A jack stand apparatus enables operators to screw adjust a load support column relative to a column support base for fully completing load-bearing distances between loads and opposed support surfacing, and thus improving safety of jack stand applications. The various embodiments of the jack stand apparatus according to the present invention may all be said to comprise a shaft support structure, a shaft construction, a pawl assembly, and a screw mechanism. In the preferred embodiment, the shaft construction is a screw type element and includes external threads. A pawl element is cooperable with the external threads, and the screw shaft construction is telescopically positionable relative to the shaft support structure for engaging an overlying load. The pawl element is engagable with the helical threads for preventing downward movement of the screw shaft construction relative to the shaft support structure for supporting loads thereupon.

A linear jack includes a first outer sleeve, an inner sleeve disposed at least partially within the first outer sleeve, a second outer sleeve disposed at least partially within the inner sleeve, a translating screw disposed at least partially within the second outer sleeve, and a cover sleeve coupled to the translating screw. The first outer sleeve is threadedly coupled to the inner sleeve. The second outer sleeve is threadedly coupled to the translating screw. The translating screw is disposed at least partially within the cover sleeve. The cover sleeve is configured to translate with the translating screw.

An up-and-down driving device allows an up-and-down driving unit to move while supporting an object's load, in a support module in which the up-and-down driving unit is movably inserted into an inner space of a fixed housing. The up-and-down driving device includes: a driving means for moving the up-and-down driving unit in an up-and-down direction; a fixed-position compression spring main module including a fixed-position compression spring having one side fixed to a lower end of the housing and the other side supporting the up-and-down driving unit and mounted in a motion direction of the up-and-down driving unit; and a variable-position compression spring supplemental module including a variable-position compression spring having one side mounted rotatably to a side of the housing and the other side fastened rotatably to the up-and-down driving unit and configured to rotate while making a predetermined angle with the motion direction of the up-and-down driving unit.

An up-and-down driving device allows an up-and-down driving unit to move while supporting an object's load, in a support module in which the up-and-down driving unit is movably inserted into an inner space of a fixed housing. The up-and-down driving device includes: a driving means for moving the up-and-down driving unit in an up-and-down direction; a fixed-position compression spring main module including a fixed-position compression spring having one side fixed to a lower end of the housing and the other side supporting the up-and-down driving unit and mounted in a motion direction of the up-and-down driving unit; and a variable-position compression spring supplemental module including a variable-position compression spring having one side mounted rotatably to a side of the housing and the other side fastened rotatably to the up-and-down driving unit and configured to rotate while making a predetermined angle with the motion direction of the up-and-down driving unit.

A linear jack includes an outer sleeve, an inner sleeve disposed at least partially within the outer sleeve, and an inner screw disposed at least partially within the inner sleeve. The outer sleeve is threadedly coupled to an outer diameter surface of the inner sleeve. The inner screw is threadedly coupled to an inner diameter surface of the inner sleeve. A thread pitch of the outer sleeve is greater than a thread pitch of the inner screw.

A linear jack includes an outer tube, a high speed assembly comprising a first rotating member threadedly coupled to a first translating member, a low speed assembly comprising a second rotating member threadedly coupled to a second translating member, wherein the low speed assembly is coupled to and translates with the first translating member. At least a portion of the high speed assembly is slidable in the outer tube between a first position, wherein the high speed assembly is engaged with a shaft, and a second position, wherein the high speed assembly is disengaged from the shaft. A thread pitch of the high speed assembly is greater than a thread pitch of the low speed assembly.

A linear jack includes an outer tube, a high speed assembly comprising a first rotating member threadedly coupled to a first translating member, a low speed assembly comprising a second rotating member threadedly coupled to a second translating member, wherein the low speed assembly is coupled to and translates with the first translating member. At least a portion of the high speed assembly is slidable in the outer tube between a first position, wherein the high speed assembly is engaged with a shaft, and a second position, wherein the high speed assembly is disengaged from the shaft. A thread pitch of the high speed assembly is greater than a thread pitch of the low speed assembly.

A telescopic pipe includes a base pipe having a base inner pipe rotated by external force, and a base outer pipe arranged to receive the base inner pipe; a connecting pipe having a connecting inner pipe coupled to the base inner pipe to be extendable to transfer rotational force, and a connecting outer pipe screw-coupled to the inner circumferential surface of the base outer pipe to be extendable; and a finishing pipe including a finishing inner pipe coupled to the connecting inner pipe to be extendable and to be rotated, and a finishing outer pipe that is interlocked by means of rotation of the finishing inner pipe and is screw-coupled to the inner circumferential surface of the connecting outer-pipe to be extendable, wherein the connecting outer pipe is interlocked by the rotational force of the extended finishing outer pipe and thus is extended and retracted along the base outer pipe.

A telescopic pipe includes a base pipe having a base inner pipe rotated by external force, and a base outer pipe arranged to receive the base inner pipe; a connecting pipe having a connecting inner pipe coupled to the base inner pipe to be extendable to transfer rotational force, and a connecting outer pipe screw-coupled to the inner circumferential surface of the base outer pipe to be extendable; and a finishing pipe including a finishing inner pipe coupled to the connecting inner pipe to be extendable and to be rotated, and a finishing outer pipe that is interlocked by means of rotation of the finishing inner pipe and is screw-coupled to the inner circumferential surface of the connecting outer-pipe to be extendable, wherein the connecting outer pipe is interlocked by the rotational force of the extended finishing outer pipe and thus is extended and retracted along the base outer pipe.

A linear jack includes a first outer sleeve, an inner sleeve disposed at least partially within the first outer sleeve, a second outer sleeve disposed at least partially within the inner sleeve, a translating screw disposed at least partially within the second outer sleeve, and a cover sleeve coupled to the translating screw. The first outer sleeve is threadedly coupled to the inner sleeve. The second outer sleeve is threadedly coupled to the translating screw. The translating screw is disposed at least partially within the cover sleeve. The cover sleeve is configured to translate with the translating screw.