Within this dataset of 21 records, one assignee leads the ranked list with 10 records, well ahead of the rest of the field. The remaining nine ranked assignees each hold a handful of records, with fifth place at 2 and tenth place at 1, so the field reads as one established leader followed by a long tail of individual inventors and small filers. This pattern suggests the mechanical core of aggregate spreading and sealant application has one dominant portfolio holder while newer sensing and control add-ons remain more fragmented.

Filings rose from 3 in 2017 to a peak of 6 in 2023, then eased to lower counts, with 2026 showing only 1 filing so far. Because publication typically lags actual filing by around 18 months, the most recent year understates real activity and should not be read as a hard decline. With fewer than four complete years of data once that lag is accounted for, no reliable growth rate can be stated from this trend.

US6161986A, an aggregate spreading apparatus and methods patent, claims a hopper with independently controllable gates, sensors that read road surface characteristics, and an electronic controller that adjusts gate operation based on those sensor readings. It is the most-cited record in this dataset at 100 citations, meaning a large share of later filings in this space built on or referenced it. Anyone designing a new sensor-controlled aggregate spreader should review its claim scope closely, particularly around independently controllable dispensing gates tied to sensor feedback, since that combination sits at the centre of the claim.