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US4277052A Expired / Lapsed US ⏱️ 0.0 years remaining

Jacking apparatus

Assignee: Individual
•
Filing: 1979-08-17
•
Granted: 1981-07-07
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Expires: 1999-08-17
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Abstract

Abstract A jacking apparatus for selectively moving a load in either of opposite directions such as vertically upwardly and downwardly. The apparatus is adapted for use in a wide range of building constructions, such as those using slipforms, wherein heavy loads are positioned by the jacking apparatus. The apparatus includes gripping elements having portions engaging elongated structural elements for effecting desired movement of the jacking apparatus in moving the load. The gripping elements are mounted on parallelogram linkage supports for maintained parallel relationship to the longitudinal extent of the elongated structural element with which they are selectively engaged. A control device is carried by the respective upper and lower gripping devices for effecting automatic control of the gripping elements in effecting a lowering of the apparatus when desired. The control is arranged to effect a sequential releasing and gripping of the elongated structural element by the gripping elements as an incident of individual movement of the respective gripping devices.

Inventors

  • 👤 Franz Kallinger

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 08:03
CPC Classifications
B; B66; B66F; B66F1/00; B66F1/02; B66F1/04; B66F1/08

Claims Analysis

Total Claims: 29
Claim 1
Independent Claim 188 words
In an apparatus for selectively moving a load, said apparatus being arranged for use with an elongated structural element having a plurality of longitudinally spaced substantially similar projecting shoulder portions, said apparatus having gripping means comprising: wall means defining a portion of the gripping means engageable with said structural element and having a grooved surface configuration complementary to said shoulder portions of the structural element; means for mounting said wall means adjacent said structural element including a parallelogram linkage carrying said wall means for causing the wall means to be maintained parallel to the longitudinal extent of the elongated structural element in engaging said element; and means for resiliently urging the wall means into engagement with said element to have mechanically interlocked engagement selectively with successive ones of said shoulder portions as said apparatus is caused to be aligned successively with said successive ones of the shoulder portions, said resilient urging means permitting said surface configuration of the wall means to adjustably seat on said shoulder portions for subsequent transfer of force from the load for firmly locking the gripping means to the element to support the load.
Claim 2
Dependent Claim 188 words
In an apparatus for selectively moving a load, said apparatus being arranged for use with an elongated structural element having a plurality of longitudinally spaced substantially similar projecting shoulder portions, said apparatus having gripping means comprising: wall means defining a portion of the gripping means engageable with said structural element and having a grooved surface configuration complementary to said shoulder portions of the structural element; means for mounting said wall means adjacent said structural element including a parallelogram linkage carrying said wall means for causing the wall means to be maintained parallel to the longitudinal extent of the elongated structural element in engaging said element; and means for resiliently urging the wall means into engagement with said element to have mechanically interlocked engagement selectively with successive ones of said shoulder portions as said apparatus is caused to be aligned successively with said successive ones of the shoulder portions, said resilient urging means permitting said surface configuration of the wall means to adjustably seat on said shoulder portions for subsequent transfer of force from the load for firmly locking the gripping means to the element to support the load.
Claim 3
Dependent Claim 41 words
The load moving apparatus of claim 1 wherein said structural element comprises a cylindrical rod and said shoulder portions comprise semiannular projections on said structural element and said wall means surface configuration defines semiannular recesses complementary to said structural element projections.
Claim 4
Dependent Claim 105 words
In an apparatus for selectively moving a load, said apparatus being arranged for use with an elongated structural element having a plurality of longitudinally spaced substantially similar projecting shoulder portions, said apparatus having gripping means comprising: wall means defining a portion of the gripping means engageable with said structural element and having a grooved surface configuration complementary to said shoulder portions of the structural element; and resilient means arranged to urge the wall means into accurate mechanically interlocked association with at least one of said structural element shoulder portions as an incident of relative logitudinal movement between said elongated structural element and said gripping means.
Claim 5
Dependent Claim 105 words
In an apparatus for selectively moving a load, said apparatus being arranged for use with an elongated structural element having a plurality of longitudinally spaced substantially similar projecting shoulder portions, said apparatus having gripping means comprising: wall means defining a portion of the gripping means engageable with said structural element and having a grooved surface configuration complementary to said shoulder portions of the structural element; and resilient means arranged to urge the wall means into accurate mechanically interlocked association with at least one of said structural element shoulder portions as an incident of relative logitudinal movement between said elongated structural element and said gripping means.
Claim 6
Dependent Claim 24 words
The load moving apparatus of claim 3 wherein said shoulder portions are spaced longitudinally of the structural element substantially uniformly a preselected distance apart.
Claim 7
Dependent Claim 21 words
The load moving apparatus of claim 3 wherein said shoulder portions are spaced apart approximately 2" longitudinally of the structural element.
Claim 8
Dependent Claim 27 words
The load moving apparatus of claim 3 wherein each said wall means surface configuration is arranged to engage concurrently a plurality of said structural element shoulder portions.
Claim 9
Dependent Claim 98 words
In an apparatus for selectively moving a load and arranged for use with an elongated structural element, said apparatus having gripping means releasably engaging the structural element for effecting the movement of the load, the improvement comprising means for mounting said gripping means adjacent said structural element including a parallelogram linkage causing the gripping means to be maintained parallel to the longitudinal extent of the elongated structural element in engaging said element, a fixed cam, and a cam follower movable with said gripping means for guiding the movement of the gripping means toward and from said structural element.
Claim 10
Dependent Claim 98 words
In an apparatus for selectively moving a load and arranged for use with an elongated structural element, said apparatus having gripping means releasably engaging the structural element for effecting the movement of the load, the improvement comprising means for mounting said gripping means adjacent said structural element including a parallelogram linkage causing the gripping means to be maintained parallel to the longitudinal extent of the elongated structural element in engaging said element, a fixed cam, and a cam follower movable with said gripping means for guiding the movement of the gripping means toward and from said structural element.
Claim 11
Dependent Claim 29 words
The load moving apparatus of claim 7 wherein said mounting means further includes means for biasing said linkage to urge said gripping means toward engagement with said structural element.
Claim 12
Dependent Claim 70 words
The load moving apparatus of claim 7 wherein said structural element is provided with a plurality of longitudinally spaced, substantially similar shoulder portions and said gripping means defines a surface configuration complementary to said shoulder portions of the structural element to have mechanically interlocked engagement selectively with successive ones of said shoulder portions as said apparatus is caused to be aligned successively with said successive ones of the shoulder portions.
Claim 13
Dependent Claim 378 words
In an apparatus for selectively raising and lowering a load and including an upper gripping means resiliently biased into gripping engagement with a vertical load supporting elongated structural element having a plurality of accurately uniformly vertically spaced shoulders, and a lower gripping means resiliently biased into gripping engagement with said structural element, means for controlling operation of the gripping means to effect an alternately descending series of engagements of said upper and lower gripping means with said structural element comprising: extensible means for moving said gripping means selectively toward and from each other a distance accurately equal to a multiple of the spacing between said shoulders; means on said gripping means defining a plurality of shoulders complementary to said structural element shoulders and correspondingly vertically spaced to be generally aligned with said structural element shoulders as an incident of the gripping means being resiliently biased into engagement with said structural element; first control means carried by said upper gripping means for causing said lower gripping means to be released from said structural element as an incident of the upper gripping means being moved downwardly to a preselected minimum spacing of the upper gripping means above the lower gripping means with the lower gripping means engaged with said structural element; and second control means carried by said lower gripping means for causing said upper gripping means to be released from said structural element as an incident of the lower gripping means being moved downwardly to a preselected maximum spacing of the lower gripping means below the upper gripping the lower gripping means below the upper gripping means with the upper gripping means engaged with said structural element, each of said gripping means comprising a support, gripping elements movably carried on the support, and biasing means for biasing the gripping elements into engagement with the structural element, each said biasing means including a connector, spring means carried by the support and biasing the connector, and means responsive to movement of the connector relative to the support for moving the gripping elements, each said control means comprising a control member extending from the gripping means carrying the same to adjacent the connector of the other gripping means, and means defining a lost motion connector between said control member and adjacent connector.
Claim 14
Dependent Claim 378 words
In an apparatus for selectively raising and lowering a load and including an upper gripping means resiliently biased into gripping engagement with a vertical load supporting elongated structural element having a plurality of accurately uniformly vertically spaced shoulders, and a lower gripping means resiliently biased into gripping engagement with said structural element, means for controlling operation of the gripping means to effect an alternately descending series of engagements of said upper and lower gripping means with said structural element comprising: extensible means for moving said gripping means selectively toward and from each other a distance accurately equal to a multiple of the spacing between said shoulders; means on said gripping means defining a plurality of shoulders complementary to said structural element shoulders and correspondingly vertically spaced to be generally aligned with said structural element shoulders as an incident of the gripping means being resiliently biased into engagement with said structural element; first control means carried by said upper gripping means for causing said lower gripping means to be released from said structural element as an incident of the upper gripping means being moved downwardly to a preselected minimum spacing of the upper gripping means above the lower gripping means with the lower gripping means engaged with said structural element; and second control means carried by said lower gripping means for causing said upper gripping means to be released from said structural element as an incident of the lower gripping means being moved downwardly to a preselected maximum spacing of the lower gripping means below the upper gripping the lower gripping means below the upper gripping means with the upper gripping means engaged with said structural element, each of said gripping means comprising a support, gripping elements movably carried on the support, and biasing means for biasing the gripping elements into engagement with the structural element, each said biasing means including a connector, spring means carried by the support and biasing the connector, and means responsive to movement of the connector relative to the support for moving the gripping elements, each said control means comprising a control member extending from the gripping means carrying the same to adjacent the connector of the other gripping means, and means defining a lost motion connector between said control member and adjacent connector.
Claim 15
Dependent Claim 17 words
The load raising and lowering apparatus of claim 10, wherein said extensible means comprises fluid-operated piston means.
Claim 16
Dependent Claim 367 words
In an apparatus for selectively raising and lowering a load and including an upper gripping means biased into gripping engagement with a vertical load supporting elongated structural element, and a lower gripping means biased into gripping engagement with said structural element, means for controlling operation of the gripping means to effect an alternately descending series of engagements of said upper and lower gripping means with said structural element comprising: extensible means for moving said gripping means selectively toward and from each other; first control means carried by said upper gripping means for causing said lower gripping means to be released from said structural element as an incident of the upper gripping means being moved downwardly to a preselected minimum spacing of the upper gripping means above the lower gripping means with the lower gripping means engaged with said structural element; and second control means carried by said lower gripping means for causing said upper gripping means to be released from said structural element as an incident of the lower gripping means being moved downwardly to a preselected maximum spacing of downwardly to a preselected minimum spacing of the upper gripping means above the lower gripping means with the lower gripping means engaged with said structural element; and second control means carried by said lower gripping means for causing said upper gripping means to be released from said structural element as an incident of the lower gripping means being moved downwardly to a preselected maximum spacing of the lower gripping means below the upper gripping means with the upper gripping means engaged with said structural element, each of said gripping means comprising a support, gripping elements pivotally carried on the support, and biasing means for biasing the gripping elements into engagement with the structural element, each said biasing means including a connector, spring means carried by the support and biasing the connector, and means responsive to movement of the connector relative to the support for pivoting the gripping elements, each said control means comprising a control member extending from the gripping means carrying the same to adjacent the connector of the other gripping means, and means defining a lost motion connector between said control member and adjacent connector.
Claim 17
Dependent Claim 367 words
In an apparatus for selectively raising and lowering a load and including an upper gripping means biased into gripping engagement with a vertical load supporting elongated structural element, and a lower gripping means biased into gripping engagement with said structural element, means for controlling operation of the gripping means to effect an alternately descending series of engagements of said upper and lower gripping means with said structural element comprising: extensible means for moving said gripping means selectively toward and from each other; first control means carried by said upper gripping means for causing said lower gripping means to be released from said structural element as an incident of the upper gripping means being moved downwardly to a preselected minimum spacing of the upper gripping means above the lower gripping means with the lower gripping means engaged with said structural element; and second control means carried by said lower gripping means for causing said upper gripping means to be released from said structural element as an incident of the lower gripping means being moved downwardly to a preselected maximum spacing of downwardly to a preselected minimum spacing of the upper gripping means above the lower gripping means with the lower gripping means engaged with said structural element; and second control means carried by said lower gripping means for causing said upper gripping means to be released from said structural element as an incident of the lower gripping means being moved downwardly to a preselected maximum spacing of the lower gripping means below the upper gripping means with the upper gripping means engaged with said structural element, each of said gripping means comprising a support, gripping elements pivotally carried on the support, and biasing means for biasing the gripping elements into engagement with the structural element, each said biasing means including a connector, spring means carried by the support and biasing the connector, and means responsive to movement of the connector relative to the support for pivoting the gripping elements, each said control means comprising a control member extending from the gripping means carrying the same to adjacent the connector of the other gripping means, and means defining a lost motion connector between said control member and adjacent connector.
Claim 18
Dependent Claim 152 words
In an apparatus for selectively raising and lowering a load and including an upper gripping means biased into gripping engagement with a vertical load supporting elongated structural element, and a lower gripping means biased into gripping engagement with said structural element, means for controlling operation of the gripping means to effect an alternately descending series of engagements of said upper and lower gripping means with said structural element comprising: extensible means for moving said gripping means selectively toward and from each other; first control means carried by said upper gripping means for causing said lower gripping means to be released from said structural element as an incident of the upper gripping means being moved means with the upper gripping means engaged with said structural element, said gripping means shoulders being firmly locked to said structural element shoulders as an incident of the gripping means gripping the structural element in supporting the load.
Claim 19
Dependent Claim 152 words
In an apparatus for selectively raising and lowering a load and including an upper gripping means biased into gripping engagement with a vertical load supporting elongated structural element, and a lower gripping means biased into gripping engagement with said structural element, means for controlling operation of the gripping means to effect an alternately descending series of engagements of said upper and lower gripping means with said structural element comprising: extensible means for moving said gripping means selectively toward and from each other; first control means carried by said upper gripping means for causing said lower gripping means to be released from said structural element as an incident of the upper gripping means being moved means with the upper gripping means engaged with said structural element, said gripping means shoulders being firmly locked to said structural element shoulders as an incident of the gripping means gripping the structural element in supporting the load.
Claim 20
Dependent Claim 326 words
In an apparatus for selectively raising and lowering a load and including an upper gripping means biased into gripping engagement with a vertical load supporting elongated structural element, and a lower gripping means biased into gripping engagement with said structural element, means for controlling operation of the gripping means to effect an alternately descending series of engagements of said upper and lower gripping means with said structural element comprising: extensible means for moving said gripping means selectively toward and from each other; first control means carried by said upper gripping means for causing said lower gripping means to be released from said structural element as an incident of the upper gripping means being moved downwardly to a preselected minimum spacing of the upper gripping means above the lower gripping means with the lower gripping means engaged with said structural element; and second control means carried by said lower gripping means for causing said upper gripping means to be released from said structural element as an incident of the lower gripping means being moved downwardly to a preselected maximum spacing of the lower gripping means below the upper gripping means with the upper gripping means engaged with said structural element, each of said gripping means comprising a support, gripping elements movably carried on the support, and biasing means for biasing the gripping elements into engagement with the structural element, each said biasing means including a connector, spring means carried by the support and biasing the connector, and means responsive to movement of the connector relative to the support for moving the gripping elements, each said control means comprising a control member extended from the gripping means carrying the same to adjacent the connector of the other gripping means, and means defining a lost motion connector between said control member and adjacent connector including a portion of the control member defining a vertically elongated slot and a follower carried by the connector and movably received in said slot.
Claim 21
Dependent Claim 326 words
In an apparatus for selectively raising and lowering a load and including an upper gripping means biased into gripping engagement with a vertical load supporting elongated structural element, and a lower gripping means biased into gripping engagement with said structural element, means for controlling operation of the gripping means to effect an alternately descending series of engagements of said upper and lower gripping means with said structural element comprising: extensible means for moving said gripping means selectively toward and from each other; first control means carried by said upper gripping means for causing said lower gripping means to be released from said structural element as an incident of the upper gripping means being moved downwardly to a preselected minimum spacing of the upper gripping means above the lower gripping means with the lower gripping means engaged with said structural element; and second control means carried by said lower gripping means for causing said upper gripping means to be released from said structural element as an incident of the lower gripping means being moved downwardly to a preselected maximum spacing of the lower gripping means below the upper gripping means with the upper gripping means engaged with said structural element, each of said gripping means comprising a support, gripping elements movably carried on the support, and biasing means for biasing the gripping elements into engagement with the structural element, each said biasing means including a connector, spring means carried by the support and biasing the connector, and means responsive to movement of the connector relative to the support for moving the gripping elements, each said control means comprising a control member extended from the gripping means carrying the same to adjacent the connector of the other gripping means, and means defining a lost motion connector between said control member and adjacent connector including a portion of the control member defining a vertically elongated slot and a follower carried by the connector and movably received in said slot.
Claim 22
Dependent Claim 316 words
In an apparatus for selectively raising and lowering a load and including an upper gripping means biased into gripping engagement with a vertical load supporting elongated structural element, and a lower gripping means biased into gripping engagement with said structural element, means for controlling operation of the gripping means to effect an alternately descending series of engagements of said upper and lower gripping means with said structural element comprising: extensible means for moving said gripping means selectively toward and from each other; first control means carried by said upper gripping means released from said structural element as an incident of the upper gripping means being moved downwardly to a preselected minimum spacing of the upper gripping means above the lower gripping means with the lower gripping means engaged with said structural element; and second control means carried by said lower gripping means for causing said upper gripping means to be released from said structural element as an incident of the lower gripping means being moved downwardly to a preselected maximum spacing of the lower gripping means below the upper gripping means with the upper gripping means engaged with said structural element, each of said gripping means comprising a support, gripping elements movably carried on the support, and biasing means for biasing the gripping elements into engagement with the structural element, each said biasing means including a connector, spring means carried by the support and biasing the connector, and means responsive to movement of the connector relative to the support for moving the gripping elements including a portion of the connector defining a slot and a follower carried by a gripping element and movably received in said slot, each said control means comprising a control member extended from the gripping means carrying the same to adjacent the connector of the other gripping means, and means defining a lost motion connector between said control member and adjacent connector.
Claim 23
Dependent Claim 316 words
In an apparatus for selectively raising and lowering a load and including an upper gripping means biased into gripping engagement with a vertical load supporting elongated structural element, and a lower gripping means biased into gripping engagement with said structural element, means for controlling operation of the gripping means to effect an alternately descending series of engagements of said upper and lower gripping means with said structural element comprising: extensible means for moving said gripping means selectively toward and from each other; first control means carried by said upper gripping means released from said structural element as an incident of the upper gripping means being moved downwardly to a preselected minimum spacing of the upper gripping means above the lower gripping means with the lower gripping means engaged with said structural element; and second control means carried by said lower gripping means for causing said upper gripping means to be released from said structural element as an incident of the lower gripping means being moved downwardly to a preselected maximum spacing of the lower gripping means below the upper gripping means with the upper gripping means engaged with said structural element, each of said gripping means comprising a support, gripping elements movably carried on the support, and biasing means for biasing the gripping elements into engagement with the structural element, each said biasing means including a connector, spring means carried by the support and biasing the connector, and means responsive to movement of the connector relative to the support for moving the gripping elements including a portion of the connector defining a slot and a follower carried by a gripping element and movably received in said slot, each said control means comprising a control member extended from the gripping means carrying the same to adjacent the connector of the other gripping means, and means defining a lost motion connector between said control member and adjacent connector.
Claim 24
Dependent Claim 294 words
In an apparatus for selectively raising and lowering a load and including an upper gripping means biased into gripping engagement with a vertical load supporting elongated structural element, and a lower gripping means biased into gripping engagement with said structural element, means for controlling operation of the gripping means to effect an alternately descending series of engagements of said upper and lower gripping means with said structural element comprising: extensible means for moving said gripping means selectively toward and from each other; first control means carried by said upper gripping means released from said structural element as an incident of the upper gripping means being moved downwardly to a preselected minimum spacing of the upper gripping means above the lower gripping means with the lower gripping means engaged with said structural element; and second control means carried by said lower gripping means for causing said upper gripping means to be released from said structural element as an incident of the lower gripping means being moved downwardly to a preselected maximum spacing of the lower gripping means below the upper gripping means with the upper gripping means engaged with said structural element, each of said gripping means comprising an arcuate support, gripping elements pivotally carried on the support, and biasing means for biasing the gripping elements into engagement with the structural element, each said biasing means including a connector, spring means carried by the support and biasing the connector, and means responsive to movement of the connector relative to the support for pivoting the gripping elements, each said control means comprising a control member extending from the gripping means carrying the same to adjacent the connector of the other gripping means, and means defining a lost motion connector between said control member and adjacent connector.
Claim 25
Dependent Claim 294 words
In an apparatus for selectively raising and lowering a load and including an upper gripping means biased into gripping engagement with a vertical load supporting elongated structural element, and a lower gripping means biased into gripping engagement with said structural element, means for controlling operation of the gripping means to effect an alternately descending series of engagements of said upper and lower gripping means with said structural element comprising: extensible means for moving said gripping means selectively toward and from each other; first control means carried by said upper gripping means released from said structural element as an incident of the upper gripping means being moved downwardly to a preselected minimum spacing of the upper gripping means above the lower gripping means with the lower gripping means engaged with said structural element; and second control means carried by said lower gripping means for causing said upper gripping means to be released from said structural element as an incident of the lower gripping means being moved downwardly to a preselected maximum spacing of the lower gripping means below the upper gripping means with the upper gripping means engaged with said structural element, each of said gripping means comprising an arcuate support, gripping elements pivotally carried on the support, and biasing means for biasing the gripping elements into engagement with the structural element, each said biasing means including a connector, spring means carried by the support and biasing the connector, and means responsive to movement of the connector relative to the support for pivoting the gripping elements, each said control means comprising a control member extending from the gripping means carrying the same to adjacent the connector of the other gripping means, and means defining a lost motion connector between said control member and adjacent connector.
Claim 26
Dependent Claim 299 words
In an apparatus for selectively raising and lowering a load and including an upper gripping means biased into gripping engagement with a vertical load supporting elongated structural element, and a lower gripping means biased into gripping engagement with said structural element, means for controlling operation of the gripping means to effect an alternately descending series of engagements of said upper and lower gripping means with said structural element comprising: extensible means for moving said gripping means selectively toward and from each other; first control means carried by said upper gripping means released from said structural element as an incident of the upper gripping means being moved downwardly to a preselected minimum spacing of the upper gripping means above the lower gripping means with the lower gripping means engaged with said structural element; and second control means carried by said lower gripping means for causing said upper gripping means to be released from said structural element as an incident of the lower gripping means being moved downwardly to a preselected maximum spacing of the lower gripping means below the upper gripping means with the upper gripping means engaged with said structural element, each of said gripping means comprising a support, gripping elements, linkage means pivotally carried on the support and swingably carrying said gripping elements for movement toward and from the structural element, and biasing means for biasing the gripping elements into engagement with the structural element, each said biasing means including a connector, and means responsive to movement of the connector relative to the support for moving the gripping elements, each said control means comprising a control member extending from the gripping means carrying the same to adjacent the connector of the other gripping means, and means defining a lost motion connector between said control member and adjacent connector.
Claim 27
Dependent Claim 299 words
In an apparatus for selectively raising and lowering a load and including an upper gripping means biased into gripping engagement with a vertical load supporting elongated structural element, and a lower gripping means biased into gripping engagement with said structural element, means for controlling operation of the gripping means to effect an alternately descending series of engagements of said upper and lower gripping means with said structural element comprising: extensible means for moving said gripping means selectively toward and from each other; first control means carried by said upper gripping means released from said structural element as an incident of the upper gripping means being moved downwardly to a preselected minimum spacing of the upper gripping means above the lower gripping means with the lower gripping means engaged with said structural element; and second control means carried by said lower gripping means for causing said upper gripping means to be released from said structural element as an incident of the lower gripping means being moved downwardly to a preselected maximum spacing of the lower gripping means below the upper gripping means with the upper gripping means engaged with said structural element, each of said gripping means comprising a support, gripping elements, linkage means pivotally carried on the support and swingably carrying said gripping elements for movement toward and from the structural element, and biasing means for biasing the gripping elements into engagement with the structural element, each said biasing means including a connector, and means responsive to movement of the connector relative to the support for moving the gripping elements, each said control means comprising a control member extending from the gripping means carrying the same to adjacent the connector of the other gripping means, and means defining a lost motion connector between said control member and adjacent connector.
Claim 28
Dependent Claim 312 words
In an apparatus for selectively raising and lowering a load and including an upper gripping means biased into gripping engagement with a vertical load supporting elongated structural element, and a lower gripping means biased into gripping engagement with said structural element, means for controlling operation of the gripping means to effect an alternately descending series of engagements of said upper and lower gripping means with said structural element comprising: extensible means for moving said gripping means selectively toward and from each other; first control means carried by said upper gripping means released from said structural element as an incident of the upper gripping means being moved downwardly to a preselected minimum spacing of the upper gripping means above the lower gripping means with the lower gripping means engaged with said structural element; and second control means carried by said lower gripping means for causing said upper gripping means to be released from said structural element as an incident of the lower gripping means being moved downwardly to a preselected maximum spacing of the lower gripping means below the upper gripping means with the upper gripping means engaged with said structural element, each of said gripping means comprising a support, gripping elements parallelogram linkage means pivotally carried on the support and swingably carrying said gripping elements for movement toward and from the structural element with said gripping elements maintained extending accurately parallel to the longitudinal extent of said structural element, each said biasing means including a connector spring means carried by the support and biasing the connector, and means responsive to movement of the connector relative to the support for moving the gripping elements, each said control means comprising a control member extending from the gripping means carrying the same to adjacent the connector of the other gripping means, and means defining a lost motion connector between said control member and adjacent connector.
Claim 29
Dependent Claim 312 words
In an apparatus for selectively raising and lowering a load and including an upper gripping means biased into gripping engagement with a vertical load supporting elongated structural element, and a lower gripping means biased into gripping engagement with said structural element, means for controlling operation of the gripping means to effect an alternately descending series of engagements of said upper and lower gripping means with said structural element comprising: extensible means for moving said gripping means selectively toward and from each other; first control means carried by said upper gripping means released from said structural element as an incident of the upper gripping means being moved downwardly to a preselected minimum spacing of the upper gripping means above the lower gripping means with the lower gripping means engaged with said structural element; and second control means carried by said lower gripping means for causing said upper gripping means to be released from said structural element as an incident of the lower gripping means being moved downwardly to a preselected maximum spacing of the lower gripping means below the upper gripping means with the upper gripping means engaged with said structural element, each of said gripping means comprising a support, gripping elements parallelogram linkage means pivotally carried on the support and swingably carrying said gripping elements for movement toward and from the structural element with said gripping elements maintained extending accurately parallel to the longitudinal extent of said structural element, each said biasing means including a connector spring means carried by the support and biasing the connector, and means responsive to movement of the connector relative to the support for moving the gripping elements, each said control means comprising a control member extending from the gripping means carrying the same to adjacent the connector of the other gripping means, and means defining a lost motion connector between said control member and adjacent connector.

References Cited (Backward Citations)

US3109289A Cited
US3203669A Cited
US3901477A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1984-07-06 1985-01-05 1985-07-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1988-07-06 1989-01-05 1989-07-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1992-07-06 1993-01-05 1993-07-07 $7700.00 Window Closed / Lapsed

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