Dividers With Hinged Lower Legs

 Sometimes you come across dividers or calipers where the lower section of one or both legs are jointed so they can swivel or rotate. This generally occurs for one of two reasons. In one case, it allows the points of the lower leg to remain vertical. Another use is to rotate another type of point into place. In this post we’ll look at examples of each of these applications. 

“Verticality”

In larger dividers, if the legs are widely separated, the points tend to slip as they cannot easily bite into the surface being measured. If the points face straight down this problem is reduced. The only downside to this is the degree of separation of the legs is reduced somewhat. What follows are several examples where this technique is used.

Sullivan's Mar. 9, 1880 patent. Unknown manufaturer. Machine screws holding lower legs likely   replacements.                        

Oscar Stoddard's Mar. 31, 1885 patent for dividers with lower legs that can swivel is similar in function to the Sullivan example above and the Copeland pair of dividers two photos down.

Stoddard 1885 patent

The dividers shown below are marked "S. Copeland Pat. May [24] 1887". Likely manufatured by Copeland and Chamberlain, Worchester MA. One removeable leg has a swivel point. A leg like this does not appear in the patent drawing and may not be original to the tool. It is similar to the legs in the Stoddard example above.

The example below is a Peck, Stowe and Wilcox No. 35. The add on, angled, fixed points are not marked in any way. They look like they may be patented, but I haven't located such a patent yet.

Finally a pair of wooden dividers (more precisely compasses) which have appeared in a previous post. The lower legs swivel and are held in place only by friction

 

Rotating in different points

A fairly common variation seen in calipers is the ability to rotate the lower legs to bring into position either inside or outside caliper points or standard straight points. An alternative method to achieve the same end is to have removable points that slide into or along side the upper section of the legs. This will be examined in a later post. 

None of the examples pictured below are marked with a manufacturer. All three are likely user made.

Until next time!