US3921819A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Boom latch mechanism
Assignee: Kidde Inc
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Filing: 1974-07-26
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Granted: 1975-11-25
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Expires: 1994-07-26
Abstract
Abstract The manual fly section of a multi-section telescopic crane boom is extended and retracted through the cooperative use of an extensible and retractable plunger on one of the boom extension cylinders and a manual locking pin insertable through registering openings of the fly section and outer mid-section of the telescopic boom. The latching plunger cooperates with a notched latch bar attached to the interior of the manual fly section and the plunger is actuated manually from the exterior of the boom by a rotary screw mechanism.
Inventors
- 👤 Stanley R Spain
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:24
CPC Classifications
B; B66; B66C; B66C23/00; B66C23/62; B66C23/64; B66C23/70; B66C23/701; B66C23/708; B66C23/705; Y; Y10; Y10T; Y10T403/00; Y10T403/32; Y10T403/32254; Y10T403/32467; Y10T403/32516
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
243 words
A latch mechanism for a telescopic boom having at least three boom sections including a boom inner section, a boom mid-section and a manual fly section each having a hollow interior and at least one power cylinder for extending and retracting the boom mid-section, a support member mounted on the boom inner section projecting forwardly into the hollow interior of said mid-section and into the hollow interior of said manual fly section telescoped in the mid-section, a manual latch assembly bodily mounted on said support member to project into the hollow interior of said manual fly section and including a manually extensible and retractable latch plunger, manually operated extension and retraction means for said plunger adapted to be selectively operated from the exterior of the telescopic boom, a latch bar fixed to said manual fly section and movable therewith relative to said latch assembly, said latch plunger being springloaded for interlocking engagement with the latch bar when the latter is moved into contact with said plunger, whereby the plunger is selectively manually operated from the exterior of the telescopic boom to be in an operative or non-operative position with respect to said latch bar, and manual means for positively coupling said manual fly section and mid-section together for movement as a unit by said power cylinder and for allowing the power cylinder to move the mid-section relative to the manual fly section when the latter is latched and said manual means is removed.
Claim 2
Dependent Claim
243 words
A latch mechanism for a telescopic boom having at least three boom sections including a boom inner section, a boom mid-section and a manual fly section each having a hollow interior and at least one power cylinder for extending and retracting the boom mid-section, a support member mounted on the boom inner section projecting forwardly into the hollow interior of said mid-section and into the hollow interior of said manual fly section telescoped in the mid-section, a manual latch assembly bodily mounted on said support member to project into the hollow interior of said manual fly section and including a manually extensible and retractable latch plunger, manually operated extension and retraction means for said plunger adapted to be selectively operated from the exterior of the telescopic boom, a latch bar fixed to said manual fly section and movable therewith relative to said latch assembly, said latch plunger being springloaded for interlocking engagement with the latch bar when the latter is moved into contact with said plunger, whereby the plunger is selectively manually operated from the exterior of the telescopic boom to be in an operative or non-operative position with respect to said latch bar, and manual means for positively coupling said manual fly section and mid-section together for movement as a unit by said power cylinder and for allowing the power cylinder to move the mid-section relative to the manual fly section when the latter is latched and said manual means is removed.
Claim 3
Dependent Claim
40 words
A latch mechanism as defined by claim 1, wherein said support for said manual latch assembly comprises a second power cylinder for the telescopic boom having a connection with a base section thereof and an inner mid-section of the boom.
Claim 4
Dependent Claim
42 words
A latch mechanism as defined by claim 1, and said manually operated extension and retraction means for said plunger including a screw shaft, a nut drivingly connected to the screw shaft, and a compression spring interposed between the nut and latch plunger.
Claim 5
Dependent Claim
57 words
A latch mechanism as defined by claim 3, and a housing for said latch plunger attached to the support and having a plunger bore, and a second compression spring in said housing engaging the housing and said latch plunger and urging the latch plunger oppositely to the direction in which it is urged by the first-named spring.
Claim 6
Dependent Claim
48 words
A latch mechanism as defined by claim 4, and manual drive shaft means coupled to said screw shaft and having a rotary input element adapted for turning by a manual tool from the exterior of the boom, the boom sections havIng alignable access openings to receive said tool.
Claim 7
Dependent Claim
34 words
A latch mechanism as defined by claim 4, and means on said latch assembly engaging said latch plunger and nut to resist rotation thereof while allowing the same to move axially in two directions.
Claim 8
Dependent Claim
59 words
A latch mechanism as defined by claim 1, wherein said latch bar has a plunger receiving notch and an inclined plunger engaging cam portion on each side of said notch, and spring means connected with said latch plunger urging it to engage in said notch and yielding to allow plunger retraction on contact with either of said cam portions.
Claim 9
Dependent Claim
38 words
A latch mechanism as defined by claim 2, and a stabilizing foot assembly on the forward end of the first-named power cylinder including wear pad means in sliding contact with the bottom wall of said manual fly section.
Claim 10
Dependent Claim
30 words
A latch mechanism as defined by claim 8, and an extension structure on the leading end of said second power cylinder and coupled to and carrying said manual latch assembly.
Claim 11
Dependent Claim
47 words
A latch mechanism as defined by claim 9, and the second power cylinder and said extension structure disposed above the first-named power cylinder and said foot assembly, and side bearing pads dependingly secured to said extension structure and slidably contacting opposite sides of said first-named power cylinder.
Claim 12
Dependent Claim
18 words
A latch mechanism as defined by claim 10, and means to independently adjust the side bearing pads laterally.
Claim 13
Dependent Claim
33 words
A latch mechanism as defined by claim 11, and said last-named means including a pair of pivoted arms carrying the side bearing pads, and independently operable screw-threaded adjusting means for each pivoted arm.
Claim 14
Dependent Claim
25 words
A latch mechanism as defined by claim 1, wherein said support member is cantilevered forwardly from its point of connection with the boom inner section.
Claim 15
Dependent Claim
236 words
A latch mechanism for a telescopic boom having at least three boom sections having an interior space including a manual fly section, a midsection and an innermost section, and power means for extending and retracting said mid-section, comprising a support member mounted on the boom innermost section projecting forwardly into the interior space of said midsection and into the interior space of said manual fly section telescoped in the midsection, a pair of cooperating latch components mounted one each on the support member and on the manual fly section for relative movement, said cooperating latch components adapted to engage and interlock in one relative position of the manual fly section to the innermost section when moved together in response to operation of said power means, and manual means for positively coupling said manual fly section and the mid-section together for movement as a unit by said power means and for allowing the power means to move the mid-section relative to the manual fly section when the latter is latched and said manual means is removed, and one of said cooperation manual latch components being manually and mechanically adjustable by a mechanical implement directly hand operable from the boom exterior between an operative or a non-operative position with respect to the other of said cooperating manual latch components thereby respectively allowing or preventing the engagement and interlocking of said cooperating latch components in said one relative position.
Claim 16
Dependent Claim
236 words
A latch mechanism for a telescopic boom having at least three boom sections having an interior space including a manual fly section, a midsection and an innermost section, and power means for extending and retracting said mid-section, comprising a support member mounted on the boom innermost section projecting forwardly into the interior space of said midsection and into the interior space of said manual fly section telescoped in the midsection, a pair of cooperating latch components mounted one each on the support member and on the manual fly section for relative movement, said cooperating latch components adapted to engage and interlock in one relative position of the manual fly section to the innermost section when moved together in response to operation of said power means, and manual means for positively coupling said manual fly section and the mid-section together for movement as a unit by said power means and for allowing the power means to move the mid-section relative to the manual fly section when the latter is latched and said manual means is removed, and one of said cooperation manual latch components being manually and mechanically adjustable by a mechanical implement directly hand operable from the boom exterior between an operative or a non-operative position with respect to the other of said cooperating manual latch components thereby respectively allowing or preventing the engagement and interlocking of said cooperating latch components in said one relative position.
Claim 17
Dependent Claim
43 words
A latch mechanism as defined by claim 14, wherein one latch component includes an extensible and retractable latch plunger, and the other latch component is a member having means to receive the latch plunger interlockingly when said components are moved together into engagement.
Claim 18
Dependent Claim
24 words
A latch mechanism as defined by claim 14, and manually operable gearing connected with said extensible and retractable latch plunger to operate the same.
Claim 19
Dependent Claim
58 words
A latch mechanism as defined by claim 16, and said gearing comprising a screw shaft having a connection with the latch plunger, spur gearing coupled with the screw shaft to drive it, and a manual drive shaft connected with the spur gearing and having a couplIng head adapted to be engaged by a manual crank wrench for turning.
Claim 20
Dependent Claim
23 words
A latch mechanism as defined by claim 17, and said connection of said screw shaft with said latch plunger comprising a yielding connection.
Claim 21
Dependent Claim
41 words
A latch mechanism as defined by claim 5, and a gear train interposed between said rotary input element and said screw shaft and allowing the rotary input element to be spaced laterally of the screw shaft on said manual latch assembly.
Claim 22
Dependent Claim
54 words
A latch mechanism as defined by claim 15, and a stabilizing device intervened between said support member and said power means and including a pair of side wear pads arranged on opposite sides of the power means, and an upper wear pad arranged at the top of the power means and engaging the same.
Claim 23
Dependent Claim
28 words
A latch mechanism as defined by claim 20, and means forming a flat bearing face for said top wear pad on the upper side of said power means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |