatable therewith and coact with said actuating element in said warm-start position and said cold-start position;
said adjusting element having a first contact location corresponding to said warm-start position and a second contact location corresponding to said cold-start position;
said actuating element having a first contact location corresponding to said warm-start position and a second contact location corresponding to said cold-start position;
said choke element being displaced in a closing direction in response to a shift of said operating-mode selector from said warm-start position whereat said first contact location of said adjusting element coacts with said first contact location of said actuating element into said cold-start position whereat said second contact location of said adjusting element coacts with said second contact location of said actuating element;
said actuating element being pivoted through a first pivot angle (α1) when pivoted from said operating position into said warm-start position and through a second pivot angle (α2) when pivoted from said warm-start position into said cold-start position;
whereas, said operating-mode selector being pivoted through a third pivot angle (γ1) when said operating-mode selector is pivoted from said operating position into said warm-start position and through a fourth pivot angle (γ2) when pivoted from said warm-start position into said cold-start position;
wherein a ratio of said second pivot angle (α2) to said first pivot angle (α1) is at least approximately 1.5 times a ratio of said fourth pivot angle (γ2) to said third pivot angle (γ1);
and,
wherein said first contact location is configured on a first actuating bolt and the second contact location is configured on a second actuating bolt.

15 more elements

A portable handheld work apparatus comprising:

a work tool;
a combustion engine for driving said work tool;
said combustion engine including a carburetor for supplying an air/fuel mixture;
said carburetor including a throttle element and a choke element accommodated therein;
said choke element having a choke shaft defining a first pivot axis;
said choke element being mounted in said carburetor with said choke shaft so as to be pivotable about said first pivot axis;
said choke element including an actuating element operatively connected to said choke shaft;
a throttle lever;
an operating-mode selector mounted in said apparatus so as to be pivotable about a second pivot axis to an operating position, a warm-start position and a cold-start position;
an adjusting element connected to said operating-mode selector so as to be fixedly rotatable therewith and coact with said actuating element in said warm-start position and said cold-start position;
said adjusting element having a first contact location corresponding to said warm-start position and a second contact location corresponding to said cold-start position;
said actuating element having a first contact location corresponding to said warm-start position and a second contact location corresponding to said cold-start position;
said choke element being displaced in a closing direction in response to a shift of said operating-mode selector from said warm-start position whereat said first contact location of said adjusting element coacts with said first contact location of said actuating element into said cold-start position whereat said second contact location of said adjusting element coacts with said second contact location of said actuating element;
said actuating element being pivoted through a first pivot angle (α1) when pivoted from said operating position into said warm-start position and through a second pivot angle (α2) when pivoted from said warm-start position into said cold-start position;
whereas, said operating-mode selector being pivoted through a third pivot angle (γ1) when said operating-mode selector is pivoted from said operating position into said warm-start position and through a fourth pivot angle (γ2) when pivoted from said warm-start position into said cold-start position;
wherein a ratio of said second pivot angle (α2) to said first pivot angle (α1) is at least approximately 1.5 times a ratio of said fourth pivot angle (γ2) to said third pivot angle (γ1);
and,
wherein said third pivot angle (γ1) is approximately of the same magnitude as said fourth pivot angle (γ2) and said second pivot angle (α2) is at least 1.5 times as large as said first pivot angle (α1).

15 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/330,386Filed 19 Dec 2011
Priority: DE 10 2011 105 15917 Jun 2011
Published: US 2012/0318236 A120 Dec 2012
Granted: 30 Jun 2015
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

F02M 1/02
Carburettors with means for facilitating engine's starting or its idling below operational temperatures: the means to facilitate starting or…
F02B 63/02
Adaptations of engines for driving pumps, hand-held tools or electric generators; Portable combinations of engines with engine-driven devices: for…
F02D 11/02
Arrangements for, or adaptations to, non-automatic engine control initiation means, e.g. operator initiated: characterised by hand, foot, or like…
F02D 11/04
Arrangements for, or adaptations to, non-automatic engine control initiation means, e.g. operator initiated: characterised by mechanical control…