Load lifting device load sensing
First Claim
1. A load lifting device, comprising:
- a load carrying member having a first end portion and a second end portion extending outwardly from said first end portion;
a first sensing means for delivering a first signal from a first sensing location adjacent said first end portion and receiving a reflection of said first signal;
a second sensing means for delivering a second signal from a second sensing location adjacent said first end portion and receiving a reflection of said second signal, said second sensing location being positioned at a lower elevation than said first sensing location;
a first reflecting means for receiving said first signal at a first reflecting location adjacent the second end portion and delivering a reflection of said first signal in a direction toward said first sensing means;
a second reflecting means for receiving said second signal at a second reflecting location adjacent the second end portion and delivering a reflection of said second signal in a direction toward said second sensing means, said first and second reflecting location being spaced from one another, said sensing and reflecting means being free from contact with a load carried on the load carrying member and providing accurate sensing of the position of the load on the load carrying member.
2 Assignments
0 Petitions
Accused Products
Abstract
Sensors associated with load carrying members are inaccurate, incorrectly sense the position of the load, and are subject to impact forces which cause premature sensor failure. A load lifting device having a load carrying member and first and second sensors and first and second reflectors on the load carrying member is provided. The sensors are mounted on a first end portion of load carrying member at longitudinally spaced apart locations and the first and second reflectors are mounted on a second end portion of the load carrying member at spaced apart locations on the second end portion. The first sensor delivers a first signal to the first reflector and receives a reflection of the first signal, and the second sensor delivers a second signal to the second reflector and receives a reflection of the first signal from the second reflector. The problems associated with inaccurate sensing of load position, damage to the sensors by impact, and premature wear due to cyclical forces are substantially reduced. The load lifting device is particularly suited for use on a material handling vehicle of the automatic guided vehicle type.
37 Citations
24 Claims
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1. A load lifting device, comprising:
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a load carrying member having a first end portion and a second end portion extending outwardly from said first end portion; a first sensing means for delivering a first signal from a first sensing location adjacent said first end portion and receiving a reflection of said first signal; a second sensing means for delivering a second signal from a second sensing location adjacent said first end portion and receiving a reflection of said second signal, said second sensing location being positioned at a lower elevation than said first sensing location; a first reflecting means for receiving said first signal at a first reflecting location adjacent the second end portion and delivering a reflection of said first signal in a direction toward said first sensing means; a second reflecting means for receiving said second signal at a second reflecting location adjacent the second end portion and delivering a reflection of said second signal in a direction toward said second sensing means, said first and second reflecting location being spaced from one another, said sensing and reflecting means being free from contact with a load carried on the load carrying member and providing accurate sensing of the position of the load on the load carrying member. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A lift mast assembly, comprising:
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a pair of spaced apart uprights; a carriage mounted on and movable along said pair of spaced apart uprights; a first load carrying member having a first end portion and a second end portion extending outwardly from said first end portion; a second load carrying member having a first end portion and a second end portion extending outwardly from said second load carrying member first end portion, said first end portions of the first and second load carrying members being connected to the carriage at spaced apart locations; a first sensing means for delivering a first signal from a first sensing location adjacent the first end portion of the first load carrying member and receiving a reflection of said first signal; a second sensing means for delivering a second signal from a second sensing location adjacent said first end portion of the first load carrying member and receiving a reflection of said second signal, said second sensing location being at a lower elevation then said first sensing location; a third sensing means for delivering a third signal from a third sensing location adjacent said first end portion of the second load carrying member and reflection of said third signal; a fourth sensing means for delivering a fourth signal from a fourth sensing location adjacent said first end portion of the second load carrying member and receiving a reflection of said fourth signal, said fourth sensing location being positioned at a lower elevation than said third sensing location; a first reflecting means for receiving said first signal at a first reflecting location adjacent the second end portion of the first load carrying member and delivering a reflection of said first signal in a direction toward said first sensing means; a second reflecting means for receiving said second signal at a second reflecting location adjacent the second end portion of the first load carrying member and delivering a reflection of said second signal in a direction toward said second sensing means, said first and second reflecting locations being spaced from one another; a third reflecting means for receiving said third signal at a third reflecting location adjacent the second end portion of the second load carrying member and delivering a reflection of said third signal in a direction toward said third sensing means; and a fourth reflecting means for receiving said fourth signal at a fourth reflecting location adjacent the second end portion of the second load carrying member and delivering a reflection of said fourth signal in a direction toward said fourth sensing means;
said third and fourth reflecting locations being spaced from one another, said sensing and reflecting means being free from contact with a load carried on the load carrying members and providing accurate sensing of the position of the load on the load carrying members. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22)
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23. An automatic guided vehicle, comprising:
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a vehicle frame having a longitudinal axis; a pair of spaced apart elevationally oriented uprights connected to said vehicle frame and longitudinally movable along said longitudinal axis between spaced apart locations on said vehicle frame; a carriage mounted on and movable along said pair of spaced apart uprights between elevationally spaced apart positions; a first load carrying member having a first end portion and a second end portion extending outwardly from said first end portion; a second load carrying member having a first end portion and a second end portion extending outwardly from said second load carrying member first end portion, said first end portions being elevationally oriented and connected to the carriage at spaced apart locations; a first sensing means for delivering a first signal from a first sensing location adjacent the first end portion of the first load carrying member and receiving a reflection of said first signal; a second sensing means for delivering a second signal from a second sensing location adjacent the first end portion of the first load carrying member and receiving a reflection of said second signal, said second sensing location being positioned at a lower elevation than said first sensing location; a third sensing means for delivering a third signal from a third sensing location adjacent the first end portion of the second load carrying member and receiving a reflection of said third signal; a fourth sensing means for delivering a fourth signal from a fourth sensing location adjacent the first end portion of the second load carrying member and receiving a reflection of said fourth signal, said fourth sensing location being positioned at a lower elevation than said sensing location; a first reflecting means for receiving said first signal at a first reflecting location adjacent the second end portion of the first load carrying member and delivering a reflection of said first signal in a direction toward said first sensing means; a second reflecting means for receiving said second signal at a second reflecting location adjacent the second end portion of the first load carrying member and delivering a reflection of said second signal in a direction toward said second sensing means, said first and second reflecting locations being spaced from one another; a third reflecting means for receiving said third signal at a third reflecting location adjacent the second end portion of the second load carrying member and delivering a reflection of said third signal in a direction toward said third sensing means; a fourth reflecting means for receiving said fourth signal at a fourth reflecting location adjacent the second end portion of the second load carrying member and delivering a reflection of said fourth signal in a direction toward said fourth sensing means, said third and fourth reflecting locations being spaced from one another, said sensing and reflecting means being free from contact with a load carried on the load carrying members and providing accurate sensing of the position of the load on the load carrying members. - View Dependent Claims (24)
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Specification