US 11,940,316 B2
Optical operating fluid detector for the optical detection of operating fluid for a hand-guided garden, forestry and/or construction machining appliance, and hand-guided garden, forestry and/or construction machining appliance
Alexander Haas, Spraitbach (DE); and Michael Pulfer, Wilen bei Wil (CH)
Assigned to Andreas Stihl AG & Co. KG, Waiblingen (DE)
Filed by Andreas Stihl AG & Co. KG, Waiblingen (DE)
Filed on Dec. 15, 2020, as Appl. No. 17/122,459.
Claims priority of application No. 19216523 (EP), filed on Dec. 16, 2019.
Prior Publication US 2021/0181007 A1, Jun. 17, 2021
Int. Cl. G01F 23/292 (2006.01); B27B 17/12 (2006.01)
CPC G01F 23/2927 (2013.01) [B27B 17/12 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A hand-guided garden, forestry and/or construction machining appliance, comprising:
an operating fluid tank, the operating fluid tank being designed for storage of operating fluid;
an operating fluid pump, the operating fluid pump being designed for delivery of operating fluid from the operating fluid tank; and
an optical operating fluid detector for optical detection of operating fluid for the hand-guided garden, forestry and/or construction machining appliance, the operating fluid detector comprising:
a light source, the light source being designed for radiation of rays of light;
an operating fluid line, the operating fluid line being designed for optical interaction of the rays of light from the light source with operating fluid in the operating fluid line for the optical detection of operating fluid; and
a light receiver, the light receiver being designed for differing reception of rays of light from the operating fluid line in dependence on a presence or absence of operating fluid in the operating fluid line, wherein
the operating fluid detector has at least one optical deflecting device, the at least one optical deflecting device being designed for deflection of the rays of light from the light source to the operating fluid line and/or for deflection of the rays of light from the operating fluid line to the light receiver,
the operating fluid line is designed for differing diversion of the rays of light from the light source in dependence on the presence or the absence of operating fluid in the operating fluid line for the optical detection of operating fluid,
an inner surface of the operating fluid line is designed for the differing refraction of the rays of light from the light source in dependence on the presence or the absence of operating fluid in the operating fluid line for the optical detection of operating fluid,
the operating fluid detector has an optical body, the body having the operating fluid line and the at least one optical deflecting device,
the operating fluid detector has a printed circuit board,
the printed circuit board carries the light source, the light receiver, and the body,
the light source is aligned for the radiation of the rays of light away from a board plane of the printed circuit board,
the light receiver is aligned for the reception of the rays of light from the operating fluid line towards the board plane,
the operating fluid line is connected downstream of the operating fluid tank and upstream or downstream of the operating fluid pump,
the garden, forestry and/or construction machining appliance has a machining tool, and
the operating fluid pump is designed for the delivery of operating fluid to the machining tool for lubricating the machining tool with operating fluid in the form of lubricating fluid.