Tripod and method

[0001] The present application claims priority to U.S. Provisional Patent Application Ser. No. 60/365,734, filed Mar. 19, 2002, the entire contents of which are specifically incorporated herein by reference.

[0002] This present disclosure relates to tripods. More specifically, this disclosure relates to exemplary tripods suitable for supporting a three dimensional coordinate measurement apparatus and method of use thereof.

[0003] There are many instances where a stable support is required to ensure that the object or device being supported remains fixed with respect to a solid surface such as a floor. For example, laboratory equipment and measurement equipment, such as three-dimensional coordinate measurement instrument, are often required to remain fixed with respect to a sturdy object or the floor to ensure that the relative position between the measurement device and the object being measured remains fixed.

[0004] One common method of ensuring stability of an apparatus has been physically bolting the apparatus to a sturdy table or floor. However, this method requires permanently altering the table or floor and makes repositioning difficult.

[0005] U.S. Pat. No. 5,402,582, issued on Apr. 4, 1995 to Simon Raab and wholly incorporated herein by reference, shows a prior art floor stand support at FIG. 3 having a three-dimensional coordinate measuring device and monitor stand supported by a large-diameter post 24 and angled support legs extending up from a solid platform. Such a design is sufficiently sturdy to allow the coordinate measurement device to easily measure coordinates within a spherical space ranging from six to eight feet (1.8-2.4 m) in diameter with a measuring accuracy of 2{circle around (9)}±0.005 inch (0.13 mm), wherein {circle around (9)}=one standard deviation.

[0006] However, it would be desirable to provide a support that is at least as sturdy as the prior art support, but one that is easily moved from one place to another within a room and collapsed for storage or transportation.

[0007] Tripods are well known in the prior art for providing a stable support that is collapsible. However, for some applications, they are not stable enough. Specifically, in applications where the center of mass of the supported device is moved from directly above the center of the tripod, the bending moment imposed on the tripod legs can cause impermissible movement of the supported device, particularly in sensitive measurement applications such as that discussed above.

[0008] In addition, existing tripods remain difficult to move from one location to another. For example, if one wishes to move a device supported by a tripod from one location in a room to another location, he or she would have to lift the device and tripod together off the floor and carry it to the new location, while avoid tripping on the extended legs. If the legs collapse downwardly, then they then must be spread back out when the tripod reaches its destination. If the apparatus being supported by the tripod is very heavy, this compounds the difficulty of carrying it as the whole assembly becomes top-heavy.

[0009] While the tripod's ability to be collapsed for storage and transportation has made them indispensable in many fields since their introduction, they remain cumbersome to set up and take down, particularly where hand tools are required for tightening clamps and other adjustments in the case of heavy-duty tripods. One reason for this difficulty is that there has not been adequate provisions in prior art tripods for storing needed hand tools so that they are readily available.

[0010] The above-discussed and other drawbacks and deficiencies of the prior art are overcome or alleviated by a novel tripod having an extensible strut for stabilizing purposes. In another aspect, a novel caster wheel mechanism permits easy relocation of the tripod. In another aspect, a multi-function support is provided. In yet another aspect, a tool rack is provided supported by the tripod. In yet another aspect, a method of using a tripod includes attaching the tripod to a stable object.

[0011] The above-discussed and other features and advantages of the presently described tripod will be appreciated and understood by those skilled in the art from the following detailed description and drawings.

[0021] FIGS. 1 and 2 show a tripod 100 having three legs 130 each comprising a crutch 136 and a lower leg 138. Each crutch 136 includes two crutch-struts 137 depending from a leg pivot 132 to a crutch clamp 143. Crutch clamp 141 includes a knob 143 for tightening crutch clamp 141 onto lower leg 138, thereby fixing said crutch clamp 141 to lower leg 138. Lower leg 138 is therefore adjustable and extensible from crutch 136. At a lower end of each lower leg 138 is a caster adapter 150 and pod 140. In an exemplary embodiment, caster adapters 150 are configured to pivot approximately 180° around lower legs 138 into either an engaged position, in which casters 152 are in contact with the floor and pods 140 are raised as shown in FIG. 2, or a disengaged position, in which casters 152 are raised off the floor and pods 140 are supporting tripod 100 as shown in FIG. 1. However, such pivot angle may be less than 180°, as long as such pivot is sufficient to disengage the casters from the horizontal floor.

[0022] Referring again to the exemplary embodiment illustrated by FIGS. 1 and 2, extending vertically downward between tripod legs 130 from head 105 is stay rod guide 160. Stays 139 extend from a stay rod yoke 145 to each crutch clamp 141 thereby coordinating legs 130. Stay rod yoke 145 includes a knob permitting stay rod yoke 145 to be clamped to stay rod guide 160 so that the collapse and expansion of legs 130 can be selectively prevented or permitted.

[0023] Exemplary platform 110 is bolted to head 105 using the threaded holes in head 105 shown in FIG. 2. Platform 110 includes, e.g., a first support 112 for attaching a three dimensional coordinate measurement apparatus and a second support 114 for attaching a computer display or monitor, as will be discussed below with reference to FIGS. 7-9. Attached to platform 110 is a tool rack 120 and one or more struts 170 (two shown).

[0024] Exemplary tool rack 120 will now be described with reference to FIGS. 4 and 4a. To the side of platform 110 is a tool rack 120 supporting a pair of tools including a wrench 125 and T-handle wrench 123. A cable 122 passes through a handle of T-handle wrench 123 and of wrench 125 thereby tying the tools to tripod 100, i.e., the rack 120 comprises a loop, or equivalent shaped aperture, through which the tools cannot pass and if both tools are removed, the cable will pass through the loop, effectively preventing either tool from being separated from tripod 100.

[0025] In an exemplary embodiment, opposite tool rack 120 on platform 110 are two struts 170 that are shown in FIGS. 1 and 4 hanging down. Each strut includes an extensible rod with a mounting bracket at its distal end. Although the struts 170 are attached directly to platform 110, they may be instead be mounted to head 105 or any other object fixed thereto, in which case the struts 170 would be indirectly attached to platform 110.

[0026] Exemplary struts 170 are shown in detail in FIGS. 5 and 6. In one embodiment, at a proximal end portion, each strut 170 has a first ball joint 172 that is bolted or otherwise attached to platform 110. Extending from ball joint 172 is a first strut portion 173, which terminates in strut clamp 174. Strut clamp 174 is configured for clamping a second strut portion 175 that is received within first strut portion 173 and is extensible therefrom. First and second strut portions 173 and 175 therefore cooperate in a telescoping fashion, with strut clamp 174 acting to lock the two strut portions in place with respect to each other. At the distal end portion of second strut portion 175 is a second ball joint 177 and clamp disk 179. While ball joints 172 and 177 have been specified, it is to be recognized that other types of joints are contemplated for use with such arm.

[0027] Struts 170 provide additional stability to tripod 100 by anchoring platform 110 to a solid object or wall. For example, tripod 100 is shown anchored to a table 200 in FIG. 7 by struts 170 clamped to an edge thereof. Mounted on platform 110 is a three dimensional coordinate measurement apparatus 210 and a computer display 220. Exemplary tripod 100 is again shown in FIG. 8, this time attached to workbench 205. FIG. 9 shows another view of the tripod 100, this time in use. It will be appreciated that struts 170 provide additional stability to tripod 100 when the center of mass of apparatuses 210 and 220 is moved from directly above the center of tripod 100.

[0028] While exemplary embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.