GB624500A - Improvements in load limit warning devices for jib cranes - Google Patents
Improvements in load limit warning devices for jib cranesInfo
- Publication number
- GB624500A GB624500A GB1264147A GB1264147A GB624500A GB 624500 A GB624500 A GB 624500A GB 1264147 A GB1264147 A GB 1264147A GB 1264147 A GB1264147 A GB 1264147A GB 624500 A GB624500 A GB 624500A
- Authority
- GB
- United Kingdom
- Prior art keywords
- contact
- jib
- switch
- fixed
- pulley
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
- B66C23/00—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
- B66C23/88—Safety gear
- B66C23/90—Devices for indicating or limiting lifting moment
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Jib Cranes (AREA)
- Control And Safety Of Cranes (AREA)
Abstract
624,500. Jib cranes. RANSOMES, SIMS, & JEFFERIES, Ltd., and WILLIAMS, A. H. May 9, 1947, No. 12641. [Class 78 (iv)] A warning device for indicating when the maximum permissible load at any position of the jib is being exceeded which device deflects the hoisting rope from its line of action and operates a switch controlling a signal circuit or motor, the switch being an electric switch, one contact of which, responsive to and dependent on the tension of the hoisting rope for effecting closure of the switch, is attached to, and movable with, the jib of the crane, this contact oscillating relatively to the other contact which ensures closure of the circuit before overloading at any angle, this latter contact being in a fixed position and shaped eccentric to the pivot about which the movable contact oscillates so that the distance between the two contacts is greater when the jib is at its maximum angular height than when the jib is horizontal. As shown in Fig. 4, the jib 2 has a tail pulley 19 and is fulcrummed on a shaft 3 which carries a fixed contact 16 eccentrically mounted with respect to the shaft. The hoisting cable 20 passes under fixed pulleys 4 and 5 and over a movable pulley 6, the pulleys being supported by a bracket 1 attached to the iib. The pulley 6, Fig. 2 is mounted on a spindle 9.in a movable jaw 10 which carries a contact 14. A member 11 fixed to the jaw slides in a guide 12 fixed to the bracket 1 and against a spring 13. On increasing the tension in the cable, the pulley 6 is thus moved inwards against the action of a spring 13. At maximum load the contact 14 touches the member 16 and closes the circuit. The distance through which the contact has to move increases with the angle of the jib, and the tension can therefore be correspondingly increased and hence the maximum load possible. A micro switch can be incorporated as an alternative switch.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1264147A GB624500A (en) | 1947-05-09 | 1947-05-09 | Improvements in load limit warning devices for jib cranes |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1264147A GB624500A (en) | 1947-05-09 | 1947-05-09 | Improvements in load limit warning devices for jib cranes |
Publications (1)
Publication Number | Publication Date |
---|---|
GB624500A true GB624500A (en) | 1949-06-09 |
Family
ID=10008437
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1264147A Expired GB624500A (en) | 1947-05-09 | 1947-05-09 | Improvements in load limit warning devices for jib cranes |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB624500A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2004078630A2 (en) * | 2003-03-05 | 2004-09-16 | Charles Patrick De Klerk | A method of operating a hoisting device and an accessory for a hoisting device |
-
1947
- 1947-05-09 GB GB1264147A patent/GB624500A/en not_active Expired
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2004078630A2 (en) * | 2003-03-05 | 2004-09-16 | Charles Patrick De Klerk | A method of operating a hoisting device and an accessory for a hoisting device |
WO2004078630A3 (en) * | 2003-03-05 | 2004-11-11 | Klerk Charles Patrick De | A method of operating a hoisting device and an accessory for a hoisting device |
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