According to Abridgements of Specifications relating to Hinges, Hinge Joints, and Door Springs: A. D. 1775-1866, Parts 1775-1866, bottom of page 3 it clearly states A. D. 1790, April 13, - No 1742. Downer, Henry, - (is recognised for) "A spring for the purpose of shutting a door"
In the same pamphlet/booklet on page 9 is reference to Joseph Smith, A. D. 1814, July 16, - No 3822. SMITH, Joseph, - "Spring hinges for doors and gates." From the description of the patent I believe this is the Smith of Smith and Turner fame.
A.D. 1814, July 16.— N° 3822. SMITH, Joseph. — " Spring hinges for doors and gates." A brass shoe, fixed on the bottom of the door, has a centre pin or pivot which passes through a fixed brass plate and is stepped into a socket. A lever, carried by the pivot (the pivot lever) and fixed to it, is furnished with a collar (or brass roller) which is between two levers on two different but concentric fulcra. The upper lever is fixed to a spindle connected with the interior of a spiral spring ; the under lever has its fulcrum on a collar con- nected with the spring box of the said spring. A fixed angular piece, in which is inserted a screw, regulates the distance of the upper and under levers when they are at rest. This invention is adapted for doors that open either one or both ways ; when the door opens to the right, the upper lever is forced back by the pivot lever, and " when opened to its extent, becomes light and easy in consequence of the spring having lost a great portion of its power, by means of the brass roller " <( having passed nearly to " the end " of the upper lever, thus, by the door opening, the pivot lever " obtains great power over the spring, and as the door *' closes, the spring regains its former strength." When the door is opened to the left, the pivot lever forces back the under lever, and the operation has the same effect as before described. A couple of toothed wheels, eccentrically pivoted, may be used instead of the upper and under levers. In fixing the door, an upper centre pin or pivot is fitted to the top of the door vertically over the pivot connected with the said brass shoe. [Printed, 6d. Drawing.]
Graces Guide appears to confirm my suspicions by the 1814 date as can be seen below although the advert from the site however does state they were established in 1799.
We also have further reference from Graces Guide and the name John Smith and a date of 1760:
of Abbey Works, Weedon Road, Northampton
1760 Company established previous to this by John Smith (records go back no further).
By 1878 Messrs. Archibald Smith and Co., hydraulic and general engineers, were in Leicester Square, London.
1880 A new factory was built at Battersea to meet the expansion of the business, and the firm's name was altered to Archibald Smith and Stevens."
So from three different sources we have the names Archibald Smith, John Smith, William Smith and the dates of 1760 and 1770 plus a number of references to a door spring invention that established the company, along with hoist manufacture.
For those interested it is therefore reasonable to assume that
1. Despite the patent of Henry Downer (1790) the first device to close a door by way of a spring/spring device is more than likely attributable to the Smith line (20 to 30 years before Downers patent), later to become Smith, Major, Stevens.
2. "Smith" of Smith and Turner is not the same Smith as the Smith, Major, Stevens line.
3. Despite their claims (unless you want to play with definitions) Smith and Turner were not the first to manufacture/produce/invent a door spring (their earliest reference only goes back as far as 1799 and in all likely hood should be 1814, either nine or twenty four years after Downer and as said possibly as many as fifty four years after Smith).
4. More investigation is needed.
I hope you find this blog post interesting and please feel free to comment.