Adjustable articulated support arm

Claim 2

An adjustable, articulated support, comprising a base member, a first arm transversely pivoted to the base member, a drum secured to the first arm, a second arm pivoted to the first arm, an arcuate guide member secured to the second arm, and an elongated flexible member anchored at one end to the base member and extending at least once around said drum and passing over said arcuate guide member to hold said support rigid against an applied load by tension in the elongated member and grip thereof on said drum, adjustment on the support being permitted by releasing the tension in said elongated flexible member, the end of said elongated flexible member remote from said anchorage on the base member being anchored to said second arm or to a further member secured to said second arm and the tensioning of the elongated flexible member being achieved by the action of gravity on the second arm plus any load carried thereby.

Claim 3

A support according to claim 1, and including a rigid link pivoted at one end to said second arm and at the other end to said base member, at least one of the pivots providing for a degree of lost motion permitting the tension in said elongated member to be released when adjustment of the support is required.

Claim 4

A support according to claim 1, wherein the radii of curvature of the guide member and the drum are substantially equal.

Claim 5

A support according to claim 3, wherein the axes of curvature of the drum and the guide member respectively substantially coincide with the axes of the pivots of the first arm on the base member and the second arm on the first arm.

Claim 6

A support according to claim 1 wherein the arcuate guide is of pulley-like form.

Claim 7

A support according to claim 1, and including a third arm transversely pivoted to the end of said second arm remote from said first arm, said arcuate guide member being constituted by a second drum around which said elongated member extends at least once, and said third arm having a second arcuate guide member secured thereto over which the elongated member passes.

Claim 8

A support according to claim 6, wherein the radii of curvature of the first and second drums and the arcuate guide member on the third arm are substantially equal.

Claim 9

A support according to claim 7, wherein the axes of the first and second drums and the arcuate guide member on the third arm substantially coincide respectively with the axes of the pivots between the first arm and the base member, the second arm and the first arm and the third arm and the second arm.

Claim 10

A support according to claim 6, wherein the end of the elongated flexible member remote from the base member is anchored to the second arm through a tensioning spring.

Claim 11

A support according to claim 6, wherein means are provided for clamping the elongated flexible member to the second arcuate guide member.

Claim 12

A support according to claim 6, wherein the second arcuate guide member is in the form of a drum and the elongateD flexible member passes at least once around the last said drum.

Claim 13

A support according to claim 9, wherein means are provided to facilitate the release of tension in the elongated flexible member.

Claim 14

A support according to claim 1, wherein the elongated flexible member is a multi-strand steel cable.

Claim 15

An adjustable, articulated support, comprising a base member, a first arm transversely pivoted to the base member, a drum secured to the first arm, a second arm pivoted to the first arm, an arcuate guide member secured to the second arm, and an elongated flexible member anchored at one end to the base member and extending at least once around said drum and passing over said arcuate guide member to hold said support rigid against an applied load by tension in the elongated member and grip thereof on said drum, adjustment of the support being permitted by releasing the tension in said elongated flexible member, the end of said elongated flexible member remote from the anchorage on the base being itself anchored to the base through a tensioning spring which assists gravity in tensioning the elongated flexible member, and means for clamping said elongated flexible member to the arcuate guide member whereby tension in that part of the elongated flexible member which extends back from the guide member and around said drum to the first said anchorage can be released by rotation of the second arm about its pivot to permit adjustment of the support.

Claim 16

An adjustable, articulated support, comprising a base member, a first arm transversely pivoted to the base member, a drum secured to the first arm, a second arm pivoted to the first arm, an arcuate guide member secured to the second arm, and an elongated flexible member anchored at one end to the base member and extending at least once around said drum and passing over said arcuate guide member to hold said support rigid against an applied load by tension in the elongated member and grip thereof on said drum, adjustment of the support being permitted by releasing the tension in said elongated flexible member, the end of said elongated flexible member remote from the anchorage on the base being itself anchored to the base through a tensioning spring which assists gravity in tensioning the elongated flexible member, and means for clamping said elongated flexible member to the arcuate guide member whereby tension in that part of the elongated flexible member which extends back from the guide member and around said drum to the first said anchorage can be released by rotation of the second arm about its pivot to permit adjustment of the support.

Claim 17

An adjustable, articulated support, comprising: a base member, a first arm transversely pivoted to the base member, a drum secured to the first arm, a second arm pivoted to the first arm, an arcuate guide member secured to the second arm, and an elongated flexible member anchored at one end to the base member and extending at least once around said drum and passing over said arcuate guide member to hold said support rigid against an applied load by tension in the elongated member and grip thereof on said drum, adjustment of the support being permitted by releasing the tension in said elongated flexible member, the tensioning of the elongated member between the anchorage and the drum and between the drum and the arcuate guide member being effected at least in part by gravity acting on the arms.

Claim 18

An adjustable, articulated support, comprising: a base member, a first arm transversely pivoted to the base member, a drum secured to the first arm, a second arm pivoted to the first arm, an arcuate guide member secured to the second arm, and an elongated flexible member anchored at one end to the base member and extending at least once around said drum and passing over said arcuate guide member to hold said support rigid against an applied load by tension in the elongated member and grip thereof on said drum, adjustment of the support being permitted by releasing the tension in said elongated flexible member, the tensioning of the elongated member between the anchorage and the drum and between the drum and the arcuate guide member being effected at least in part by gravity acting on the arms.

Claim 19

A support according to claim 15, wherein the tensioning of the elongated member beyond the arcuate guide member is effected by means of a spring.