Obs. [f. SPRING v.1] A bar or cross-piece to which the ends of a horses traces are attached; a swingle-tree. Also attrib.
1623. Althorp MS., in Simpkinson, Washingtons (1860), p. xlii. To Butlin 6 daies paling, and making springtrees for the coach.
1648. Wilkins, Math. Magic, I. iv. 26. At each of its extremities there is a severall spring-tree to which either horses or oxen may be fastned.
a. 1723. Wren, Disc. Archit., in Phillimore, Times, etc. (1881), 346. At the end of this Rope is a Spring-tree (as our Coachmen use for ye two fore Horses).
1766. Compl. Farmer, s.v. Madder 5 I 1/1. The part where the links of the spring-tree bar are fastened. Ibid., s.v. Potatoe 6 E 3/2. I put a double spring-tree bar to the cultivator, to avoid the poaching of the horses.