Source : Webster's Revised Unabridged Dictionary (1913)

   {Spring lock}, a lock that fastens with a spring.

   {Spring mattress}, a spring bed.

   {Spring of an arch} (Arch.) See {Springing line of an arch},
      under {Springing}.

   {Spring of pork}, the lower part of a fore quarter, which is
      divided from the neck, and has the leg and foot without
      the shoulder. [Obs.] --Nares.

            Sir, pray hand the spring of pork to me. --Gayton.

   {Spring pin} (Locomotive Engines), an iron rod fitted between
      the springs and the axle boxes, to sustain and regulate
      the pressure on the axles.

   {Spring rye}, a kind of rye sown in the spring; -- in
      distinction from winter rye, sown in autumn.

   {Spring stay} (Naut.), a preventer stay, to assist the
      regular one. --R. H. Dana, Jr.

   {Spring tide}, the tide which happens at, or soon after, the
      new and the full moon, and which rises higher than common
      tides. See {Tide}.

   {Spring wagon}, a wagon in which springs are interposed
      between the body and the axles to form elastic supports.
      

   {Spring wheat}, any kind of wheat sown in the spring; -- in
      distinction from winter wheat, which is sown in autumn.

Source : WordNet®

spring mattress
     n : a mattress containing springs in a rigid frame