G.R. No. 36650 - Vargas vs. Chua

Angel Vargas, plaintiff and appellee, is the registered owner of United States Patent No. 1,507,530 covering certain plow improvements issued on September 2, 1924. He manufactures and sells these plows in the Philippines.
Defendants and appellants are Petronila Chua, Coo Pao (alias Coo Paoco), Coo Teng Hee, and the commercial partnership Cham Samco & Sons along with its partners.
Petronila Chua manufactures and sells plows similar to those covered by Vargas' patent. Coo Teng Hee obtains these plows from Petronila Chua and sells them through his hardware store. Cham Samco & Sons buys these plows from Coo Teng Hee and other sources and sells them in its Manila store.
Cham Samco & Sons did not appeal from the original judgment.

Vargas sought to enjoin the defendants from manufacturing, selling, or offering for sale plows similar to his patented models (Exhibits B, B-1, B-2).
He also petitioned for an accounting of profits earned by defendants from the manufacture and sale of such plows, and for damages equivalent to double those profits.

Vargas is the owner of US Patent No. 1,507,530, duly registered in the Philippines.
Since issuance of the patent, Vargas has continuously manufactured and sold the patented plows of various sizes (Nos. 1 to 5).
Defendants, particularly Petronila Chua, have manufactured and sold plows of the type and design represented by Exhibits B, B-1, and B-2, corresponding to sizes 2, 4, and 5.
Defendant Coo Teng Hee has been purchasing these plows from Petronila Chua and reselling them in Iloilo.
Defendant Cham Samco & Sons has purchased from Coo Teng Hee and other sources and sold in Manila plows of similar design.
The plaintiff's plows are known in the trade as “Arados Vargas” and he is the sole manufacturer of such.
A former patent held by Vargas (No. 1,020,232), issued March 12, 1912, covering the earlier model plow, was declared null and void by the Philippine Supreme Court in a prior case (Vargas vs. F. M. Yaptico & Co.). The subject of this prior patent corresponds to Exhibit 3-Chua.

The Court of First Instance ruled in favor of Vargas, enjoining the defendants from further infringing activity and ordering accounting of profits.
Defendants appealed, raising four errors:

The trial court erred in declaring the patented plow (Exhibit F) distinct from the old model plow (Exhibit 3-Chua) whose patent was voided.
The trial court mistook an improvement on the plow for a new plow itself.
The trial court erred in rendering judgment in favor of plaintiff.
The court erred in not dismissing the complaint with costs against plaintiff.

Whether the plow described in Patent No. 1,507,530 (Exhibit F) constitutes a real invention or an improvement that may be granted patent protection, as distinct from the older model plow covered by the previously voided patent (Exhibit 3-Chua).
Whether the plaintiff is entitled to injunction and damages against defendants for infringing the patent.